Jeffrey D. Labban

The effects of acute exercise on cognitive performance: a meta-analysis.

There is a substantial body of literature related to the effects of a single session of exercise on cognitive performance. The premise underlying this research is that physiological changes in response to exercise have implications for cognitive function. This literature has been reviewed both narratively and meta-analytically and, although the research findings are mixed, researchers have generally concluded that there is a small positive effect. The purpose of this meta-analysis was to provide an updated comprehensive analysis of the extant literature on acute exercise and cognitive performance and to explore the effects of moderators that have implications for mechanisms of the effects. Searches of electronic databases and examinations of reference lists from relevant studies resulted in 79 studies meeting inclusion criteria. Consistent with past findings, analyses indicated that the overall effect was positive and small (g=0.097 n=1034). Positive and small effects were also found in all three acute exercise paradigms: during exercise (g=0.101; 95% confidence interval [CI]; 0.041-0.160), immediately following exercise (g=0.108; 95% CI; 0.069-0.147), and after a delay (g=0.103; 95% CI; 0.035-0.170). Examination of potential moderators indicated that exercise duration, exercise intensity, type of cognitive performance assessed, and participant fitness were significant moderators. In conclusion, the effects of acute exercise on cognitive performance are generally small; however, larger effects are possible for particular cognitive outcomes and when specific exercise parameters are used.

The effects of physical activity on attention deficit hyperactivity disorder symptoms: the evidence.

UNLABELLED Evidence supports the beneficial effects of physical activity (PA) on cognitive performance and suggests that effects might be particularly large for children. However, limited research has explored PA as a means of managing behavioral symptoms and improving cognitive performance of children with attention deficit hyperactivity disorder (ADHD). The etiology of ADHD and the putative mechanisms for the effects of PA on cognitive performance suggest that PA might be especially important for this population. OBJECTIVE The purpose of this paper is to review the literature regarding the potential of PA for ADHD symptom management, particularly in regard to behavioral and cognitive symptoms. METHODS Literature was reviewed for published and unpublished research specifically examining the effects of PA on cognitive and/or behavioral symptoms of ADHD. Additionally, potential mechanisms were addressed. RESULTS Albeit limited, current research generally supports the potential for acute and chronic PA to mitigate ADHD symptoms. CONCLUSION Given the generally supportive extant literature and the challenges that face children with ADHD, future research exploring the potential of PA with this population is advocated.

Effects of Acute Exercise on Long-Term Memory

In this study, we tested the effect of acute exercise on long-term memory, specifically the timing of exercise relative to the memory challenge. We assessed memory via paragraph recall, in which participants listened to two paragraphs (exposure) and recounted them following a 35-min delay. Participants (n = 48) were randomly assigned to one of three groups: exercise prior to exposure, exercise after exposure, or no-exercise. Exercise consisted of 30 min on a cycle ergometer, including 20 min at moderate intensity. Only the exercise-prior group recalled significantly more than the control group (p < .05). Differences among the exercise groups failed to reach significance (p = .09). Results indicated that acute exercise positively influenced recall and that exercise timing relative to memory task may have an impact on this effect.

Brothers leading healthy lives: outcomes from the pilot testing of a culturally and contextually congruent HIV prevention intervention for black male college students

We used a treatment group-only design to pilot test a newly developed intervention to increase condom use among higher risk heterosexually active African American/black male college students. A community-based participatory research partnership developed the intervention called Brothers Leading Healthy Lives. Following an initial screening of 245 men, 81 eligible men were contacted for participation. Of the 64 men who agreed to participate, 57 completed the intervention and 54 of those completed the 3-month follow-up assessment, for a 93% completion rate. Results show significant changes between the baseline and 3-month follow-up assessments in behavioral outcomes, including reductions in unprotected sex, increase in protection during last intercourse, and fewer condom use errors. Most potential mediators (knowledge, attitudes, intentions, and condom use self-efficacy) also changed significantly in the expected direction. These demonstrated changes provide good evidence that men exposed to this intervention will see changes that reduce their risk for HIV.

The Effects of Acute Exercise on Memory and Brain-Derived Neurotrophic Factor (BDNF)

Acute exercise benefits cognition, and some evidence suggests that brain-derived neurotrophic factor (BDNF) plays a role in this effect. The purpose of this study was to explore the dose-response relationship between exercise intensity, memory, and BDNF. Young adults completed 3 exercise sessions at different intensities relative to ventilator threshold (Vt) (VO2max, Vt - 20%, Vt + 20%). For each session, participants exercised for approximately 30 min. Following exercise, they performed the Rey Auditory Verbal Learning Test (RAVLT) to assess short-term memory, learning, and long-term memory recall. Twenty-four hours later, they completed the RAVLT recognition trial, which provided another measure of long-term memory. Blood was drawn before exercise, immediately postexercise, and after the 30-min recall test. Results indicated that long-term memory as assessed after the 24-hr delay differed as a function of exercise intensity with the largest benefits observed following maximal intensity exercise. BDNF data showed a significant increase in response to exercise; however, there were no differences relative to exercise intensity and there were no significant associations between BDNF and memory. Future research is warranted so that we can better understand how to use exercise to benefit cognitive performance.

Effects of an acute bout of exercise on memory in 6th grade children

Research supports the positive effects of exercise on cognitive performance by children. However, a limited number of studies have explored the effects specifically on memory. The purpose of this study was to compare the effects of an acute bout of exercise on learning, short-term memory, and long-term memory in a sample of children. Children were randomly assigned to an exercise condition or to a no-treatment control condition and then performed repeated trials on an auditory verbal learning task. In the exercise condition, participants performed the PACER task, an aerobic fitness assessment, in their physical education class before performing the memory task. In the control condition, participants performed the memory task at the beginning of their physical education class. Results showed that participants in the exercise condition demonstrated significantly better learning of the word lists and significantly better recall of the words after a brief delay. There were not significant differences in recognition of the words after an approximately 24-hr delay. These results provide evidence in a school setting that an acute bout of exercise provides benefits for verbal learning and long-term memory. Future research should be designed to identify the extent to which these findings translate to academic measures.

Obesity indices are predictive of elevated C-reactive protein in long-haul truck drivers.

BACKGROUND Obesity rates in long-haul truck drivers have been shown to be significantly higher than the general population. We hypothesized that commercial drivers with the highest levels of general obesity and abdominal adiposity would have higher concentrations of high sensitivity C-reactive protein (CRP), a marker of inflammation. METHODS Survey and anthropometric data were collected from 262 commercial drivers. Weight, circumference measures, and blood analysis for CRP (N = 115) were conducted and compared to National Health and Nutrition Examination Survey (NHANES) data. CRP values were non-normally distributed and logarithmically transformed for statistical analyses. RESULTS BMI, waist circumference, sagittal abdominal diameter, and CRP were significantly higher than in the general population. Anthropometric indices that included height (BMI, waist-to-height ratio, and sagittal diameter-to-height ratio), were most predictive of CRP values. CONCLUSIONS Abdominal obesity is prevalent in commercial vehicle drivers and is an important indicator of the presence of inflammation in this population. Am. J. Ind. Med. 59:665-675, 2016.

The Relationship Between Physical Activity and Perceived Health Status in Older Women: Findings from the Woman’s College Alumni Study

Using data collected from the Woman’s College (WC) Alumni Study, the purpose of this study was to determine whether perceived health status is related to physical activity in older women. A multiple linear regression analysis was conducted to examine the relationship between amounts of physical activity and self-reported health status. The results of the current study reveal that the level of physical activity is significantly correlated with perceived health status. The findings of this study have implications for the assessment of older individuals’ health and may lead to interventions that are tailored to increase physical activity among older women.

Innovative Research Exploring the Effects of Physical Activity and Genetics on Cognitive Performance in Community-Based Older Adults

Physical activity is predictive of better cognitive performance and lower risk of Alzheimers disease (AD). The apolipoprotein E gene (APOE) is a susceptibility gene for AD with the e4 allele being associated with a greater risk of AD. Cross-sectional and prospective research shows that physical activity is predictive of better cognitive performance for those at greater genetic risk for AD. However, the moderating role of APOE on the effects of a physical activity intervention on cognitive performance has not been examined. The purpose of this manuscript is to justify the need for such research and to describe the design, methods, and recruitment tactics used in the conductance of a study designed to provide insight as to the extent to which cognitive benefits resulting from an 8-month physical activity program are differentiated by APOE e4 status. The effectiveness of the recruitment strategies and the feasibility of recruiting APOE e4 carriers are discussed.

Effects of prolonged and repeated immersions on heart rate variability and complexity in military divers

BACKGROUND The influence of prolonged and repeated water immersions on heart rate variability (HRV) and complexity was examined in 10 U.S. Navy divers who completed six-hour resting dives on five consecutive days. Pre-dive and during-dive measures were recorded daily. METHODS Dependent variables of interest were average heart rate (HR), time-domain measures of HRV [root mean square of successive differences of the normal RR (NN) interval (RMSSD), standard deviation of the NN interval (SDNN)], frequency-domain measures of HRV [low-frequency power spectral density (psd) (LFpsd), low-frequency normalized (LFnu), high-frequency psd (HFpsd), high-frequency normalized (HFnu), low-frequency/ high-frequency ratio (LF/HF)], and non-linear dynamics of HRV [approximate entropy (ApEn)]. A repeated-measures ANOVA was performed to examine pre-dive measure differences among baseline measures. Hierarchical linear modeling (HLM) was performed to test the effects of prolonged and repeated water immersion on the dependent variables. RESULTS Pre-dive HR (P=0.005) and RMSSD (P⟨0.001) varied significantly with dive day while changes in SDNN approached significance (P=0.055). HLM indicated that HR decreased during daily dives (P=0.001), but increased across dive days (P=0.011); RMSSD increased during daily dives (P=0.018) but decreased across dive days (P⟨0.001); SDNN increased during daily dives (P⟨0.001); LF measures increased across dive days (LFpsd P⟨0.001; LFnu P⟨0.001), while HF measures decreased across dive days (HFpsd P⟨0.001; HFnu P⟨0.001); LF/HF increased across dive days (P⟨0.001); ApEn decreased during daily dives (P⟨0.02) and across dive days (P⟨0.001). CONCLUSIONS These data suggest that the cumulative effect of repeated dives across five days results in decreased vagal tone and a less responsive cardiovascular system.