Flexing your arm to lift a weight seems like a simple maneuver, but you might be doing it wrong.
Whether you use a large and complicated system of pulleys and weights to work out, or stick to running and calisthenics, knowing the correct way to exercise is important. Incorrectly performed exercise can mean you're not getting the benefits you're looking for, and can even lead to injury.
"There's almost always a safer alternative to a risky exercise," said Stephen Ball, an associate professor of nutrition and exercise physiology at the University of Missouri. He's created a series of videos that show how to exercise safely.
Here are seven exercises people commonly do incorrectly, and how to do them right.