Power, cardiorespiratory fitness and physical activity in young people with cerebral palsy

Objectives Physical activity (PA) levels in young people with cerebral palsy (YPwCP) remain consistently low. Previous research suggests that fitness parameters such as muscular strength and cardiovascular capacity are interrelated with mobility and PA levels in YPwCP. This study aimed to (1) describe fitness parameters and PA levels in YPwCP, (2) explore associations between fitness parameters and PA, and (3) evaluate the reliability of accelerometer-based PA measurement. Methods A cross-sectional study was conducted with an embedded test–retest reliability assessment of accelerometer-measured PA over a one-month interval. Participants included 36 YPwCP (19 males, 17 females; mean age 15.5 ± 0.7 years), classified within GMFCS levels I–III. Cardiorespiratory endurance (VO 2 max) was assessed using an incremental cycle ergometer test, and leg power was measured using the Five-Times Sit-to-Stand (5xSTS). PA was measured via self-report using the Physical Activity Questionnaire for Adolescents (PAQ-A) and via device-measured data using a wrist-worn accelerometer over seven consecutive days. Results We found low levels of PA. The 5xSTS completion time showed moderate to strong correlations with self-reported PA ( ρ =−0.384, p≤0.01) and device-measured vigorous PA ( ρ =−0.566, p≤0.01). VO 2 max was positively but not significantly associated with total PA ( ρ =0.173) and moderate-to-vigorous PA ( ρ =0.115). Accelerometry demonstrated good reliability (ICC=0.796). Conclusions These findings suggest that accelerometer has good reliability in YPwCP but highlight low levels of PA measured by self-report and accelerometer. Higher lower-limb power, assessed by faster 5xSTS test, was associated with greater PA.