Mild exercise improves executive function with increasing neural efficiency in the prefrontal cortex of older adults

Abstract

This study examined whether a 3-month mild-exercise intervention could improve executive function in healthy middle-aged and older adults in a randomized control trial. Ultimately, a total of 81 middle-aged and older adults were randomly assigned to either an exercise group or a control group. The exercise group received 3 months of mild cycle exercise intervention (3 sessions/week, 30–50 min/session). The control group was asked to behave as usual for the intervention period. Before and after the intervention, participants did color-word matching Stroop tasks (CWST), and Stroop interference (SI)-related reaction time (RT) was assessed as an indicator of executive function. During the CWST, prefrontal activation was monitored using functional near-infrared spectroscopy (fNIRS). SI-related oxy-Hb changes and SI-related neural efficiency (NE) scores were assessed to examine the underlying neural mechanism of the exercise intervention. Although the mild-exercise intervention significantly decreased SI-related RT, there were no significant effects of exercise intervention on SI-related oxy-Hb changes or SI-related NE scores in prefrontal subregions. Lastly, changes in the effects of mild exercise on NE with advancing age were examined. The 81 participants were divided into two subgroups (younger-aged subgroup [YA], older-aged subgroup [OA], based on median age [68 years.]). Interestingly, SI-related RT significantly decreased, and SI-related NE scores in all ROIs of the prefrontal cortex significantly increased only in the OA subgroup. These results reveal that a long-term intervention of very light-intensity exercise has a positive effect on executive function especially in older adults, possibly by increasing neural efficiency in the prefrontal cortex.

Cognitive Enhancement Strategies for Older Adults: An Evaluation of Different Training Modalities to Improve Executive Function—A Systematic Review and Meta-Analysis

“…In Table 1 , we summarize the sample characteristics of all the articles included [ 27 , 28 , 29 , 30 , 31 , 32 , 33 , 34 ]. A total of 463 older adults, each over 65 years old, were included in this systematic review.…”

“…Four articles [ 27 , 29 , 32 , 33 , 34 ] reported results about aerobic exercise. The only study that could not be incorporated into the meta-analysis was the Byun et al study [ 33 ], because after requesting the data from the authors, no response was received, and the data could not be incorporated. The study conducted by Hyodo et al [ 27 ] focused on an acute bout of moderate aerobic exercise.…”

“…The sample size varied between 16 [27] and 119 [28] individuals, with an average age between 65.8 [29] and 75.2 [28] For the control group, six studies included a non-training group, one included an educational session [28], and another one included stretching exercises [30]. Finally, regarding the study variables, executive function was assessed with the Stroop Color Test in four studies [29,30,33,34], with the Stroop Task Performance in one study [27], with the Mini Mental State Exam in one study [31], with the Task Switching Test in one study [28], and with the Wisconsin Card Sorting Test (WCST) in one study [32]…”

Effects of low-intensity home-based exercise on cognition in older persons with mild cognitive impairment: a direct comparison of aerobic versus resistance exercises using a randomized controlled trial design

“…The improvements in cognitive function from aerobic and resistance exercise were in line with previous findings. A previous study concluded that mild aerobic exercise intervention improved executive function, namely, inhibitory control, in older adults (35). Similarly, systematic reviews (8-10, 36) suggested that moderate-intensity aerobic exercise intervention increased global cognitive function, working memory and attention in older people with MCI.…”

Exercise-induced neuroplasticity: a new perspective on rehabilitation for chronic low back pain

“…Different forms of exercise, such as running, light activity, and aerobic exercise, can regulate synaptic plasticity, improve cognition, and enhance spatial learning and memory ( Brockett et al, 2015 ; Khoury et al, 2023 ). Research shows that during active movement in mice, the liver can release β -hydroxybutyrate, which inhibits the deacetylation of histone acetyltransferase and increases BDNF levels in the hippocampus, thereby promoting synaptic plasticity ( Byun et al, 2023 ). Aerobic exercise can increase the number of synapses and dendritic density in the medial prefrontal cortex and hippocampus, thereby improving brain functional connectivity ( Erickson et al, 2011 ).…”