Effect of rapid weight loss on performance in combat sport male athletes: does adaptation to chronic weight cycling play a role?

Background Studies failing to show a negative effect of rapid weight loss (RWL) on performance have been conducted in athletes who have been cycling weight for years. It has been suggested that chronic weight cycling could lead combat athletes to become resistant to the stresses associated with weight loss. To investigate the effects of RWL up to 5% of body mass on high-intensity intermittent performance in weight cyclers (WC) and non-weight cyclers (non-WC).Methods Eighteen male combat athletes (WC: n=10; non-WC: n=8) reduced up to 5% of their body mass in 5days. Body composition, high-intensity performance and plasma lactate were assessed preweight loss and postweight loss. Athletes had 4h to re-feed and rehydrate following the weigh-in. Food intake was recorded during the weight loss and the recovery periods.Results Athletes significantly decreased body mass, lean body mass (most likely due to fluid loss) and fat mass following weight loss. No significant changes in performance were found from preweight loss to postweight loss in both groups. Plasma lactate was significantly elevated after exercise in both groups, but no differences were found between groups and in response to RWL. for all these variables no differences were observed between groups. Athletes from both groups ingested high amounts of energy and carbohydrates during the recovery period after the weigh-in.Conclusions Chronic weight cycling does not protect athletes from the negative impact of RWL on performance. the time to recover after weigh-in and the patterns of food and fluid ingestion during this period is likely to play the major role in restoring performance to baseline levels.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Univ São Paulo, Sch Phys Educ & Sport, Lab Appl Nutr & Metab, São Paulo, BrazilUniv São Paulo, Fac Med, Lab Assessment & Conditioning Rheumatol, São Paulo, BrazilUniversidade Federal de São Paulo, Discipline Expt Neurol, São Paulo, BrazilUniv São Paulo, Sch Phys Educ & Sport, Martial Arts & Combat Sports Res Grp, São Paulo, BrazilUniversidade Federal de São Paulo, Discipline Expt Neurol, São Paulo, BrazilFAPESP: 2012/22516-6FAPESP: 2011/17059-2Web of Scienc