Exercising More Than 150 min/wk After Concussion Is Associated With Sleep Quality Improvements

Objective: To examine whether a high volume of aerobic exercise after concussion (>150 min/wk) is associated with improved sleep quality over a 1-month period. We hypothesized that more than 150 min/wk of exercise would be associated with improved sleep quality across concussion recovery. Design: Prospective cohort observational study. Setting: Sports medicine clinic. Participants: Adolescents initially tested 8.4 +/- 3.5 (range, 2-18) days postconcussion who returned for a follow-up assessment 34.3 +/- 7.7 (range: 20-49) days postconcussion. Main Outcome Measures: Participants completed the Pittsburgh Sleep Quality Index and the Post-Concussion Symptom Inventory. No specific exercise or sleep recommendations were given beyond what their treating physician provided. Between study visits, participants recorded exercise performed via wrist-worn actigraphy. We calculated average exercise minutes per week and grouped participants as those who exercised more than 150 min/wk versus those who exercised 150 min/wk or less. Results: Thirty-six adolescents participated. Fifteen (42%) recorded more than 150 min/wk of aerobic exercise (age = 14.0 +/- 1.7 years; 47% female; mean = 5.6 +/- 1.2 d/wk of exercise; mean = 49.2 +/- 17.5 min/session), and 21 recorded 150 min/wk or less of aerobic exercise (age = 15.0 +/- 1.9 years; 76% female; mean = 2.7 +/- 1.6 d/wk of exercise; mean = 30.2 +/- 7.8 min/session). There were no significant group differences in the proportion of those who self-reported beginning physical activity prior to enrollment (47% vs 33%; P = .42) or for initial sleep quality rating (8.0 +/- 3.7 vs 8.6 +/- 4.1; P = .67) or initial concussion symptom severity rating (34.9 +/- 28.0 vs 42.6 +/- 25.9; P = .40). The group that exercised more than 150 min/wk between visits demonstrated significantly greater median PSQI rating improvements than those who exercised 150 min/wk or less, with a large effect size noted (median change [interquartile range] = 5 [3, 7] vs 1 [0, 4]; P = .008; Cohen d = 0.96). Conclusion: Current recommendations suggest that subsymptom aerobic exercise can be beneficial after concussion. Our findings indicate that an exercise volume of more than 150 min/wk led to greater sleep quality improvements than those who exercised below this level.