Finding it hard to fit in fitness? Just getting through a day of school and after-school commitments can leave most of us wondering where to find time. Experts recommend that teens do 60 minutes or more of physical activity every day. Most of that should be moderate to vigorous aerobic activity. Aerobic activity is anything that gets your heart going — like biking, dancing, or running. Then take a few minutes for some strength training. Exercises like the ones below help build muscle and boost metabolism. Flexibility is the third component of well-rounded exercise. Check out yoga as one way to stay flexible. You can do these three strength-building exercises at home. There's no need for special equipment, expensive gym fees, or lots of time. Just check with your doctor, PE teacher, or coach first to be sure these exercises are OK for you. Sit Backs: Step 1 Sit on floor, legs bent Arms straight in front Sit Backs: Step 2 Lean back gradually Keep arms straight and tummy tight Take it as far back as comfortable Slowly return to sitting position Repeat Chair Squats: Step 1 Stand tall Chair behind you Chair Squats: Step 2 Arms straight in front Slowly start to sit down Stop before your butt hits the chair Slowly straighten to standing Repeat Butterfly Breath: Step 1 Stand tall Feet hip width apart Arms lifted out to the sides Butterfly Breath: Step 2 Exhaling, lift right knee and touch it with left elbow Inhaling, return to position one Switch sides and repeat About Sets and Reps Most fitness instructors recommend repeating a particular strength training exercise several times in a row. These are known as repetitions, or “reps,” and they’re done in “sets.” Each set consists of a specific number of reps, usually between 8 and 15. Fitness instructors often recommend that people rest after one set and then perform another set (or more) of the same number of reps. For the exercises shown above, start with 10 reps, adding sets of 10 as you get comfortable. Rest for 30 seconds between sets. Back to Articles Related Articles Why Exercise Is Wise Getting the right amount of exercise can rev up your energy levels and even help you to feel better emotionally. Find out why. Read More How Can I Get Motivated to Exercise? Find out what the experts have to say. Read More Exercise Log Keeping an exercise log is a great way to stay motivated and reach exercise goals. Read More Strength Training Is working out with weights safe for teens? The best way to build muscle tone and definition is to combine aerobic and flexibility exercises with the right kind of strength training. Read More Weight Management: Strength Training Exercises (Video) These videos guide teens through basic strength training exercises. Anyone can do these exercises, and they work well as part of a weight-loss plan. Read More Sports and Exercise Safety Playing hard doesn't have to mean getting hurt. The best way to ensure a long and injury-free athletic career is to play it safe from the start. Find out how. Read More Stretching You may have heard mixed things about stretching before working out. Here are the cold, hard facts on warming up, stretching, and cooling down. Read More Dynamic Stretching (Video) These videos guide you through 8 dynamic stretches that target different muscles and areas of the body. Read More Yoga Looking for a workout program that's easy to learn, requires little or no equipment, and soothes your soul while toning your body? Read about yoga - and watch our slideshow for some easy poses to try. Read More Welcome Home Yoga (Video) Unwind after a long day at school with this yoga routine for teens. Read More Study Break Yoga (Video) Yoga is a great way to take a study break because it refocuses and re-energizes both the body and mind. This routine uses poses that work for teens. Read More Note: All information is for educational purposes only. For specific medical advice, diagnoses, and treatment, consult your doctor. © 1995-2021 KidsHealth®. All rights reserved. Images provided by The Nemours Foundation, iStock, Getty Images, Veer, Shutterstock, and Clipart.com.