Sex Differences in Physical Activity and Energy Expenditure after Adolescent Concussion

Sex differences may exist in physical activity (PA) behavior among adolescents. PA is recommended soon after a concussion to improve recovery outcomes. Our purpose was to examine sex differences in PA engagement after adolescent concussion.

Male and female adolescent athletes, within 21 d of concussion, wore wrist-worn actigraphy devices for 1 wk to quantify three variables: steps per day, caloric expenditure, and resting heart rate (RHR). We used linear mixed models with random slopes and random intercepts for participants to examine sex differences for each outcome over the monitoring period, adjusting for variables that differed between sexes.

We enrolled 122 adolescents with concussion: n = 62 female athletes (11.4 ± 4.6 d postinjury, age = 15.6 ± 1.4 yr) and n = 60 male athletes (10.9 ± 4.8 d postinjury, age = 15.5 ± 1.9 yr). After adjusting for symptom severity, body mass index, and anxiety/depression history, female athletes expended fewer calories ( β = -336 calories; 95% confidence interval [CI]: -553 to -159; P < 0.001) than males, but daily step count ( β = -568 steps·d -1 ; 95% CI: -2261 to 1124; P = 0.51) and RHR ( β = 3.06 beats·min -1 ; 95% CI: -1.97 to 8.09; P = 0.23) were similar between sexes across the week. Both steps per day ( β = 353 steps·d -1 ; 95% CI: 115 to 591; P = 0.004) and caloric expenditure ( β = 38.2 calories; 95% CI: 15.4 to 61.0; P = 0.001) increased each day for the overall sample, although the rate at which they increased did not significantly differ by sex (sex × time interaction: P = 0.10, P = 0.07, respectively).

Compared with males, female athletes recorded lower caloric expenditure but similar steps per day and RHR during a 1-wk monitoring period after concussion. PA and caloric expenditure increased throughout the monitoring week, independent of sex, which may reflect improvement in symptoms or a gradual increase in PA based on guidance from their medical provider.