Better together - efficacy of combined physical and cognitive training in young adults for enhancing physical and cognitive performance: a randomized controlled trial.

Background: Young adults face heightened cognitive demands from modern work and societal pressures, necessitating interventions to support cognitive performance. Research on concurrent training, whereby physical and cognitive training are performed simultaneously, suggests benefits for enhancing physical and cognitive performance in a time-efficient manner. This study aimed to evaluate the effect of concurrent training on physical and cognitive performance in young, healthy adults compared to separate or physical-only training. Methods: A 12-week randomized controlled trial was conducted with 107 participants (25 ± 6 yrs, 58 females) allocated to one of three groups: 1) bi-weekly stationary cycling (physical); 2) bi-weekly physical training while performing simultaneous cognitive training (concurrent); or 3) bi-weekly physical training plus bi-weekly cognitive training (separate). Physical training involved stationary cycling at 70%-80% of maximal heart rate achieved during baseline testing. Cognitive training was delivered using an adaptive, multi-domain computer program. Physical and cognitive performance was assessed before and after the 12-week intervention via a cognitive battery and maximal cardiorespiratory fitness test. To assess differences in intervention efficacy, all participants randomized with baseline assessments were included in intention-to-treat analysis using linear mixed effects models. Results: Across all interventions, response speed improved in tasks requiring rapid executive function including Visual Search, Stroop, and Category Switch. However, the concurrent and physical training groups achieved this improvement with comparatively smaller declines in accuracy. Reaction time in the Psychomotor Vigilance Task increased across groups, with the physical group showing slower reaction time and more lapses than the concurrent and separate training groups. Cardiorespiratory fitness improved most for the separate group, but, despite this, time-to-exhaustion improved in all groups with no difference between interventions. Conclusion: The results of this study demonstrate improvement to components of cognitive performance in young adults over a 12-week intervention. Reaction time improved across various cognitive tasks for all groups, however, the concurrent group demonstrated this improvement most consistently, and with less compromises to accuracy. Despite the separate group appearing favourable for cardiorespiratory fitness, there were no differences for time-to-exhaustion. Given the time-efficient nature of concurrent training, this modality shows promise for developing both physical and cognitive performance in young healthy adults, relative to other active interventions.