10. It enhances emotional well-being. Most people report that they feel calm and have a sense of well-being after they exercise. Exercise, according to one theory, releases beta-endorphin, a natural substance in the body that is hundreds of times more potent than morphine. Another theory points to serotonin as the cause of the exercise high. Increased levels of serotonin in the central nervous system are associated with feelings of well-being, heightening of appetite, and lessening of mental depression. The weight loss that accompanies exercise can also cause people to feel better about themselves.
Downward dog is another Sun Salutation pose that tones the arms. For this pose, your body will form a reverse V-shape with your heels pressed down or close to the floor and your hands flat on the floor. Ideally, your spine will follow a straight line toward the ground with your hips pressed back. You may need to bend your knees to keep your body in the reverse V-shape.
HOW TO DO IT: Start in a high plank with your hands underneath your shoulders. Jump your feet outside your hands and drop into a deep squat position, pushing your knees out and keeping your feels flat on the floor while prying your chest open with your hands. Return to the starting position and repeat. For an added challenge, try moving both forward and backward.
If you're ready to move on from classic Bulgarian split squats, Swan's amped-up variation gets your upper body in on the action for a true total-body exercise. "This combination move works your legs, butt, chest, back, arms, and core," she says. "And it not only hits all the major muscle groups—it also lets you work on balance." Give it a shot and you'll see why.