Exercise is healthy and coolWhen you do exercise, you breathe fast and your heart pumps blood around your body. The blood carries oxygen from your lungs to your muscles. Your muscles help your joints to move.With regular exercise, you:build strong muscleskeep a healthy weightsleep well at nightfeel good about yourselffeel less worried or stressedfeel ready to learn at schoolThere are three main kinds of exercise:Aerobic exerciseAerobic exercise needs lots of oxygen. It makes you breathe fast. Aerobic exercise is good for your heart. Swimming and tennis are examples of aerobic exercise. When you run, skip, and jump in the playground, that's aerobic exercise, too.Strength trainingStrength training is good for your muscles. Strong muscles support your joints and stop you from getting hurt. Cycling and rowing are examples of strength training. When you do handstands in the playground, that's strength training, too.Flexibility trainingFlexibility training helps your body stretch and bend. It is good for your muscles and joints. Gymnastics and judo are examples of flexibility training. When you touch your toes, that's flexibility training, too.