need for speed?

Weight training will improve your health no matter what, but slow or fast reps yield di erent results.

No o ense to Charles Atlas, but the science behind weight training has advanced by leaps and bounds since the days of sand being kicked in the faces of 98-pound weaklings.

Today, one particular debate pits the merits of slow repetitions against fast reps.

First, let’s define a full repetition. A full rep is both the positive and negative muscle movement. So a full rep of a bench press, for example, means pushing the weight out almost fully from your chest (positive movement) and then lowering the weight back down to your chest (negative movement).

Both slow and fast repetitions have benefits, but yield di erent results. Slow reps better stimulate muscle growth, while fast reps can give you more overall strength.

Slow Reps

A slow repetition should take 10 seconds to complete: four seconds of positive movement, two seconds of pause to slow momentum, spur muscle resistance and minimize injury, and four seconds of negative movement.

By lifting slowly, you are stimulating blood flow to muscles, as well as prolonging muscle tension. As a result, slow reps grow and build muscles (“bulk”).

Fast Reps

Lifting weights “fast” is not an excuse to encourage injury by “throwing” weights around. It’s important to maintain proper form and control of the weight even if lifting more rapidly. With fast reps, cut lift times down significantly: one second of positive movement, pause a fraction to slow the momentum of the weight and one second of negative movement.

Fast reps minimize muscle tension and thus don’t “bulk up” muscles. Instead, fast reps will give muscles greater definition and can produce greater overall power and strength.

Negative Rep Training

Rehabilitating, senior or novice weightlifters are encouraged to perform negative reps only. Such training necessitates a trainer to spot the weightlifter. The trainer/spotter helps the weightlifter perform the positive movement of the lift and then lets the weightlifter finish the rep by handling the negative movement on his or her own. Negative rep training can be considered resistance training, because the weightlifter is focused fully on resisting the weight of the barbell.

Although positive reps take much more energy and potentially invite injury, negative reps are easier to control, and therefore are a better fit for an older adult, someone recovering from injury or a beginner.