Effects of volume-matched acute resistance exercise at different intensities on high-order and core executive functions in older adults

Emerging evidence suggests that acute resistance exercise (RE) can enhance executive function (EF) in older adults; however, the extent to which exercise intensity, independent of total exercise volume, differentially influences higher-order and core EF components remains unclear. The present study examined the effects of volume-matched acute RE at different intensities on planning (higher-order EF) and response inhibition (core EF) in older adults. Twenty-nine community-dwelling older adults (mean age: 68.62 ± 5.73 years) completed four counterbalanced conditions: low-intensity RE (LIRE; 45% one-repetition maximum [1-RM], 10 repetitions, 4 sets), moderate-intensity RE (MIRE; 60% 1-RM, 10 repetitions, 3 sets), high-intensity RE (HIRE; 75% 1-RM, 12 repetitions, 2 sets), and a seated reading control condition. Total exercise volume was equated across all RE conditions. EF was assessed using the Tower of London task to evaluate planning and the stop-signal task to assess response inhibition. The results indicated that acute RE selectively enhanced EF relative to the control condition. For planning, move-related indices improved, with higher Total Correct Scores following LIRE and MIRE. Only MIRE yielded a lower Total Move Score than both the control and HIRE conditions, whereas time-related indices remained unaffected. For response inhibition, stop-signal reaction time was reduced following LIRE and MIRE, while HIRE did not differ from the control condition. In contrast, secondary stop-signal task indices (i.e., Go reaction time, Go accuracy, and stop probability) remained unchanged. In conclusion, when exercise volume is held constant, acute RE selectively enhances planning quality and efficiency, as well as response inhibition, in older adults, with MIRE showing the most consistent advantages, underscoring the importance of intensity selection beyond volume control when prescribing acute RE to support EF enhancement in aging populations.