Increasing cardiorespiratory fitness levels is difficult for experienced athletes because A. they are not motivated to increase their levels of cardiorespiratory fitness
B. they cannot commit the training time to increase their cardiorespiratory fitness
C. they have already achieved high levels of cardiorespiratory fitness
D. none of the above
Please select the best answer from the choices provided.
A
B
ОООО
ОС
D