Author(s): SKUREWICZ, M., WINOWIECKA, N., SAWICKA, A., JOST, Z., CHROBOCZEK, M., LASKOWSKI, R., OLEK, R.A., KUJACH, S., Institution: ACADEMY OF PHYSICAL EDUCATION AND SPORTS, Country: POLAND, Abstract-ID: 2415

INTRODUCTION:
The aging process naturally involves not only a decline in physical fitness, but also in cognitive functions. Both factors present considerable challenges to the independence and quality of life of the elderly. Interestingly, a growing body of evidence suggests that engaging in physical exercise holds considerable promise in enhancing cognition, which seems to be particularly important since populations are aging societies. Our previous research has shown that high-intensity interval exercise (HIIE) can improve the physical fitness and cognitive function of young people, but the results of studies among seniors are still ambiguous. Multiple animal and human studies have revealed that exercise enhances human cognition via exercise-enhanced neurotrophins and catecholamine synthesis, which is known to mediate neural plasticity and energy metabolism in the brain. However, the neural mechanisms responsible for the post-exercise improvement of cognitive functions in elderly are still being sought. The purpose of the present study was to assess the acute effect of HIIE on executive function focusing on underlying neural and neurobiological factors in older adults.
METHODS:
The study involved twenty (n=20) elderlies. The counterbalanced, crossover, randomized trial consisted of two sessions: control (CTL) and high-intensity interval exercise (HIIE). The HIIE protocol comprised eight 60s cycling bouts at ~90% HRmax intensity separated by 60s passive rest. The participants performed the Stroop test and Trial Making Test (TMT-A and TMT-B) before and after exercise or control condition. Cortical activation has been measured by applying functional Near-Infrared Spectroscopy (fNIRS). Moreover, before and after the HIIE to assess the concentration of brain-derived neurotrophic factor (BDNF), Klotho, Cathepsin B, and Irisin, venous blood samples were collected and the ELISA method was applied.
RESULTS:
HIIE contributed to a significantly shorter execution time in the TMT-B test. Moreover, an increased prefrontal activation (dorsolateral prefrontal cortex-DLPFC and middle frontal gyrus-MFG) has been observed following an acute bout of HIIE. Additionally, we found a significant increase in peripheral Klotho and Cathepsin B concentration. Despite the lack of significance, BDNF and Irisin concentrations showed a trend towards increased value.
CONCLUSION:
The results suggest that the proposed HIIE protocol can effectively improve executive function in the elderly, which can be attributed to increased activation in cortical areas relevant to cognitive functioning as well as synthesis or release of neuro-supportive protein.

This work was supported by the Polish National Science Center under Grant No: 2019/33/B/NZ7/01980