Lack of effects of acute exercise intensity on mnemonic discrimination.

The hippocampus is thought to support episodic memory by pattern separation, thereby supporting the ability to discriminate high similarity items. Past research evaluating whether acute exercise can improve mnemonic discrimination of high similarity items is mixed. The present experiment attempts to extend these prior mixed findings by evaluating the effects of multiple exercise intensities on hippocampal-dependent, mnemonic discrimination and memory performance. Fifty-seven young adults completed a three-condition (control, moderate-intensity, and vigorous-intensity), within-subjects crossover pretest-posttest comparison. We observed no effects of acute exercise on recognition memory or mnemonic discrimination. We discuss the implications of these null findings with the broader literature by discussing the complexity of this potential exercise-mnemonic discrimination relationship, including the unique role of exercise intensity, differences in the level of processing (e.g., conceptual vs. perceptual), and unique brain regions involved in mnemonic discrimination.

Age-varying association between depression and cognitive function among a national sample of older U.S. immigrant adults: the potential moderating role of physical activity.

OBJECTIVES: This study aimed to (1) investigate age-associated trends in depression and cognition, (2) determine whether the association between depression and cognition varies across age, and (3) test whether this association is moderated by different levels of physical activity among older U.S. immigrant adults aged 60 to 80 years. METHODS: Using national data on elderly U.S. immigrants (N = 375) from the 2011-2014 NHANES, we employed weighted intercept-only linear time-varying effect modeling (TVEM) and weighted linear TVEM to address our research questions. RESULTS: Weighted intercept-only linear TVEM indicated no trend in depression, but its mean peaked at age 67. Cognition consistently decreased with age, reaching its lowest point at age 78. Weighted linear TVEM revealed a significant inverse association between depression and cognition at some age ranges, with the strongest association at around age 66. Yet, we did not find the moderational relation of physical activity to this age-varying association. CONCLUSIONS: Although we observed a significant inverse relationship between depression and cognition at a certain age point, physical activity did not moderate the age-varying association. Understanding of age-varying effects on the depression-cognition interaction will promote prevention efforts targeting aging immigrant populations at highest risk for these health outcomes. Further work is needed to test moderating effects of other health behaviors on this association across age.Supplemental data for this article is available online at https://doi.org/10.1080/13607863.2022.2056139 .

Effects of acute exercise on memory: Considerations of exercise intensity, post-exercise recovery period and aerobic endurance.

Accumulating research demonstrates that acute exercise can enhance long-term episodic memory. However, it is unclear if there is an intensity-specific effect of acute exercise on long-term episodic memory function and whether this is influenced by the post-exercise recovery period, which was the primary objective of this experiment. Another uncertainty in the literature is whether aerobic endurance influences the interaction between exercise intensity and post-exercise recovery period on long-term episodic memory function, which was a secondary objective of this study. With exercise intensity and post-exercise recovery period occurring as within-subject factors, and fitness as a between-subject factor, 59 participants (Mage = 20 years) completed 12 primary laboratory visits. These visits included a 20-min bout of exercise (Control, Moderate, and Vigorous), followed by a recovery period (1, 5, 10, and 15 min) and then a word-list episodic memory task, involving an encoding phase and two long-term recall assessments (20-min and 24-h delayed recall). The primary finding from this experiment was that moderate and vigorous-intensity exercise improved memory function when compared to a non-exercise control. A secondary finding was that individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, had greater memory performance after exercise (moderate or vigorous) when compared to after a control condition. Additionally, individuals with higher levels of aerobic endurance, compared to their lesser fit counterparts, generally performed better on the memory task with longer post-exercise recovery periods. Future research should carefully consider these parameters when evaluating the effects of acute exercise on long-term episodic memory.

Individuals with hypertension have lower plasma volume regardless of weight status.

Increased plasma volume is often reported as a cause or symptom of hypertension in individuals with obesity. However, these individuals are often compared to normal weight normotensive individuals. Since higher plasma volumes have been reported in larger individuals, it is possible that plasma volume is actually lower in obese hypertensive individuals compared to normotensive obese individuals. This may be important for better understanding the clinical manifestation of hypertension between weight categories. National Health and Nutritional Examination Survey (cycles 1999-2018) data were used to examine the relationship between plasma (derived from the Straus formula), blood pressure (measured with an automated device) and body mass index. We observed an inverse relationship between estimated plasma volume and systolic (B = -1.68 (95% CI: -2.06, -1.30) mmHg), p < 0.0001), diastolic (B = -3.35 (95% CI: -3.61, -3.08) mmHg) p < 0.0001), and mean arterial pressure (B = -2.79 (95% CI: -3.05, -2.53) mmHg) p < 0.0001). The relationship between estimated plasma volume and diastolic blood pressure (interaction term: B = -0.069 (-0.10, -0.03), p < 0.0001) did depend on BMI. The "normal weight" group had the lowest slope and this slope was significantly different from the "obese" (B = -1.47 (95% CI: -1.88, -1.07)) and "overweight" (B = -1.11 (-1.55, -0.67)) groups. Plasma volume is lower in hypertensive individuals regardless of weight status, but this relationship is more pronounced among obese individuals.

Acute exercise on memory: application of the retrieval-induced forgetting paradigm.

Accumulating research has shown that acute exercise can enhance memory function. Although counterintuitive, acute exercise may also facilitate aspects of forgetting. Specifically, retrieving a subset of items from memory can facilitate the retention of retrieved items (retrieval practice) and inhibit the subsequent retrieval of non-retrieved items from the same category (retrieval-induced forgetting; RIF). Given that acute exercise has been shown to enhance cognition-related inhibition, acute exercise may facilitate RIF, which was evaluated in three experiments. In Experiment 1, a sample of 180 young adults completed either a control (N = 60), moderate-intensity acute exercise (N = 57), or vigorous-intensity acute exercise session (N = 63). Both acute exercise sessions lasted 20 min and occurred prior to the study list. Participants then completed a standard RIF protocol, with the final test occurring via a recognition task. Acute exercise, regardless of intensity, had no effect on RIF. Experiment 2 (N = 225) was similar to Experiment 1 but used a cued recall final test, and also showed no effects of acute exercise on RIF. In Experiment 3 (N = 158), two cued recall tests were implemented, with acute exercise occurring between the two tests. Acute exercise, but not a control scenario, preserved the RIF effect across the cued recall assessments. These findings suggest that acute exercise prior to study may not influence RIF, but when positioned between two recall assessments, acute exercise may preserve the RIF effect over time.

Association Between Estimated Pulse Wave Velocity and Cognitive Performance in Older Black and White Adults in NHANES.

BACKGROUND: Aging-associated cognitive decline is greater in non-Hispanic Black (NHB) adults than non-Hispanic White (NHW) adults. An important risk factor for cognitive decline with aging is arterial stiffening, though the importance to racial variation remains poorly understood. OBJECTIVE: We examined the association of an estimate of arterial stiffness with cognitive function in a bi-racial sample of 60-85-year-old adults (N = 3,616, 26.5% NHB) enrolled in the National Health and Nutrition Examination Survey (NHANES) between 1999-2002 and 2011-2014. METHODS: As a measure of vascular aging, pulse wave velocity was estimated (ePWV) using an equation incorporating age and mean arterial pressure and expressed as m/s. Using the digit symbol substitution test (DSST), cognitive function was expressed as the number of correctly matched symbols (out of 133) within 120 s. Linear regression models examined associations between ePWV and DSST. RESULTS: In models that adjusted for sex, education, smoking, body mass index, history of cardiovascular disease, and hypertension, ePWV was inversely associated with DSST score in NHB adults (ß= -3.47, 95% CI = -3.9 to -3.0; p < 0.001) and NHW adults (ß= -3.51, 95% CI = -4.4 to -2.6; p < 0.001). CONCLUSION: ePWV is inversely associated with a measure of cognitive function in older Black and White adults. ePWV may be a useful measure of vascular aging that can offer insight into cognitive aging.

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.

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.

Motor behavior-induced prefrontal cortex activation and episodic memory function.

BACKGROUND: The objective of this paper was to evaluate the potential individual and combined effects of acute exercise coupled with bilateral interhemispheric activation on episodic memory function. Six experiments were conducted. METHODS: Experiment 1 was a within-subject, counterbalanced experiment. Participants completed four visits, including 1) exercise and saccadic eye movements, 2) exercise only, 3) saccadic eye movements only, and 4) no exercise and no saccadic eye movements (control). A word-list memory assessment was employed, including a long-term (20-min delay) memory evaluation. In Experiment 2, we evaluated the effects of saccadic eye movements on prefrontal cortex oxygenation, a proxy for neuronal activity. Similarly, in our third experiment, we evaluated the effects of acute exercise on prefrontal cortex oxygenation. Thus, experiments 2 and 3 were employed to provide mechanistic insights from the results shown in experiment 1. Experiment 4 replicated Experiment 1, but instead of increasing prefrontal cortex activation via saccadic eye movements, we used a fist clenching protocol. Experiment 5 evaluated the effects of fist clenching on prefrontal cortex oxygenation. RESULTS: Collectively, these 5 experimental studies showed that acute exercise (Experiment 1), saccadic eye movements (Experiment 1), and fist clenching (Experiment 4) enhanced memory function, and that acute exercise (Experiment 3), saccadic eye movements (Experiment 2) and fist clenching (Experiment 5) all increased prefrontal cortex oxygenation. Experiment 6 demonstrated that prefrontal cortex oxygenation was positively associated with episodic memory function. CONCLUSION: These six experiments suggest that several behaviors, such as acute exercise, saccadic eye movements and fist clenching may improve memory function and may, potentially, do so via increases in prefrontal cortex oxygenation.

Association among length of residence, physical activity, and obesity in the US immigrants: A regression-based mediation analysis.

OBJECTIVES: To examine the mediated relationship between objectively measured obesity, accelerometer-based moderate-to-vigorous physical activity (MVPA), and length of residence among US immigrants. METHODS: A total of 885 adults (≥18 years) who were born outside the United States from the 2003 to 2006 National Health and Nutrition Examination Survey were included in the analysis. The participants were categorized into two groups (i.e., living in the United States ≥15 years vs. <15 years). MVPA time (minutes/day) was measured by ActiGraph accelerometry. Obesity was defined as body fat percentage measured by dual-energy X-ray absorptiometry. Regression-based mediation analysis was conducted using SURVEY procedures in SAS version 9.4. RESULTS: When controlling for covariates, immigrants living in the United States for ≥15 years were significantly less likely to spend time participating in MVPA (c; ß = -4.50, p = .04), and more likely to be at high risk of obesity (a; ß = 1.70, p = .01) compared to those living in the United States for <15 years. Also, the relationship between obesity and MVPA was statistically significant (b; ß = -0.80, p = .003). Length of residence was indirectly associated with MVPA (ab; ß = -1.37, p = .03), suggesting that obesity mediated the association of length of residence on MVPA (c'; ß = -3.13, p = .20). CONCLUSIONS: Obesity mediated the association between length of residence and MVPA in the US immigrants. These findings may encourage long-term US immigrants to prevent and treat obesity for increasing the amount of MVPA time.

Evaluation of the transient hypofrontality theory in the context of exercise: A systematic review with meta-analysis.

Accumulating research suggests that, as a result of reduced neural activity in the prefrontal cortex (PFC), higher-order cognitive function may be compromised while engaging in high-intensity acute exercise, with this phenomenon referred to as the transient hypofrontality effect. However, findings in this field remain unclear and lack a thorough synthesis of the evidence. Therefore, the purpose of this meta-analysis was to evaluate the effects of in-task acute exercise on cognitive function, and further, to examine whether this effect is moderated by the specific type of cognition (i.e., PFC-dependent vs. non-PFC-dependent). Studies were identified by electronic databases in accordance with the PRISMA guidelines. In total, 22 studies met our inclusion criteria and intercept only meta-regression models with robust variance estimation were used to calculate the weighted average effect sizes across studies. Acute exercise at all intensities did not influence cognitive function (ß = -0.16, 95% CI = [-0.58, 0.27], p = .45) when exercise occurred during the cognitive task, and no significant moderation effects emerged. However, there was evidence that cognitive task type (PFC-dependent vs. non-PFC-dependent) moderated the effect of high-intensity acute exercise on a concomitant cognitive performance (ß = -0.81, 95% CI = [-1.60, -0.02], p = .04). Specifically, our findings suggest that PFC-dependent cognition is impaired while engaging in an acute bout of high-intensity exercise, providing support for the transient hypofrontality theory. We discuss these findings in the context of reticular-activating and cognitive-energetic perspectives.

Acute and Chronic Exercise Effects on Human Memory: What We Know and Where to Go from Here.

Although the acquisition, storage, and retrieval of memories was once thought to happen within a single memory system with multiple processes operating on it, it is now believed that memory is comprised of both distinct and interacting brain systems [...].

Association of physical activity on memory interference: Boston Puerto Rican Health Study.

Background : The objective of this study was to evaluate the association between habitual physical activity engagement on memory interference. The present analysis used cross-sectional data from the Boston Puerto Rican Health Study (n=1,241; mean age= 57.2; 72.1% female). Methods : Physical activity was evaluated via self-report. Memory interference was evaluated using a word-list paradigm. The memory task included learning a list of 16 words (List A; 5 trials), followed by a distractor list (List B), and then an immediate recall of List A. Proactive interference occurs when preceding stimuli (e.g., Trial 1 and Trial 5 of List A) interferes with performance on a subsequent stimuli (List B). Retroactive interference occurs when subsequent stimuli (List B) interferes with the recall of previously encoded stimuli (Trial 5). Results : For proactive interference, there was no association between physical activity and the difference between performance on List B and Trial 1 of List A (ß=0.00001; P =0.96). Similarly, for retroactive interference, there was no association between physical activity and the difference between the short delay recall and Trial 5 of List A (ß=0.0002; P=0.50). Conclusion : The present study did not observe an association between habitual physical activity on attenuating memory interference.

The association of self-reported physical activity on human sensory long-term potentiation.

Exercise has been shown to enhance synaptic plasticity, therefore, potentially affecting memory. While the mechanism(s) responsible for this relationship have been explored in animal models, current research suggests that exercise may possess the ability to induce synaptic long-term potentiation (LTP). Most of the LTP mechanistic work has been conducted in animal models using invasive procedures. For that reason, the purpose of the present experiment was to investigate whether self-reported exercise is related to human sensory LTP-like responses. Nineteen participants (MAGE = 24 years; 52.6% male) completed the study. Long-term potentiation-like responses were measured by incorporating a non-invasive method that assess the change in potentiation of the N1b component produced from the visual stimulus paradigm presented bilaterally in the visual field. Results demonstrated that those with higher levels of moderate-to-vigorous physical activity (MVPA) had a greater N1b change from baseline to the early time period assessment, r = -0.43, p = 0.06. Our findings provide some suggestive evidence of an association between self-reported MVPA and LTP-like responses. Additional work is needed to support that the potentiation of the human sensory N1b component in the observed study is due to the exercise-induced synaptic changes similar to that detailed in prior animal research.

Physical Activity, Inflammation, Coronary Artery Calcification, and Incident Coronary Heart Disease in African Americans: Insights From the Jackson Heart Study.

OBJECTIVE: To examine associations between physical activity (PA), inflammation, coronary artery calcification (CAC), and incident coronary heart disease (CHD) in African Americans. METHODS: Among Jackson Heart Study participants without prevalent CHD at baseline (n=4295), we examined the relationships between PA and high-sensitivity C-reactive protein, the presence of CAC (Agatston score ≥100), and incident CHD. Based on the American Heart Association's Life's Simple 7 metrics, participants were classified as having poor, intermediate, or ideal PA. RESULTS: After adjustment for possible confounding factors, ideal PA was associated with lower high-sensitivity C-reactive protein levels (ß, -0.15; 95% CI, -0.15 to -0.002) and a lower prevalence of CAC (odds ratio, 0.70; 95% CI, 0.51-0.96) compared with poor PA. During a median of 12.8 years of follow-up, there were 164 incident CHD events (3.3/1000 person-years). Ideal PA was associated with a lower rate of incident CHD compared with poor PA (hazard ratio, 0.55; 95% CI, 0.31-0.98). CONCLUSION: In a large community-based African American cohort, ideal PA was associated with lower inflammation levels, a lower prevalence of CAC, and a lower rate of incident CHD. These findings suggest that promotion of ideal PA may be an important way to reduce the risk of subclinical and future clinical CHD in African Americans.

The Effects of Acute Exercise on Short- and Long-Term Memory: Considerations for the Timing of Exercise and Phases of Memory.

The specific questions addressed from this research include: (1) Does high-intensity acute exercise improve memory?, (2) If so, do the mechanisms occur via encoding, consolidation, or retrieval? and (3) If acute exercise occurs in multiple phases of memory (e.g., before encoding and during consolidation), does this have an additive effect on memory? Three experimental, within-subject, counterbalanced studies were conducted among young adults. High-intensity exercise involved a 20-minutes bout of exercise at 75% of heart rate reserve. Memory was evaluated from a word-list task, including multiple evaluations out to 24-hours post-encoding. The timing of the exercise and memory assessments were carefully positioned to evaluate whether any improvements in memory were driven by mechanisms related to encoding, consolidation, and/or retrieval. We demonstrated that high-intensity acute exercise enhanced memory. This effect was robust (repeatable) and occurred through encoding, consolidation and retrieval-based mechanisms. Further, incorporating acute exercise into multiple phases of memory additively enhanced memory function.

Effects of acute aerobic and resistance exercise on episodic memory function.

Accumulating research provides suggestive evidence that acute aerobic exercise may, potentially, enhance episodic memory function post-exercise. Limited research has evaluated whether acute resistance exercise may also enhance episodic memory post-exercise. Furthermore, whether these two exercise modalities have a differential effect on post-exercise episodic memory is relatively unknown. To address these research questions, three experimental studies were conducted (N = 104) among young adults (18-25 years). The experiments implemented acute bouts of aerobic or resistance exercise for 15 min. Episodic memory was comprehensively evaluated post-exercise with a list-learning paradigm and a computerised assessment of what-where-when aspects of episodic memory. Various manipulations (e.g., between vs. within-group) of the study design were implemented across the experiments. Across these three experiments, we failed to find consistent evidence of either type of acute exercise affecting episodic memory performance post-exercise.

The Impact of Acute Exercise Timing on Memory Interference.

This study evaluated whether the timing of acute exercise can attenuate a memory interference effect. Across two experiments, participants completed an AB/AC memory task. Participants studied eight word pairs; four denoted AB (e.g., Hero - Apple) and four control (DE) pairs. Following this List 1, participants studied eight additional word pairs (List 2); four denoted AC, re-using words from the AB pairs (e.g., Hero - Project) and four control (FG) pairs. Following their study of both lists, participants completed a cued recall assessment. In Experiment 1 (N = 100), an acute exercise bout occurred before the AB/AC memory interference task, and the participants' three lab visits (successive conditions) were control, moderate-intensity (50% HRR; heart rate reserve) exercise, and vigorous-intensity (80% HRR) exercise. In Experiment 2 (N = 68), the acute exercise occurred between List 1 and List 2, and the participants' two lab visits (successive conditions) were a (80% HRR) vigorous-intensity exercise visit and a control visit. Across both experiments, we observed evidence of both proactive and retroactive interference (p < .05), but acute exercise, regardless of intensity, did not attenuate this interference (p > .05). Acute moderate-intensity exercise was better than control or vigorous-intensity exercise in enhancing associative memory (p < .05), independent of interference. In Experiment 2, vigorous intensity exercise was associated with more pronounced interference (p < .05). Our results suggest that acute exercise can enhance associative memory performance, with no attenuation of interference by exercise.

Serial-multiple mediation of enjoyment and intention on the relationship between creativity and physical activity.

The purpose of the present study was to examine a serial-multiple mediation of physical activity (PA) enjoyment and PA intention in the relationship between creativity and PA level (i.e., moderate-to-vigorous PA). A total of 298 undergraduate and graduate students completed a self-reported questionnaire evaluating creativity, PA enjoyment, PA intention, and PA level. Data analysis was conducted using descriptive statistics, Pearson correlation coefficient, ordinary least-squares regression analysis, and bootstrap methodology. Based on the research findings, both PA enjoyment (ß = 0.06; 95% CI [0.003, 0.12]) and PA intention (ß = 0.08; 95% CI [0.03, 0.13]) were found to be a mediator of the relationship between creativity and PA level, respectively. Moreover, the serial-multiple mediation of PA enjoyment and PA intention in the relationship between creativity and PA level was statistically significant (ß = 0.02; 95% CI [0.01, 0.04]). These findings underscore the importance of shaping both cognitive and affective functions for PA promotion and provide additional support for a neurocognitive affect-related model in the PA domain. In order to guide best practices for PA promotion programs aimed at positively influencing cognition and affect, future PA interventions should develop evidence-based strategies that routinely evaluate cognitive as well as affective responses to PA.

Structural and functional brain signatures of endurance runners.

Although endurance running (ER) seems to be a simple repetitive exercise, good ER performance also requires and relies on multiple cognitive and motor control processes. Most of previous neuroimaging studies on ER were conducted using a single MRI modality, yet no multimodal study to our knowledge has been performed in this regard. In this study, we used multimodal MRI data to investigate the brain structural and functional differences between endurance runners (n = 22; age = 26.27 ± 6.07 years; endurance training = 6.23 ± 2.41 years) and healthy controls (HCs; n = 20; age = 24.60 ± 4.14 years). Compared with the HCs, the endurance runners showed greater gray matter volume (GMV) and cortical surface area in the left precentral gyrus, which at the same time had higher functional connectivity (FC) with the right postcentral and precentral gyrus. Subcortically, the endurance runners showed greater GMV in the left hippocampus and regional inflation in the right hippocampus. Using the bilateral hippocampi as seeds, further seed-based FC analyses showed higher hippocampal FC with the supplementary motor area, middle cingulate cortex, and left posterior lobe of the cerebellum. Moreover, compared with the HCs, the endurance runners also showed higher fractional anisotropy in several white matter regions, involving the corpus callosum, left internal capsule, left corona radiata, left external capsule, left posterior lobe of cerebellum and bilateral precuneus. Taken together, our findings provide several lines of evidence for the brain structural and functional differences between endurance runners and HCs. The current data suggest that these brain characteristics may have arisen as a result of regular ER training; however, whether they represent the neural correlates underlying the good ER performances of the endurance runners requires further investigations.