Emily MacDonald ¹ Liam Pellerine ¹ Katerina Miller ² Ryan Frayne ¹ Myles OBrien ^3*

• ¹ Dalhousie University, Halifax, Nova Scotia, Canada
• ² Nova Scotia Health Authority, Halifax, Nova Scotia, Canada
• ³ Université de Sherbrooke, Sherbrooke, Canada

Health-related quality of life (HRQoL) is a patient perceived measure of physical, social, and emotional health. An acquired brain injury (ABI) occurs due to damage to the brain after birth. Individuals with ABIs typically present with lower HRQoL and require additional support to maintain their HRQoL. Structured exercise training improves HRQoL in individuals with an ABI, but little research has investigated habitual, real-world activity. Most activity research characterizes moderate-vigorous physical activity (MVPA) in absolute terms, however, relative physical activity levels have been promoted for research in clinical populations. We test if higher MVPA duration in absolute/relative levels is associated with higher HRQoL in outpatients with an ABI. Twenty-six adults (54±13 years, 16 female) with an ABI completed the Quality of Life After Brain Injury questionnaire, a six-minute walk test (measure of aerobic fitness; 490±105 m) and wore an activPAL 24 hr/d for 7 days. Participants had an average HRQoL score of 53.4 ± 15.0 (out of 100), with 20/26 having an impaired HRQoL (score <60). Absolute MVPA (74.6±91.0 min/week, b = 0.09, p=0.03), but not total (565.7 ± 264.8 min/week, p = 0.47), light physical activity (LPA; 491.1 ± 224.3 min/week, p=0.98) nor step count (5960 ± 3037 steps/day, p=0.24) was associated with HRQoL. Neither relative LPA (521.4 ± 244.9) nor relative MVPA (33.5 ± 34.9 min/week) were associated with HRQoL (both, p>0.14). Targeting more absolute MVPA, but not necessarily relative MVPA, may be an effective strategy for interventions aiming to improve HRQoL for those with ABIs.