How to Burn Fat & Build Muscle for Teens

Warm up thoroughly before exercising with a circuit of hamstring stretches, chest stretches, walking lunges and arm circles.

Do a circuit of planks, pushups, squats, lunges and hip bridges. Do each exercise 15 times -- hold the plank for 30 seconds -- and repeat the circuit four times. Rest about 30 to 60 seconds between exercises.

Add weight slowly. For the squat, take a 5-pound dumbbell and hold it with both hands in front of your chest with your elbows underneath. When this gets easier, increase the weight by another 5 pounds. To build muscle, use dumbbells, barbells or kettlebells to add resistance to your exercises.

Commit to working out at least three times per week and mark it in your calendar, or ask your friends to hold you accountable. If you exercise regularly, you will continue to build muscle and get results. If you lose motivation and stop training, you'll stop making gains and start backsliding.

Include at least one serving of vegetables, lean meats and whole grains in every meal. This will keep you healthy, keep your metabolism high and support muscle and tissue growth.

Eat whole, unprocessed foods. If it came out of a box, it's probably processed.

If you still aren't burning fat, increase the number of days you exercise by one. For example, if you're only exercising once a week, bump it to two; if you're exercising twice a week, bump it to three. This way, you're burning more calories than before, which will help you burn fat. Also, your body will change faster.

If you still aren't losing fat, create a food diary and track it daily. The Centers for Disease Control and Prevention website has a great printable template.

Lower your calorie intake by 500 per day if you still aren't losing fat. To do this, count how many calories you eat every day by using an online calorie estimator. Then, see if your body fat goes down. If your body-fat levels don't decrease, slowly reduce your caloric intake further.