Adults can exercise with moderate intensity for two hours and thirty minutes per week. Older adults (65+) should exercise 60 minutes per day. Children 6-17 should exersice 75 minutes per day. Adults should include 5 hours of muscle strengthening per week. The answer choices.

C. Children should exercise 30 mins to an hour a half a day

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.