Background Chronic exercise training has been shown be to positively associated with executive function (EF) in older adults. However, whether the exercise training effect on EF is affected by moderators including the specific sub-domain of EF, exercise prescription variables, and sample characteristics remains unknown. Objectives This systematic and meta-analytic review of randomized controlled trials (RCTs) investigated the effects of exercise training on EF in older adults and explored potential moderators underlying the effects of exercise training on EF. Methods In accordance with the PRISMA guidelines, the electronic databases MEDLINE (PubMed) and EMBASE (Scopus) were searched from January 2003 to November 2019. All studies identified for inclusion were peer-reviewed and published in English. To be included, studies had to report findings from older (> 55 years old), cognitively normal adults or adults with mild cognitive impairment (MCI) randomized to an exercise training or a control group. The risk of bias in each study was appraised using the Cochrane risk-of-bias tool. Fixed-effects models were used to compare the effects of exercise training and control conditions on EF assessed at baseline and post-intervention. In addition, subgroup analyses were performed for three moderators (i.e., the specific sub-domain of EF, exercise prescription variables, and sample characteristics). Results Thirty-three RCTs were included. Overall, exercise training was associated with a significant small improvement in EF [Q(106) = 260.09, Hedges’ g = 0.21; p < 0.01]. The EF sub-domain moderator was not significant [Q(2) = 4.33, p > 0.05], showing that the EF improvement in response to exercise is evident for measures of inhibition, updating, and shifting. Regarding exercise prescription variables, results were significantly moderated by frequency of exercise training [Q(1) = 10.86, p < 0.05], revealing that effect sizes (ESs) were larger for moderate frequency (g = 0.31) as compared to low frequency exercise (g = 0.15). The results also showed type of exercise training moderated the ESs [Q(4) = 26.18, p < 0.05], revealing that ESs were largest for other forms of exercise (g = 0.44), followed by Tai Chi and yoga (g = 0.38), resistance exercise (g = 0.22), aerobic exercise (g = 0.14), and combined exercise (g = 0.10). In addition, The results showed moderated length of training the ESs [Q(2) = 16.64, p < 0.05], revealing that ESs were largest for short length (g = 0.32), followed by mid length (g = 0.26) and long length (g = 0.09). No significant difference in effects was observed as a function of exercise intensity [Q(1) = 2.87 p > 0.05] and session time [Q(2) = 0.21, p > 0.05]. Regarding sample characteristics, the results were significantly moderated by age [Q(2) = 20.64, p < 0.05], with significant benefits for young-old (55–65 years old) (g = 0.30) and mid-old (66–75 years old) (g = 0.25), but no effect on EF for old-old (more than 75 years old). The results were also significantly moderated by physical fitness levels [Q(1) = 10.80, p < 0.05], revealing that ESs were larger for sedentary participants (g = 0.33) as compared to physically fit participants (g = 0.16). In addition, results were also significantly moderated by cognitive status [Q(1) = 11.44, p < 0.05], revealing that ESs were larger for participants with cognitively normal (g = 0.26) as compared to those with mild cognitive impairment (g = 0.08). No significant differences in effects were observed as a function of sex [Q(2) = 5.38, p > 0.05]. Conclusions Exercise training showed a small beneficial effect on EF in older adults and the magnitude of the effect was different across some moderators.

Several studies have demonstrated that exercise helps reduce or prevent cognitive deterioration among older adults, and recent studies have further examined the effects of resistance-exercise training on cognition. The purpose of this review was to examine the role of resistance-exercise training on cognition in healthy older adults. Specifically, it describes the definition, health benefits, and the design of resistance-exercise training. The authors also review the research related to resistance exercises and cognition and found that this exercise modality may enhance specific cognitive performances. Next, they examine the potential mechanisms underlying resistance exercise and cognitive enhancement. Finally, they consider potential therapeutics and recommendations for further research on resistanceexercise training and cognition in older adults.

This study examined whether acute moderate intensity exercise results in a general or selective improvement in cognitive function. In addition, multiple stimulus-locked ERP components and serum BDNF levels were assessed to investigate potential neurobiological mechanisms underlying acute exercise effects on select aspects of cognitive performance. Thirty young adults were recruited and participated in exercise and reading control sessions in a counterbalanced order. Following treatments, the Stroop task was administrated, and N1, N2, P3, and N450 components of the ERP waveform were recorded and analyzed. Additionally, blood samples were withdrawn immediately following exercise or rest conditions prior to administration of the Stroop task. Acute exercise facilitated response times for both Stroop congruent and incongruent task conditions, with a similar magnitude of improvement. Larger P3 and reduced N450 amplitudes as well as decreased N450 latency were observed following exercise, but no effects on N1 and N2 components were found. This dose of exercise also did not influence serum BDNF levels. These findings suggest that moderate intensity acute exercise results in a generalized rather than selective improvement in cognition. The facilitation may be related to an increase in attentional or neural resource allocation and conflict detection processes reflected by longer latency endogenous components (P3, N450), but is not influenced by earlier sensory and monitoring processes revealed by earlier ERP components or by serum levels of BDNF.

The purpose of this study is to extend the literature by examining the effects of an acute bout of moderate to vigorous intensity aerobic exercise on the executive functions of planning and problem solving assessed using a Tower of London Task (TOL Task). Forty-two participants were randomly assigned into either exercise or control group, and performed the TOL Task, before and immediately following exercise or a control treatment. The exercise group performed 30 min of exercise on a stationary cycle at moderate to vigorous intensity while the control group read for the same length of time. Results indicated that the exercise group achieved improvements in TOL Task scores reflecting the quality of planning and problem solving, but not in those reflecting rule adherence and performance speed. These findings indicate that an acute bout of aerobic exercise has facilitative effects on the executive functions of planning and problem solving.

The purpose of the present study was to examine how obesity and cardiovascular fitness are associated with the inhibition aspect of executive function from behavioral and electrophysiological perspectives. One hundred college students, aged 18–25 years, were categorized into four groups of equal size on the basis of body mass index and cardiovascular fitness: a normal-weight and high-fitness (NH) group, an obese-weight and high-fitness (OH) group, a normal-weight and low-fitness (NL) group, and an obese-weight and low-fitness (OL) group. Behavioral measures of response time and number of errors, as well as event-related potential measures of P3 and N1, were assessed during the Stroop Task. The results revealed that, in general, the NH group exhibited shorter response times and larger P3 amplitudes relative to the NL and OL groups, wherein the OL group exhibited the longest response time in the incongruent condition. No group differences in N1 indices were also revealed. These findings suggest that the status of being both normal weight and having high cardiovascular fitness is associated with better behavioral and later stages of electrophysiological indices of cognitive function.