Dynamic stretches are part of an effective warm-up because they can help a. lubricate the muscles used in the activity
b. decrease cardiovascular difficulty in the activity
c. expand lung capacity for the activity
d. build endurance for the activity

People who utilizes the progression principle will ensure their exercise program increases in frequency, intensity, time, and type. the changes need to happen gradually in order to ensure they make gains in their fitness program. a person who doesn't utilize the progression principle can still gain health benefits from exercising, but will not continue to improve in cardiovascular fitness.