To improve your aerobic capacity<span>, complete 20-30mins of work at </span>your<span> 3-5km race pace broken down into intervals, with 50-80% of the interval time added as recovery. For example, a runner with a 5km PB of 25mins could run 6 x 1km repeats, aiming to run each in just under 5mins, with 2:30mins recovery.</span>
Answer: The answer is variable.
Explanation: Scientists may do a start out hypothesis on the info they have. But if something changes in that experiment, it is the Variable.
Hope this helps!
I think the answer is nervous system and muscular system work together but i could be wrong.
