Jennifer L. Etnier
In developing a senior lecture for the 2014 national meeting of the North American Society for the Psychology of Sport and Physical Activity, I had the opportunity to reflect upon a career of research and to focus on three interesting questions that my colleagues and I have attempted to address. These questions have led to several studies that all revolve around identifying ways to increase the effects of exercise on cognitive performance. In particular, the questions examine the possibility of increasing effects by focusing on particular populations (e.g., older adults, children) and by increasing our understanding of dose-response relationships between exercise parameters (e.g., intensity, duration) and cognitive outcomes. I present empirical evidence relative to each of these questions and provide directions for future research on physical activity and cognitive functioning.
Jennifer L. Etnier
Jennifer L. Etnier
Alzheimer's disease is a chronic illness characterized by clinical cognitive impairment. A behavioral strategy that is being explored in the prevention of Alzheimer's disease is physical activity. Evidence from randomized controlled trials (RCTs) testing the effects of physical activity for cognitively normal older adults supports that physical activity benefits cognitive performance. Evidence from prospective studies supports a protective effect of physical activity with reductions in the risk of cognitive decline ranging from 28% to 45%. RCTs with cognitively impaired older adults also generally support positive effects with greater benefits evident for aerobic interventions. Research examining the potential moderating role of apolipoprotein E (APOE) has yielded mixed results, but the majority of the studies support that physical activity most benefits those who are at greatest genetic risk of Alzheimer's disease. Future directions for research are considered with an emphasis on the need for additional funding to support this promising area of research.
Jennifer Gapin and Jennifer L. Etnier
Children with attention-deficit hyperactivity disorder (AD/HD) consistently perform worse on executive function (EF) tasks relative to those without AD/HD. Physical activity has a small effect on cognition in children and may be particularly beneficial for children with AD/HD by impacting fundamental EF deficiencies that characterize this disorder. The purpose of this study was to explore the extent to which physical activity is associated with EF in children with AD/HD. Eighteen boys (M age = 10.61, SD = 1.50) with AD/HD were recruited to complete four EF tasks. Physical activity was measured with an accelerometer that provided daily minutes of moderate-to-vigorous intensity physical activity; this measure was a significant predictor of performance on the Tower of London planning task, adjusted R 2 = .28, F(1, 16) = 7.61, p < .05, and was positively associated with other EF measures. These results suggest that higher physical activity is associated with better EF performance in AD/HD children.
SeYun Park and Jennifer L. Etnier
Background: Evidence supports that a single session of exercise has benefits for cognitive performance following exercise. Although the vast majority of research has been conducted with young adults, very few studies to date have tested these effects in adolescents (high school aged students). As executive function (EF) develops through late adolescence and into young adulthood, it is important to assess the extent to which acute exercise benefits EF in adolescents. The primary purpose of this study was to assess the effect of moderate-intensity acute exercise on subsequent EF performance in this population. Methods: Healthy high school students (N = 22; age: 15.90 [0.29] y) volunteered to participate in the study. Using a within-subjects design with order of conditions randomized and counterbalanced, participants performed the Stroop Test, the Symbol Digit Modalities Test, and the Tower of London Test following control and following exercise with sessions performed on different days. Results: Exercise resulted in significant benefits for Stroop Color, Stroop Color-Word tests, Symbol Digit Modalities Test, Tower of London total moves, and Tower of London total excess moves. Conclusions: These results provide an important extension to the literature by confirming that 20 minutes of moderate-intensity exercise benefits EF performance in high school students.
Victoria Kjos and Jennifer L. Etnier
Identifying alternative exercise modalities in an effort to stimulate and promote participation in physical activity, especially among older adults, is a critical health consideration. The purpose of this study was to compare physiological and psychological responses to medical qigong with self-paced brisk walking. Older women (55–79 years) performed 22 min of either qigong or walking on two separate days. During exercise performance, heart rate and ratings of perceived exertion were assessed. Psychological affect, blood pressure, and pulse rate were assessed before and after the exercise bouts. Heart-rate data indicated that both forms of exercise were at a moderate level of intensity. In addition, similar values were found for the physiological and psychological variables as a function of the two forms of exercise. Therefore, it was concluded that this form of medical qigong can be considered a moderate-intensity physical activity that should have both physiological and psychological benefits for older women.
Jennifer L. Etnier and Benjamin A. Sibley
The purpose of this study was to examine the interactive effects of hormone-replacement therapy (HRT) and physical activity (PA) on the cognitive performance of older women. Postmenopausal women (n = 101) were recruited to complete a PA questionnaire, provide demographic information, and perform the digit-symbol substitution task (DSST) and the trail-making tests (TMT). Regression analyses were conducted for participants with complete data for each cognitive test (DSST n = 62; TMT n = 69). For both tasks, results indicated that PA and education were positively related and age was negatively related to cognitive performance. The interaction of HRT with PA did not add to the predicted variance of either measure of cognitive performance. This was true even after limiting the HRT users to women using unopposed estrogen. It is concluded that the beneficial relationship between PA and these two measures of cognitive performance in postmenopausal women exists irrespective of HRT use.
Benjamin A. Sibley and Jennifer L. Etnier
The purpose of this study was to quantitatively combine and examine the results of studies pertaining to physical activity and cognition in children. Studies meeting the inclusion criteria were coded based on design and descriptive characteristics, subject characteristics, activity characteristics, and cognitive assessment method. Effect sizes (ESs) were calculated for each study and an overall ES and average ESs relative to moderator variables were then calculated. ESs (n = 125) from 44 studies were included in the analysis. The overall ES was 0.32 (SD = 0.27), which was significantly different from zero. Significant moderator variables included publication status, subject age, and type of cognitive assessment. As a result of this statistical review of the literature, it is concluded that there is a significant positive relationship between physical activity and cognitive functioning in children.
Jennifer L. Etnier and Yu-Kai Chang
The purpose of the present commentary is to introduce relevant issues with respect to the measurement of executive function in physical activity studies. Suggested definitions of executive function are introduced, and executive function tasks that are commonly used in the neuropsychological literature are presented and briefly described. The extant literature on physical activity and cognition is discussed, and issues relative to the limitations of this body of literature are raised. In summary, research on the effect of physical activity on executive function is still in its infancy. We encourage researchers in this field to provide a clear definition of executive function, to carefully consider the relevance of published effect sizes to their own research questions, and to consider either providing a logical rationale for their selection of particular executive function measures or to use multiple measures of executive function when exploring relationships between physical activity and executive function.