Question

select the correct answer.
what do cardio activities increase?
a. heart rate
b. muscle strength
c. range of motion
d. muscle mass

Explanation:

Cardio activities (like running, cycling) are designed to work the cardiovascular system. During cardio, the heart has to pump more blood, so heart rate increases. Muscle strength, range of motion, and muscle mass are more related to strength - training or flexibility exercises, not cardio. So the correct option is A.

Answer:

A. heart rate