The effects of aerobic exercise intensity on memory in older adults

Abstract

Aerobic exercise may enhance memory in older adults. However, the optimal intensity and underlying mechanism are unclear. This community-based study examined the effect of aerobic exercise intensity on memory and general cognitive abilities. Brain-derived neurotrophic factor (BDNF) was examined as a potential mechanism. Sixty-four sedentary older adults participated in 1 of 3 groups: (i) high-intensity interval training (HIIT); (ii) moderate continuous training (MCT); or (iii) stretching control (CON). Prior to and following the intervention, high-interference memory was assessed using a Mnemonic Similarity task and executive functions were assessed using Go Nogo and Flanker tasks. HIIT led to the greatest memory performance compared with MCT and CON (F[2,55] = 6.04, p = 0.004) and greater improvements in memory correlated with greater increases in fitness (rs (46) = 0.27, p = 0.03). Exercise intensity seemed to matter less for executive functioning, as positive trends were observed for both HIIT and MCT. No significant differences in BDNF were found between groups. Overall, these results suggest that aerobic exercise may enhance memory in older adults, with the potential for higher intensity exercise to yield the greatest benefit. While our findings suggest that BDNF does not regulate these adaptations, the mechanisms remain to be determined. Novelty High-intensity interval training results in the greatest memory performance in inactive older adults compared with moderate continuous training or stretching. Improvement in fitness correlates with improvement in memory performance.

Effect of High Intensity Interval Training Compared to Continuous Training on Cognitive Performance in Young Healthy Adults: A Pilot Study

“…These findings support our second hypothesis that greater improvements in executive functioning will result from HIIT compared to MICE. The results of our study confirm certain results from the literature in children [35], adolescents [33], young adults [37], or the elderly who are healthy [34] or have had a stroke [36]. In addition, our results on the trail making task are consistent with those reported by Pallesen et al who reported an effect of intermittent high intensity training only on the Trail B and not on the Trail A [36].…”

“…Among the studies that achieved positive results, they only compared HIIT to active controls, and as such, the effects of exercise intensity per se were not examined. Only Kovacevic et al [34] found that HIIT had a greater impact on cognitive function than MICE in older adults. In younger adults, the evidence that HIIT is the optimal strategy to improve cognitive performance is unclear and the only data available is contradictory.…”

“…Although these results are encouraging, there is no clear evidence that HIIT has a superior effect on cognitive function compared to MICE [16]. Recently, original studies have provided more responses with null [31,32] or positive results [33][34][35][36][37] in animal and human studies. Among the studies that achieved positive results, they only compared HIIT to active controls, and as such, the effects of exercise intensity per se were not examined.…”

Effects of a Physical Activity Intervention on Physical Fitness of schoolchildren: The Enriched Sport Activity Program

“…An example of such phenomenon can be seen either regarding structural adaptations, such as increase of the brains gray matter and volume [15,16], an increase in the level of neurotrophins [17], and increased brain blood flow [18]. Also, functional adaptations, such as modifications in the neuronal network [19], which have also been seen to increase academic achievement [20] and improve memory and attention [18,21] can be found. Hence, poorer fitness levels correlate to poorer cognitive abilities [22].…”

“…However, such increase in cognitive functioning has been seen to be greater in those populations with a poor physical fitness level or those displaying mental or physical disabilities [23]. The majority of the studies linking the increase in neuroplasticity and cognitive function towards exercise tend to consider aerobic exercise as the primary form of exercise modality able to influence cognitive function [13,18,21]. Vice versa, limited evidence is available, explaining the possible mechanisms able to increase physical fitness through the implementation of cognitive-oriented tasks.…”