Background: Little is known regarding long-term consequences (≥5 years) of sport-related concussion (SRC) sustained during adolescence. Adolescent SRC has been linked to athlete considerations of sport participation and subsequent retirement from sport during this critical developmental period. Prolonged SRC symptoms can reduce ability to perform physical activity, and research suggests inactivity can extend years post-injury. Therefore, SRC may affect long-term physical activity, which may result in decreased cardiorespiratory fitness and increased adiposity.
Objectives: (1) To examine cardiorespiratory fitness, adiposity and associations with physical activity between three groups: adolescent SRC 5-15 years prior; adolescent musculoskeletal injury (MSK) 5-15 years prior; and individuals who played adolescent sport but were uninjured. (2) To explore whether biological sex-modified relationships assessed by the primary objective.
Methods: Young adults (16-33 years old) who sustained SRC (n = 54) or MSK (n = 52) during adolescent sport and uninjured individuals (n = 50) were recruited (n = 156) from previous Sport Injury Prevention Research Centre studies and word-of-mouth. Participants completed a cycle-ergometer maximal exertion test, dual-energy X-ray absorptiometry scanning, and wore actigraphs for 1-week post-testing. Outcome measures of cardiorespiratory fitness [peak oxygen consumption (VO2peak[ml/min])] and adiposity [fat mass index (FMI)] were examined in relation to cohort, sex, time since injury, lean mass index and moderate-to-vigorous physical activity [daily MVPA (min)] via multiple linear regression.
Results: In relation to the uninjured cohort, MSK (mean difference = 297.14 ml/min; β = 2.88; 95%CI: 0.99-4.76, p = 0.003) and SRC (mean difference = 268.01 ml/min; β = 2.61; 95%CI: 0.77-4.44, p = 0.006) cohorts demonstrated higher VO2peak and this did not differ based on biological sex. FMI did not differ for MSK (mean difference= -0.10 kg/m2; β= -0.02; 95%CI: -0.22-0.18, p = 0.847) or SRC (mean difference=-0.22 kg/m2; β= -0.05; 95%CI: -0.24-0.15, p = 0.642) cohorts relative to the uninjured cohort for both males and females.
Conclusions: It is possible to maintain adequate long-term cardiorespiratory fitness and adiposity following adolescent SRC relative to those who only sustained sport related MSK injuries or did not sustain significant injuries as adolescents/adults.
Keywords: Concussion; adiposity; adolescent; cardiorespiratory fitness; injury; long term; musculoskeletal injury; physical activity; sport injury; sport-related concussion.