# data[].attributes.body
its goes up as the heart has to work harder to supply the body with

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this is a target where your heart rate should either be 50% or 70% 

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this is a target where your heart rate should either be 50% or 70% 

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adrenaline which causes an increase in breathing rate and heart rate before starting exercise.

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This is to measure whether a persons heart rate is in the correct zone when taking part in exercise 

# data[].attributes.subject
This is to measure whether a persons heart rate is in the correct zone when taking part in exercise 

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This is the amount of blood pumped by the heart per minute.

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cardiac output

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Blood flow increases as the muscles demand more of an oxygen supply. This makes the heart work faster to supply, your arteries get wider (vasodilate) to allow a larger amount of blood to flow through.

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Your blood pressure increases during exercise as it needs to go to the working muscles

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120/80 norm data

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Systolic is the maximum pressure against the arteries when the heart contracts.  Diastolic is minimum pressure within the arteries between the hearts contractions.

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stroke volume is the amount of blood pumped from the left ventricle per beat.