Adding to this site’s archived articles addressing rapid extreme weight cut practices in combat sports, a recent study was published in the Journal of The Physician and Sports Medicine evaluating competition results in boxing with athletes who practiced Rapid Weight Gain after weigh ins.
In the study, titled Rapid Weight Gain in Professional Boxing and Correlation With Fight Decisions, the authors reviewed 71 bouts sanctioned by the International Boxing Federation and looked at how much weight athletes gained from weigh in to competition and further reviewed the weight discrepancy between opponents.
The data revealed that “correlations between weight gain and weight discrepancy were not found” although there were cases with “alarming” weight gain and weight discrepancy.
Below is the studies full abstract:
Abstract
Introduction: Boxing is a sport where athletes compete in several weight categories. Professional boxers typically dehydrate to cut their weight for the weigh-in (24h before the contest) and then rehydrate before the fight. The International Boxing Federation (IBF) mandates a second weigh-in 12h before the fight.
Objectives: 1) To quantify the weight gain (WG) from the 1st to the 2nd weigh-in; 2) to investigate whether rapid WG affects boxing performance (win/loss rate) and 3) whether weight discrepancy (WD) between boxers exposes them to increased health risks (rate of fights ended before time limit).
Methods: From official weigh-in reports of 71 IBF fights (142 fighters) the following data were gathered/calculated for each boxer: age, weight division, 1st weight, 2nd weight, WG between weigh-ins (kg and %), WD between opponents, and fight decision.
Results: Between the weigh-ins, the average WG was 2.52±1.37kg (range -0.3/6.4kg) and 3.8±2.2% of the initial body weight (range -0.4/9.3%) and the average WD 1.94±1.50kg (maximum 7.10kg). Both WG and WD did not affect match outcomes. We observed tendencies for higher loss rate among boxers gaining more weight, and for higher victory rate in boxers with larger WD, however without reaching significance. A significant negative correlation was found between the 1st weight and the WG, both in absolute (r=-0.278, p=0.001) and relative value (r=-0.497, p<0.0001).
Conclusions: Although correlations between WG, WD and boxing performance were not found, single cases with an alarming high WG and WD were noted.
Combat Sports Law 
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