Cognitive Resource Allocation and Balance Performance in Healthy Young Adults: A Pilot Randomised Crossover Trial Investigating Cognitive Depletion and Replenishment Across Balance Task Intensities

Introduction: Balance control relies on cognition. Studies have found that cognitive resources are more likely to be depleted during complex balance tasks, whereas meditation may aid their replenishment. However, existing research has focused on task complexity rather than intensity. This study addressed this by using the validated 100-point Balance Intensity Scale-Therapist (BIS-T) to objectively define low (<30/100) and high (>70/100) intensity balance tasks. This study aimed to evaluate the feasibility and methodological rigour of the protocol to investigate 1) cognitive resources allocation and depletion during low- versus high-intensity balance tasks under varying cognitive loads; and 2) effectiveness of recovery strategies in enhancing balance and cognitive resource restoration.

Methods: A pilot randomised crossover trial tested healthy adults (18–30 years) with no balance or cognitive impairment. Participants completed two sessions of low- or high-intensity single-leg stance (SLS) tasks, with or without a cognitive task (balance task only or with serial subtraction), followed by one of the three recovery strategies (no break, passive recovery: 2-min quiet sitting, active recovery: 2-min guided meditation). The primary outcome was sway velocity, measured using a Balance Master.

Results: Twenty -two participants were recruited. Feasibility was acceptable (100% recruitment, 100% retention, no adverse events). A three-way mixed ANOVA revealed a significant main effect of Balance Intensity, with higher overall sway velocity observed under high intensity compared to low intensity (F = 43.669, p=< .001). No significant differences emerged across recovery conditions for overall levels. However, the change from pre- to post-test varied by recovery type and was further moderated by intensity. Specifically, under high intensity, the no-recovery group showed an increase in sway velocity from pre- to post-task, whereas the passive- and active-recovery groups exhibited decreases in sway velocity; changes were minimal under low intensity.

Conclusions: High-intensity tasks demand more cognitive resources. While recovery strategies showed limited effects, meditation may aid recovery. The protocol was feasible, although practice effects, ceiling effects, and the design of the cognitive task may have confounded the results. Therefore, future studies that precisely tailor balance tasks and extend washout periods are needed. Overall, this protocol was feasible, making it suitable for progression to larger trials investigating the optimisation of recovery in balance training.