A major new meta-analysis of 26 studies and over 600 subjects examined whether the negative (lowering) or positive (lifting) phase of an exercise drives more muscle growth. Results showed that for upper body muscles, emphasizing the negative phase produced a small but statistically significant advantage in hypertrophy. For lower body muscles, both phases produced similar growth. Overall, across the whole body, the two phases were roughly equivalent. The practical takeaway is to control your negatives — especially for upper body work — but the popular belief that negatives are dramatically superior to positives for muscle growth is not strongly supported by the current evidence. Both phases contribute meaningfully to gains.
