The exercise prescriptions for Justin, a 13-year-old who is class I obese, recommend cardiovascular activity 5-7 days per week for 45-60 minutes at a moderate then progressing intensity of 40-60% of his heart rate reserve. Muscular strength and endurance training is suggested 3-5 days per week for 30-45 minutes at 60-70% of his 1 repetition maximum. Flexibility training 3 days per week is also prescribed. The principles of progression, regularity, and overload will be utilized by increasing intensity and weight over time while maintaining consistency to optimize results. Activity-specific exercises like running, soccer, and free weights are suggested.