The prolonged effects of acute aerobic exercise on executive function in healthy older adults
LE3 .A278 2020
Bachelor of Kinesiology
Older adults aged 65 and over are the fastest-growing age group in Canada and are expected to represent a quarter of the population by 2036. Aerobic exercise is a crucial and inexpensive modality that can be used to prevent or slow the progression of age-related declines in cognition. Acute bouts of aerobic exercise (AE) have been shown to positively effect executive functions (EF) although the optimal modalities are unknown. Previous research has observed effects of acute AE on cognition for up to 2 hours. The aim of this study is to explore the extent to which an acute bout of moderate-intensity continuous exercise (MICE) versus high- intensity interval training (HIIT) improves EF in older adults after exercise. It was hypothesized that after one session of MICE and HIIT training, both protocols will improve cognition, where improvements are more significant in the HIIT protocol. It was also hypothesized that cognition would be greater 45 minutes after (T45) exercise cessation compared to 0 minutes after (T0). Twenty-four older adults (men= 10, women= 15; mean age= 68 ± 5 years) completed a MICE and HIIT session on the cycle ergometer to which they were assigned in a randomized and counterbalanced order. A color-words Stroop task was completed pre- and post-exercise to measure reaction time (RT). Reaction time improved significantly in both HIIT (1372 ± 212 ms vs 1230 ± 210 ms, p < 0.01) and MICE (1372 ± 212 ms vs 1253 ± 245 ms, p < 0.02) protocols directly after exercise. However, in the executive component of the task (Stroop 4), HIIT RT continued to improve 45 minutes after exercise, creating a statistically significant difference between both interventions (p < 0.04). These results indicate that, while both protocols can improve EF, HIIT may be a more effective modality as it is able to prolong improvements in EF in older adults. Additionally, this suggests that exercise intensity plays an important role in modulating the effect of acute aerobic exercise on EF in older adults.
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