Decreased Sleep Is an Independent Predictor of In-Season Injury in Male Collegiate Basketball Players

BACKGROUND: Although decreased sleep has been associated with decreased performance, increased illness risk, and impaired well-being in athletes, the relationship between sleep and injury risk in collegiate athletes is unknown. PURPOSE/HYPOTHESIS: To evaluate the independent effects of sleep duration and subjective well-being on in-season injury in male collegiate basketball athletes. We hypothesized that decreased sleep would be associated with an increased risk of in-season injury. STUDY DESIGN: Cohort study; Level of evidence, 2. METHODS: During 2 consecutive seasons, 19 male National Collegiate Athletic Association Division I basketball players reported mood, fatigue, stress, soreness, sleep duration (hours), and previous day’s training load every morning. Well-being measures were recorded on a scale from 0 (worst) to 5 (best), and all time-loss injuries were recorded by the team athletic trainer. Separate mixed-effects logistic regression models were used to evaluate the effects of sleep and subjective well-being on in-season injury, with adjustment for same-day training load and individual repeated measures. To determine the independence of sleep and well-being as predictors of injury, each well-being variable was included in a separate mixed-effects logistic regression model, with sleep and training load as covariates. RESULTS: During the study period, 32 injuries were recorded. In the initial separate prediction models, in-season injury was significantly predicted by mood (odds ratio [OR], 0.50; 95% CI, 0.37-0.66), fatigue (OR, 0.44; 95% CI, 0.33-0.59), stress (OR, 0.57; 95% CI, 0.42-0.76), soreness (OR, 0.41; 95% CI, 0.32-0.54), and sleep duration (OR, 0.57; 95% CI, 0.49-0.66) (P < .001 for all). In the multivariable models, sleep duration remained a significant, independent predictor in each of the subsequent multivariable models (OR, 0.52-0.69; P < .001 for all) as did soreness (OR, 0.65; 95% CI, 0.44-0.95; P = .024), whereas mood (OR, 1.2; 95% CI, 0.76-1.9; P = .43), fatigue (OR, 1.1; 95% CI, 0.65-1.9; P = .68), and stress (OR, 1.1; 95% CI, 0.75-1.5; P = .69) were no longer significant. CONCLUSION: Increased sleep duration is independently associated with a reduced risk of in-season injury in male collegiate basketball players, even after adjustment for training load and subjective well-being. The effects of mood, fatigue, and stress on injury were no longer evident after adjustment for the effect of sleep duration.