Myth: Lifting a weight is what stimulates muscle growth
Fact: Lifting and lowering a weight stimulates muscle growth
In any free-weight exercise, there are two basic motions. One is called the concentric (lifting) phase; the other, the eccentric (lowering) phase. During the concentric phase of an exercise, the muscle shortens or contracts. During the eccentric phase of an exercise, just the opposite happens – the muscle lengthens.
A prime example is the bench press. When you lift the weight, pressing it from your chest to the lock-out position, that’s the concentric of positive phase of the exercise; when you lower the weight from the lock-out position to the chest, that’s the eccentric or negative portion of the exercise.
Enough evidence now exists to concretely state that lowering the weight is just as important as lifting it. It’s true! It turns out that weight lowering causes much of the muscle-cell damage that stimulate an adaptation. You see, when you lengthen the muscle, which occurs during that eccentric portion of an exercise, you literally tear portions of the muscle fibers, signaling a stage of remodeling, or muscle growth. (You’ll know when you’ve experienced this phenomenon because a day or two after your workout, your muscles will be sore. That’s a sign that the “earth has moved”.)
So, when you lift those barbells and dumbells, keep in mind that you should not just haphazardly let gravity return it to its starting position. Always, and I repeat, always contract your muscles during the eccentric phase of an exercise – always let the weight down smoothly and slowly. If you don’t, you’re simply wasting your time.
The bottom line is, you must focus on lifting and lowring those weights.