Sex Differences in the Treatment Effect of Targeted Heart Rate Aerobic Exercise in Adolescents with Acute...

Prescribed aerobic exercise is the recommended treatment for athletes with sport-related concussion (SRC) who present with exercise intolerance. A recent randomized controlled trial (RCT) found that higher volumes of aerobic exercise, compared with lower volumes, may not be as efficacious in adolescent females with SRC compared with adolescent males. We reanalyzed data from our previously published randomized controlled trials (RCT) and hypothesized that prescribed aerobic exercise, and not stretching, within 10 days of injury would result in faster recovery after SRC in males compared with females. The first RCT (n = 103) recruited from 2015 to 2018 and the second RCT (n = 115) recruited from 2018 to 2020. Sexes were compared in each RCT, then samples were stratified by sex, and intervention groups were compared using a Log-rank test. There were no significant differences in recovery times between males and females in either RCT, regardless of intervention. When stratified by sex and comparing intervention groups, males in RCT1 who were prescribed aerobic exercise (n = 28) recovered 6 days faster than males prescribed stretching (n = 27, p = 0.004) but there was no significant difference for females (aerobic exercise [n = 24] vs. stretching [n = 24, 3-day difference, p = 0.564]). In RCT2, males prescribed aerobic exercise (n = 39) recovered 8 days faster than the stretching group (n = 34, p = 0.020), whereas there was no significant difference for females (aerobic exercise [n = 22] vs. stretching [n = 20, 3-day difference, p = 0.587]). This reanalysis of prior RCT data revealed that male adolescents after SRC recovered significantly faster by 7-8 days when prescribed aerobic exercise within 10 days of injury, whereas female adolescents had a nonsignificant improvement of 3 days. Future adequately powered studies should account for variability between sexes.