Marshall is 20 years old. He is currently doing 100 minutes a week of moderate-intensity aerobic physical activity and 25 minutes a week of vigorous-intensity aerobic physical activity, and he lifts weights involving all major muscle groups 2 days per week. What change should he make to meet Federal Guidelines for Physical Activity? a. Complete muscle-strengthening activities that involve all major muscle groups 3 or more days per week.
b. Marshall is already meeting guidelines.
c. Complete 200 minutes a week of moderate-intensity aerobic physical activity.
d. Complete 75 minutes of vigorous-intensity aerobic physical activity