Effects of acute high-Intensity resistance exercise on cognitive function and oxygenation in prefrontal cortex.

Purpose: Moderate-intensity exercise is known to be the best effective intensity to enhance cognitive function, including memory and learning. However, the effects of high-intensity exercise in comparison with moderate- intensity exercise on cognitive function remain controversial. The aim of this study was to investigate the effect of high-intensity resistance exercise on cognitive function.

Methods: Thirty-six healthy female college students volunteered to participate in this study. The participants were divided into four groups: (i) control group (CON); (ii) high-intensity resistance exercise group (HIR); (iii) high-intensity aerobic exercise group (HIA); and (iv) combined moderate-intensity exercise group (MIC). Immediately prior to and after exercise, the solved number (SN) and reaction times (RT) in the Stroop test (neutral task, NT and incongruent task, IT), as well as the tissue oxygen index (TOI) in the left and right prefrontal cortex (PFC) were measured in all groups.

Results: In the NT, both HIR and MIC groups showed significant improvements in SN and RT compared with the CON group. Meanwhile, performance in the HIA group was significantly attenuated compared with that in the MIC group. In the IT, only the MIC group showed a significant increase in SN and RT compared with the CON group. Furthermore, the TOI in the PFC (left PFC in the NT, and bilaterally in the IT) was significantly lower in the HIR group compared with that in the CON group.

Conclusion: The results of this study show worse cognitive performance and decreased PFC oxygenation in high-intensity exercise compared with moderate-intensity exercise and controls. These results suggest that high-intensity exercise may not improve cognition as effectively as moderate-intensity exercise.