What would the independent variable in this experiment be?

I need to know. Our class took our resting heart rate and then did jumping jacks for a minute straight and took our new heart rate and recorded it. We did this in the same room with the same people using the same stopwatch for ten days. Independent variable?|||I can see two independant variables here.


1) Whether you were at rest or had just done jumping jacks when you took your heart rate;


2) How many days has passed since the start of the experiment when you took your heart rate.





Both of those variable could likely have an effect on the measured heart rate. Doing jumping jacks will obviously increase your rate compared to what it was just before. But doing daily exercice may also influence your heart rate over the lapse of 10 days. I'm not sure if 10 days would be enough to have any impact, especially if the exercice only lasts 1 minute, but it'd be worth checking.





I'd recommend doing a table with 4 columns, as follows:


Day (1, 2, 3,... 10);


Heart rate at rest;


Heart rate after 1 minute of jumping jacks;


Difference between the two (rate after jumps minus rate at rest).