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.
Jennifer L. Etnier and Benjamin A. Sibley
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.
Benjamin A. Sibley and Sian L. Beilock
In the current work we asked whether executive function, as measured by tests of working memory capacity, might benefit from an acute bout of exercise and, more specifically, whether individuals who are lower or higher in working memory to begin with would be more or less affected by an exercise manipulation. Healthy adults completed working memory measures in a nonexercise (baseline) session and immediately following a 30-min self-paced bout of exercise on a treadmill (exercise session). Sessions were conducted 1 week apart and session order was counterbalanced across participants. A significant Session × Working Memory interaction was obtained such that only those individuals lowest in working memory benefited from the exercise manipulation. This work suggests that acute bouts of exercise may be most beneficial for healthy adults whose cognitive performance is generally the lowest, and it demonstrates that the impact of exercise on cognition is not uniform across all individuals.
Jennifer L. Etnier, Benjamin A. Sibley, Jeremy Pomeroy, and James C. Kao
Research suggests that there are differences in response time (RespT) as a function of age but that aerobic fitness might have a facilitatory effect on RespT. This study was designed to examine this relationship while addressing methodological issues from past research. Men from 3 age groups completed speeded tasks, a physical activity questionnaire, and an aerobic-fitness test. Results indicated that age has a negative impact on RespT (specifically premotor time and movement time). The interaction of aerobic fitness by age was also a significant predictor of RespT (specifically movement time) such that aerobic fitness was positively related to speed of performance for older participants. It is concluded that aerobic fitness might serve a preservative function for speeded tasks in older adults.
Benjamin A. Sibley, Jennifer L. Etnier, and Guy C. Le Masurier
Recent reviews of the literature have demonstrated that exercise has a positive impact on cognitive performance. The purpose of this study was to assess the impact of an acute bout of aerobic exercise on executive functioning in college-age adults. For the experimental intervention, the effects of 20 min of self-paced moderate-intensity exercise on a treadmill were compared to the effects of a 20-min sedentary control period. Executive functioning was assessed using Stroop color-word interference and negative priming tests. Results indicated that the bout of exercise led to improved performance on the Stroop color-word interference task but no change in performance on the negative priming task. This finding suggests that exercise may facilitate cognitive performance by improving the maintenance of goal-oriented processing in the brain.