RESUMEN
PURPOSE: Combat-sport athletes commonly undergo rapid weight loss prior to prebout weigh-in and subsequently rapid weight gain (RWG) prior to competition. This investigation aimed to evaluate the effect of RWG and weight differential (WD) between opponents on competitive success. METHODS: A retrospective cohort study was performed using data from professional mixed martial arts (MMA) and boxing events held between 2015 and 2019. The primary outcome was RWG (relative and absolute) between weigh-in and competition stratified by bout winners and losers. Binary logistic regression was used to explore the relationships among bout outcome, RWG, and WD between competitors on the day of their bout. RESULTS: Among 708 MMA athletes included, winners regained more relative body mass (8.7% [3.7%] vs 7.9% [3.8%], P < .01) than losers. In 1392 included male boxers, winners regained significantly more relative body mass (8.0% [3.0%] vs 6.9% [3.2%], P < .01) than losers. Each percentage body mass increase resulted in a 7% increased likelihood of victory in MMA and a 13% increase in boxing. The relationship between RWG and competitive success remained significant in regional and male international MMA athletes, as well as boxers. WD predicted victory in international mixed martial artists and boxers. WD predicted victory by knockout or technical knockout in international MMA athletes and regional boxers. CONCLUSION: This analysis of combat-sport athletes indicates that RWG and WD influence competitive success. These findings raise fair-play and safety concerns in these popular sports and may help guide risk-mitigating regulation strategies.
Asunto(s)
Boxeo , Artes Marciales , Humanos , Masculino , Estudios Retrospectivos , Aumento de Peso , Artes Marciales/fisiología , AtletasRESUMEN
OBJECTIVES: Weight classifications are used in boxing and other combat sports to match opponents of similar size. Professional boxers commonly engage in a potentially harmful practice known as rapid weight loss or 'weight cutting' to make weight the day prior to competition before rehydrating and refueling. This investigation describes the prevalence and magnitude of rapid weight gain in boxers following weigh-in as well as differences in practice with respect to weight class and promotion. METHODS: This analysis describes official weight data from male professional boxers collected by the California State Athletic Commission between 2015 and 2018. A total of 399 athletes were included in the study. RESULTS: Among included athletes, 389 (97.5%) athletes gained weight between official weigh-in and competition. Total absolute body mass gained was 4.4 ± 2.2 kg corresponding to a total relative body mass gain of 7.2 ± 3.5%. Boxers competing in international promotions gained significantly more body mass than regional competitors (8.0 ± 3.0% vs. 6.6 ± 3.7%; p < 0.001). In total, 82 (20.6%) athletes gained 10% body mass or more before competition. More international competitors reached this 10% threshold than regional competitors (25.3% vs. 17.4%; p = 0.03). CONCLUSIONS: These findings indicate high prevalence and magnitude of RWG in professional boxing, particularly in boxers competing in elite international promotions.
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Boxeo , Artes Marciales , Humanos , Masculino , Peso Corporal , Conducta Competitiva , Pérdida de Peso , Aumento de Peso , AtletasRESUMEN
Rationale: In acute respiratory distress syndrome (ARDS), the effect of positive end-expiratory pressure (PEEP) may depend on the extent to which multiorgan dysfunction contributes to risk of death, and the precision with which PEEP is titrated to attenuate atelectrauma without exacerbating overdistension. Objectives: To evaluate whether multiorgan dysfunction and lung mechanics modified treatment effect in the EPVent-2 (Esophageal Pressure-guided Ventilation 2) trial, a multicenter trial of esophageal pressure (Pes)-guided PEEP versus empirical high PEEP in moderate to severe ARDS. Methods: This post hoc reanalysis of the EPVent-2 trial evaluated for heterogeneity of treatment effect on mortality by baseline multiorgan dysfunction, determined via Acute Physiology and Chronic Health Evaluation II (APACHE-II). It also evaluated whether PEEP titrated to end-expiratory transpulmonary pressure near 0 cm H2O was associated with survival. Measurements and Main Results: All 200 trial participants were included. Treatment effect on 60-day mortality differed by multiorgan dysfunction severity (P = 0.03 for interaction). Pes-guided PEEP was associated with lower mortality among patients with APACHE-II less than the median value (hazard ratio, 0.43; 95% confidence interval, 0.20-0.92) and may have had the opposite effect in patients with higher APACHE-II (hazard ratio, 1.69; 95% confidence interval, 0.93-3.05). Independent of treatment group or multiorgan dysfunction severity, mortality was lowest when PEEP titration achieved end-expiratory transpulmonary pressure near 0 cm H2O. Conclusions: The effect on survival of Pes-guided PEEP, compared with empirical high PEEP, differed by multiorgan dysfunction severity. Independent of multiorgan dysfunction, PEEP titrated to end-expiratory transpulmonary pressure closer to 0 cm H2O was associated with greater survival than more positive or negative values. These findings warrant prospective testing in a future trial.
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Esófago/fisiología , Respiración con Presión Positiva/métodos , Respiración Artificial/efectos adversos , Síndrome de Dificultad Respiratoria/mortalidad , Síndrome de Dificultad Respiratoria/terapia , Sobrevida , Lesión Pulmonar Inducida por Ventilación Mecánica/etiología , Adulto , Humanos , Imágenes en Psicoterapia/métodos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Respiración Artificial/métodos , Factores de RiesgoRESUMEN
Rapid weight loss or "weight cutting" is a common but potentially harmful practice used in mixed martial arts competition. Following the official weigh-in, competitors refeed and rehydrate themselves in a process known as rapid weight gain (RWG) to realize a potential competitive advantage. While data from surveys and small series have indicated the majority of mixed martial arts athletes engage in rapid weight loss, there is a lack of officially collected data from sanctioning organizations describing its prevalence. The present investigation represents a summary of the data collected between December 2015 and January 2018 by the California State Athletic Commission. In total, 512 professional mixed martial artists (455 males and 57 females) were included. Of these, 503 (98%) athletes gained body mass between weigh-in and their bouts. Total RWG between weigh-in and competition was 5.5 ± 2.5 kg, corresponding to an 8.1% ± 3.6% body mass increase. Total RWG was 5.6 ± 2.5 kg (8.1% ± 3.6%) for males and 4.5 ± 2.3 kg (8.0% ± 3.8%) for females. More than one quarter of men and one third of women gained >10% body mass between weigh-in and competition. Athletes from leading international promotions gained more absolute, but not relative, body mass than those from regional promotions. Our findings indicate RWG is nearly ubiquitous in professional , with a similar prevalence in male and female athletes. Trends based on promotion suggest a larger magnitude of RWG in presumably more experienced and/or successful mixed martial artists from leading international promotions.