Bodybuilding Science

Slower Reps for Faster Gains in Size and Strength.

- Michael J. Rudolph

Optimal strength gains are typically achieved by high-intensity training requiring the use of heavy weights within a low repetition range, while the best hypertrophic response is ordinarily stimulated using moderate weights at a higher volume involving an elevated repetition range. Heavier weights augment strength principally by inducing greater neuromuscular activation of fast-twitch muscle fibers, which contract more forcefully than slow-twitch muscle fibers, producing more power. The increased activation of fast-twitch muscle fibers from high-intensity training ultimately leads to greater strength gains. On the other hand, higher volume training more specifically amplifies muscle growth, in large part, by increasing muscle time under tension— which increases metabolic stress, encouraging muscle hypertrophy.

BOOST STRENGTH

Even though it is commonly recommended that training with weight around 70 percent of your one-repetition maximum (1RM) is required for optimal muscle growth, slower lifting movements, with lighter weight, can also stimulate considerable muscle growth by raising the time that the muscle is under tension, to an even greater degree. The increase in time under tension puts ample stress on the muscle tissue, inducing considerable muscular growth. It has also been shown that the activation of muscular contraction can also be increased while lifting lighter weights more slowly, suggesting that this training approach can also enhance strength.1,2 In fact, some recent research published in the International Journal of Sports Medicine has shown that 3 performing low-load, high-repetition squats while executing the movement at a slower pace can trigger superior gains in strength and muscle size relative to the use of heavier loads.