Jerking while lifting weights: When you have to jerk the weight, it`s likely you`re jerking other muscles as well. This can lead to strain and injury, with the muscles of the back being particularly vulnerable. Control the weight, don`t let it control you.

Consuming energy bars and sports drinks during moderate workouts: Unless you`re working out for longer than two hours per day, you don`t need to supplement with high-energy bars and drinks. (High-energy is often a code word for high-calorie.)