The temporal relationship between moderate to vigorous physical activity and secondary conditions during the first year after moderate-severe TBI

To determine the cross-sectional and temporal relationships between minutes per week of moderate to vigorous physical activity (MVPA) as measured by a wrist-worn accelerometer and secondary conditions in the first year after moderate to severe traumatic brain injury (TBI).Prospective longitudinal cohort study.Four inpatient rehabilitation centers.Individuals (N = 180) with moderate-severe TBI enrolled in the TBI Model Systems Study.Participants wore a wrist accelerometer for 7 days immediately post discharge, and for 7 consecutive days at 6- and 12-months post injury.Minutes per week of MVPA from daily averages based on wrist worn accelerometer. Secondary conditions included depression (Patient Health Questionnaire-9), fatigue (PROMIS Fatigue), Pain (Numeric Rating Scale), Sleep (Pittsburgh Sleep Quality Index), and cognition (Brief Test of Adult Cognition by Telephone).At baseline, 6 and 12 months, 61%, 70% and 79% of the sample achieved at least 150 minutes per week of MVPA. The correlations between minutes of MVPA between baseline, 6 and 12 months were significant (r = 0.53-0.73), as were secondary conditions over these time points. However, no significant correlations were observed between minutes of MVPA and any secondary outcomes cross-sectionally or longitudinally at any time point.Given the robust relationships physical activity has with outcomes in the general population, further research is needed to understand the effect of physical activity in individuals with moderate-severe TBI.