1. flexibility is the amount of body fat compared to the amount of lean muscle mass.

true or false?

2. one function of the many functions of the cardiorespiratory system is to transport and exchange gases.

true or false?

Because without physical activity, the body has extra "energy" if you will, and so when it is time for bed you are not tired, so you end up staying up all night. also there is probably an effect on your internal clock, which messes with your melatonin production which goes hand in hand with your sleep cycle