Decline in executive control during acute bouts of exercise as a function of exercise intensity and fitness level

A mechanistic understanding of cognitive performance deficits concurrent with vigorous intensity exercise

This study aimed to evaluate whether cerebral oxygenation of the prefrontal cortex and associative-dissociative focus while completing the task mediate changes in cognition during exercise. Seventy-five young college-aged adults participated in this within-subjects randomized cross-over two-arm experimental design. During each session, participants completed a Stroop task four separate times: at baseline, two times during the exercise session, and at post-test. The experimental arm session involved participants cycling first at a moderate intensity, followed by cycling at a vigorous intensity. The active control arm session involved participants cycling at a very light intensity to ensure any effects were attributable to the level of exertion rather than the control of motor coordination. Cerebral oxygenation of the prefrontal cortex was assessed using fNIRS, while associate-dissociate attention was assessed using a self-report scale to provide insight into two hypothesized mechanisms which may contribute to alterations in cognition during exercise. Replicating well-established findings, results showed that during vigorous-intensity exercise, accuracy rates decreased for the most cognitively demanding conditions of the Stroop task, while reaction times were generally shorter compared to baseline. Neither shifting of attention in response to the dual-task nor prefrontal cortex oxygenation were observed to mediate cognitive deficits associated with vigorous exercise.

Effects of aquatic exercise intervention on executive function and brain-derived neurotrophic factor of children with autism spectrum disorder

BACKGROUND

Limited knowledge exists regarding the effectiveness of aquatic exercise intervention for improving executive function (EF) in children with autism spectrum disorder (ASD). Additionally, the impact of aquatic exercise on brain-derived neurotrophic factor (BDNF) in children with ASD requires further investigation.

AIMS

This study aimed to explore the effects of a 12-week aquatic exercise intervention on core EF and BDNF levels in children with ASD.

METHODS AND PROCEDURES

Thirty children with ASD were assigned to an experimental or control group. The experimental group underwent a 12-week aquatic exercise intervention, while the control group engaged in supervised free activities. Pre- and post-intervention assessments measured EF and BDNF levels.

OUTCOMES AND RESULTS

The experimental group showed significant improvements (p < 0.05) in inhibition control, cognitive flexibility, and BDNF levels. However, working memory did not significantly improve. The control group exhibited no significant changes in EF or BDNF levels.

CONCLUSIONS AND IMPLICATIONS

Aquatic exercise appears to be a beneficial intervention for cognitive development in children with ASD, as it enhances inhibition control, cognitive flexibility, and BDNF levels in children with ASD. Furthermore, the observed improvements in EF following aquatic exercise intervention in children with ASD may be associated with increased BDNF levels.

Differential effects of acute cardiovascular exercise on explicit and implicit motor memory: The moderating effects of fitness level

A single bout of cardiovascular exercise (CE) performed after practice can facilitate the consolidation of motor memory. However, the effect is variable and may be modulated by different factors such as the motor task's or participant's characteristics and level of awareness during encoding (implicit vs explicit learning). This study examines the effects of acute CE on the consolidation of motor sequences learned explicitly and implicitly, exploring the potential moderating effect of fitness level and awareness. Fifty-six healthy adults (24.1 ± 3.3 years, 32 female) were recruited. After practicing with either the implicit or explicit variant of the Serial Reaction Time Task (SRTT), participants either performed a bout of 16 min of vigorous CE or rested for the same amount of time. Consolidation was quantified as the change in SRTT performance from the end of practice to a 24 h retention test. Fitness level (V̇O2peak) was determined through a graded exercise test. Awareness (implicit vs explicit learning) was operationalized using a free recall test conducted immediately after retention. Our primary analysis indicated that CE had no statistically significant effects on consolidation, regardless of the SRTT's variant utilized during practice. However, an exploratory analysis, classifying participants based on the level of awareness gained during motor practice, showed that CE negatively influenced consolidation in unfit participants who explicitly acquired the motor sequence. Our findings indicate that fitness level and awareness in sequence acquisition can modulate the interaction between CE and motor memory consolidation. These factors should be taken into account when assessing the effects of CE on motor memory.

Medium chain triglycerides with a C8:C10 ratio of 30:70 enhances cognitive performance and mitigates the cognitive decline associated with prolonged exercise in young and healthy adults

INTRODUCTION

Prolonged exercise has been linked to a decline in cognitive function due to a variety of factors, such as a drop in oxygen in the prefrontal cortex and an increase in stress hormones and neurotransmitters. Medium chain triglycerides (MCTs) may possibly offset this decline as they provide energy for the brain via both direct and indirect pathways, alongside promoting chronic physiological adaptations within the brain.

METHODS

Participants were divided into two groups; MCT (n = 9) and Placebo (n = 10). The MCT gels contained 6 g of MCT with a C8:C10 ratio of 30:70, whereas the placebo gels contained carbohydrates of similar calorific value to the MCT gels. Participants visited the laboratory on three occasions (familiarisation/fitness test, pre-supplementation, post-supplementation), during which they performed a battery of cognitive tasks assessing domains such as processing speed, working memory, selective attention, decision making and coordination, before and after a prolonged bout of exercise (60 mins at 90% gas exchange threshold (GET). A 2-week supplementation period between visits 2 and 3 involved the ingestion of 2 gels per day.

RESULTS

Exercise resulted in detriments in most cognitive tasks pre-supplementation for both groups, and post-supplementation for the Placebo group (main effect ps< 0.05). Post-supplementation, the effect of exercise was mediated in the MCT group for all cognitive tasks (main effect ps< 0.05), except for the Digit and Spatial Span Backwards test phases (main effect ps> 0.05). Furthermore, MCT supplementation enhanced before-exercise cognitive performance and in some measures, such as working memory, this was maintained after-exercise (interaction effect ps> 0.05).

CONCLUSIONS

Chronic MCT supplementation enhanced before-exercise cognitive performance and offset the cognitive decline caused by a prolonged bout of exercise. In some cases, improvements in before-exercise cognitive performance were maintained after-exercise.

The effect of acute high-intensity interval training and Tabata training on inhibitory control and cortical activation in young adults

Introduction

Physical exercise not only benefits peoples' health, but also improves their cognitive function. Although growing evidence suggests that high-intensity interval training (HIIT) is a time-efficient exercise regime that can improve inhibitory control performance by enhancing cortical activation in the prefrontal cortex, less is known about how Tabata training, a subset of HIIT that requires no equipment or facilities to perform, affects inhibitory control and cortical activation in young adults. Therefore, we aimed to reveal the effect of an acute bout of HIIT and Tabata training on inhibitory control and attempted to identify its potential neural substrates.

Methods

Forty-two young adults (mean age: 19.36 ± 1.36 years; 21 females) performed the Stroop task and Simon task before and after acute HIIT, Tabata training, or a control session, and cortical hemodynamic changes in the prefrontal area were monitored by functional near-infrared spectroscopy (fNIRS) during the tasks. Both HIIT and Tabata interventions lasted for a total of 12 min. The HIIT participants performed ergometer cycling at their 80% maximal aerobic power at 90-100 rpm, and the Tabata participants performed a total of 8 intense activities, such as jumping jacks, high knees, and butt kickers, without using equipment or facilities, keeping the heart rate at 80-95% of their maximum heart rate. Participants in the control group watched a sport video while sedentary. Cognitive tasks data and fNIRS data were analyzed by repeated-measures three-way ANOVA.

Results and discussion

Our results indicated that both the HIIT and Tabata groups exhibited reduced reaction times after the intervention, and there were alterations in activation patterns in the dorsolateral and ventrolateral prefrontal cortices.

Exercise-Related Effects on Executive Functions During a Simulated Underwater Extravehicular Activity

OBJECTIVE

Investigation of cognitive performance during extravehicular activities (EVAs) in a space-analog setting.

BACKGROUND

EVAs performed by humans in microgravity on the International Space Station (ISS) call for high cognitive performance during upper-body workload. Higher cardiovascular demands interact with cognitive performance, but no knowledge exists about EVA's special requirements. This study simulates EVA-training underwater to investigate its effects on the executive functions inhibition and switching.

METHOD

In a counterbalanced crossover design, 16 divers (age: 28 ± 2.4 years; eight females) performed two conditions (i.e., EVA vs. Inactivity [INACT]) in 3-5 m submersion (diving gear; not in a space-suit). EVA included 30 min of moderate-, followed by 30 min of high-intensity upper-body exercise intervals, paired with EVA-specific cognitive-motor tasks. INACT included no exercise in submersion and neutral buoyancy. Both conditions included cognitive testing at pre, mid (after the first 30 min), and post (after the second 30 min) on a tablet computer. Reaction times (RTs) and response accuracy (ACC) were calculated for both tasks.

RESULTS

ACC was significantly lower during EVA compared with INACT for inhibition (post: p = .009) and switching (mid: p = .019) at post (p = .005). RTs for inhibition were significantly faster during EVA (p = .022; ηp2 = 0.320).

CONCLUSION

Specific physical exercise, intensity, duration, and tasks performed during the EVA might differently affect the exercise-cognition interaction and need further investigation, especially for future long-term space travel.

APPLICATION

Future research might serve to improve mission success and safety for EVAs and long-term space travel.

Monitoring Inattention in Construction Workers Caused by Physical Fatigue Using Electrocardiograph (ECG) and Galvanic Skin Response (GSR) Sensors

Physical fatigue is frequent for heavy manual laborers like construction workers, but it causes distraction and may lead to safety incidents. The purpose of this study is to develop predictive models for monitoring construction workers' inattention caused by physical fatigue utilizing electrocardiograph (ECG) and galvanic skin response (GSR) sensors. Thirty participants were invited to complete an attention-demanding task under non-fatigued and physically fatigued conditions. Supervised learning algorithms were utilized to develop models predicting their attentional states, with heart rate variability (HRV) features derived from ECG signals and skin electric activity features derived from GSR signals as data inputs. The results demonstrate that using HRV features alone could obtain a prediction accuracy of 88.33%, and using GSR features alone could achieve an accuracy of 76.67%, both through the KNN algorithm. The accuracy increased to 96.67% through the SVM algorithm when combining HRV and GSR features. The findings indicate that ECG sensors used alone or in combination with GSR sensors can be applied to monitor construction workers' inattention on job sites. The findings would provide an approach for detecting distracted workers at job sites. Additionally, it might reveal the relationships between workers' physiological features and attention.

Runners with better cardiorespiratory fitness had higher prefrontal cortex activity during both single and exercise-executive function dual tasks: an fNIRS study

Objective: This study investigated the relationship between executive function and prefrontal cortex oxygenation during exercise in young adults with different Cardiorespiratory fitness (CRF) levels. Methods: A total of 28 amateur runners (n = 14) and sedentary college students (n = 14) were recruited. The maximum oxygen uptake estimated for the sub-maximal intensity run (4.97 miles/h) was used to indicate the different CRF levels. After 1 week, participants must complete the Stroop and 2-Back tasks in silence while performing moderate-intensity exercise. Using 19-channel functional near-infrared spectroscopic (fNIRS) to examine changes in prefrontal cortex oxyhemoglobin. Results: There was no significant difference in the correctness of the Stroop and 2-Back tasks between the two groups during exercise, but the amateur runner group showed an acceleration in reaction time. fNIRS results showed that during the exercise 2-Back task, the left dorsolateral prefrontal cortex oxyhemoglobin was higher in the amateur runner group than in the sedentary group. Conclusion: Executive function during exercise was similarly improved in participants with better fitness, suggesting that CRF provides an excellent metabolic reserve and directed allocation for cognitive tasks during exercise.

Paradoxical improvement of cognitive control in older adults under dual-task walking conditions is associated with more flexible reallocation of neural resources: A Mobile Brain-Body Imaging (MoBI) study

Combining walking with a demanding cognitive task is traditionally expected to elicit decrements in gait and/or cognitive task performance. However, it was recently shown that, in a cohort of young adults, most participants improved performance when walking was added to performance of a Go/NoGo response inhibition task. The present study aims to extend these previous findings to an older adult cohort, to investigate whether this improvement when dual-tasking is observed in healthy older adults. Mobile Brain/Body Imaging (MoBI) was used to record electroencephalographic (EEG) activity, three-dimensional (3D) gait kinematics and behavioral responses in the Go/NoGo task, during sitting or walking on a treadmill, in 34 young adults and 37 older adults. Increased response accuracy during walking, independent of age, was found to correlate with slower responses to stimuli (r = 0.44) and with walking-related EEG amplitude modulations over frontocentral regions (r = 0.47) during the sensory gating (N1) and conflict monitoring (N2) stages of inhibition, and over left-lateralized prefrontal regions (r = 0.47) during the stage of inhibitory control implementation. These neural activity changes are related to the cognitive component of inhibition, and they were interpreted as signatures of behavioral improvement during walking. On the other hand, aging, independent of response accuracy during walking, was found to correlate with slower treadmill walking speeds (r = -0.68) and attenuation in walking-related EEG amplitude modulations over left-dominant frontal (r = -0.44) and parietooccipital regions (r = 0.48) during the N2 stage, and over centroparietal regions (r = 0.48) during the P3 stage. These neural activity changes are related to the motor component of inhibition, and they were interpreted as signatures of aging. Older adults whose response accuracy 'paradoxically' improved during walking manifested neural signatures of both behavioral improvement and aging, suggesting that their flexibility in reallocating neural resources while walking might be maintained for the cognitive but not for the motor inhibitory component. These distinct neural signatures of aging and behavior can potentially be used to identify 'super-agers', or individuals at risk for cognitive decline due to aging or neurodegenerative disease.

Associations between cardiorespiratory fitness, monocyte polarization, and exercise-related changes in mnemonic discrimination performance in older adults

Biological aging is accompanied by a chronic pro-inflammatory state that may facilitate losses in hippocampal-dependent mnemonic discrimination. Aerobic exercise training promotes adaptations that include improved immune competency, higher cardiorespiratory fitness, and maintenance of hippocampal function. However, it is poorly understood whether, in active older adults, baseline immune cell profiles and cardiorespiratory fitness are possible mechanisms that facilitate the long-term benefits to hippocampal dependent mnemonic discrimination performance. This within-subjects study with counterbalanced conditions aimed to investigate whether baseline monocyte polarization and cardiorespiratory fitness influenced performance in the mnemonic similarity task (MST) and related Lure Discrimination Index (LDI) score after an acute bout of exercise. Twenty-one active older adults (M = 68 ± 5 yrs) underwent baseline testing in which blood samples were collected and cardiorespiratory fitness measured. Participants then returned and completed a seated rest or moderate intensity aerobic exercise condition in which the MST was proctored prior to and 5 min after each condition. A linear mixed effects model was used in which Participant ID was a random effect and Condition (rest v. exercise), Time (pre- v post-), and order were fixed main effects. Simple linear regression models were used to determine the variance accounted for by monocyte phenotypes and cardiorespiratory fitness for LDI scores post-condition. Post-rest LDI scores were significantly lower than post-exercise LDI scores (t(20) = -2.65, p < 0.02, d = -0.57). Intermediate monocytes were significant predictors of the change in pre- to post-exercise LDI scores (F(1, 19) = 6.03, p = 0.024, R² = 0.24) and cardiorespiratory fitness was a significant predictor of the difference between post-condition LDI scores (F(1, 19) = 6.71, p = 0.018, R² = 0.26). Our results suggest baseline cardiorespiratory fitness and intermediate monocytes may relate to the integrity of hippocampal-dependent mnemonic discrimination performance, and possibly the degree of responsiveness to aerobic exercise interventions.

Effect of acute physical exercise on inhibitory control in young adults: High-intensity indoor cycling session

There is growing evidence that physical exercise (PE) may boost cognitive performance. However, criteria regarding PE intensity, duration, and frequency are still being studied. We hypothesize that high PE intensities have effects on inhibitory control. For this reason, our aim was to study the effect of acute PE on IC in healthy young students of a bachelor's degree in physical education and exercise via a 20-minute indoor cycling session at 80-90% HRmax intensity. We devised an experimental group design (n = 9) relative to a control group (n = 10) with pre-and-post-test IC measures. A Stroop task (two conditions) was administered to undergraduate students (Mage = 23.3, SD = 1.6) of a bachelor's degree program in Physical Education and Sports Sciences from a public university in Colombia. The computed MANOVA did not show an interaction effect between the experimental task of Stroop A-B x measure x group. However, a main effect of reduced response time was obtained after PE in the experimental group. Other main effects were observed in the number of correct and incorrect trials in the Stroop-B condition. The experimental group showed fewer correct answers after PE, and the control group showed fewer errors. It is concluded that high-intensity PE confers favorable effects on inhibitory control.

The effects of acute high-intensity aerobic exercise on cognitive performance: A structured narrative review

It is well established that acute moderate-intensity exercise improves cognitive performance. However, the effects of acute high-intensity aerobic exercise on cognitive performance have not been well characterized. In this review, we summarize the literature investigating the exercise-cognition interaction, especially focusing on high-intensity aerobic exercise. We discuss methodological and physiological factors that potentially mediate cognitive performance in response to high-intensity exercise. We propose that the effects of high-intensity exercise on cognitive performance are primarily affected by the timing of cognitive task (during vs. after exercise, and the time delay after exercise). In particular, cognitive performance is more likely to be impaired during high-intensity exercise when both cognitive and physiological demands are high and completed simultaneously (i.e., the dual-task paradigm). The effects may also be affected by the type of cognitive task, physical fitness, exercise mode/duration, and age. Second, we suggest that interactions between changes in regional cerebral blood flow (CBF), cerebral oxygenation, cerebral metabolism, neuromodulation by neurotransmitters/neurotrophic factors, and a variety of psychological factors are promising candidates that determine cognitive performance in response to acute high-intensity exercise. The present review has implications for recreational, sporting, and occupational activities where high cognitive and physiological demands are required to be completed concurrently.

Effect of Exercise Intensity on Psychomotor Vigilance During an Incremental Endurance Exercise in Under-19 Soccer Players

The aim of this study was to analyze the acute effects of an incremental resistance test on psychomotor vigilance in 16 soccer players under-19 years old (age 16.42 ± 0.85 years). Borg 15-point subjective perception of effort scale, the psychomotor vigilance task test, and the Yo-Yo intermittent recovery test were used. Four evaluation sessions were conducted with different intensities of efforts (30%-40%, 60%-75%, 80%-90%, and 100%) on different days (counterbalanced order). A repeated-measures analysis of variance was performed in the reaction time of the psychomotor vigilance task. The results showed that participants responded faster during efforts between 80% and 90% of maximal oxygen uptake (501.20 ± 70.77 ms). From that threshold, the players decreased their performance through a longer reaction time (601.23 ± 85.05 ms; p value < .001). The main findings were that the reaction time performance was worse at the lowest and highest effort conditions (5 and 17 km/hr, respectively). This fact helps to focus on the importance of designing and proposing training tasks with medium-high efforts to provoke optimal reaction times in young soccer players.

Agility and change-of-direction speed are two different abilities also during the execution of repeated trials and in fatigued conditions

Agility and change of direction speed are two different abilities, but no study has investigated if this difference exists also in fatigued conditions, and whether fatigue develops in a different way in a repeated-trial scenario. Fourteen soccer players (age: 17.0 ± 0.4 yrs; height: 176.9 ± 6.5 cm; body mass: 69.2 ± 6.4 kg) competing in a national-level youth league completed in a randomized counter-balanced crossover design a repeated agility protocol (RA) and a repeated change-of-direction one (RCOD), both consisting in performing 20 consecutive repetitions (work:rest ratio 1:5). The 20 repetitions were divided into 4 blocks (each block containing 5 repetitions) for the analysis. Results show that agility and COD are two different abilities both in rest and fatigue conditions: block 1 RA vs 1 RCOD (p < 0.001; ES = 2.02 huge; r = 0.17 poor; r² = 0.03), 2 RA vs 2 RCOD (p < 0.001; ES = 2.3 huge; r = 0.51 fair; r² = 0.26), 3 RA vs 3 RCOD (p < 0.001; ES = 2.38 huge; r = 0.54 fair; r² = 0.29), and 4 RA vs 4 RCOD (p < 0.001; ES = 2.7 huge; r = 0.41 fair; r² = 0.17). However, the fatigue development in both conditions was similar, with a percentage decrement score (S_dec) of 7.5% for RA, and 7.3% for RCOD. Ratings of perceived exertions (RPE) were similar too (7.3 ± 1.7, and 6.6 ± 1.9, for RA and RCOD, respectively). However, a significant fatigue-related performance impairment arose earlier in RA (block 2) than in RCOD (block 3). Total RA and total RCOD times were significantly different (p < 0.001; ES = 2.65 huge; r = 0.41 fair; r² = 0.17), suggesting that they are two different and independent abilities.

Executive Function Level in Cadets’ Shooting Performance

Executive functions (EF) are crucial to a person’s unique abilities, enabling one to achieve goals, adapt to new situations and manage social interactions. EF are also very important for the effective performance of military tasks including the shooting performance (SP) of soldiers. The aim of this study was to investigate the association of EF with SP and gender differences in the level of these traits among cadets of the General Tadeusz Kosciuszko Military University of Land Forces in Wroclaw i.e., 156 persons (19 females and 137 males). The level of EF and processes related to attention was measured with usage of the Color Trails Test (CTT-1 and CTT-2). SP was assessed on the basis of scores from four different small arms and rifle shootings at a fixed target and at emerging targets. The relations between explained and explanatory variables were assessed using Spearman correlation. The variation in the mean values of CTT scores and SP of men and women was compared using the Mann–Whitney U test for independent samples. The results of the present study did not reveal any significant differences between women and men in the level of EF and SP. The key finding of the present study is that the higher SP of males in all shooting events of the study and of females in pistol shooting were significantly correlated with higher executive functions.

Psychological Responses to Progressive Exercise Until Voluntary Exhaustion: A Study of Adolescent Male Basketball Players

The affective experience during and after exercise helps determine motivation, commitment, and adherence to sports. Choice reaction time (RT) is critical in decision-making and sports performance. In this within-subjects laboratory experiment, we scrutinized core affect and choice RT in 18 male adolescent basketball players during exercise sessions performed to voluntary exhaustion and during a control condition. The adolescents performed choice RT tasks in one of two exercise conditions and in the control session. Participants' feeling states differed between exercise and control sessions and decreased slightly even after moderate exercise intensity. Core affect also declined as the workload increased, but it remained pleasant-activated in all conditions. The RT errors increased at the peak exercise intensity. These results suggest that while high-intensity training might negatively affect young athletes' feeling states and impair their decision-making, their core affect remained positive, with large inter-individual variability. We discuss the practical implications of these results in adolescents' sports.

Can exercise shape your brain? A review of aerobic exercise effects on cognitive function and neuro-physiological underpinning mechanisms

It is widely accepted that physical exercise can be used as a tool for the prevention and treatment of various diseases or disorders. In addition, in the recent years, exercise has also been successfully used to enhance people's cognition. There is a large amount of research that has supported the benefits of physical exercise on human cognition, both in children and adults. Among these studies, some have focused on the acute or transitory effects of exercise on cognition, while others have focused on the effects of regular physical exercise. However, the relation between exercise and cognition is complex and we still have limited knowledge about the moderators and mechanisms underlying this relation. Most of human studies have focused on the behavioral aspects of exercise-effects on cognition, while animal studies have deepened in its possible neuro-physiological mechanisms. Even so, thanks to advances in neuroimaging techniques, there is a growing body of evidence that provides valuable information regarding these mechanisms in the human population. This review aims to analyze the effects of regular and acute aerobic exercise on cognition. The exercise-cognition relationship will be reviewed both from the behavioral perspective and from the neurophysiological mechanisms. The effects of exercise on animals, adult humans, and infant humans will be analyzed separately. Finally, physical exercise intervention programs aiming to increase cognitive performance in scholar and workplace environments will be reviewed.

Interrelationships between exercise, functional connectivity, and cognition among healthy adults: A systematic review

The main purpose of this systematic review was to examine past literature focusing on the potential relationship between exercise (or physical activity or cardiorespiratory fitness [CRF]) and functional brain connectivity in healthy adults. Among the studies meeting this purpose, we also evaluated studies investigating whether, and how, functional connectivity may influence the exercise-cognition relationship. A systematic review was employed through several electronic databases (PsychInfo, PubMed, and Google Scholar) in accordance with PRISMA guidelines. The literature search identified 656 records, and a total of 12 studies met the inclusion criteria. Among these 12 studies, there were 4, 7, and 1 study, respectively, examining the relationship between exercise and frontal lobe connectivity, temporal lobe connectivity, and whole-brain connectivity. Also, 7 studies examined the relationship between functional connectivity and cognitive performance across multiple brain regions as a function of exercise. Existing literature suggests that CRF, habitual physical activity, and varying intensities of acute exercise can strengthen functional connections among a wide variety of regions and subcortical structures of the human brain. These exercise-induced functional connectivity changes within and between specific brain structures/networks supporting cognitive processing may improve various domains of cognitive function. Given these complex associations, a thorough understanding of how functional connectivity plays a mediating role in the exercise-cognition interaction is needed in future studies.

A Review of Cognitive Changes During Acute Aerobic Exercise

A growing body of work has investigated the effects of acute, or single bouts of, aerobic exercise on cognitive function. However, review of this research has largely focused on changes following exercise, with less focus on cognitive changes during exercise. The purpose of this review is to discuss the critical characteristics of this literature to date, including: (1) what has been done, (2) what has been found, and (3) what is next. Furthermore, previous meta-analytic reviews have demonstrated there is a small positive effect on cognition when measured during exercise, with executive functions showing the largest effects. However, these reviews group executive functions together. Here we explore how inhibition, working memory and cognitive flexibility are individually impacted by factors such as exercise intensity or duration. Searches of electronic databases and reference lists from relevant studies resulted in 73 studies meeting inclusion criteria. Studies were grouped by executive and non-executive cognitive domains, intensity and duration of exercise bouts. Within the executive domain, we found that effects on working memory and cognitive flexibility remain mixed, effects on inhibition are clearer. Moderate intensity exercise improves response time, vigorous intensity impairs accuracy. Moderate to vigorous intensity improves response time across non-executive domains of attention, motor speed and information processing, with no significant effects on accuracy. Memory processes are consistently improved during exercise. Effects of exercise duration on response time and accuracy are nuanced and vary by cognitive domain. Studies typically explore durations of 45 min or less, extended exercise durations remain largely unexplored. We highlight factors to consider when assessing exercise-cognition relationships, as well as current gaps and future directions for work in this field.

Acid-Base Balance, Blood Gases Saturation, and Technical Tactical Skills in Kickboxing Bouts According to K1 Rules

Simple Summary

The aim of our study was to analyze the changes in ABB after a three-round kickboxing fight and the level of technical and tactical skills presented during the fight. Fighting in kickboxing under K1 rules takes place with a high presence of anaerobic metabolism. Kickboxing athletes must have a good tolerance for metabolic acidosis and the ability to conduct an effective duel despite ABB disorders. Properly developed post-workout regeneration also plays an extremely important role.

Abstract

Background: Acid–base balance (ABB) is a major component of homeostasis, which is determined by the efficient functioning of many organs, including the lungs, kidneys, and liver, and the proper water and electrolyte exchange between these components. The efforts made during competitions by combat sports athletes such as kickboxers require a very good anaerobic capacity, which, as research has shown, can be improved by administering sodium bicarbonate. Combat sports are also characterized by an open task structure, which means that cognitive and executive functions must be maintained at an appropriate level during a fight. The aim of our study was to analyze the changes in ABB in capillary blood, measuring levels of H⁺, pCO₂, pO₂, HCO₃⁻, BE and total molar CO₂ concentration (TCO₂), which were recorded 3 and 20 min after a three-round kickboxing bout, and the level of technical and tactical skills presented during the fight. Methods: The study involved 14 kickboxers with the highest skill level (champion level). Statistical comparison of mentioned variables recorded prior to and after a bout was done with the use of Friedman’s ANOVA. Results: 3 min after a bout, H⁺ and pO₂ were higher by 41% and 11.9%, respectively, while pCO₂, HCO₃⁻, BE and TO₂ were lower by 14.5%, 39.4%, 45.4% and 34.4%, respectively. Furthermore, 20 min after the bout all variables tended to normalization and they did not differ significantly compared to the baseline values. Scores in activeness of the attack significantly correlated (r = 0.64) with pre–post changes in TCO₂. Conclusions: The disturbances in ABB and changes in blood oxygen and carbon dioxide saturation observed immediately after a bout indicate that anaerobic metabolism plays a large part in kickboxing fights. Anaerobic training should be included in strength and conditioning programs for kickboxers to prepare the athletes for the physiological requirements of sports combat.

Acute effects of exercise on cerebrovascular response and cognitive performance in individuals with stable coronary heart disease

BACKGROUND

Individuals with coronary heart disease (CHD) exhibit cognitive deficits and cerebrovascular dysfunctions, and are at higher risk of developing dementia. Cognitive function in individuals with CHD has never been studied during acute aerobic exercise. Given the increasing popularity of training at high peak power output (PPO), its impact on cerebrovascular and cognitive functions in individuals with CHD should be further studied.

METHOD

Thirty-eight individuals with CHD and 16 healthy controls completed two exercise bouts at 30% and 70% of their individualized PPO on an ergocycle while performing a cognitive task including non-executive and executive conditions. Variations of oxy- deoxy-hemoglobin, and total hemoglobin concentrations were measured on left prefrontal cortex at both PPO using near-infrared spectroscopy.

RESULTS

Cognitive task performances were equivalent between groups at all intensity levels. Individuals with CHD exhibited larger variation of deoxyhemoglobin in the executive condition and larger variation in total hemoglobin concentration in all task conditions compared to healthy controls at 70% of PPO.

CONCLUSION

Exercising at high intensity seems to have a larger impact on cerebral blood volume in CHD patients compared to healthy age-matched controls. Higher exercise intensity has negative impacts on cerebral blood volume variations during a cognitive task in CHD patients and could potentially lead to other neurocognitive dysfunctions. Other studies are needed to determine if a cognitive task administered during an exercise test could help identify individuals with CHD at higher risk of developing cognitive decline.

Aperture Crossing in Virtual Reality: Physical Fatigue Delays Response Time

Visual perception and cognitive (i.e., decision-making) abilities facilitate successful avoidance of obstacles in a person's environment. However, detrimental changes to cognition can occur after physical fatigue is induced by strenuous exercise. The purpose of the current study was to determine if obstacle avoidance behaviors reflect similar negative effects following physically fatiguing exercise. A virtual reality (VR) closing-gap aperture crossing task was completed by 13 recreationally active individuals to assess the effects of physical fatigue on passability judgements and response time. Participants approached closing apertures that moved at one of seven speeds while deciding to either pass through the closing aperture or stop. Participants completed four blocks of trials over a 7-day period (i.e., pre- and post-tests on the fatiguing day and control day). No significant differences for passability judgements were found across each of the blocks, but there was a significant reduction in response time on the post-test exercise day. Thus, physical fatigue increased the time required to make, and follow through on, a decision. The current findings suggest that processes requiring more cortical areas and processing (i.e., response time) may be more detrimentally affected by physically fatiguing exercise compared to dichotomous visuomotor tasks (i.e., passability judgements).

Acute Effects of Moderate versus High-Intensity Strength Exercise on Attention and Mood States in Female Physical Education Students

The presumed benefits of exercise/physical activity on the brain are an important public health issue. However, the experimental approach to understanding the effects of physical activity on the brain, and more particularly on cognitive functions, has only been studied recently. In particular, females remain underrepresented in the research, despite having a specific training/exercise adaptation/response. The aim of the present study was to examine the acute effects of high- and moderate-intensity strength exercise (3 sets of 8–10 repetitions and 3 sets of 6 repetitions, respectively, with each session lasting approximately 30 min) on attention and mood states in female physical education students. Forty-six female physical education students (M_age = 20.02 ± 1.05 years, M_{Body Mass Index} = 21.07) volunteered to participate in this study. They were divided into three groups: a moderate-intensity strength exercise group (MISEG: n = 15), a high-intensity strength exercise group (HISEG: n = 16), and a control group (CG: n = 15). Attention and psychological states were assessed using the d2 test, Rating of Perceived Exertion (RPE) and the Brunel Mood Scale (BRUMS) questionnaire, respectively, before and after each session. The data showed that in the MISEG attention increased, in terms of concentration (p = 0.05). RPE values, fatigue and confusion were higher for the HISEG than the CG (p < 0.05) and the MISEG (p < 0.05). Vigour was higher for the MISEG than other groups (p < 0.05). In conclusion, moderate-intensity resistance exercise is an appropriate method to improve attention in female participants. The elevated cognitive performance may be due to the changes in RPE and mood states (fatigue, vigour and confusion subscales).

The Effects of Exercise Interventions on Executive Functions in Children and Adolescents with Autism Spectrum Disorder: A Systematic Review and Meta-analysis

BACKGROUND

Both chronic and acute exercise interventions have reported positive effects on executive functions (EFs) in general populations. However, data on changes in EFs in children and adolescents with autism spectrum disorder (ASD) in response to exercise interventions are still unclear.

OBJECTIVE

This systematic review and meta-analysis aimed to synthesize available empirical studies concerning the effects of exercise interventions on EFs in children and adolescents with ASD.

METHODS

In accordance with the Preferred Reporting Items for Systematic Review and Meta-analyses guidelines, the electronic databases CINAHL Complete (via EBSCOhost), SPORTDiscus with Full Text (via EBSCOhost), MEDLINE (via EBSCOhost), Web of Science, ProQuest, and Education Resources Information Center (ERIC; via EBSCOhost) were searched from inception to January 2021. Two authors independently extracted data and conducted a risk-of-bias analysis using the Physiotherapy Evidence Database scale. Randomized controlled trials/quasi-experimental designs that used acute or chronic exercise interventions and assessed EFs through neurocognitive tasks or questionnaires among children and adolescents with ASD were included. In total, 259 articles were identified, of which 15 full texts were independently assessed for eligibility by two authors. In total, 14 articles underwent systematic review, and seven were selected for meta-analysis.

RESULTS

Overall, chronic exercise interventions had a small to moderate positive effect on overall EFs in children and adolescents with ASD (g = 0.342; 95% confidence interval [CI] 0.084-0.600; p < 0.01). Regarding domain-specific EFs, chronic exercise interventions had a small to moderate positive effect on cognitive flexibility (g = 0.312; 95% CI 0.053-0.570; p < 0.01) and inhibitory control (g = 0.492; 95% CI 0.188-0.796; p < 0.01). However, our review found a non-significant effect size (g = 0.212; 95% CI - 0.088 to 0.512) on working memory.

CONCLUSIONS

Chronic exercise interventions appear to have beneficial effects on overall EFs in children and adolescents with ASD, particularly in relation to cognitive flexibility and inhibitory control.

Effects of acute exercise at different intensities on fine motor-cognitive dual-task performance while walking: A functional near-infrared spectroscopy study

Studies on the effects of acute exercises on cognitive functions vary greatly and depend on the duration and intensity of exercise and the type of cognitive tasks. This study aimed to investigate the neural correlates that underpin the acute effects of high-intensity interval (HIIE) versus moderate-intensity continuous exercise (MCE) on fine motor-cognitive performance while walking (dual-task, DT) in healthy young adults. Twenty-nine healthy right-handers (mean age: 25.1 years ± 4.04; 7 female) performed the digital trail-making-test (dTMT) while walking (5 km/h) before and after acute exercise. During task performance, the hemodynamic activation of the frontopolar area (FPA), dorsolateral prefrontal (DLPFC), and motor cortex (M1) was recorded using functional near-infrared spectroscopy (fNIRS). Both HIIE and MCE resulted in improved dTMT performance, as reflected by an increase in the number of completed circles and a reduction in the time within and between circuits (reflecting improvements in working memory, inhibition, and decision making). Notably, HIIE evoked higher cortical activity on all brain areas measured in the present study than the MCE group. To our knowledge, these results provide the first empirical evidence using a mobile neuroimaging approach that both HIIE and MCE improve executive function during walking, likely mediated by increased activation of the task-related area of the prefrontal cortex and the ability to effectively use, among other things, high fitness levels as neural enrichment resources.

Visual search under physical effort is faster but more vulnerable to distractor interference

Cognition and action are often intertwined in everyday life. It is thus pivotal to understand how cognitive processes operate with concurrent actions. The present study aims to assess how simple physical effort operationalized as isometric muscle contractions affects visual attention and inhibitory control. In a dual-task paradigm, participants performed a singleton search task and a handgrip task concurrently. In the search task, the target was a shape singleton among distractors with a homogeneous but different shape. A salient-but-irrelevant distractor with a unique color (i.e., color singleton) appeared on half of the trials (Singleton distractor present condition), and its presence often captures spatial attention. Critically, the visual search task was performed by the participants with concurrent hand grip exertion, at 5% or 40% of their maximum strength (low vs. high physical load), on a hand dynamometer. We found that visual search under physical effort is faster, but more vulnerable to distractor interference, potentially due to arousal and reduced inhibitory control, respectively. The two effects further manifest in different aspects of RT distributions that can be captured by different components of the ex-Gaussian model using hierarchical Bayesian method. Together, these results provide behavioral evidence and a novel model for two dissociable cognitive mechanisms underlying the effects of simple muscle exertion on the ongoing visual search process on a moment-by-moment basis.

The Association Between Light Physical Activity and Cognition Among Adults: A Scoping Review

Background

The physical and cognitive benefits of moderate-vigorous intensity physical activity (MVPA) for adults have been well documented. Recently, there has been increasing interest in the independent health benefits of light-intensity physical activity (LPA). This research has primarily focused on the relationship between LPA and morbidity and mortality risk, with few studies investigating cognitive associations. The purpose of this scoping review was to catalog existing evidence on the association between device-based or technologically measured LPA and cognition among adults, identify trends in the literature, and recommend future areas for research.

Methods

Six electronic databases were searched between January and June 2020. Forty published studies met the inclusion criteria, which included both healthy and clinical young and older adult populations. Among the 40 articles were 14 acute exercise studies, 4 randomized control trials (RCTs), 18 cross-sectional studies, and 4 longitudinal studies.

Results

7/14 (50%) acute, 3/4 (75%) RCT, 10/18 (56%) cross-sectional, and 2/4 (50%) longitudinal studies reported a significant, positive relationship between LPA and one or more cognitive outcomes. These heterogeneous findings can largely be attributed to the diverse study designs and populations, as well as the numerous assessments used to test the cognitive domains.

Conclusion

These collective findings suggest LPA may be a potential lifestyle intervention to improve cognition across adulthood. However, the inconsistent approaches used among these studies suggest a more concerted, unified scientific approach is needed to further understand the LPA-cognition relationship.

Effects of Verbal Priming With Acute Exercise on Convergent Creativity

The acute effects of moderate-intensity treadmill exercise during anagram problem solving on subsequent creativity performance has yet to be empirically investigated, which was this study's purpose. A two-visit (counterbalanced order), within-subject experiment was conducted among individuals aged 18-35. For the acute exercise visit, participants engaged in a 15-minute bout of moderate-intensity treadmill exercise while solving anagram problems. For the anagram only visit, participants engaged in 15 minutes of seated rest while solving anagram problems. Average RAT performance was higher for the exercise + anagram problem-solving visit (M = 10.51, SD = 3.25) compared to anagram-solving + seated rest (M = 9.29, SD = 4.12). The difference between conditions was statistically significant, t(44) = 2.385, p = .021, Cohen's d = 0.36. These findings demonstrate that acute exercise coupled with anagram problem-solving, prior to RAT completion, is a potential strategy for enhancing verbal convergent creative thinking.

Shedding Light on the Effects of Moderate Acute Exercise on Working Memory Performance in Healthy Older Adults: An fNIRS Study

Numerous studies have reported the beneficial effects of acute exercise on executive functions. Less is known, however, about the effects of exercise on working memory as one subcomponent of executive functions and about its effects on older adults. We investigated the effects of acute moderate-intensity exercise on working memory performance, the respective cortical hemodynamic activation patterns, and the development and persistence of such effects in healthy older adults. Forty-four participants (M: 69.18 years ± 3.92; 21 females) performed a letter 2-back task before and at three time points after (post 15 min, post 30 min, and post 45 min) either listening to an audiobook or exercising (15 min; 50% VO2-peak). Functional near-infrared spectroscopy (fNIRS) was used to assess cortical hemodynamic activation and brain-behavior correlations in the fronto-parietal working memory network. Overall, we found no group differences for working memory performance. However, only within the experimental group, 2-back performance was enhanced 15 min and 45 min post-exercise. Furthermore, 15 min post-exercise frontal activation predicted working memory performance, regardless of group. In sum, our results indicate slight beneficial effects of acute moderate-intensity exercise on working memory performance in healthy older adults. Findings are discussed in light of the cognitive aging process and moderators affecting the exercise-cognition relationship.

Cognitive Impairment during High-Intensity Exercise: Influence of Cerebral Blood Flow

PURPOSE

Cognitive performance appears to be impaired during high-intensity exercise, and this occurs concurrently with a reduction in cerebral blood flow (CBF). However, it is unclear whether cognitive impairment during high-intensity exercise is associated with reduced CBF. We tested the hypothesis that a reduction in CBF is responsible for impaired cognitive performance during high-intensity exercise.

METHODS

Using a randomized crossover design 17 healthy males performed spatial delayed response and Go/No-Go tasks in three conditions (exercise [EX], exercise+CO2 [EX+CO2], and a nonexercising control [CON]). In the EX and EX+CO2, they performed cognitive tasks at rest and during 8 min of moderate and high-intensity exercise. Exercise intensity corresponded to ~50% (moderate) and ~80% (high) of peak oxygen uptake. In the EX+CO2, the participants inspired hypercapnic gas (2% CO2) during high-intensity exercise. In the CON, they performed the cognitive tasks without exercise.

RESULTS

Middle cerebral artery mean velocity increased during high-intensity exercise in the EX+CO2 relative to the EX (69.4 [10.6] cm·s, vs 57.2 [7.7] cm·s, P < 0.001). Accuracy of the cognitive tasks was impaired during high-intensity exercise in the EX (84.1% [13.3%], P < 0.05) and the EX+ CO2 (85.7 [11.6%], P < 0.05) relative to rest (EX: 95.1% [5.3%], EX+CO2: 95.1 [5.3%]). However, no differences between the EX and the EX+CO2 were observed (P > 0.10). These results demonstrate that restored CBF did not prevent cognitive impairment during high-intensity exercise.

CONCLUSIONS

We conclude that a reduction in CBF is not responsible for impaired cognitive performance during high-intensity exercise.

Understanding cognitive performance during exercise in Reserve Officers' Training Corps: establishing the executive function-exercise intensity relationship

Military performance depends on high-level cognition, specifically executive function (EF), while simultaneously performing strenuous exercise. However, most studies examine cognitive performance following, not during, exercise. Therefore, our aim was to examine the relationship between EF and exercise intensity. Following familiarization, 13 Reserve Officers' Training Corp cadets (age = 19.6 ± 2 yr, five women) completed a graded exercise test (GxT) and two executive function exercise tests (EFETs) separated by a duration of ≥24 h. The EFET was a combined iPad-based EF test (Cedar Operator Workload Assessment Tool) and GxT. Heart rate (HR) and prefrontal cortex (PFC) oxygenation [near-infrared spectroscopy (NIRS)] were continuously recorded. The EF score was analyzed for accuracy of responses (%hit rate). Heart rate reserve was calculated to normalize exercise intensity (%HRR). For PFC oxygenation recordings, NIRS variables were used to calculate the tissue saturation index (%TSI). Data from EFET trials were averaged into a singular response. The %hit rate declined at heart rate reserves (HRRs) of ≥80%, reaching nadir at 100% HRR (74.09 ± 10.63%, P < 0.01). The tissue saturation index (TSI) followed a similar pattern, declining at ≥70% of HRR and at a greater rate during EFET compared with during GxT (P < 0.01), reaching a nadir in both conditions at 100% HRR (60.39 ± 2.94 vs. 63.13 ± 3.16%, P < 0.01). Therefore, EF decline is dependent on exercise intensity, as is %TSI. These data suggest that reductions in EF during high-intensity exercise are at least in part related to attenuated PFC oxygenation. Thus, interventions that improve PFC oxygenation may improve combined exercise and EF performance.NEW & NOTEWORTHY The executive functioning aspect of cognition was evaluated during graded exercise in Reserve Officers' Training Corps cadets. Executive function declined at exercise intensities of ≥80% of heart rate reserve. The decline in executive function was coupled with declines in the oxygenation of the prefrontal cortex, the brain region responsible for executive functioning. These data define the executive function-exercise intensity relationship and provide evidence supporting the reticular activation hypofrontality theory as a model of cognitive change.

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.

Physical and Cognitive Performance During Upper-Extremity Versus Full-Body Exercise Under Dual Tasking Conditions

The purpose of this study was to investigate physical and cognitive performance during dual task conditions of upper-extremity (UE) or full-body (FB) rowing exercise. In a crossover counterbalanced design, college-aged male and female participants completed five conditions: (a) Sitting, (b) Single task UE rowing, (c) Single task FB rowing, (d) Dual task UE rowing, and (e) Dual task FB rowing. For single task UE and FB rowing conditions, participants were asked to row as hard as possible. After sitting and dual-task conditions, we administered the Paced Auditory Serial Addition Test (PASAT) and a word-list memory test. We analyzed participants' absolute differences (single task - dual task) in power output and their cognitive test scores to compare UE and FB rowing. There were no significant absolute differences from sitting to dual task conditions of UE and FB rowing for either PASAT (p = 0.958) or word list memory (p = 0.899) cognitive scores. Absolute power output loss from single to dual task conditions was significantly higher in FB versus UE for PASAT (p = 0.039; d = 0.54) and word list memory (p = 0.021; d = 0.66) in the dual task condition. These results suggest that, while cognitive performance was preserved regardless of the amount of muscle mass activated during dual task rowing, physical performance suffered more during FB than UE rowing under the dual task condition. These findings have important implications for optimizing cognitive and physical performance in dual task situations.

The effects of aerobic exercise intensity on memory in older adults

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.

Combined and Isolated Effects of Acute Exercise and Brain Stimulation on Executive Function in Healthy Young Adults

Abstract: Acute cognitive enhancement has been sought by healthy young individuals to improve academic and professional performance. Among several methods, physical exercise interventions and transcranial direct current brain stimulation (tDCS) have shown promise in impacting executive functions. Here, we observed a set of new findings about the causal effect of acute aerobic exercise and tDCS across three facets of executive function: Inhibition (as measured by a flanker task) was selectively impacted by acute aerobic exercise but not tDCS, whereas working memory (as measured by an n-back task) was impacted by both acute aerobic exercise and tDCS, with effects emerging on distinct processing components for each manipulation. Sustained attention (as measured by the Mackworth clock task), on the other hand, was not impacted by acute aerobic exercise or tDCS. Interestingly, no effects of combining acute aerobic exercise and tDCS emerged. We argue that understanding the unique and combined contributions of these cognitive enhancement techniques can not only contribute to a deeper mechanistic explanation in healthy individuals but also inform future research with clinical and aging populations.

Variability in Executive Control Performance Is Predicted by Physical Activity

Physical activity (PA) promotes neurogenesis and has neuroprotective effects on the brain, bolstering the structural and functional resources necessary for improved cognitive functioning. Intraindividual variability (IIV) in cognitive performance is linked to neuropsychological structure and functional ability. Despite evidence of the neurogenerative and neuroprotective effects of PA, limited investigation into the link between PA and IIV has been conducted. Across three studies we investigate the effect of PA on IIV in reaction time (RT) on three modified Flanker Tasks. The International PA Questionnaire was used to evaluate PA while the Attention Network Test (ANT) and two additional modified Flanker Tasks were used to assess executive control and attentional performance. RT coefficients of variation (RTCV) were calculated for each participant by dividing the standard deviation by the mean RT for each stimuli condition. Analysis revealed that basic RT was not associated with PA nor was PA predictive of IIV on the modified Flanker Tasks. However, three consistent findings emerged from analysis of the ANT. First, RTCV and moderate PA were positively related, such that more self-reported moderate PA was associated with greater IIV. Conversely, RTCV and vigorous PA were negatively related. Finally, when controlling for the effects of PA on IIV in young adults, variability decreases as age increases. In sum, PA is predictive of IIV on attentional and executive control tasks in young adults, though only at particular intensities and on certain tasks, indicating that task type and cognitive load are important determinants of the relationship between PA and cognitive performance. These findings are consistent with prior literature that suggests that the role of PA in young adults is reliant on specific interventions and measures in order to detect effects more readily found in adolescent and aging populations.

Effect of Acute Physical Exercise on Executive Functions and Emotional Recognition: Analysis of Moderate to High Intensity in Young Adults

Physical exercise (PE) is associated with cognitive changes and brain function. However, it is required to clarify the effect of PE in different intensities, population groups conditions and the EF duration over different cognitive domains. Besides, no studies are known to have evaluated the contextual emotional recognition. Therefore, we studied the effect of acute PE of moderate intensities up to higher ones to the executive functions and the contextual emotional recognition. The participants were evaluated and classified in two experiments according to the IPAQ short form self-report and control measures. In both experiments, the groups were randomized, controlled, and exposed to one session of indoor cycling through intervals of high measure intensity (75–85% HRmax). Experiment 1 comprised young adults who were physically active (PA) and healthy, apparently (n = 54, M_age = 20.7, SD = 2.5). Experiment 2 involved young adults who were physically inactive (IP) and healthy, apparently (n = 36, M_age = 21.6, SD = 1.8). The duration was the only factor that varied: 45 min for PA and 30 min for PI. The executive functions were evaluated by the Stroop, TMT A/B, and verbal fluency, and the emotional recognition through a task that includes body and facial emotions in context, simultaneously. The analysis of factorial mixed ANOVA showed effects on the right choices of the indoor cycling groups in the PA, and the time response in PI. Also, other effects were observed in the controlled groups. TMT-A/B measures showed changes in the pre-test–post-test measures for both experiments. Verbal fluency performance favored the control group in both experiments. Meanwhile, the emotional recognition showed an effect of the PE in error-reduction and enhanced the scores in the right choices of body emotions. These results suggest that the EF with intensities favored cognitive processes such as inhibitory control and emotional recognition in context. We took into account the importance of high-complexity tasks design that avoid a ceiling effect. This study is the first on reporting a positive effect of PE over the emotional contextual recognition. Important clinical and educational implications are presented implications which highlight the modulatory role of EF with moderate to high intensities.

Dynamics of cognitive performance at rest and after exhaustive exercise in top-three world-ranked mixed martial arts athletes: a series of case studies

Cognitive performance plays a key role in sports performance, especially in combat sports such as mixed martial arts (MMA). Studies with active and sedentary individuals showed either no change or decreased cognitive performance during or immediately after exercise. However, it is possible that elite MMA athletes would present preserved/improved cognitive performance after exhaustive exercise. In this series of cases studies, we tested this hypothesis by submitting three elite MMA athletes from the Bellator MMA® and UFC® to a cognitive assessment before, immediately after and 15 min after exhaustive exercise. A modified computerized version of the Stroop Test was used to test cognitive inhibition performance, from which reaction time (RT) and accuracy were obtained. The athletes performed an incremental exercise on a cycle simulator until volitional exhaustion. Immediately after exercise RT improved consistently in all three athletes (-6.5%; -8.0%; -15.0%), while accuracy presented a small increase (2.6%), decreases (-3.8%) or no change. Fifteen minutes after exercise, RT remained improved in two athletes (-9.1% and -15.5) or slightly increased (0.4%), while accuracy presented small increase in all athletes (0.5%; 1.3%; 2.1%) compared to pre-exercise. This result indicates that elite MMA athletes may present improved cognitive performance immediately after exhaustive exercise, which suggests that cognitive-motor training for MMA should be considered when planning a training program.

The Potential Mechanisms of Exercise-induced Cognitive Protection: A Literature Review

Dementia has become a major health concern for the aging population of the United States. Studies indicate that participation in moderate exercise, with training, has been shown to have a beneficial impact on cognition. Thus, exercise and its effects on cognitive function has become an important area of research. This review summarizes the current literature on the potential mechanisms of the benefits of exercise for cognitive function.

The interactive effects of acute exercise and hypoxia on cognitive performance: A narrative review

Acute moderate intensity exercise has been shown to improve cognitive performance. In contrast, hypoxia is believed to impair cognitive performance. The detrimental effects of hypoxia on cognitive performance are primarily dependent on the severity and duration of exposure. In this review, we describe how acute exercise under hypoxia alters cognitive performance, and propose that the combined effects of acute exercise and hypoxia on cognitive performance are mainly determined by interaction among exercise intensity and duration, the severity of hypoxia, and duration of exposure to hypoxia. We discuss the physiological mechanism(s) of the interaction and suggest that alterations in neurotransmitter function, cerebral blood flow, and possibly cerebral metabolism are the primary candidates that determine cognitive performance when acute exercise is combined with hypoxia. Furthermore, acclimatization appears to counteract impaired cognitive performance during prolonged exposure to hypoxia although the precise physiological mechanism(s) responsible for this amelioration remain to be elucidated. This review has implications for sporting, occupational, and recreational activities at terrestrial high altitude where cognitive performance is essential. Further studies are required to understand physiological mechanisms that determine cognitive performance when acute exercise is performed in hypoxia.

Exercise intensity-dependent effects of arm and leg-cycling on cognitive performance

Physiological responses to arm and leg-cycling are different, which may influence psychological and biological mechanisms that influence post-exercise cognitive performance. The aim of this study was to determine the effects of maximal and submaximal (absolute and relative intensity matched) arm and leg-cycling on executive function. Thirteen males (age, 24.7 ± 5.0 years) initially undertook two incremental exercise tests to volitional exhaustion for arm-cycling (82 ± 18 W) and leg-cycling (243 ± 52 W) for the determination of maximal power output. Participants subsequently performed three 20-min constant load exercise trials: (1) arm-cycling at 50% of the ergometer-specific maximal power output (41 ± 9 W), (2) leg-cycling at 50% of the ergometer-specific maximal power output (122 ± 26 W), and (3) leg-cycling at the same absolute power output as the submaximal arm-cycling trial (41 ± 9 W). An executive function task was completed before, immediately after and 15-min after each exercise test. Exhaustive leg-cycling increased reaction time (p < 0.05, d = 1.17), while reaction time reduced following exhaustive arm-cycling (p < 0.05, d = -0.62). Improvements in reaction time were found after acute relative intensity arm (p < 0.05, d = -0.76) and leg-cycling (p < 0.05, d = -0.73), but not following leg-cycling at the same absolute intensity as arm-cycling (p > 0.05). Improvements in reaction time following arm-cycling were maintained for at least 15-min post exercise (p = 0.008, d = -0.73). Arm and leg-cycling performed at the same relative intensity elicit comparable improvements in cognitive performance. These findings suggest that individuals restricted to arm exercise possess a similar capacity to elicit an exercise-induced cognitive performance benefit.

The effects of cardiorespiratory fitness on executive function and prefrontal oxygenation in older adults

Reviews on cardiovascular fitness and cognition in older adults suggest that a higher level of cardiorespiratory fitness may protect the brain against the effects of aging. Although studies reveal positive effects of cardiorespiratory fitness on executive function, more research is needed to clarify the underlying mechanisms of these effects in older adults. The aim of the current study was to assess the association between cardiorespiratory fitness level, cerebral oxygenation, and cognitive performance in older adults (OAs). Seventy-four OAs (68 ± 6.3 years) gave their written, informed consent to participate in the study. Complete data was collected from 66 participants. All participants underwent a cycle ergometer maximal continuous graded exercise test in order to assess their peak power output (PPO) and a neuropsychological paper and pencil tests (Trail Making Test A and B) while changes in left prefrontal cortex oxygenation were measured with functional near-infrared spectroscopy (fNIRS). The results reveal increased cardiorespiratory fitness was associated with decreased response time (i.e., better performance) on the Trail Making Test (B) (standardized β = - 0.42, p < 0.05). Cerebral oxygenation in higher fit older adults mediated the relationship with improved executive functioning (standardized β = - 0.08, p < 0.05). Specifically, in older adults with higher cardiorespiratory fitness (based on a median split), cerebral oxygenation was related to executive functioning but no such relationship existed in lower fit adults.

Decrease in Attentional Performance After Repeated Bouts of High Intensity Exercise in Association-Football Referees and Assistant Referees

Referees and assistant referees are submitted to high physical stress during matches. Pressure to make decisions in front of large crowds is another potential stressor. These two stressors can impair attention executive control, depending on physical fitness and individual vulnerability or resilience to situational pressure. Error percentage for referees and assistants may reach around 14% during a soccer match. Although previous studies have suggested that soccer referees and assistants should take cognitive assessments, they are only required by Fédération Internationale de Football Association (FIFA) to demonstrate knowledge of the rules and pass annually in a fitness test (FIFA-Test). This study aimed to assess attention performance in referees and assistants before and after the mandatory FIFA-Test. It is hypothesized that the high physical demands associated with the pressure to pass the FIFA-Test would interfere with attention performance. The sample included 33 referees and 20 assistants. The Continuous Visual Attention Test (CVAT) consisted of a 15-min Go/No-go task. Performance in the CVAT is based on four variables: omission and commission errors, reaction time, and variability of reaction time (VRT). Failure in the CVAT was defined by a performance below the 5th percentile of the age- and sex-matched normative data in at least one variable of the CVAT. Before the FIFA-Test all participants performed the CVAT. The second CVAT began 3-7 min directly following completion of the FIFA-test. Considering only the officials who passed both the FIFA-Test and the first CVAT (19 referees and 15 assistants), 44% (9 referees and 6 assistants) exhibited a performance decline in the second CVAT. A significant increase in VRT was found after the high intensity exercise. As increase in VRT is thought to reflect executive dysfunctions and lapses of attention, we concluded that physical fitness alone may not be enough to help officials cope with the physical and contextual stresses associated with the FIFA-Test. These data suggest that over 35% of soccer referees and their assistants who were considered physically able to referee matches may not be mentally prepared for the attentional demands of refereeing soccer matches.

Transcranial Direct Current Stimulation over the Left Dorsolateral Prefrontal Cortex Improves Inhibitory Control and Endurance Performance in Healthy Individuals

The dorsolateral prefrontal cortex (DLPFC) is a crucial brain region for inhibitory control, an executive function essential for behavioral self-regulation. Recently, inhibitory control has been shown to be important for endurance performance. Improvement in inhibitory control was found following transcranial direct current stimulation (tDCS) applied over the left DLPFC (L-DLPFC). This study examined the effect tDCS on both an inhibitory control and endurance performance in a group of healthy individuals. Twelve participants received either real tDCS (Real-tDCS) or placebo tDCS (Sham-tDCS) in randomized order. The anodal electrode was placed over the L-DLPFC while the cathodal electrode was placed above Fp2. Stimulation lasted 30min with current intensity set at 2mA. A Stroop test was administered to assess inhibitory control. Heart rate (HR), ratings of perceived exertion (RPE), and leg muscle pain (PAIN) were monitored during the cycling time to exhaustion (TTE) test, while blood lactate accumulation (∆B[La^-]) was measured at exhaustion. Stroop task performance was improved after Real-tDCS as demonstrated by a lower number of errors for incongruent stimuli (p=0.012). TTE was significantly longer following Real-tDCS compared to Sham-tDCS (p=0.029, 17±8 vs 15±8min), with significantly lower HR (p=0.002) and RPE (p<0.001), while no significant difference was found for PAIN (p>0.224). ∆B[La^-] was significantly higher at exhaustion in Real-tDCS (p=0.040). Our findings provide preliminary evidence that tDCS with the anodal electrode over the L-DLPFC can improve both inhibitory control and endurance cycling performance in healthy individuals.

Impact of Carbohydrate Ingestion on Cognitive Flexibility and Cerebral Oxygenation during High-Intensity Intermittent Exercise: A Comparison between Maple Products and Usual Carbohydrate Solutions

BACKGROUND

The aim of this study was to compare the effects of carbohydrate (CHO) drinks (6% per volume) sweetened with maple (syrup or sap) to a commercial sports drink, glucose, and a control solution (water) on cognitive flexibility during high-intensity intermittent exercise.

METHODS

Eighty-five active men completed six 3-min bouts at 95% of their maximal aerobic power on a stationary bike, with 3 min of passive rest between efforts. Subjects were randomly allocated to an ingestion condition. Following each exercise bout, subjects ingested 166 mL of the experimental solution, drinking a total of 1 L of the same solution throughout the experimentation. Cognitive flexibility was measured using reaction time and accuracy on the Stroop task. The cognitive task was performed a total of 10 times, including 15 and 30 min post-exercise. Glycemia and cerebral oxygenation were also measured at each time point. Statistical analyses were performed using a two-way ANOVA (Condition × Time) with repeated measures.

RESULTS

The ingestion of maple products and the commercial sports drink led to a lesser increase in glycemia than glucose ingestion. CHO ingestion, when compared to water, induced a slight reduction in reaction times on the cognitive task, especially in the switching trials. CHO ingestion had no impact on cerebral oxygenation.

CONCLUSIONS

This study shows that CHO ingestion, regardless of its type, tends to improve cognitive performance throughout exercise, especially during difficult cognitive tasks.

Enhancing Children's Motor Memory Retention Through Acute Intense Exercise: Effects of Different Exercise Durations

Physical exercise has been proposed as a viable means to stimulate motor learning. Exercise characteristics, including intensity and duration, may play a role in modulating the exercise effect on motor learning. While some evidence exists regarding the benefits of intense and relatively long exercise, little is known about the effect of short exercise bouts on motor learning, especially in children. This study aimed to assess the effect of long versus short intense exercise bouts on the adaptation and consolidation of a rotational visuomotor adaptation task. The participants were 71 healthy children from two sites divided into three groups: long exercise bout (LONG), short exercise bout (SHORT), and no exercise (CON). Children performed a rotated (clockwise 60° rotation) motor task on four different occasions: an adaptation set and 1 h, 24 h, and 7 days delayed retention sets. Exercise bouts were performed prior to the adaptation set. Results showed a group effect during motor adaptation [F(2,68) = 3.160; p = 0.049; η p 2 = 0.087], but no statistical differences were found between groups. Regarding retention tests, both exercise groups (LONG and SHORT) showed superior retention compared to CON group [F(2,68) = 7.102; p = 0.002; η p 2 = 0.175]. No differences were found between exercise groups, indicating similar benefits for the two exercise interventions. Overall, whether the exercise duration was long or short, exercise improved motor memory retention as an estimate of memory consolidation process. The use of short exercise bouts may be suitable to improve children's motor memory consolidation in environments where time constraints exist.

Intensity-Dependent Effects of Acute Exercise on Executive Function

Numerous studies suggest beneficial effects of aerobic exercise at moderate intensity on cognition, while the effects of high-intensity exercise are less clear. This study investigated the acute effects of exercise at moderate and high intensities on executive functions in healthy adults, including functional MRI to examine the underlying neural mechanisms. Furthermore, the association between exercise effects and cardiorespiratory fitness was examined. 64 participants performed in two executive function tasks (flanker and Go/No-go tasks), while functional MR images were collected, following two conditions: in the exercise condition, they cycled on an ergometer at either moderate or high intensity (each n = 32); in the control condition, they watched a movie. Differences in behavioral performance and brain activation between the two conditions were compared between groups. Further, correlations between cardiorespiratory fitness and exercise effects on neural and behavioral correlates of executive performance were calculated. Moderate exercise compared to high-intensity exercise was associated with a tendency towards improved behavioral performance (sensitivity index d') in the Go/No-go task and increased brain activation during hit trials in areas related to executive function, attention, and motor processes (insula, superior frontal gyrus, precentral gyrus, and supplementary motor area). Exercise at high intensity was associated with decreased brain activation in those areas and no changes in behavioral performance. Exercise had no effect on brain activation in the flanker task, but an explorative analysis revealed that reaction times improved after high-intensity exercise. Higher cardiorespiratory fitness was correlated with increased brain activation after moderate exercise and decreased brain activation after high-intensity exercise. These data show that exercise at moderate vs. high intensity has different effects on executive task performance and related brain activation changes as measured by fMRI and that cardiorespiratory fitness might be a moderating factor of acute exercise effects. Thus, our results may contribute to further clarify the neurophysiological mechanisms underlying the beneficial effects of exercise on cognition.

No evidence of the effect of cognitive load on self-paced cycling performance

Objectives

To test the hypothesis that cognitive load (low vs. high load) during a 20 min self-paced cycling exercise affects physical performance.

Design

A pre-registered (https://osf.io/qept5/), randomized, within-subject design experiment.

Methods

28 trained and experienced male cyclists completed a 20 min self-paced cycling time-trial exercise in two separate sessions, corresponding to two working memory load conditions: 1-back or 2-back. We measured power output, heart rate, RPE and mental fatigue.

Results

Bayes analyses revealed extreme evidence for the 2-back task being more demanding than the 1-back task, both in terms of accuracy (BF₁₀ = 4490) and reaction time (BF = 1316). The data only showed anecdotal evidence for the alternative hypothesis for the power output (BF₁₀ = 1.52), moderate evidence for the null hypothesis for the heart rate (BF₁₀ = 0.172), anecdotal evidence for RPE (BF₁₀ = 0.72) and anecdotal evidence for mental fatigue (BF₁₀ = 0.588).

Conclusions

Our data seem to challenge the idea that self-paced exercise is regulated by top-down processing, given that we did not show clear evidence of exercise impairment (at the physical, physiological and subjective levels) in the high cognitive load condition task with respect to the low working memory load condition. The involvement of top-down processing in self-pacing the physical effort, however, cannot be totally discarded. Factors like the duration of the physical and cognitive tasks, the potential influence of dual-tasking, and the participants’ level of expertise, should be taken into account in future attempts to investigate the role of top-down processing in self-paced exercise.