Is there a relationship between rapid weight changes and self-reported injury in combat sports athletes? A 14-month study of 24 combat sports events

Objectives

To explore the potential association between rapid weight changes and self-reported injury status (presence or absence of injury) 7 days following competitive events among male and female combat sports competitors.

Design

A 14-month study of 24 events.

Methods

A weight management questionnaire was completed 1-day post-competition, and an injury questionnaire was completed 7 days post-competition. These online questionnaires provided data on body mass and injury status. Mixed effects logistic regression models were used to analyse the odds ratios of rapid weight change variables and their impact on athletes' self-reporting as injured or non-injured.

Results

There were 172 responses (155 athletes) to both questionnaires (37 females (24 %) and 118 males (76 %)); 88 athletes (51 %) reported no injury, and 84 (49 %) reported injury. Rapid weight loss 7 days (RWL − 7 days) and 24 h (RWL − 24 h) before weigh-ins was 4.9 % ± 3.4 % and 2.6 % ± 2.1 % for females, and 6.1 % ± 3.2 % and 3.0 % ± 1.9 % for males. Mixed effects logistic regression models returned the highest odds ratio for male RWL − 24 h (odds ratio: 1.20, 95 % confidence interval: 1.00–1.43, p = 0.044). This indicates that for a 1 % increase in male RWL − 24 h before official weigh-ins, the likelihood of reporting an injury increases by a factor of 1.2.

Conclusions

Male RWL − 24 h before weigh-ins is associated with reporting an injury at 7 days post-competition. Therefore, athletes and coaches should carefully consider and aim to limit pre-competition rapid weight loss to minimise the likelihood of injury.