What explains this conditioning response?

A client does interval training with an ACE certified Personal Trainer twice each week to improve overall running performance After 12 weeks of training, the client has been able to run the same distance in less time and has a lower exercise heart rate during interval training.

What explains this conditioning response?
A . Increased type ll fibers
B . Decreased cardiac output
C . Increased mitochondrial density
D . Decreased stroke volume

View Answer

Answer: D