Acute resistance exercise load modulates brain haemodynamics, working memory, and inhibitory performance

Area of Science:

• Exercise Physiology
• Cognitive Neuroscience
• Neuroscience

Background:

• Acute resistance exercise (RE) is known to improve executive function (EF).
• However, the differential effects of varying exercise intensities on specific EF domains and brain hemodynamics remain underexplored.

Purpose of the Study:

• To investigate the impact of high-load (HRE) versus moderate-load (MRE) resistance exercise on executive functions (inhibition, working memory).
• To examine the associated changes in brain hemodynamics using functional near-infrared spectroscopy (fNIRS).

Main Methods:

• Forty-two healthy adults were randomized into HRE (75% 1RM), MRE (50% 1RM), or control (CON) groups.
• Executive functions were assessed using Stroop and N-back tasks pre-exercise, immediately post-exercise, and 45 minutes post-exercise.
• Brain hemodynamics were monitored using fNIRS during cognitive tasks.

Main Results:

• HRE led to moderate improvements in inhibition (Stroop) and working memory (2-back task).
• MRE showed moderate improvements in working memory but weaker effects on inhibition.
• HRE was associated with significant increases in right hemisphere oxygenated hemoglobin (O2Hb), indicating enhanced brain activity, particularly under high cognitive load.

Conclusions:

• High-load resistance exercise demonstrates superior efficacy in enhancing executive functions compared to moderate-load RE.
• HRE elicits more pronounced and sustained changes in brain hemodynamics, suggesting a stronger neurophysiological basis for cognitive improvements.