Aftereffects of Cognitively Demanding Acute Aerobic Exercise on Working Memory

The effects of moderate-intensity aerobic exercise on cognitive function in individuals with stroke-induced mild cognitive impairment: a randomized controlled pilot study

OBJECTIVE

To assess the impact of moderate-intensity aerobic exercise on working memory in stroke-induced mild cognitive impairment (MCI).

DESIGN

Randomized, double-blind controlled study.

SUBJECTS AND METHODS

Twenty MCI patients from the Fifth Affiliated Hospital of Guangzhou Medical University (December 2021 to February 2023), aged 34-79, 2-12 months post-stroke, were divided into an experimental group (EG) and a control group (CG), each with 10 participants. The EG underwent standard rehabilitation plus 40 minutes of aerobic exercise, while the CG received only standard therapy, 5 times weekly for 2 weeks. Working memory was tested using the n-back task, and overall cognitive function was measured with the MOCA and MMSE Scales before and after the intervention.

RESULTS

The EG showed higher 3-back correctness (71.80 ± 14.53 vs 56.50 ± 13.66), MOCA scores (27.30 ± 1.57 vs 24.00 ± 3.13), and improved visuospatial/executive (4.60 ± 0.52 vs 3.30 ± 1.06) and delayed recall (4.30 ± 0.82 vs 3.00 ± 1.56) on the MOCA scale compared with the CG.

CONCLUSION

Moderate-intensity aerobic exercise may enhance working memory, visuospatial/executive, and delayed recall functions in stroke-induced MCI patients.

Mindfulness induction and executive function after high-intensity interval training with and without mindful recovery intervals

OBJECTIVES

Determine the effect of incorporating mindfulness-based activities into the recovery intervals of high-intensity interval training (HIIT) on mindfulness induction and subsequent executive function performance.

DESIGNS

A within-subject crossover trial.

METHODS

Forty adults participated in two experimental conditions, including a 30-min bout of HIIT involving mindfulness recovery intervals (Mindful) and a 30-min bout of HIIT without mindfulness recovery intervals (Non-mindful), on two separate days in counterbalanced order. Before and after each condition, participants completed the flanker task, switch-flanker task, and n-back task to measure inhibitory control, cognitive flexibility, and working memory, respectively.

RESULTS

A higher level of mindfulness state was observed following the Mindful condition than the Non-mindful condition. Dispositional mindfulness was positively correlated with the level of the mindful state only during the Mindful condition but not the Non-mindful condition. The switch-flanker response accuracy was improved from the pretest to posttest during the Non-mindful condition but remained unchanged over time during the Mindful condition. Time-related improvements in the flanker and n-back task outcomes were observed for both the Mindful and Non-mindful conditions and did not differ between conditions.

CONCLUSION

Although incorporating mindfulness-based activities during the recovery intervals of HIIT successfully led to greater state-related mindfulness, such a heightened mindful state did not correspond with additional modulation in inhibitory control and working memory performance while attenuating HIIT-related positive changes in task performance requiring cognitive flexibility.

Effects of Physical Exercise on Executive Functions among College Students in China: Exploring the Influence of Exercise Intensity and Duration

BACKGROUND

This study investigates the effects of exercise intensity and duration on executive functions among college students in China.

METHOD

Participants in this study were Chinese college students divided into four groups based on exercise duration and intensity. Each group engaged in physical exercise twice a week for six weeks. Group 1 performed low-intensity exercises for 10 min per session; Group 2 performed low-intensity exercises for 20 min per session; Group 3 performed high-intensity exercises for 10 min per session; and Group 4 performed high-intensity exercise for 20 min per session. Executive functions were assessed in all subjects before the experiment (time 1), after one exercise session (time 2), at the end of the exercise program (time 3), and six weeks after the exercise program (time 4). A mixed ANOVA with a 2 (exercise intensity: low/high) × 2 (duration: short/long) × 4 (time of measurement: time 1/time 2/time 3/time 4) design was employed, with exercise intensity and exercise duration as independent variables and executive functions as the dependent variable.

RESULTS

Mixed ANOVA showed that the results revealed a significant main effect of measurement time on working memory accuracy (p < 0.001) and reaction time (p < 0.001); inhibition control accuracy (p < 0.001) and reaction time (p < 0.001); cognitive flexibility accuracy (p < 0.001) and reaction time (p < 0.001). A single session of high-intensity exercise significantly improved executive functions in college students. Both low-intensity and high-intensity exercise were effective in enhancing executive functions, with high-intensity exercise demonstrating better maintenance of the effect.

CONCLUSION

Both exercise intensity and exercise duration were found to enhance executive functions in college students, with exercise intensity showing greater effectiveness than exercise duration.

Effects of cognitive demand during acute exercise on inhibitory control and its electrophysiological indices: A randomized crossover study

The aim of this study was to examine the effects of cognitive demand during acute exercise on the behavioral and electrophysiological correlates of inhibitory control. In a within- participants design, 30 male participants (age range = 18-27 years) performed 20-min sessions of high cognitive-demand exercise (HE), low cognitive-demand exercise (LE), and an active control (AC) on separate days in a randomized order. A moderate-to-vigorous intensity interval step exercise was used as the exercise intervention. During the exercise periods, the participants were instructed to respond to the target among competing stimuli to impose different cognitive demands with their feet. A modified flanker task was administered to assess inhibitory control before and after the interventions, and electroencephalography was used to derive stimulus-elicited N2 and P3 components. Behavioral data showed that the participants performed significantly shorter reaction time (RT), regardless of congruency and a reduced RT flanker effect following HE and LE compared with the AC condition with large (ds = -0.934 to -1.07) and medium effect sizes (ds = -0.502 to -0.507), respectively. Electrophysiological data revealed that compared with the AC condition, acute HE and LE had facilitative effects on stimuli evaluation, as indicated by significantly shorter N2 latency for congruent trials and P3 latency regardless of congruency with medium effect sizes (ds = -0.507 to -0.777). Compared with the AC condition, only acute HE elicited more efficient neural processes in conditions requiring high inhibitory control demand, as indicated by significantly shorter N2 difference latency, with a medium effect size (d = -0.528). Overall, the findings suggest that acute HE and LE facilitate inhibitory control and the electrophysiological substrates of target evaluation. Acute exercise with higher cognitive demand may be associated with more refined neural processing for tasks demanding greater amounts of inhibitory control.

Acute effects of mindful interval exercise on cognitive performance in a higher education setting

Interval exercise (IE) has been shown to have acute facilitating effects on cognition; however, the existing literature has been limited to laboratory settings and has focused on manipulating the parameters of exercise bouts during IE. This study included two classroom-based experiments to (1) investigate the effect of an acute bout of IE delivering mindfulness activity during its recovery intervals (mindful IE) on cognitive performance, and (2) compare cognitive performance following acute bouts of mindful IE with non-mindful IE. Experiment 1: Using a class-based within-subject crossover design, 59 participants completed the Stroop, d2, and trail-making tests to measure inhibitory control, attention, and cognitive flexibility, after a 30-min non-exercise or mindful IE session on separate counterbalanced days. Experiment 2: Using a similar design, 70 participants were assigned to two groups to receive a non-exercise and an IE session with (mindful) or without (non-mindful) mindfulness-based recovery intervals on separate counterbalanced days. Results from Experiment 1 showed superior d2 performance following the mindful IE than the non-exercise session. Although Experiment 2 found exercise-related decreases in commission error rate during the d2 test in both groups, the non-mindful group showed additional decreases in omission and total error rates. Further, higher scores on the nonreactivity facet of dispositional mindfulness were correlated with larger decreases in omission and total error rates during the d2 test for the mindful IE group. No exercise-related effect was found for outcomes of the Stroop and trail-making tests in both experiments. These findings in the selective improvements in d2 test performance are the first to suggest the feasibility of integrating mindfulness activity into the recovery intervals of IE for enhanced cognitive performance that may depend on individual differences in dispositional mindfulness.

Executive function during exercise is diminished by prolonged cognitive effort in men

The speed and accuracy of decision-making (i.e., executive function (EF) domains) is an integral factor in many sports. At rest, prolonged cognitive load (pCL) impairs reaction time (RT). In contrast, exercise improves RT and EF. We hypothesized that RT and EF during exercise would be diminished by prolonged 'dual tasking' as a consequence of pCL. To test the hypothesis, twenty healthy male participants performed four conditions [resting control (Rest), pCL only (pCL_Rest), exercise only (EX), and pCL + exercise (pCL_EX)] in a randomized-crossover design. Both exercise conditions utilized a 50-min cycling exercise protocol (60% VO₂ peak) and the pCL was achieved via a 50-min colour-word Stroop task (CWST). Compared with Rest, pCL_Rest caused a slowed CWST RT (P < 0.05) and a large SD (i.e., intraindividual variability) of CWST RT (P < 0.01). Similarly, compared with EX, the slowed CWST RT (P < 0.05) and large SD of CWST RT (P < 0.01) were also observed in pCL_EX. Whereas the reverse-Stroop interference was not affected in pCL_Rest (P = 0.46), it was larger (i.e., declined EF) in pCL_EX than EX condition (P < 0.05). These observations provide evidence that the effort of pCL impairs RT and EF even during exercise.

The effects of acute high-intensity interval exercise on the temporal dynamics of working memory and contralateral delay activity

The present investigation examined the acute effects of high-intensity interval exercise (HIIE) on temporal changes in behavioral and neuroelectrical indices of working memory. Young adults (n = 22) performed a visual working memory change detection task of equiprobable 2- to 5-dot set sizes while contralateral delay activity (CDA) and N2pc ERP components were assessed at three consecutive time periods (40-min, 54-min, and 68-min) following three separate counterbalanced 9-min sessions of seated rest, HIIE-aerobic (treadmill intervals of moderate- and high-intensity run/walk periods) and HIIE-aerobic/resistance (intervals of rest and body-weight calisthenics). Behavior results revealed greater 4-dot accuracy for HIIE-aerobic/resistance compared to seated rest only at 40-min, maintenance of 5-dot accuracy across time for HIIE-aerobic compared to HIIE-aerobic/resistance and seated rest, and greater temporal stability in overall accuracy performance (i.e., inter-class correlation between temporally adjacent assessments) for both HIIE conditions compared to seated rest. CDA and N2pc results revealed no change in amplitude across time and between HIIE-aerobic, HIIE-aerobic/resistance, and seated rest. However, greater temporal stability in CDA amplitude was observed for HIIE-aerobic compared to seated rest. These findings suggest that short bouts of HIIE may serve as an effective modality for improvements and temporal stabilization in behavior with some evidence for stabilization of neuroelectrical indices of working memory capacity. Together, these data broadly suggest that short acute bouts of exercise may facilitate improvements in underlying mental operations responsible for temporal stability in cognitive and neurocognitive function.

The Effects of Acute Virtual Reality Exergaming on Mood and Executive Function: Exploratory Crossover Trial

Background

Virtual reality (VR) exergaming is a new intervention strategy to help humans engage in physical activity to enhance mood. VR exergaming may improve both mood and executive function by acting on the prefrontal cortex, expanding the potential benefits. However, the impact of VR exergaming on executive function has not been fully investigated, and associated intervention strategies have not yet been established.

Objective

This study aims to investigate the effects of 10 minutes of VR exergaming on mood and executive function.

Methods

A total of 12 participants played the exergame “FitXR” under 3 conditions: (1) a VR exergame condition (ie, exercise with a head-mounted display condition [VR-EX]) in which they played using a head-mounted display, (2) playing the exergame in front of a flat display (2D-EX), and (3) a resting condition in which they sat in a chair. The color-word Stroop task (CWST), which assesses executive function; the short form of the Profile of Mood States second edition (POMS2); and the short form of the Two-Dimensional Mood Scale (TDMS), which assess mood, were administered before and after the exercise or rest conditions.

Results

The VR-EX condition increased the POMS2 vigor activity score (rest and VR-EX: t₁₁=3.69, P=.003) as well as the TDMS arousal (rest vs 2D-EX: t₁₁=5.34, P<.001; rest vs VR-EX: t₁₁=5.99, P<.001; 2D-EX vs VR-EX: t₁₁=3.02, P=.01) and vitality scores (rest vs 2D-EX: t₁₁=3.74, P=.007; rest vs VR-EX: t₁₁=4.84, P=.002; 2D-EX vs VR-EX: t₁₁=3.53, P=.006), suggesting that VR exergaming enhanced mood. Conversely, there was no effect on CWST performance in either the 2D-EX or VR-EX conditions. Interestingly, the VR-EX condition showed a significant positive correlation between changes in CWST arousal and reaction time (r=0.58, P=.046). This suggests that the effect of exergaming on improving executive function may disappear under an excessively increased arousal level in VR exergaming.

Conclusions

Our findings showed that 10 minutes of VR exergaming enhanced mood but did not affect executive function. This suggests that some VR content may increase cognitive demands, leading to psychological fatigue and cognitive decline as an individual approaches the limits of available attentional capacity. Future research must examine the combination of exercise and VR that enhances both brain function and mood.

The Immediate and Sustained Effects of Moderate-Intensity Continuous Exercise and High-Intensity Interval Exercise on Working Memory

This study investigated the immediate and delayed effects of moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) on working memory. Fifty healthy young adults (mean age = 19.96 ± 1.03 years) engaged in (1) a MICE session, 20 min of continuous running on a treadmill at an intensity of 40–59% of heart rate reserve (HRR); (2) a HIIE session, 10 sets of 1 min running at an intensity of 90% HRR, interspersed by 1 min self-paced walking at 50% HRR; and (3) a control session, resting in a chair and reading books for 24 min. A spatial 2-back task was performed to assess working memory before, immediately after and 30 min after each intervention. Reaction time in the 2-back task was significantly reduced immediately after both MICE and HIIE interventions. The enhanced working memory associated with HIIE sustained for 30 min after the exercise, whereas the beneficial effects associated with MICE returned to the pre-exercise level at 30 min after the exercise. These results suggest that although both MICE and HIIE enhance working memory in young adults, the positive effect sustains longer in HIIE than that in MICE. The current study extends the existing knowledge base by suggesting that improvements in working memory with HIIE last longer than with MICE.

Comparison of the Sustainability Effects of High-Intensity Interval Exercise and Moderate-Intensity Continuous Exercise on Cognitive Flexibility

This study examined the immediate and sustained effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on cognitive flexibility in young adults. Participants (n = 56) engaged in (1) a session of HIIE, involving 10 sets of one-minute treadmill running at an intensity targeting 90% heart rate reserve (HRR) interspersed with self-paced walking at 50% HRR; (2) a session of MICE, involving a 20 min treadmill running at an intensity of 40-59% HRR; and (3) a control session, involving 24 min of resting on separate days in a counterbalanced order. Using a more-odd shifting task, cognitive flexibility was assessed before the intervention (t0), immediately after the session (t1), and then at 30 min (t2) after the session. During the more-odd shifting task, the switch cost of response time (RT) immediately after the HIIE was significantly reduced compared to that before exercise, suggesting beneficial effects on cognitive flexibility. Additionally, the impacts of HIIE were maintained for 30 min post-exercise. However, improved cognitive flexibility was not observed until 30 min after the MICE intervention. HIIE might represent a time-efficient approach for enhancing cognitive flexibility.

Acute Effect of Cognitive Compromise during Physical Exercise on Self-Regulation in Early Childhood Education

Self-regulation (SR) in pre-schoolers is a strong predictor of different aspects of mental health and wellbeing. However, SR only recently has been examined concerning physical activity and its effects on cognitive performance. In the present study, 49 preschool children aged 4-5 years were submitted to classroom movement breaks (CMBs) of 15-min with different degrees of difficulty. Before beginning the intervention, SR (i.e., head, toes, knees and shoulders test, HTKS) and skill levels were assessed for tasks demand adjustment to individual resources and the counterbalanced assignment of the participants to the groups. Similarly, after the intervention, the performance on the HTKS was re-evaluated. There was a general intervention effect on the SR of pre-schoolers, regardless of the difficulty level of the task [F (3) = 11.683, p-value < 0.001, η2p = 0.438]. Nevertheless, it seems that only when CMBs stimulate the children cognitively with optimal difficulty, is it possible to obtain benefits. We recommend providing teachers with professional support when implementing physical activity breaks in their daily program to generate an individualized level of cognitive load that would allow children to reach the optimal challenge point.

Cognitive effects of acute aerobic exercise: Exploring the influence of exercise duration, exhaustion, task complexity and expectancies in endurance-trained individuals

The cognitive effects of acute aerobic exercise were investigated in endurance-trained individuals. On two occasions, 21 cyclists; 11 male (VO_2max: 57 ± 9 mL·kg^-1·min^-1) and 10 female (VO_2max: 51 ± 9 mL·kg^-1·min^-1), completed 45 min of fixed, moderate-intensity (discontinuous) cycling followed by an incremental ride to exhaustion. Cognitive function was assessed at Baseline, after 15 and 45 min of exercise (15EX and 45EX) and at Exhaustion using a 4-Choice Reaction Time (CRT) test and the Stroop test (Incongruent and Congruent Reaction Time [RT]). A sham capsule was administered on one occasion to determine whether the cognitive response to exercise was robust to the influence of a placebo. CRT, Congruent RT and Incongruent RT decreased (improved) at 15EX, 45EX and Exhaustion compared to Baseline (p's<0.005). While CRT and Congruent RT were faster at 45EX than 15EX (p's<0.020), Incongruent RT was not (p= 1.000). The sham treatment did not affect cognition. When performed at a moderate-intensity, longer duration exercise (up to 45 min) may improve cognition to a greater extent than shorter duration exercise; however, the magnitude of improvement appears to decrease with increasing task complexity. HI/EE performed following a sustained bout of dehydrating activity may not impair cognition.

Exploring Active Travel and Leisure-Time Physical Activity Relationships With Cognition Among Older Adults

Leisure-time physical activity (LTPA) is known to benefit cognition among older adults, but the impact of active travel is unclear. To explore this relationship, data from the 2011-2014 National Health and Nutritional Examination Survey (N = 2,702; mean age = 70) were retrieved on the self-reported frequency and duration of active travel (walking/cycling for transport, >20 min), LTPA engagement (e.g., sport), and three cognitive outcomes. Four groups were created according to physical activity guidelines (600 metabolic equivalent of task/week): inactive (n = 1,790), active travelers (n = 210), engaging in LTPA (n = 579), and engaging in both (n = 123). Analysis of covariance (and follow-up comparisons) revealed a significant main effect for each cognition variable, after adjusting for the covariates, indicating that those engaging in LTPA performed the best. Although correlational, these findings suggest that LTPA engagement may be important for cognition among older adults, but active travel did not provide added benefit.

Acute effects of aerobic exercise on response variability and neuroelectric indices during a serial n-back task

To determine the neuroelectric underpinnings of exercise-induced changes in working memory, this study investigated the acute effects ofaerobic exercise (AE) on the P3 component of an event-related potential and brain oscillations during a serial n-back task. Task-related electroencephalography was collected in 23 young adults following 20 min of rest and AE on separate, counterbalanced days. The results revealed reductions in standard deviation of response time and coefficient of variation of response time following AE compared to rest. Neuroelectric analyses showed increased P3 amplitude following AE compared to rest. Task-related frontal alpha desynchronization was stronger in the 2-back compared with the 1-back task following AE, while no such modulation was observed following rest. These findings suggest AE may temporarily enhance working memory, as reflected by decreases in response variability, which are accompanied by neuroelectric indices reflecting greater upregulation of attentional processes.

Comparison of the effects of running and badminton on executive function: A within-subjects design

Multiple cross-sectional studies have shown that regular complex exercises, which require cognitive demands (e.g., decision making) and various motions, are associated with greater positive effects on executive functions compared to simple exercises. However, the evidence of a single bout of complex exercises is mixed, and investigations on the acute effect of complex exercise using a well-controlled within-subjects research design are few. Therefore, we compared the acute effects of complex exercise on inhibitory functions with those of simple running. Twenty young adults performed three interventions, which were running, badminton, and seated rest as a control condition for 10 min each. During each intervention, oxygen consumption and heart rate were monitored. A Stroop test and a reverse-Stroop test were completed before and after each intervention. The intensities of the badminton and running were equivalent. Badminton significantly improved performance on the Stroop task compared to seated rest; however, running did not enhance performance on the Stroop task relative to seated rest. A single bout of complex exercise elicits a larger benefit to inhibitory function than a single bout of simple exercise. However, the benefit of complex exercise may vary depending on the type of executive functions.