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The three energy systems - the ATP-PC system, Lactate system, and Aerobic system - play a significant role in determining the intensity and duration of various activities in football. Understanding how these energy systems work can influence the planning of a training program for football players. Here's how:

1. ATP-PC System:

High-Intensity Bursts: The ATP-PC system provides energy for short bursts of high-intensity activities, such as sprinting, jumping, or tackling.

Training Emphasis: To enhance this system, training programs should focus on short, intense drills and exercises, such as sprints and agility drills. This helps improve a player's ability to generate quick bursts of power.

2. Lactate System:

Medium to High-Intensity Activities: The glycolytic system is responsible for providing energy during medium to high-intensity efforts lasting for a few seconds to a couple of minutes.

Training Emphasis: Football players need to develop their glycolytic system to perform activities like repeated sprints, tackling, and defending. Interval training, circuit training, and drills that mimic game situations are essential components of their training regimen.

3. Aerobic System:

Prolonged, Low to Moderate-Intensity Efforts: The oxidative system is crucial for sustaining energy during lower to moderate-intensity activities over a longer duration, such as jogging and maintaining endurance throughout a match.

Training Emphasis: To improve the oxidative system, football players should engage in aerobic training, such as long-distance runs or continuous jogging, to build their cardiovascular endurance. This ensures they can maintain their performance levels throughout the full duration of a match.

The key to effective training program planning in football is to address all three energy systems to ensure that players have the necessary energy resources for the various demands of the game. A well-rounded program should include a combination of strength and power training (to enhance the ATP-PCr system), interval training and anaerobic conditioning (to improve the glycolytic system), and endurance training (to boost the oxidative system). Additionally, periodization, which involves planning training phases to peak at specific times (e.g., during the season), is essential for optimizing performance and preventing overtraining.

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There are various ways to load a given exercise or execute a given movement - successful trainers know how to choose the loading or movement pattern for each activity that best reflects the client's training goal(s). Common loading patterns include, but are certainly not limited to: bilateral, unilateral, contralateral, ipsilateral, asymmetrical and unfamiliar.

Front Squat - Bilateral Step-Up - Unilateral

Most fitness professionals know the difference and reasons for choosing between bilateral and unilateral exercises - bilateral work allows for greater total loading for greater strength gain potential while unilateral work generally allows for greater ranges of motion and more selective muscle activation (among other differences). Unfamiliar loading involves the trainer simply applying a loading pattern the client is not used to for improvements in neuromuscular coordination and novelty (e.g., single-sided sand-bag squat vs barbell back squat).

When it comes to contralateral vs ipsilateral loading (both are unilateral) the reasons to choose one over the other focuses more on the desired level of stability and muscle recruitment specificity. Contralateral exercises allow for:

contralateral stability as each side of the body will counteract rotational and translator forces created by the movement; making it much easier to maintain proper form.

Ipsilateral exercises are quite the opposite, they allow for:

one side of the body must work intensely to negate rotational and other forces to minimize compensatory movements and maintain form.

Essentially, ipsilateral exercises greatly increase central stability requirements and help develop neuromuscular recruitment specificity as well as the ability to deal with offsetting forces during sports and other dynamic activities. The potential downside to ipsilateral movement is that it may reduce the potential for loading and/or range of motion.

One of the easiest ways to experience the difference in central requirements between a contralateral and ipsilateral movement is to perform the athlete's plank using both movement patterns. When trying the ipsilateral movement after mastering the contralateral variation - one will quickly and personally recognize the greater difficulty maintain proper form and stability! If you are not familiar with this exercise, see our YouTube video here: https://youtu.be/f3K3mBWfpck

DB OH Bulgarian Start DB OH Bulgarian End

Another exercise example is the Single-Arm Overhead Bulgarian Squat. When performing the movement with the weight in the same hand as the forward leg (ipsilateral), the focus will be on glute activation and minimization of compensatory movements. When the load is on the opposite side of the forward leg (contralateral), central stability and range of motion are challenged.

Summary: contralateral = greater stability and high range of motion potential; ipsilateral = asymmetrical forces increase stability demands and coordinated muscle activation to offset disruptive forces

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There are various ways to load a given exercise or execute a given movement - successful trainers know how to choose the loading or movement pattern for each activity that best reflects the client's training goal(s). Common loading patterns include, but are certainly not limited to: bilateral, unilateral, contralateral, ipsilateral, asymmetrical and unfamiliar.

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GPS technology in professional sports | Sport Performance Analysis

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Global Positioning System technology has been used in professional sport for some time, in both training sessions and during competition. Through the use of Electronic Performance and Tracking System (EPTS) devices, teams can track player’s movement on the pitch and collect vast amounts of data on t

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All team sports apart from American Football reported a greater frequency of high and very high intensity decelerations compared to accelerations. Importantly, the damaging consequences of frequent and intense decelerations imply that specific loading strategies, to inoculate players from negative deceleration outcomes, may be advisable.

There was a small decrease in the frequency of high and very high intensity accelerations and decelerations from the first to the second half periods of elite competitive match play, suggesting intense accelerations and decelerations could be particularly vulnerable to neuromuscular fatigue and consequently to an exacerbated risk of incurring injury.

In advancing the specificity of acceleration and deceleration training prescriptions, future research should look to 'individualise' and 'contextualise' acceleration and deceleration occurrences during match play.

Introduction

Research has also shown that during elite team sports competitive match play there is a second half decline in the frequency and distance spent accelerating and decelerating at high intensity [ 16, 17, 18, 19, 20], suggesting that these actions may be particularly sensitive to fatigue development and injury risk [ 21]. Collation and analysis of data from studies reporting temporal changes in the occurrence of higher intensity accelerations and decelerations during competitive match play would help acquire knowledge regarding the magnitude of the decline and potential impact that this may have on match performance and injury risk. Therefore, careful monitoring of each of these specific actions during training and match play is of significant importance to effective player load management systems, and is common practice amongst practitioners working with players at the elite level [ 22].

Global positioning system (GPS) devices are most commonly used to quantify the occurrence and characteristics of higher intensity accelerations and decelerations during competitive match play. With rapid advancements in this technology, together with approval by sports governing bodies to allow usage within official competitive match play, there has been an exponential increase in studies that have reported data on match-play movement demands. The results of this research have been summarised in recent systematic reviews and meta-analyses [ 23, 24, 25]. Despite this knowledge base, there is currently no systematic review or meta-analysis that has specifically focused on quantifying and comparing the occurrence of higher intensity accelerations and decelerations during competitive match play across a range of team sports in elite players. Furthermore, given the evident importance of these actions and the increasing number of studies measuring these actions using GPS devices there is also a need to systematically appraise the methodological procedures being used with view to identifying potential or necessary improvements in current practice.

Therefore, the aim of this systematic review and meta-analysis was to compare high (> 2.5 m·s −2) and very high (> 3.5 m·s −2) intensity acceleration and deceleration demands in elite team sports competitive match play. A temporal analysis of changes in the frequency of high and very high intensity accelerations and decelerations from the first to the second half periods of match play was also performed. A secondary aim was to review the methodological procedures used to quantify the occurrence of high and very high intensity accelerations and decelerations during elite competitive match play when measured using GPS devices.

Methods

Study Design

The planning and documentation of the current review were conducted in accordance with PRISMA (Preferred Reporting Items for Systematic Review and Meta-analysis) guidelines [ 26], with a meta-analysis following the Cochrane collaboration guidelines [ 27].

Search Strategy

Systematic searches of four electronic databases (CINAHL, MEDLINE, SPORTDiscus, Web of Science) were conducted by the lead author (DH) to identify peer-reviewed articles published in the English language between 1 January, 2010 and 1 April, 2018. The search strategy was developed using PICO (population, intervention, comparator, outcome) elements [ 26]. Related search terms synonymous to team sports (population), acceleration and deceleration (comparators), and match play (outcomes) were developed in accordance with those used by McLaren et al. [ 28]. Additional search terms were identified from pilot searching (screening of titles, abstracts and full text of papers previously known). Boolean operators 'OR' and 'AND' were used to construct the final search phrase (Table 1).

Screening Strategy and Study Selection

All electronic search results were initially exported to Microsoft Excel (Microsoft, Redmond, WA, USA) by the lead author (DH). Identification of eligible studies followed a three-stage process. First, duplicate studies were removed (DH). Second, studies that were clearly 'out of scope' were excluded following screening of the title and abstract (DH)-if a clear decision could not be made at this stage, studies were taken forward. The final stage was completed independently by two authors (DH, CC) and involved removal of studies by the exclusion criteria following screening of the full text. Any discrepancies ( n  = 13) on the final inclusion-exclusion status were resolved by consensus discussion.

Data Extraction

All data were extracted into a custom-made Microsoft Excel sheet by one author (DH). During the data extraction process, studies that used the same data across multiple studies were excluded, with only the earliest publication date used. This resulted in the exclusion of a further five [ 14, 29, 30, 31, 32] studies (Table 2, exclusion criteria: #10). Data extracted were organised according to the sample studied (sport, position, age, body mass, stature), competition details (type, year, number of matches, data files) and classification of 'eliteness' (semi-elite, competitive elite, successful elite, world-class elite). The classification of 'eliteness' given to each study sample was undertaken independently by two authors (DH, CC) using a modified version of the model (Table S1 of the Electronic Supplementary Material [ESM]) and classification (Table S2 of the ESM) proposed by Swann et al. [ 33], which allows consistent within- and between-sport comparisons to be made. Any discrepancies were resolved by consensus discussion before the final classification was given (Table S3 of the ESM).

In line with recent recommendations [ 34, 35] for the collecting, processing and reporting of data from GPS devices, we also recorded the device brand and model details, software version, sampling frequency (Hz), minimal effort duration (MED), number of satellites used and horizontal dilution of precision. These guidelines were also used to produce a checklist (Table S4 of the ESM) that helped to inform judgements (Table S5 of the ESM) on the risk of bias (RoB) for each included study within the areas of 'data collection', 'data processing' and 'normative profile' (further information in Sect. 2.6).

The mean, standard deviation and number of observations (match data files) were extracted for all acceleration and deceleration events and also categorised according to the temporal profile (first half, second half, full match), measurement approach (absolute or relative: number of efforts, distance covered, time spent) and intensity threshold (m·s −2) used to delineate the occurrence of a high and very high intensity acceleration and deceleration.

Missing Data

If the mean, standard deviation (SD) and number of data files could not be obtained from published records, the corresponding authors [ 17, 18, 20, 36] were contacted (via e-mail, social media) for further information. If the corresponding authors could not provide data for the full match, but periods of play had been reported (first and second half), then the full match mean and SD were calculated using the formula for combining group data as recommended in the Cochrane guidelines [ 27]:

$${\text{Combined}}\;{\text{group}}\;{\text{mean}} = \frac{{(N_{1} M_{1} ) + (N_{2} M_{2} )}}{{(N_{1} + N_{2} )}},$$

where N equals the number of data files and M equals the mean number of accelerations or decelerations for each group.

$${\text{Combined}}\;{\text{group}}\;{\text{SD}} = \sqrt {\frac{{\left( {{\text{SD}}_{1}^{2} + {\text{SD}}_{2}^{2} } \right)}}{2}} ,$$

where SD equals the standard deviation for the number of accelerations and decelerations completed for each group.

Combined means and SDs were only used for one study [ 18] that reported relative acceleration and deceleration events (i.e. per minute).

Assessment of Risk of Bias

In accordance with Cochrane collaboration guidelines, a 'domain-based' evaluation was undertaken, in which critical assessments are made to inform a judgement about the overall RoB for each included study [ 27]. Numerous methodological factors associated with GPS devices have been shown to influence the quantification of acceleration and deceleration events during match play [ 34, 35]. Furthermore, a range of contextual, tactical and fatigue-related factors, amongst others, may influence match running profiles in team sports [ 37]. Therefore, the domain most relevant to the outcomes of this review was 'detection bias', which appraises the systematic differences between groups in how outcomes are determined [ 27]. First, using recent guidelines [ 34, 35] a checklist was produced (Table S4 of the ESM) that identified key entries ('data collection', 'data processing', 'normative profile') and associated criteria that could be used to facilitate overall judgement (Table S5 of the ESM) about RoB for each individual entry. Two reviewers (DH, CC) independently completed the checklist using six response options: (1) 'yes', (2) 'no', (3) 'no information', (4) 'not applicable', (5) 'probably yes' and (6) 'probably no' as recommended by the Cochrane Collaboration guidelines [ 27]. A final judgement (Table S4 of the ESM) about RoB for each key entry was then made by each reviewer (DH, CC) using three possible outcomes: (1) low RoB: plausible bias unlikely to seriously alter the results; (2) unclear RoB: plausible bias that raises some doubts about the results; and (3) high RoB: plausible bias that seriously weakens confidence in the results [ 27]. The inter-rater agreement (kappa) was 0.63 (quality control), 0.79 (event identification) and 1.00 (normative profile), which are considered to be good to excellent magnitudes of agreement [ 27]. Any discrepancies in the final judgement of RoB between reviewers were resolved by consensus discussion.

Data Analysis and Interpretation of Results

A meta-analysis was performed using Review Manager Software for Mac (RevMan 5.2; Cochrane Collaboration, Oxford, UK). The inverse random-effects model for continuous data was used for statistical analysis because it accounts for heterogeneity of the included studies [ 27]. The meta-analysis sought to compare full match sport and positional differences in the frequency of high-intensity accelerations and decelerations. The type of sport was considered a priori to be a key moderating variable because significant differences in match-activity profiles between field-based sports have been shown to exist, even when accounting for differences in match duration [ 38]. To illustrate temporal changes in acceleration and deceleration outputs from the first to the second half periods of match play, a further two meta-analyses were completed, with the different intensity thresholds ('high' and 'very high') used as sub-groups.

One author (DH) entered the mean, SD and total number of observations for each separate meta-analysis. The effect magnitude was calculated using the standardised mean difference (SMD) alongside 95% confidence intervals (CIs) and presented in forest plots using GraphPad software (Prism 7, GraphPad Software Inc., La Jolla, CA, USA). The SMD includes a correction (Hedges's g) for small sample bias and expresses results in a uniform scale despite differences in how the outcome variable was measured [ 27]. The SMD was interpreted with a qualitative scale using the thresholds outlined by Hopkins et al. [ 39]: < 0.2 = trivial; 0.2-0.6 = small; 0.6-1.2 = moderate; 1.2-2.0 = large; 2.0-4.0 = very large; and > 4.0 = extremely large. The percentage of total variation between and within subgroups due to heterogeneity was measured using the I ² statistic for quantifying inconsistency in study results [ 40]. The magnitude of inconsistency was interpreted according to the criteria of Higgins et al. [ 40]: low (0-25%), moderate (26-74%) and high (75-100%). P  < 0.05 was considered statistically significant.

Results

Search Results

The initial search identified 8269 articles across four databases (CINAHL = 834, MEDLINE = 2129, SPORTDiscus = 2390, Web of Science = 2916). Then 8211 studies were removed following screening of the study title and abstract because of duplication ( n = 3917) or not meeting the inclusion criteria ( n = 4294). A further 43 records were removed using the exclusion criteria after screening the full text, resulting in 15 studies that met the inclusion criteria. A further four studies that met the inclusion criteria were identified from other sources, resulting in 19 studies meeting the inclusion criteria. Two of these studies [ 16, 41] were not considered for the meta-analysis because of reporting distance and time-related variables only, but was included in the descriptive qualitative synthesis. This resulted in 17 independent studies that provided 115 estimates being included in the meta-analysis (Fig. 1). From these 17 studies, 99 estimates were used to examine the differences in the frequency of high and very high intensity accelerations vs. decelerations in competitive match play. The remaining 16 estimates obtained from five of these studies were used to examine the temporal changes in high and very high intensity accelerations and decelerations from the first to the second half periods of match play.

Step-by-step process leading to the identification of studies eligible for a systematic review. ACC Acceleration, DEC Deceleration, GPS global positioning system, ORA original research article

Study Characteristics

Measurement of High-Intensity Accelerations and Decelerations

Table 4 illustrates the different methodologies used across studies to measure high-intensity accelerations and decelerations during match play. Almost half of the included studies in this review used the brand GPSports (47%, n = 9), while 32% ( n = 6) used Catapult Sports and 21% ( n = 4) used STATSports. Sixty-three percent ( n = 12) of studies used GPS with a raw 10-Hz sampling frequency, with the remaining 32% ( n = 7) of studies using 5 Hz. Four of the studies [ 29, 36, 42, 49] that captured data at 5 Hz incorporated an interpolation algorithm that resulted in a 15-Hz output. The MED used to delineate the minimal time required to be above the specified high-intensity acceleration or deceleration threshold for an effort to be recorded was reported in four studies [ 17, 36, 43, 46] and ranged between 0.2 and 1 s. The number of satellites used to infer GPS signal quality was reported in four studies [ 16, 44, 46, 50] and ranged from 4 to 13. Horizontal dilution of precision used to indicate the accuracy of the GPS horizontal positional signal was reported in two studies [ 16, 44] and values ranged from 0.8 to 1. The most common threshold used to classify the start of high-intensity acceleration or deceleration was 3 m·s −2 ( n = 11, 58%). Six studies [ 20, 36, 42, 48, 49, 50] also used a very high intensity threshold starting at either 3.5 m·s −2 ( n = 1) or 4 m·s −2 ( n = 5). Variables used to report high or very high intensity acceleration and decelerations included frequency ( n = 17 studies), distance covered ( n = 3 studies) and time spent ( n = 1 study). Sixteen studies reported data in absolute terms (total match duration), whilst five studies reported these variables relative to time (i.e. number per minute). Only one study [ 45] reported data using both absolute and relative formats.

Risk of Bias

The overall RoB judgement (low, unclear and high) for each key entry (data collection, data processing and normative profile) and for each individual study is reported in Table 4. Across all studies, the greatest RoB (40% high RoB) was observed in the data collection domain (Fig. 2), as the majority of studies did not report the number of satellites obtained (85%) or the horizontal dilution of precision (90%). Notably, within this entry, 70% ( n = 14) of the studies used a GPS device with a 10-Hz sampling frequency. The greatest amount of uncertainty (65%) was in the data processing domain, as only eight studies [ 17, 19, 20, 36, 43, 46, 47, 48] reported the MED. The lowest risk of bias (35% low RoB) was the normative profile domain, in which nearly half (45%, n = 9) of the studies [ 16, 18, 41, 42, 43, 44, 46, 48, 50, 51] used greater than ten matches in total, and over half (60%, n = 12) of the studies [ 18, 20, 29, 42, 43, 44, 45, 46, 47, 50, 51] reported position-specific acceleration and deceleration data. The number of matches used to characterise the average high-intensity acceleration and deceleration demands ranged between 1 and 42.

Meta-Analysis: Frequency of High-Intensity Accelerations and Decelerations

Sixteen studies (5220 files, 67 SMD) across seven sports: American Football (294 files, 9 SMD), Australian Football (1180 files, 11 SMD), hockey (226 files, 4 SMD), rugby league (799 files, 14 SMD), rugby sevens (51 files, 2 SMD), rugby union (516 files, 16 SMD) and soccer (2154, 11 SMD) reported the frequency of high-intensity accelerations and deceleration events (Fig. 3). An heterogeneity analysis showed a significant high percentage of total variation ( p < 0.00001, I ² = 99%) between sports (Table 5). Only American Football demonstrated a higher frequency of high-intensity accelerations compared to decelerations (SMD = 1.26, 95% CI 1.06-1.43). All other sports had a greater frequency of high-intensity decelerations compared to accelerations with SMD ranging from moderate (− 0.69) in hockey to large (− 1.74) in soccer. The percentage of total variation amongst estimates in American Football and hockey was low ( p = 0.51-0.9, I ² = 0%). In all other sports, a significant moderate to high percentage of total variation was evident ( p < 0.003, I ²  = 57-97%).

Forest plot displaying the standardized mean differences (SMD) and 95% confidence intervals (CIs) in the frequency of high (> 2.5 m ·s −2) intensity accelerations vs. decelerations in elite team sports competitive match play. aFrequency relative to time (n ·min −1). ADJ adjustable, B3 back three, BK back, BR back row, CD central defender, CM central midfielder, CTR centre, DB defensive back, DE defensive end, DEF defender, DT defensive tackle, FD fixed defender, FF fixed forward, FR front row, FWD forward, HB half back, HUF hit-up forward, MB mobile backs, MF mobile forwards, MID midfielder/centre, LB linebacker, OB outside back, OL offensive linesman, QB quarter back, RB running back, RKS rucks, SD standard deviation, SEN senior, SR second row, TB tall backs, TE tight end, TF tall forwards, U20 under 20, WD wide defender, WM wide midfielder, WR wide receiver, WRF wide-running forward

Meta-Analysis: Frequency of Very High Intensity Accelerations and Decelerations

Six studies (1169 files, 32 SMD) across four sports: American Football (294 files, 9 SMD), rugby sevens (225 files, 4 SMD), rugby union (516 files, 16 SMD) and soccer (134, 3 SMD) reported the frequency of very high intensity accelerations and decelerations (Fig. 4). An heterogeneity analysis showed a significantly high percentage of total variation ( p < 0.00001, I ² = 94%) between sports (Table 5). Only American Football had a greater frequency of very high intensity accelerations compared to decelerations (SMD = 0.19, 95% CI − 0.42 to 0.80), although the difference was trivial. All other sports had a greater frequency of very high intensity decelerations compared to accelerations with SMD ranging from trivial (− 0.12) in rugby sevens to very large (− 3.19) in soccer. The percentage of total variation across studies and positional roles ranged from moderate ( p = 0.11, I ² = 31%) in rugby union to high ( p < 0.00001, I ²  = 89-95%) in all other sports.

Forest plot displaying the standardized mean differences (SMD) and 95% confidence intervals (CIs) in the frequency of very high (> 3.5 m·s −2) intensity accelerations vs.decelerations in elite team sports competitive match play. aFrequency relative to time (n·min −1). B3 back three, BK back, BR back row, DB defensive back, DE defensive end, DEF defender, DOM domestic, DT defensive tackle, FR front row, FWD forward, HB half back, INT international, LB linebacker, MID midfielder/centres, QB quarter back, OL offensive linesman, RB running back, SD standard deviation, SEN senior, SR second row, TE tight end, U20 under 20s, WR wide receiver

Meta-Analysis: Temporal Changes

High and Very High Intensity Accelerations: Temporal Changes

Five studies [ 17, 19, 20, 36, 49] covering two sports (rugby sevens, soccer) reported temporal changes in the frequency of high and very high intensity accelerations between the first and second half periods of match play. There was a low percentage ( p = 0.45-0.93, I ² = 0%) of total variation due to heterogeneity between and within the high and very high intensity subgroups (Table 5). The SMD for both high (0.50) and very high intensity (0.49) sub-groups showed a small decrease in the frequency of accelerations completed from the first to the second half periods of match play (Fig. 5 a). In rugby sevens, the SMD ranged between small (0.33) to moderate (0.97), whilst in soccer the decrease was small (SMD = 0.10-0.50).

Forest plots displaying the standardized mean difference (SMD) and 95% confidence intervals (CIs) in the a temporal changes in the frequency of high (> 2.5 m ·s −2) and very high (> 3.5 m ·s −2) intensity accelerations and b high (> 2.5 m ·s −2) and very high (> 3.5 m ·s −2) intensity decelerations from the first to the second half periods of match play. aFrequency relative to time (n ·min −1). SD standard deviation

High and Very High Intensity Decelerations: Temporal Changes

Five studies [ 17, 19, 20, 36, 49] covering two sports (rugby sevens, soccer) reported temporal changes in high and very high intensity decelerations between the first and second half periods of match play. There was a low percentage ( p = 0.72, I ² = 0%) of total variation due to heterogeneity between the high and very high intensity subgroups. Within the high and very high-intensity subgroups, a moderate percentage ( p = 0.08-0.22, I ² = 34-53%) of total variation due to heterogeneity was evident across studies (Table 5). The SMD for both high (0.54) and very high intensity (0.46) sub-groups showed a small decrease in the frequency of decelerations performed from the first to the second half periods of match play (Fig. 5 b). In rugby sevens, the SMD ranged between trivial (0.00) and moderate (0.66), whilst in soccer it ranged between small (SMD = 0.47) and moderate (0.78).

Descriptive Analysis: Distances and Time Spent Accelerating and Decelerating

Three studies investigating Australian Football [ 44], rugby union [ 41] and soccer [ 16] reported the absolute distance spent accelerating and decelerating at high intensity (Fig. 6a). Only the study by Johnston et al. [ 44] reported positional differences. Australian Football had the highest full match distance (194 m) spent accelerating at high intensity followed by soccer (178 m) and rugby union (94 m). In Australian Football, midfielders reported the highest total match distance (202 m) spent accelerating at high intensity, followed by fixed defenders (190 m), fixed forwards (176 m) and rucks (133 m). Soccer had the highest full match distance (162 m) spent decelerating at high intensity, followed by Australian Football (149 m) and rugby union (54 m).

a Distances and b times spent accelerating and decelerating at high intensity during elite competitive match play. AF Australian football, FF fixed forward, FD fixed defender, MID midfielder, RKS ruckman, RU rugby union, SOC soccer

Only one study [ 44] investigating Australian Football reported the time spent accelerating and decelerating at high intensity (Fig. 6 b). On average, all players spent a longer time (89 s) accelerating at high intensity compared to decelerating (64 s). Fixed defenders and midfielders spent the longest time accelerating (91 and 90 s, respectively) and decelerating (66 and 66 s, respectively) at high intensity amongst all positional roles. Rucks had the lowest time (69 s) spent accelerating, whilst fixed forwards had the lowest time (51 s) spent decelerating. No studies reported either the distance or time spent accelerating or decelerating at very high intensities.

Discussion

To our knowledge, this is the first meta-analysis to compare differences between the most intense (> 2.5 m·s −2) accelerations and decelerations in elite team sports competitive match play. Over half (55%) of the included studies investigated players classified as 'world-class' elite. As such, this review provides high-performance practitioners with novel insights into the acceleration and deceleration demands of players at the highest standards of match play. Using recent guidelines [ 34, 35], a secondary aim was to review current methodological limitations around the measurement of high-intensity accelerations and decelerations, with a view to recommending future directions. The main finding from our meta-analysis is that American Football was the only sport with a higher frequency of high (SMD = 1.26) and very high (SMD = 0.19) intensity accelerations compared to decelerations. In all other sports, there was a greater frequency of high (SMD = − 0.48 to − 1.74) and very high (SMD = − 0.32 to − 3.19) intensity decelerations compared to accelerations.

Frequency of High-Intensity Accelerations Compared to Decelerations

In all team sports apart from American Football, there was a greater frequency of high-intensity decelerations compared to accelerations (SMD = − 0.69 to − 1.74). The largest difference (SMD = − 1.74) was found in soccer, although a significant high variation ( I ² = 97%) was evident between teams and positional estimates. The evolution of elite soccer match play requires contemporary players to perform more short high-intensity actions to fulfil tactical responsibilities, whilst in and out of possession, and during ball possession transitions [ 3, 52]. Whilst these studies have shown an evolutionary progression in the frequency of rapid accelerations, the findings of our meta-analysis illustrate the prevalence of high-intensity decelerations to soccer match-play performance. Although high-intensity decelerations have been shown to be very short in duration (72% less than 1 s duration) [ 53], they comprise the highest magnitude of mechanical load per metre-reportedly up to 65% greater than any other match-play activity and around 37% more than similarly intense accelerations [ 7]. Even in elite players, this load places a significant demand on the ability to repeatedly absorb high eccentric braking forces, of which the cumulative effect following match play is associated with markers of exercise-induced muscle damage [ 12, 54], deficits in countermovement jump concentric and eccentric phase performance [ 10, 12], and asymmetry in hamstring isometric strength [ 55], effects that have been shown to last up to 64 hours post-match. The muscle damage resulting from repeated intense decelerations is caused by strain to muscle fibres during eccentric (lengthening) contractions that result in disruption of the integrity of muscle cells [ 56]. Unlike maximum voluntary force that can also be affected by concentric exercise (metabolic fatigue), the rate of force development is particularly affected by muscle damage resulting in a diminished capacity to both produce and attenuate forces in very short time periods that is commonly required to enhance sports performance and reduce injury risk [ 57, 58]. Specific attention to loading strategies that can "mechanically protect" players from these damaging consequences of high-intensity decelerations are necessary [ 9]. For example, studies examining the repeated bout effect have shown that greater resistance to muscle damage can be obtained by prior eccentric or isometric exercise [ 59, 60]. Implementing such strategies in preparation for match play could attenuate the amount of damage accumulated per deceleration effort, resulting in less mechanical fatigue and a reduced risk of tissue failure occurring (this representing an increased 'deceleration efficiency') [ 61].

Our findings also highlight significant team and positional differences in the frequency of high-intensity decelerations compared to accelerations in soccer. In a study by Tierney et al. [ 51], wide midfielders completed the most high-intensity decelerations ( n = 62) of any position, and also had the highest difference (SMD = − 3.71) in the frequency of high-intensity decelerations ( n = 62) compared to accelerations ( n = 35). This reflects positional-specific movement demands whereby wide midfielders are required to perform various changes in direction both before and after high-intensity efforts to meet technical and tactical requirements when in and out of possession [ 62, 63]. Additionally, coaches and other support staff should be aware of the fluctuations in high-intensity accelerations and decelerations that result from tactical changes in game play. For example, in the study by Tierney et al. [ 51], wide midfielders performed 20% more high-intensity decelerations when playing in a 3-4-3 ( n = 66) compared to a 4-4-2 ( n = 53) formation. These findings have important implications for the design of training micro-cycles. For instance, players who perform a high frequency of decelerations over a number of weeks may be at an increased risk of injury, whilst a moderate frequency may provide a protective effect, thereby reducing the chance of injury occurring [ 64].

Significant team and positional differences in the frequency of high-intensity decelerations compared to accelerations were also observed in all codes of rugby ( I ² = 57-97%). Both rugby league and rugby union had a greater (SMD = 0.99 and 1.11, respectively) frequency of high-intensity decelerations compared to accelerations. In rugby sevens, the difference in high-intensity decelerations compared to accelerations was large (SMD = 1.56), although the CI overlapped both trivial positive and negative effects. Whilst rugby sevens is played under the same laws and pitch dimensions as rugby union, the fewer players per team (7 compared to 15) permits larger spaces [ 65], requiring players to possess exceptional acceleration and maximal speed capabilities to achieve success in both attacking (defenders beaten, line breaks) and defensive plays (defensive rucks, dominant tackles) [ 66]. Both studies [ 36, 49] included in our meta-analysis obtained estimates from international rugby sevens tournaments across multiple matches. In the study by Suarez-Arrones et al. [ 36], differences in the frequency of high-intensity accelerations and decelerations were trivial. However, the absolute number of high-intensity accelerations ( n = 13.1) and decelerations ( n = 13.6) per match was greater than for all positions reported in senior and under 20 international rugby union players [ 50], despite total game duration being up to 80% less than rugby union. Indeed, using a total game time of 14 min, this would represent an average density of high-intensity accelerations and decelerations of approximately 1 action per minute. This average density is different to that of Furlan et al. [ 49] who reported a very large (SMD = 3.07) difference in the number of high intensity decelerations (1.8 n·min) compared to accelerations (0.4 n·min) in international rugby sevens players.

Based on these studies, it seems that there could be a large variability in the frequency of high-intensity accelerations and decelerations required to be performed during international match play. This could be owing to a range of physical (high-speed running ability, resistance to muscle damage-especially on day 1 of tournaments, neuromuscular fatigue), technical (number of contacts, tackle proficiency), psychological (well-being, perceived recovery) and situational (tournament day, score during match, opposition world ranking, travel requirements) related factors that have been shown to influence the match-activity profiles of international rugby sevens players [ 67, 68, 69, 70, 71, 72, 73].

Nonetheless, such a high density of high-intensity accelerations and decelerations in combination with physical contacts (rucks, mauls, scrums, tackles) is likely associated with the significant increase in muscle damage [ 68, 72] that coincides with deficits in neuromuscular function [ 68] and psychological disturbances [ 72, 73] following rugby sevens match play. Because rugby sevens players are required to perform multiple matches on consecutive days, with little time (~ 3 hours) for regeneration, strategies that can help enhance and maintain players' physical and psychological readiness between matches are essential to successful performance, and have been carefully considered in recent research [ 74, 75]. In fact, some of these practices may be transferable to those involved in the preparation of rugby league and rugby union players whose aim is to develop a higher intensity of game play, whilst simultaneously reducing the muscular damage commonly associated with these actions [ 72].

The higher frequency of high-intensity decelerations compared to accelerations in both rugby league and rugby union is likely associated with increased spatial constraints, which restrict opportunity for high-speed running, and thereby demands players to perform more rapid short deceleration movements [ 46]. Unique positional responsibilities associated with offensive and defensive actions imply that high-intensity decelerations will accrue through differing task demands. For example, forwards are involved in a heightened number of heavy collisions [ 41, 45] that demand deceleration prior to contact to successfully perform the skill and reduce the amount of load accumulated [ 76, 77]. In contrast, backs have less involvement in collisions and are further away from the ball, permitting opportunities to use rapid deceleration movements to perturb the defensive line [ 45, 50, 78].

Amongst the team sports included in this meta-analysis, Australian Football had the second largest difference (SMD = − 1.15) in the frequency of high-intensity decelerations ( n = 51-125) compared to accelerations ( n = 38-103). A larger pitch size than other team sports, coupled with a no 'offside' rule, permits a higher contribution of continued high-speed running [ 43]. Despite this, both high-intensity accelerations (~ 15%) and decelerations (~ 20%) have been shown to be the largest contributors to post-match markers of muscle damage, denoted by elevated levels of creatine kinase (CK) in Australian Football players [ 11]. Similarly, research by Young et al. [ 13] also found significant correlations between high-intensity accelerations and decelerations and CK levels in Australian Football players, but only the volume (represented by distance covered) of high-intensity decelerations was significantly different between the low- and high-CK groups. It is noteworthy that Australian Football players who cover more high-intensity deceleration distance also report a higher perceived match load, despite this being essential for increasing the amount of possessions and disposals of the ball that can contribute to match success [ 14]. This is exemplified by the match-activity profile of elite Australian Football players containing more high-intensity decelerations per minute than sub-elite players [ 30]. Collectively, these findings highlight the importance of high-intensity decelerations to Australian Football match-play performance together with the damaging consequences of these actions. Similar to recommendations previously suggested for soccer practitioners, those involved in the preparation of Australian Football players should look to implement interventions that reduce a player's susceptibility to deceleration-induced tissue damage [ 11], likely arising from the intense eccentric muscle contractions experienced when braking abruptly.

In hockey, the results of our meta-analysis showed that only the defensive and midfield positions had a greater (SMD = 0.78) frequency of high-intensity decelerations (0.9-1.0 n·min) compared to accelerations (0.7-0.8 n·min). In the forward position, differences between high-intensity accelerations (0.9 n·min) and decelerations (1.0 n·min) were trivial, suggesting that some forward players may complete more high-intensity accelerations than decelerations during match play. Previous studies have also shown that forward positions accelerate to higher intensities more frequently than defenders and midfielders [ 79, 80]. This difference could be due to the unlimited interchange rule that reduces effective playing time; meaning less total distance and energy is expended, therefore allowing a higher intensity intermittent profile to be maintained [ 79]. From a tactical perspective, rotating forward positions more frequently can help to maintain high-intensity output across periods of play, resulting in more technical contributions and enhanced team performance statistics [ 81].

Although the frequencies of high-intensity accelerations have been shown to be different between positional roles in hockey, the relative frequency of high-intensity decelerations was similar across all positions (0.9-1.0 n·min). As the ability to decelerate at high intensity can also influence a player's change of direction performance [ 82], these actions may have particular importance to hockey match-play performance outcomes. Furthermore, both high-intensity accelerations and decelerations have been shown to be the match-activity variables most sensitive to fatigue development during hockey match play [ 18]. Performance advantages could therefore be obtained by strategies that help to increase and maintain players' capacity to both accelerate and decelerate rapidly throughout match play.

An interesting finding of the present meta-analysis was that all positional roles in American Football are required to perform more (SMD = 0.91-1.45) high-intensity accelerations ( n = 15-38) compared to decelerations ( n = 8-19) during competition. This finding was unique to American Football and supports the significant time and investment that is placed on the assessment and development of an American Footballer's rapid acceleration and top speed capabilities. Indeed, these abilities have been shown to differentiate between drafted and non-drafted players in the National Football League (NFL) Scouting Combine [ 83] and are important in predicting future successful performance in the NFL, including the amount of prestigious accolades (i.e. Pro Bowl, All Pro) players achieve [ 84].

On this basis of these findings, practitioners supporting American Football players may need to prioritise loading strategies during training sessions that develop muscle-tendon tissue structures' capacity to attenuate high eccentric forces. Practitioners should also be cognisant of periods during the season when American Football players may be more susceptible to eccentric-induced muscle damage, for example, following periods of training with a dominance of concentric conditioning in which vulnerability to damage can be increased (such as when preparing for the NFL 40-yard dash) [ 101].

Frequency of Very High Intensity Accelerations Compared to Decelerations

Very high (> 3.5 m·s −2) intensity accelerations and decelerations were reported across four sports including American Football [ 42], rugby sevens [ 36], rugby union [ 50] and soccer [ 20]. The difference between very high intensity accelerations and decelerations in both American Football (SMD = 0.19) and rugby sevens (SMD = − 0.12) was trivial. However, the heterogeneity analysis showed a large ( I ² = 92-94%) variation across the estimates (positions and teams) within each of these sports. In American Football, a noteworthy finding from the meta-analysis was that the offensive lineman was the only position reporting a greater frequency of very high intensity decelerations ( n = 7) compared to accelerations ( n = 2), with the difference being very large (SMD = − 2.47). The offensive linemen are required to operate in confined chaotic spaces around the scrimmage with a primary responsibility of blocking opponents from tackling their own team's ball carrier [ 42]. The results of our meta-analysis suggest that these actions may rely heavily on high impulse braking actions that allow for rapid decelerations and directional changes to be made to manoeuvre effectively around such congested areas of the field, and in response to the dynamic unpredictable movements of their own and opposition players. The offensive linemen are also the heaviest of all positional roles, which may further augment the magnitude of braking forces required to decelerate such high whole body momentum. These factors contribute to a high-risk loading profile that increases the chances of soft-tissue injuries occurring within this specific positional role [ 102]. Practitioners should select specific exercises for offensive linesmen that target the development of the neuromuscular capabilities required to produce and attenuate the high forces associated with decelerating rapidly, whilst also ensuring a high level of perceptual-cognitive training that will harness the ability to skilfully apply braking forces during emergent and unpredictable situations. The evident unpredictability of loads associated with decelerating rapidly also have hugely important implications for the management of load throughout the season, and return to sports participation programmes following injury [ 103, 104].

Similar to the high-intensity category, soccer demonstrated the highest (SMD = − 3.19) frequency of very high intensity decelerations compared to accelerations. The SMD ranged from very large (− 2.40 to − 2.79) in defenders ( n = 24 vs. 7) and attackers ( n = 16 vs. 5) to extremely large (− 4.43) in midfielders ( n  = 32 vs. 8). Given the previously discussed consequences of high-intensity decelerations to match performance and the development of cumulative fatigue (during and post-match), additional research is needed to gain a more comprehensive understanding around the prevalence and significance of very high intensity decelerations to soccer match-play performance, and readiness to play.

Temporal Changes in High and Very High Intensity Accelerations and Decelerations

Understanding how specific match-play activities may influence player fatigue and recovery profiles is of significant interest to practitioners [ 105]. The results of our meta-analysis show there was a small (SMD = 0.46-0.54) decrease in the frequency of high and very high intensity accelerations and decelerations from the first to the second half periods of match play. As higher intensity accelerations and decelerations have been particularly associated with post-match decrements in neuromuscular fatigue and perceptual disturbances, it is also likely that these actions have a particularly profound effect on changes to match-related movement ability and efficiency. Despite this consequence, limited studies have actually examined the actual fatigue response induced by actual match-play activities, but instead focused on using simulation protocols that induce a lower mechanical load that is reflected in lower levels of muscle damage (i.e. CK) and feelings of muscle soreness [ 105].

When examining the actual influence of specific match-play activities (soccer in this example), it has been shown that the distance and frequency of high-speed running completed by a player during match play can lead to decrements in the ability to produce horizontal forces when accelerating maximally [ 106]. This consequently leads to reductions in sprint performance times that could be decisive in critical match-play actions. The individual estimates obtained in our meta-analysis show that rugby sevens reported the largest decrease (SMD = 0.97) in the frequency of high-intensity accelerations from the first ( n = 7.8) to the second half ( n  = 5.3) period of match play. Collectively, these findings suggest that a high frequency of accelerations together with the opportunity to sprint for longer distances (which is also apparent in rugby sevens match play) may be particularly detrimental to the ability to produce horizontal forces when accelerating at high intensity.

Despite these findings, to our knowledge, no previous study has examined the potential acute transient fatiguing effects of performing a high frequency of high-intensity decelerations during match play. Our meta-analysis shows that a small decrease in high and very high intensity decelerations occurs from the first to the second half periods of match play with the largest (SMD = 0.78) decrease ( n = 67 to 56) reported in soccer. When rapid decelerations are required to be performed frequently following maximal sprint acceleration, fatigue and sprint performance are further exacerbated when compared to sprinting with no enforced deceleration [ 107]. Such a high frequency of rapid decelerations leaves players vulnerable to muscle damage, which can impair force production capacity leading to declines in the performance of activities such as sprinting and changing direction [ 108]. Future research should look to investigate the temporal changes in high-intensity accelerations and decelerations during match play, and the factors that could help to maintain repeated high-intensity acceleration and deceleration performance throughout match play.

Methodological Limitations of Eligible Studies

Previous reviews examining the use of wearable GPS devices for quantifying match-activity demands have identified that there is a lack consistency and consensus in the methodological procedures used across studies [ 23, 25]. Using recent guidelines [ 34, 35], we produced a checklist to evaluate the methodological differences (data collection, data processing and normative profile) between studies in how high and very high intensity accelerations and decelerations were determined. To collect data, over 60% of the studies included in our meta-analysis used GPS devices (Catapult Sports; n = 2, STATSports; n = 4, GPSports; n = 3) with a 10-Hz sampling frequency. Using a 10-Hz sampling frequency, it has been shown that the occurrence of high-intensity accelerations and decelerations can be reliably obtained, although distance- and time-related variables are less reliable [ 109, 110, 111]. In studies that used a 5-Hz sampling frequency, the RoB was rated as high because this sampling frequency has been shown to be less reliable than 10 Hz [ 109, 110].

The MED and filtering technique used are two extremely important data processing features that can also significantly change the quality, reliability and usefulness of acceleration and deceleration data [ 34, 111]. The MED delineates the minimal time in which an acceleration or deceleration needs to be maintained above a pre-defined threshold for it to be identified as an effort. Even small changes (0.1 s) in MED can result in substantial differences in the frequency of high-intensity efforts [ 35], for example, a lower MED is capable of detecting shorter and higher rates of acceleration and deceleration, whilst also being more susceptible to measurement error that could result in multiple accelerations or decelerations being given to a single effort [ 35, 112]. To prevent this, criteria that delineate the end of an acceleration or deceleration could be used in conjunction with the MED, such as when the acceleration falls below 0 m·s −2 or a certain threshold [ 34, 35]. However, no study in our meta-analysis reported this information, meaning it cannot be discounted that the frequency of high-intensity accelerations or decelerations was overestimated. Furthermore, despite the importance of the MED, our checklist showed that only eight studies [ 17, 19, 20, 36, 43, 46, 47, 48] reported the MED, and across these studies the duration (0.2-1 s) selected was inconsistent.

Because low and high MEDs can result in over- and under-estimates, respectively, this again might raise doubt around the accuracy of the higher intensity acceleration and deceleration frequencies that are reported in current research studies. To aid comparisons between studies and to improve the accuracy of data reported, practitioners and researchers should consider carefully the criterion used to delineate both the start and end of an acceleration or deceleration, and also ensure this information is clearly reported within the methodology.

Finally, another methodological limitation was associated with the development of a 'normative profile'. Based on previous research, we chose ten matches to be representative of a 'normative profile' [ 113]. However, we acknowledge future research is needed to specifically examine how many games are required to ascertain that the stabilisation of high-intensity accelerations and decelerations have occurred, notably with regard to inter-match variability. Nonetheless, using this criteria, five studies [ 10, 17, 19, 36, 49] were rated as a high risk of bias because of using fewer than ten matches and not presenting position-specific data.

Limitations and Future Directions

Whilst the results of this meta-analysis have a number of evident limitations, a range of factors can be identified to help direct future practice aimed at measuring high-intensity accelerations and decelerations during match play. First, all studies included in the meta-analysis utilised 'generic' or 'arbitrary' high-intensity acceleration and deceleration thresholds. Although these 'generic' thresholds allow "like for like" comparisons, they do not take into account individual differences in maximal acceleration and deceleration capacities that can result in significant differences in data output, particularly at higher intensities, and in players with higher maximal accelerative capabilities [ 114]. Furthermore, Sonderegger et al. [ 115] showed that if the running speed immediately prior to an acceleration being initiated is not considered, a number of high-intensity accelerations could be missed. Whilst these few studies have made a contribution to enhancing the quantification of high-intensity accelerations, there is currently no research to date that has individualised thresholds based on a player's maximal deceleration capacity. Because high-intensity decelerations permit the highest rates of velocity change, future research that adopts a threshold-based approach should look to establish exclusive high-intensity acceleration and deceleration thresholds, rather than using a shared threshold that is commonly adopted across current practice.

We also acknowledge that a major limitation of the threshold-based approach, together with other methods (i.e. Ave Acc/Dec) that have been proposed, is a lack of contextualisation with regard to the specific movement sequences and the technical and tactical requirements of different positional roles [ 63]. When additional layers of contextual information are provided, novel position-specific training interventions can be developed [ 116, 117]. Examples include the starting speed at which accelerations and decelerations are initiated, distance of the acceleration or deceleration, actions that precede or follow the acceleration or deceleration, and their technical or tactical purposes. Furthermore, because higher intensity accelerations and decelerations have been classified as the major external loads in team sports [ 5], further insights into the internal mechanical stresses placed on soft tissues during different magnitudes of acceleration and deceleration could be obtained by integrated inertial sensors providing estimates of foot impulses during accelerated or decelerated running using metrics such as a force load [ 112].

Finally, all studies included in this review reported average acceleration and deceleration data from players who completed at least 75% of match duration. Future research should look to analyse acceleration and deceleration occurrences across smaller time periods so the magnitude and temporal location of peak demands can be more precisely identified [ 109]. This approach could also be useful when analysing substitute players, whom upon entering the field of play may produce a higher frequency of intense accelerations and decelerations, therefore requiring different pre-entry warm-up strategies to ensure optimal preparation [ 118].

Conclusions

High-intensity accelerations and decelerations are particularly important measures of external biomechanical load in team sports. This is the first meta-analysis to compare high and very high intensity acceleration and deceleration demands in elite team sports competitive match play. In all team sports, apart from American Football, there was a greater frequency of high and very high intensity decelerations compared to accelerations. There is a small reduction in the frequency of high and very high intensity accelerations and decelerations from the first to the second half periods of match play. These findings have important implications for practitioners involved in ensuring elite players are optimally prepared for the high-intensity biomechanical loading demands of competitive match play. This review has also highlighted that there is currently a lack of consensus or consistency in the methodological procedures used to quantify higher intensity accelerations and decelerations during match play when using GPS devices.

Future research should establish measurement procedures that allow for valid, reliable and precise information to be obtained on individual high-intensity acceleration and deceleration demands. Finally, to permit more accurate individualised programming prescription, other contextual information relating to how and when high-intensity accelerations and decelerations are occurring during match play, should also be provided.

Acknowledgements

The authors express gratitude to the authors who provided additional data for studies included in the meta-analysis. The authors also thank Dr. Sam Orange for advice on the presentation of statistical data.

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1. School of Sport, York St John University, Lord Mayors Walk, York, YO31 7EX, UK

Damian J. Harper

2. Institute of Coaching and Performance, School of Sport and Wellbeing, University of Central Lancashire, Preston, PR1 2HE, UK

Damian J. Harper, Christopher Carling & John Kiely

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Correspondence to Damian J. Harper.

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Damian Harper, Chris Carling and John Kiely have no conflicts of interests that are directly relevant to the content of this article.

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Harper, D.J., Carling, C. & Kiely, J. High-Intensity Acceleration and Deceleration Demands in Elite Team Sports Competitive Match Play: A Systematic Review and Meta-Analysis of Observational Studies. Sports Med 49, 1923-1947 (2019). https://doi.org/10.1007/s40279-019-01170-1
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High-Intensity Acceleration and Deceleration Demands in Elite Team Sports Competitive Match Play: A Systematic Review and Meta-Analysis of Observational Studies - Sports Medicine

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Background The external movement loads imposed on players during competitive team sports are commonly measured using global positioning system devices. Information gleaned from analyses is employed to calibrate physical conditioning and injury prevention strategies with the external loads imposed during match play. Intense accelerations and decelerations are considered particularly important indicators of external load.

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Agility is an essential skill in football. These agility drills for football will help improve speed, strength, power and acceleration within your team.

Designing agility and quickness programmes for football is extremely challenging. Mainly because it involves almost constant movement over two 45 minute periods. Given this amount of movement, agility becomes key to a player's effectiveness. Agility training has the ability to not only enhance performance, but also a player's overall game.

In this article, adapted from Developing Agility and Quickness, 2nd Edition, you'll find 7 agility drills for football to help improve your overall game.

What is agility?

To get the most out of agility drills for football, it's important to understand why agility is so important. Agility is the same in football as it is in any other sport. It's about how quickly you can change direction without it affecting your balance. Footballers that are extremely agile, like Lionel Messi, can stop quickly, change directions and keep moving in one fluid movement.

Some people think that agility can't be developed. However, it's something attackers have to work on in order to beat defenders. Once you know how agility can improve your game, you'll start to notice the changes once you start doing agility training.

Programme Design

Due to the wide range of movements needed for a full match across the various positions, designing agility drills for football can be challenging. However, by analysing the target movement specifications of the sport, coaches can classify football movements. Following this, coaches can put the movements into a basic structure and build an effective agility programme.

It's helpful to determine what players are trying to achieve when breaking down football movements. Coaches can do this by using target classifications. At any given time, players are likely to be doing one of three movements:

Initiation movements - Starting or changing the direction of movement

Actualisation movements - Trying to move at maximal velocity

Transition movements - Waiting in transition to react to a football-specific stimulus.

Although agility training usually focuses on initiation and actualisation movements, far less emphasis is placed on transition movements. Usually, when players are taught these movements, they're taught incorrectly. The emphasis is placed on movement speed instead of control. A player's ability to start and move at maximal velocity usually depends on whether they're in the right position to enable effective subsequent movement. The table (8.1) below shows the key movements within each classification.

Table 8.1. The key movements within each of the different classifications.

Effective agility training

Effective agility training balances the requirements of the exercise and the ability of the player. Therefore sessions designed for elite players should look different to sessions for beginners. Because of this, football specific agility programmes should include a progression in movement challenge and complexity as players move through the stages of development.

In the first stages, players benefit from closed drills. These allow the speed of the drills to be controlled. They often consist of single movement patterns (e.g. shuffling). At this stage, coaches should develop players' ability in all of the identified movement patterns for football. This ensures there are no weak links in movement ability. The following list provides the system for game-speed development. As players maintain proper movement patters at one stage, they can move on to the next level.

1. First, develop general and stable fundamental movement patterns

2. Develop key movement combinations, moving from closed to open drills

3. Develop sport-specific movements in-game context

4. Perform sport-specific movements in-game context

As players develop, coaches should combine movement patterns in ways that fit football. For example, backpedal drills can conclude with sprints to the rear, side or forward. These combinations are common in football.

Coaches can also use drills that are increasingly open. Players should respond to a range of stimuli. For example, a player can incorporate backpedalling into a sprint drill. Next, players can perform a drill that sees them change direction in response to the coach's signal. Then in response to another player's movement. These types of drills can include a great variety in terms of distances, speeds, directions and stimuli.

Sample Agility Drills for Football

The following is a sample session of agility drills for football. These drills can be used to develop change of direction speed and quickness. Ian Jeffreys suggests players start with a dynamic warm-up before moving onto more vigorous activity. This has been further explained in our recent blog post, What is the RAMP Warm-Up?. More warm-up drills can also be found in Developing Agility and Quickness, 2nd Edition.

Sessions should be designed based on the overall goal of the session and the type of player. Generally, beginners should focus on the technical aspects of performance, with less emphasis on application. However, for advanced players, it should be the opposite.

For all players, the focus should be on the quality of training rather than the number of drills performed. The aim should be to enhance agility. Therefore, the focus should be on ensuring that technique and work quality are equal to the player's abilities.

Work-to-rest ratios should ensure that each repetition is started from a state of full recovery. However, this is dependent on the player's ability and level of conditioning. For sprint-type activities, walk-back recoveries are recommended. For agility-type activities, activity time should be in the 2- to 5- second range. Followed by an adequate rest duration to maintain performance for subsequent repetitions. Generally, 4 to 8 repetitions are recommended, although this can vary depending on duration. It's also important to observe the session. If technique or work quality deteriorates, this might signal that players are fatigued.

Lateral Shuffle and Stick

Place two cones 5 to 10 yards apart. Players should begin in an athletic position facing cone 1. When ready, they shuffle to cone 2 while keeping the hips low and the hips, shoulders and torso parallel to the cones. Once the player reaches the cone, the player immediately sticks the finish position (figure 1).

Figure 1. Proper finish position of the lateral shuffle and stick

Feet should be almost flat, pointed forward and wider apart that the knees. In turn, the knees should be wider than the hips. The player holds in the position for a brief pause to make sure the position can be maintained in a stable manner. There should be no further movements during the pause. Once stability is achieved, another movement can be started.

Lateral Shuffle and Pushback

Place two cones 5 to 10 yards apart. Begin in an athletic position facing cone 1. Move laterally from cone 1 to cone 2. When the player reaches the cone, they should plant the outside leg and explosively push back to move in the opposite direction.

Lateral Shuffle Mirror

Place two cones 10 yards apart. Two players face each other in an athletic position (figure 2). One assumes the role of attacker and the other of the defender. The players should move laterally between the cones with the attacker trying to lose the defender. In turn, the defender tries to stay with the attacker. This drill should last between 3 to 6 seconds.

Figure 2. Side view of athletic position

Run to Cone and Cut

Place two cones 5 yards apart. Have the player assume an athletic position next to cone 1 and facing cone 2. With a self-start, tell the player to run towards cone 2. Once the player has reached the cone, they should make a cut step and then accelerate in the opposite direction.

Coach's Signal Variation

For an open version of this drill see figure 3. The coach stands 2 yards behind the second cone. The player runs towards cone 2 as before, however before they reach the cone, the coach should give verbal or visual signals to instruct them to move in a certain direction. The player should make a cut step and accelerate in the given direction.

Figure 3. Coach giving player instructions on change of direction movement

Run and Cut

For this drill, place two cones 10 yards apart. The attacker starts at cone 1, with the defender standing in an athletic position at cone 2. The drill begins once the attacker moves forward and tries to get to the end of the zone (cone 2). The defender also moves forward and adjusts their movements as they try to tag the attacker. The depth of the zone can be adjusted as needed.

Get to the Point

Place two goals (or two sets of cones) 10 yards apart. The defender starts a few feet away from the attacker, as in a game situation. On the coach's signal, the attacker tries to cut and move either to the near post or to the far post. To add another element, another player can deliver a ball to the attacker on the cut towards the goal. The attacker then tries to direct the ball into the goal, whilst the defender tries to clear it.

6 Agility Drills for Football

1. Lateral Shuffle and Stick

2. Lateral Shuffle and Pushback

3. Lateral Shuffle Mirror

4. Run to Cone and Cut

5. Run and Cut

6. Get to the Point

Further Reading

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7 agility drills for football to improve your speed and quickness

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Agility is an essential skill in football. These agility drills for football will help improve speed, strength, power and acceleration within your team. Designing agility and quickness programmes for football is extremely challenging. Mainly because it involves almost constant movement over two 45 minute periods.

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With the current state of COVID-19, coaches and personal trainers alike are trying to find remedies to continue to train and exercise with minimal equipment. For our athletes, many of them only have access to bodyweight exercises. The following exercises only require bodyweight and potentially a chair or step for a couple variations. The best place to perform the exercises are outside. Not only will you have more space, but getting some good ole fashioned vitamin D from the sun is a huge additional benefit for the immune system. Watch the video below to see all 15 exercises in action.

Now that you've seen all 15 exercises in action, let's briefly talk about each exercise and what we'd like to see from an execution standpoint. At the end, we'll provide you some sample workouts you can do that use only these exercises.

Broad Jump

The broad jump is an excellent plyometric exercise focused on jumping for distance. Each jump is considered it's own repetition. We personally like to coach the exercise to walk back to the starting jump position to allow for a minor bit of rest to ensure maximal effort on each jump. Use the hands to help provide momentum to achieve maximal distance. Stick the landing the best you can, and land in a good athletic position.
More details on the broad jump can be found here.
Reactive Broad Jump

This broad jump variation requires a bit more space than the typical broad jump. The mechanics and execution are the same, but after each jump, the athlete will immediately perform another rep, and usually for distance. Think about jumping as far as you can successively with the least amount of jumps. The goal is to limit the amount of time on the ground on each rep.

Two Way Broad Jump

For this broad jump variation, we're going to begin with a minor jump backwards. This jump should be about a yard or less. This is called a counter-movement jump, and helps place us in a slightly different starting position, but also eccentricly loading us to have more pop off the ground. Perform this like a typical broad jump, resetting after each rep. Keep in mind, to limit the time you're on the ground for your counter-movement jump backwards.

Seated Broad Jump

This particular broad jump variation is excellent for developing starting strength and power. It's slightly more difficult than the standard broad jump, but most of the mechanics are the same. Adjusting the height of the box/chair can make it easier or harder, based upon what the athlete needs or based on their sport. Slightly raise the feet off the ground with a minor lean back, then drive the feet hard into the ground and jump as far as you can.

Kneeling Jump to Broad Jump

This is one of the most advanced broad jump variations that we use. Performing a kneeling jump can be difficult for many youth athletes, but if this is possible, is makes for a great progression to use with the broad jump. The athlete will start from their knees in a tall kneeling position. From here, they will rock their hips back to their ankles, and drive up as hard as they can looking to land on their feet. As soon as the feet have hit the ground, the athlete will perform a max distance broad jump. This not only gets us two explosive movements from the hips, but also limits ground contact time. The initial kneeling jump is a great feedback on how hard an athlete is actually working to get from the ground to their feet.

Depth Drop

Now that we've covered all of our horizontal jumping, we can look at our vertical jumps. The depth drop is an exercise we like to work on with athletes to develop landing mechanics and how to land in an athletic position. The depth drop can also be used with other jumps, and can be used for an overload stimulus (dropping from a height that an athlete can not actually jump). This is a simple plyometric exercise, but can have huge benefits long term when really mastered. The athlete simply steps off a small box or ledge, and when hitting the ground, emphasizes that the hips stay higher than the knees and the body remains relatively rigid and stiff.
You can learn more about the depth drop here.
Pogo Jumps/Hops

Pogo hops/jumps are great jumping exercises for most athletes. This particular vertical jumping exercise emphasizes minimal ground contact time and develops the calves and achilles stretch-shortening cycle. Typically this is performed for distance, but with minimal space it can be performed for repetitions as well. Focus on jumping mainly from the ankles with a slight knee bend each repetition. Use of the arms is highly emphasized to aid in momentum but also general jumping mechanics. Think about jumping on a pogo stick, but using your legs.
More information on pogo jumps/hope can be found here.
Power Skip

This vertical jump exercise is excellent for beginner youth athletes, but even sees benefits with our older athletes. This skipping variation provides good triple extension on a single leg, but uses momentum to help aid in achieving height. We like to coach this like the athlete is performing a layup in basketball. Each jump should be performed for maximum height, and not to worry about distance covered.

Bodyweight Vertical Jump

This is one of our standard vertical jump exercises we use in conjunction with box jumps. We are simply jumping for maximum height on each repetition, focusing on a good landing position after each rep. The use of the arms is highly encouraged, and athletes should focus on hinging hips back versus bending at the knees. Reset after each jump.
More information on the bodyweight vertical jump can be found here.
Split Squat Vertical Jump

This is an advanced single leg vertical jumping variation. It has many benefits to develop single leg power, however, it also has prerequisite strength due to being very demanding. The athlete will start in a split stance position, jumping as high as they can pushing off from the lead leg. The athlete will switch legs mid-air, and jump as high as they can again after descending into another split squat. This would be ideal for athletes that already have ample lower body strength and power. We do not recommend this for beginner athletes.
We have more information on the split squat jump here.
Forward Line Hops

For our next section of jumps, we have line hops. These are simpler plyometrics that can be implemented to decrease ground contact time and work on "quick feet". This exercise we focus on jumping forward and back over a small line or implement, usually for time or reps. We like forward line hops to help teach kids how to work on basic jumping and landing mechanics while also having to accelerate and decelerate in space. Be sure to emphasize good jumps before speed. Once the mechanics are down, the speed will come with time.

Lateral Line Hops

Just like forward line hops, this exercise is similar but we will be jumping from side to side. Younger athletes generally have a harder time with this variation thant the forward one, as they will try to rush through the exercise quickly, and trip over their own feet. Just like with forward line hops, emphasize the jumping and landing mechanics first, and then the speed will come.
We've done more information on lateral line hops, here.
Single Leg Lateral Line Hops

This is a progression from your typical lateral line hops, to using a single leg. Balance will definitely be taxed on this by younger athletes, and even some advanced athletes struggle to own their positioning. As with the rest of the line hops, work first on basic mechanics and owning each position as you jump. As this comes and they get into a rhythm, speed will come naturally. Use this exercise to also tell which leg might need more attention on change of direction deficits.

Lateral Bounds

Bounding is a huge component is many sports, and we love using them here at THIRST. I think lateral bounds are a great progression from single leg line hops, as we are working in the same plane, but working on producing more force from each leg, and landing from that force on the opposite leg. As with the rest of our jumps, focus on sticking the landing on each rep before advancing to more speed and reactive ability. Each jump should be for max distance. Really reach for the landing on the opposite leg as well.
We have more information on lateral bounds, here.
ACL Lateral Hops

This lateral bounding progression is a mix between basically all the jumps we mentioned above. It's a great hybrid exercise, working in multiple planes and can be used for just about any athlete. The athlete will be trying to jump from one leg to the other, over an invisible fence. We use lines to help emphasize where that "fence" might be. Each jump should be for max height and distance, to get over the "fence" as much as possible. Once this is down, speed can be introduced and moving forward in space. These work much better for distance if possible, but can also be done in place is space is limiting factor.

Sample Plyometric Workouts

Beginner

A1) Forward Line Hops - 3×20 seconds
B1) Depth Drop - 5×5*Drill landing mechanics*
C1) Pogo Hops/Jumps - 3×10 yards
D1) Power Skip - 3×20 yards
E1) Lateral Line Hops - 4×10 seconds

Intermediate

A1) Broad Jump - 4×5
B1) Bodyweight Vertical Jump - 3×6
C1) Power Skip - 4×20 yards
D1) Lateral Bounds - 3×5 per side
E1) Forward Line Hops - 3×20 seconds

Advanced

A1) Seated Broad Jump - 3×5
B1) Split Squat Vertical Jumps - 3×5 per leg
C1) ACL Lateral Hops - 3×10 yards
D1) Pogo Hops/Jumps - 4×15 yards
E1) Single Leg Lateral Line Hops - 3×15 seconds per side

Summary

There are an infinite number of plyometric exercises that can be done, and with good sound thinking, they can be implemented to help provide results. While this article was written with COVID-19 in mind, know that these can be done year-round to help you become a better athlete or coach. Just take into consideration where the athlete is in their development, strength, experience, and time of year when implementing these exercises. Hope to see you faster, jumping higher, and dominating on the field/court.

Feeling confused? Have questions? Did we blow your mind with something? Let us know in the comments section.

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15 Plyometric Exercises You Can Do At Home

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With the current state of COVID-19, coaches and personal trainers alike are trying to find remedies to continue to train and exercise with minimal equipment. For our athletes, many of them only have access to bodyweight exercises. The following exercises only require bodyweight and potentially a chair or step for a couple variations.

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Characteriositics of Sport and Fitness Demands

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Characteriositics of Sport and Fitness Demands 2

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Training Methods for Cardiovascular Fitness and Muscular Endurance

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Training Methods for Cardiovascular Fitness and Muscular Endurance

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Characteriositics of Sport and Fitness Demands help 4

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Training Methods for Speed Strength and Power

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Training Methods for Speed Strength and Power

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Characteriositics of Sport and Fitness Demands help 3

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Characteriositics of Sport and Fitness Demands help 5

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Characteriositics of Sport and Fitness Demands help

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Characteriositics of Sport and Fitness Demands help 2