How Much and How Hard?
Frequency: 3-5 days per week
Aerobic exercise: a minimum if 3 days a week are necessary to reach most exercise goals and minimize health benefits
Strength training: a minimum of 2 days per week
Flexibility training: a minimum of 3-5 days per week
Duration
Aerobic: 20-60 minutes of continuous aerobic activity
Strength: 1-3 sets of 8-12 repetitions
Stretching: Stretch all muscle groups and hold positions for 10-30 seconds