The effect of breaking sitting time with physical activity breaks on cognitive performance in young people with cerebral palsy: an exposure response cross-over feasibility design

Abstract Objectives To assess the feasibility of methods and estimate the potential effect of interrupting sedentary behaviour, with intermittent or continuous physical activity breaks, on cognitive performance in young people with Cerebral Palsy. Methods A randomised three-arm exposure response cross-over design with process evaluation. Participants were recruited throughout the Thames Valley, UK between 01/11/2018 to 31/03/2020. The three 2 h activity exposure visits included: (i) sitting only (controls), (ii) sitting plus 20 min of moderate-to-vigorous activity burst, or (iii) 4×5 min of moderate-to-vigorous activity bursts, during a 2.5 h sedentary session. Measures of feasibility were sought. Cognitive performance outcomes (using the Eriksen Flanker task and Forward and Backward Digit Span) were delivered before and after the 2 h testing period. Results 36 participants were randomised (age 13.2±2.7, Gross-Motor Functional Classification System 1–3). Study retention was 83 % across all three interventions and overall missing data for measures was 4 %. A small intervention effect was found in reaction time in the 4×5 min physical activity exposure session compared to the sedentary control condition (0.42; 95 % CI 0.40 to 0.79). There were two research-related minor adverse effects, an allergic reaction to the FreeStyle Libre and feeling faint and vomiting after consumption of glucose solution. Both events were resolved and participants continued with the study. Conclusions The study design and intervention implementing short bursts of physical activity was feasible and indicated a potential effect on reaction time as a measure of cognitive performance in young people with cerebral palsy.