Rapid weight loss (RWL) followed by rapid weight gain (RWG) are common practices among combat sports athletes to gain a competitive advantage. However, the impact of weight manipulation on physical performance remains unclear. 19 male athletes (M = 24.6 ys, SD = 5) underwent baseline strength assessments, followed by a 7-day RWL and a 2-hour RWG.
We measured their physical strength using a battery of dynamic and anaerobic tests, including the countermovement jump (CMJ) and upper limb Wingate test. On average, participants reduced 5% and gained 2.6% of body weight during RWL and RWG, respectively.
Using mixed-effects models, we observed statistically significant decreases in peak forces (1.5 - 9.3%) post RWL across dynamic tests and increased fatigue index (6%) in the Wingate test. We observed statistically significant increases in peak forces (1.8% - 7.4%) Post RWG, compared to post RWL.
Our findings suggest that RWL negatively impacts physical performance in combat sports athletes, but RWG may partially reverse these effects.