The term negative (or negative reps) refers to the eccentric or lengthening phase of a muscle contraction. The concentric or positive phase occurs when you contract and shorten the muscle, like when you curl a dumbbell. The negative phase, then, is the lowering of the weight back to the start point. Although most people focus on the positive portion of a move, your muscles are stronger under eccentric loads, making negative reps a valuable strength-builder and muscle-shaper.
When doing negatives, lift the weight quickly through the positive portion of the rep or have someone assist you in getting there, then lower the weight as slowly as possible through the negative portion of the rep. Resist the pull of the weight and fight gravity to make your negative slow and controlled. Repeat immediately once you reach the bottom of the rep.
This month is a great time to use negatives: You’re trying to add muscle to your frame, which will help define your shape and boost your metabolism. Do them as instructed by your coaches, and make sure your muscles are thoroughly warmed up and ready to rock before hitting them with negatives.