Jennifer L. Etnier

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.

A Comprehensive Review of Health Benefits of Qigong and Tai Chi

Objective. Research examining psychological and physiological benefits of Qigong and Tai Chi is growing rapidly. The many practices described as Qigong or Tai Chi have similar theoretical roots, proposed mechanisms of action, and expected benefits. Research trials and reviews, however, treat them as separate targets of examination. This review examines the evidence for achieving outcomes from randomized controlled trials (RCTs) of both. Data Sources. The key words Tai Chi, Taiji, Tai Chi Chuan, and Qigong were entered into electronic search engines for the Cumulative Index for Allied Health and Nursing (CINAHL), psychological literature (PsycINFO), PubMed, Cochrane database, and Google Scholar. Study Inclusion Criteria. RCTs reporting on the results of Qigong or Tai Chi interventions and published in peer-reviewed journals from 1993 to 2007. Data Extraction. Country, type and duration of activity, number/type of subjects, control conditions, and reported outcomes were recorded for each study. Synthesis. Outcomes related to Qigong and Tai Chi practice were identified and evaluated. Results. Seventy-seven articles met the inclusion criteria. The nine outcome category groupings that emerged were bone density (n = 4), cardiopulmonary effects (n = 19), physical function (n = 16), falls and related risk factors (n = 23), quality of life (n = 17), self-efficacy (n = 8), patient-reported outcomes (n = 13), psychological symptoms (n = 27), and immune function (n = 6). Conclusions. Research has demonstrated consistent, significant results for a number of health benefits in RCTs, evidencing progress toward recognizing the similarity and equivalence of Qigong and Tai Chi.

Physical Activity, Fitness, Cognitive Function, and Academic Achievement in Children: A Systematic Review.

BACKGROUND The relationship among physical activity (PA), fitness, cognitive function, and academic achievement in children is receiving considerable attention. The utility of PA to improve cognition and academic achievement is promising but uncertain; thus, this position stand will provide clarity from the available science. OBJECTIVE The purpose of this study was to answer the following questions: 1) among children age 5-13 yr, do PA and physical fitness influence cognition, learning, brain structure, and brain function? 2) Among children age 5-13 yr, do PA, physical education (PE), and sports programs influence standardized achievement test performance and concentration/attention? STUDY ELIGIBILITY CRITERIA This study used primary source articles published in English in peer-reviewed journals. Articles that presented data on, PA, fitness, or PE/sport participation and cognition, learning, brain function/structure, academic achievement, or concentration/attention were included. DATA SOURCES Two separate searches were performed to identify studies that focused on 1) cognition, learning, brain structure, and brain function and 2) standardized achievement test performance and concentration/attention. PubMed, ERIC, PsychInfo, SportDiscus, Scopus, Web of Science, Academic Search Premier, and Embase were searched (January 1990-September 2014) for studies that met inclusion criteria. Sixty-four studies met inclusion criteria for the first search (cognition/learning/brain), and 73 studies met inclusion criteria for the second search (academic achievement/concentration). STUDY APPRAISAL AND SYNTHESIS METHODS Articles were grouped by study design as cross-sectional, longitudinal, acute, or intervention trials. Considerable heterogeneity existed for several important study parameters; therefore, results were synthesized and presented by study design. RESULTS A majority of the research supports the view that physical fitness, single bouts of PA, and PA interventions benefit childrens cognitive functioning. Limited evidence was available concerning the effects of PA on learning, with only one cross-sectional study meeting the inclusion criteria. Evidence indicates that PA has a relationship to areas of the brain that support complex cognitive processes during laboratory tasks. Although favorable results have been obtained from cross-sectional and longitudinal studies related to academic achievement, the results obtained from controlled experiments evaluating the benefits of PA on academic performance are mixed, and additional, well-designed studies are needed. LIMITATIONS Limitations in evidence meeting inclusion criteria for this review include lack of randomized controlled trials, limited studies that are adequately powered, lack of information on participant characteristics, failure to blind for outcome measures, proximity of PA to measurement outcomes, and lack of accountability for known confounders. Therefore, many studies were ranked as high risk for bias because of multiple design limitations. CONCLUSIONS The present systematic review found evidence to suggest that there are positive associations among PA, fitness, cognition, and academic achievement. However, the findings are inconsistent, and the effects of numerous elements of PA on cognition remain to be explored, such as type, amount, frequency, and timing. Many questions remain regarding how to best incorporate PA within schools, such as activity breaks versus active lessons in relation to improved academic achievement. Regardless, the literature suggests no indication that increases in PA negatively affect cognition or academic achievement and PA is important for growth and development and general health. On the basis of the evidence available, the authors concluded that PA has a positive influence on cognition as well as brain structure and function; however, more research is necessary to determine mechanisms and long-term effect as well as strategies to translate laboratory findings to the school environment. Therefore, the evidence category rating is B. The literature suggests that PA and PE have a neutral effect on academic achievement. Thus, because of the limitations in the literature and the current information available, the evidence category rating for academic achievement is C.

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.

Motor performance and motor learning as a function of age and fitness.

Past studies have shown that electroencephalographic alpha activity increases as people learn to perform a novel motor task. Additionally, it has been suggested that motor performance and learning decline as people age beyond 60 years, and it has been hypothesized that physical fitness may attenuate this decline through its impact on the cerebral environment. This study was designed to replicate past research by assessing changes in alpha activity as a function of learning and to extend past research by examining differences in motor performance, motor learning, and alpha activity as a function of age and fitness. VO2max was assessed in 41 older (ages 60-80 years) and 42 younger (ages 20-30 years) participants. Participants were randomly assigned to experimental or control conditions, which differed in the amount of practice received. Participants performed trials on the mirror star trace on both an acquisition and a retention day. Results indicated that younger participants performed better and had greater learning than older participants. Fitness was not found to impact either performance or learning. Participants in the experimental group improved more than those in the control group and maintained this difference at retention, which suggests that learning occurred. Associated with these improvements in performance capabilities was an increase in alpha power.

Fluid intelligence in an older COPD sample after short- or long-term exercise

PURPOSE Research supports an association between aerobic fitness and cognitive functioning in chronic obstructive pulmonary disease (COPD) patients. However, the impact of exercise intervention duration has not been satisfactorily examined. Therefore, the purpose of this study was to examine the effects of a 3-month and an 18-month exercise intervention on the cognitive functioning of an older COPD sample. METHODS COPD patients (56-80 yr) were given a 3-month exercise program and then were randomly assigned to continue for an additional 15 months (long-term group) or to leave the exercise program (short-term group). Age and education were assessed before involvement in the exercise intervention (baseline). Fluid intelligence, pulmonary function, aerobic fitness, and depression were assessed at baseline, at 3 months, and at 18 months. RESULTS After 3 months of exercise, results indicated that cognitive function and walk distance improved significantly. Results also indicated that the gain in cognitive function was reliably predicted by the decrease in VE at VO2peak. At 18 months, results indicated that cognitive performance did not differ between the short- and long-term exercise groups, but that walk distance improved significantly for the long-term group, but not for the short-term group. Results of a regression analysis showed that the cognitive performance improvement from 3 months to 18 months was predicted by the gain in walk distance and by the decrease in VE at VO2peak. CONCLUSION It is concluded that improvements in aerobic fitness are associated with gains in fluid intelligence after 3 and 18 months of exercise training in COPD patients. However, at 18 months, exercise group was not predictive of the gains in cognitive performance. Therefore, a 3-month exercise program may be a sufficient impetus to foster these cognitive gains in COPD patients.

Dose-response relation between exercise duration and cognition.

PURPOSE The study aimed to provide evidence-based recommendations for the prescription of a single session of exercise to improve cognitive performance. In particular, the purpose was to determine the dose-response relation between exercise duration and cognitive performance for a moderate-intensity session of aerobic exercise. METHODS Twenty-six healthy young men participated in a reading control treatment and three exercise treatments presented in a random order. The exercise treatments were designed on the basis of the American College of Sports Medicine guidelines and consisted of a 5-min warm-up, a 5-min cooldown, and cycling at moderate intensity (approximately 65% HR reserve) for 10, 20, or 45 min. The Stroop test was administrated after completion of each assigned treatment. RESULTS Exercise at moderate intensity for 20 min resulted in significantly better cognitive performance, as assessed by shorter response time and higher accuracy. This result was found regardless of the type of cognitive function assessed. In addition, a curvilinear dose-response relation between exercise duration and cognitive performance was observed. CONCLUSIONS An exercise session consisting of a 5-min warm-up, 20 min of moderate-intensity exercise, and a 5-min cooldown improves cognition, whereas shorter or longer durations of moderate exercise have negligible benefits. This study provides the foundation for the prescription of a single session of moderate exercise to facilitate cognitive function in healthy younger adults.

Exploring the Relationship Between Exercise-Induced Arousal and Cognition Using Fractionated Response Time

Although a generally positive effect of acute exercise on cognitive performance has been demonstrated, the specific nature of the relationship between exercise-induced arousal and cognitive performance remains unclear. This study was designed to identify the relationship between exercise-induced arousal and cognitive performance for the central and peripheral components of a response time task at two different levels of task difficulty. Sixteen male participants performed both simple and choice response time tasks at eight different arousal levels (from 20% to 90% heart rate reserve). Performance on the simple and choice response time tasks was examined after fractionating the response time into its central component, premotor time, and peripheral components, motor, and movement time. A priori trend analysis was used to test both linear and quadratic relationships. Results indicated that exercise-induced arousal has a positive influence on the peripheral components of response time tasks; however, it has a limited impact on the central components of these tasks.

Navigational Aids and Learner Control in Hypermedia Instructional Programs

This study examined the effects of learner control and navigational aids on performance in a hypermedia instructional program. Results indicated that students who were permitted to move freely within the program and had access to navigational aids, interacted more with the program and this was associated with higher performance on the posttest. The findings revealed that students who had control over the sequence of their instruction deviated from a linear path significantly more often when provided with navigational aids such as those used in this study. Navigational aids may provide a structure that promotes more explanatory behavior or interaction for students under learner control conditions.