Abstract
This study investigated the effect of different resistance increments during warm-up on snatch performance of male weightlifters. Nine male college weightlifters were recruited. The 3 warm-up protocols were performed every 7 days with a randomized order: 1. Power snatch exercise with 10 % resistance increment (50 %, 60 %, 70 %, and 80 % of one-repetition maximum); 2. Power snatch exercise with 15 % resistance increment (50 %, 65 %, and 80 % of one-repetition maximum); 3. Self-selected resistance increment. Participants were tested based on 85 % maximum weight snatch after warm-up. Snatch performance was measured using peak vertical ground reaction force. Postural stability was measured using center-of-pressure displacement. Activation of seven shoulder, back, and leg muscles was measured using electromyography on the dominant side. In snatch performance, the 10 % increment protocol had a significantly higher peak vertical ground reaction force during the second-pull phase than the 15 % increment (d = 0.92, p < 0.05) and self-selected (d = 1.32, p < 0.05) protocols. In postural stability, no significant differences in center-of-pressure displacement among the three protocols were observed. For muscle activation, the 10 % increment protocol resulted in significantly higher activation of shoulder (d = 1.2-2.2, p < 0.05) during the second-pull phase than the other two protocols and higher activation of hip muscles (d = 1.73, p < 0.05) than self-selected protocol. To conclude, a warm-up protocol combining slow progression is preferable in improving power output during snatch in male weightlifters, probably through facilitating the activation of proximal limb muscles. It can enhance training quality while potentially reducing the risk of sports injuries.