Effects of 4-week moderate-intensity aerobic training on stress reactivity, decision-making, and prefrontal brain activity under acute stress in emerging adults.

Abstract

Objectives: The present study aimed to investigate whether 4-week moderate-intensity aerobic training has beneficial effects on stress reactivity, decision-making, and associated prefrontal brain activity in presence of acute stress in emerging adults.

Design: A randomized controlled trial.

Methods: Forty-one emerging adults (age range: 18-26 years) were randomly assigned to the moderate-intensity aerobic training group (n = 21, 22.76 ± 2.51 years) or control group (n = 20, 22.05 ± 1.36 years). The moderate-intensity aerobic training group underwent supervised cycling for 4 weeks, while the control group did not receive any intervention. All participants completed a challenging mental work task (operation span task) as an acute stress manipulation, followed by a two-step decision-making task with functional near-infrared spectroscopy to measure prefrontal cortex activation before and after the intervention. We also assessed state anxiety , visual analog scales, and heart rate variability as indicators of stress level.

Results: The operation span task was effective at inducing psychological stress. After the intervention, the moderate-intensity aerobic training group exhibited lower state anxiety than the control group (t = -2.979, p = 0.005, d = -0.931). The intervention group additionally showed higher orbitofrontal activation and significantly greater post-test reward-option selection improvement compared to the control group (t = 3.492, p = 0.001, d = 1.106), indicating enhanced reward sensitivity.

Conclusions: These findings indicated that 4-week moderate-intensity aerobic training enhanced reward-based decision-making and reduced psychological stress. The increased activation in the orbitofrontal cortex was likely associated with the improvements in state anxiety and decision-making.