Physical activity and caloric expenditure after adolescent concussion: a comparison with uninjured controls

Abstract

Purpose: Concussion-induced pathophysiology creates an energetic imbalance within the brain. Though physical activity (PA) is recommended to facilitate recovery, individualized factors such as symptom severity and/or energy availability may be barriers to PA engagement and may need to be considered to promote concussion recovery. Our purpose was to compare PA over a one-week period between adolescents with and without a recent concussion.

Methods: Adolescent athletes within 3 weeks of concussion and uninjured athletes wore wrist-worn actigraphy devices for one week to quantify three outcomes: PA (steps/day), caloric expenditure, and resting heart rate (RHR). We used linear mixed models with random slopes and random intercepts for participants to examine between-group differences for each outcome over the monitoring period, adjusting for variables that differed between groups.

Results: We enrolled and followed 149 adolescents for one week: 85 with concussion (starting at 9.2 ± 3.5 days post-injury, age = 15.3 ± 1.8 years, 52% female) and 64 uninjured controls (age = 15.4 ± 1.5 years, 61% female). After adjusting for covariates, the concussion group took fewer steps/day (β = -4837 steps/day; 95%CI: -6266, -3409; p < 0.001) and expended fewer calories (β = -338 calories; 95%CI: -512, -164; p = 0.001) than controls during the monitoring period. RHR was similar between groups (β = 0.74 beats/min; 95%CI: -2.41, 3.88; p = 0.65).

Conclusion: Adolescents after recent concussion demonstrated lower PA and expended fewer calories than uninjured controls, indicating that it may take several weeks after concussion to resume PA levels similar to uninjured peers. Our results may reflect participants following concussion guidelines/physician guidance to gradually increase PA during concussion recovery as tolerated without symptom exacerbation, leading to less PA engagement compared to controls. Further research into energy needs after concussion may inform therapeutic targets to facilitate recovery.

Keywords: Exercise; brain injury; energy availability; recovery; wearables.