The contractile proteins in muscles are called:
a. actin and myosin.
b. enzymes and cofactors.
c. contractin and relaxin.
d. adenosine and creatine.
Question 2
Adults should perform moderate-intensity or vigorous-intensity aerobic exercise throughout the week in episodes of at least:
a. 5 minutes.
b. 10 minutes.
c. 20 minutes.
d. 45 minutes.