Nearly two out of three combat sport athletes have poor sleep quality, with rapid weight loss of more than 4% body weight nearly tripling the odds, according to a cross-sectional study of 498 athletes published in Frontiers in Psychology.
Combat sport athletes face unique sleep challenges from high training loads, pre-competition weight cutting, and the physiological demands of their sport. Researchers in Turkiye assessed sleep quality using the Pittsburgh Sleep Quality Index (PSQI) across athletes competing in both Olympic (judo, wrestling, taekwondo, boxing) and non-Olympic (kickboxing, Muay Thai, Brazilian Jiu-Jitsu) disciplines.
What they found
- 65% of all athletes were classified as poor sleepers (PSQI > 5) — a rate substantially higher than the general young adult population
- Rapid weight loss >4% carried the strongest association: nearly threefold increased odds of poor sleep (OR = 2.70, 95% CI 1.80-4.00)
- Olympic sport athletes had 75% higher odds of poor sleep than their non-Olympic counterparts (OR = 1.75, 95% CI 1.25-2.45)
- Male athletes had 65% higher odds than female athletes (OR = 1.65, 95% CI 1.20-2.30)
- Sport age (years of training) showed a modest but significant effect: 3% increase in odds per year (OR = 1.03, 95% CI 1.01-1.05)
Why it matters
These findings highlight that sleep is a modifiable risk factor in combat sports performance and recovery. Rapid weight loss — a widespread practice in combat sports for making weight class — emerged as the strongest predictor by a wide margin, suggesting that weight-cutting protocols may directly undermine the sleep quality athletes need for competition readiness.
Olympic combat sports may impose additional demands through higher training intensity, stricter competition schedules, or more entrenched weight-cutting culture.
Limits
The study used self-reported sleep quality (PSQI), which may not correlate perfectly with objective sleep measures. The cross-sectional design cannot determine causality — poor sleep may be a consequence of training demands, a cause of other issues, or both. Sport-specific factors (e.g., training volume, competition frequency) were not individually analyzed.
Bottom line
Poor sleep is prevalent among combat sport athletes and strongly linked to aggressive weight-cutting practices. Coaches and athletes should consider sleep monitoring as part of training management, and weight loss protocols should account for their sleep-disrupting effects.
Source
Eroglu S, et al. Sleep quality in Olympic and non-Olympic combat sports: associations with sex, rapid weight loss, and sport age (a PSQI-based analysis). Front Psychol. 2026 Jun 3;17:1847782. DOI: 10.3389/fpsyg.2026.1847782. PMID: 42317690.