The short-term aftereffects of a bout of moderate aerobic exercise were hypothesized to facilitate children’s executive functioning as measured by a visual task-switching test. Sixty-nine children (mean age = 9.2 years) who were overweight and inactive performed a category-decision task before and immediately following a 23-min bout of treadmill walking and, on another session, before and following a nonexercise period. The acute bout of physical activity did not influence the children’s global switch cost scores or error rates. Age-related differences in global switch cost scores, but not error scores, were obtained. These results, in concert with several studies conducted with adults, fail to confirm that single bouts of moderately intense physical activity influence mental processes involved in task switching.
Philip D. Tomporowski, Catherine L. Davis, Kate Lambourne, Mathew Gregoski and Joseph Tkacz
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.
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.
Linda Schücker, Christian Knopf, Bernd Strauss and Norbert Hagemann
The aim of this study was to examine differentiated effects of internally focused attention in endurance sports. Thirty-two active runners ran 24 min on a treadmill at a fixed speed of moderate intensity. For each 6-min block, participants had to direct their attention on different internal aspects (movement execution, breathing, or feeling of the body) or received no instructions. Oxygen consumption (VO2) was measured continuously to determine running economy. Results revealed that the different internal focus instructions had differentiated effects on VO2: A focus on breathing as well as a focus on the running movement led to higher VO2 than a focus on feeling of the body which showed similar VO2 as the control condition. We conclude that an internal focus of attention is solely detrimental to performance when directed to highly automated processes (e.g., breathing or movement). However, an internal focus on how the body feels during exercise does not disrupt movement efficiency.
Jasmin C. Hutchinson and Costas I. Karageorghis
We examined independent and combined influences of asynchronous music and dominant attentional style (DAS) on psychological and psychophysical variables during exercise using mixed methods. Participants (N = 34) were grouped according to DAS and completed treadmill runs at three intensities (low, moderate, high) crossed with three music conditions (motivational, oudeterous, no-music control). State attentional focus shifted from dissociative to associative with increasing intensity and was most aligned with DAS during moderate-intensity exercise. Both music conditions facilitated dissociation at low-to-moderate intensities. At high exercise intensity, both music conditions were associated with reduced RPE among participants with an associative DAS. Dissociators reported higher RPE overall during moderate and high intensities. Psychological responses were most positive in the motivational condition, followed by oudeterous and control. Findings illustrate the relevance of individual differences in DAS as well as task intensity and duration when selecting music for exercise.
Barbara Resnick, Kathleen Michael, Marianne Shaughnessy, Eun Shim Nahm, Susan Kopunek, John Sorkin, Denise Orwig, Andrew Goldberg and Richard F. Macko
Self-report measures of physical activity have well-known drawbacks, and physiologic measures alone do not account for behavioral variables important in the perception and performance of physical activity. Therefore, we considered multiple measures to quantify physical activity in community-dwelling men and women with chronic stroke.
This analysis included data from a volunteer sample of 87 individuals at least 6 months poststroke. Physical activity was measured using self-report questionnaires, step activity monitors, self-efficacy expectations related to exercise, and VO2peak from treadmill testing, and a model of physical activity was tested.
Most of the variance in objective physical activity was explained by VO2peak, and most of the variance in subjective physical activity was explained by self-efficacy expectations. There were significant discrepancies between subjective and objective findings.
This study helps to understand the perspective of stroke survivors with regard to physical activity.
Danielle R. Bouchard, K. Ashlee McGuire, Lance Davidson and Robert Ross
One hundred forty-six abdominally obese adults age 60–80 yr were studied to investigate the interaction between cardiorespiratory fitness (CRF) and obesity on functional limitation. Obesity was determined by fat mass (FM), CRF was determined by a maximal treadmill test, and functional limitation was based on 4 different tasks that are predictive of subsequent disability. Both FM (r = –.34, p ≤ .01) and CRF (r = .54, p ≤ .01) were independently associated with functional limitation in bivariate analysis. After further control for sex, age, and the interaction term (CRF × FM), FM was no longer independently associated with functional limitation (p = .10). Analyses were also based on sex-specific tertiles of FM and CRF. The referent group demonstrated significantly lower functional limitation than the low-CRF/low-FM and the low-CRF/high-FM groups (both p ≤ .05). These results highlight the value of recommending exercise for abdominally obese adults.
Lauren Gulka, James Dziura and Loretta DiPietro
Little attention has been paid to the study of transient growth hormone (GH) responses to exercise in older women. We determined the effect of a single bout of exercise on GH in fit and unfit older (age 55 to 81 y; n = 19) and younger (age 18 to 25 y; n = 19) women.
Exercise consisted of five 15-min intervals of treadmill exercise at 75% VO2peak. Blood samples were taken before, during, and following exercise for determination of plasma GH and insulin concentrations.
GH responses to exercise were attenuated in older compared with younger women (P < 0.01); however, these age differences were minimized in older age by fitness level. Adjusted area under the curve for GH was 5.50 and 1.76 µg/L · 102 for fit and unfit older women (P < 0.01), and 8.46 and 8.46 µg/L · 102 for fit and unfit younger women.
Low levels of cardiorespiratory fitness in older women may require a greater relative exercise stimulus to augment meaningful GH responses.
Benjamin J. Darter, Kathleen F. Janz, Michael L. Puthoff, Barbara Broffitt and David H. Nielsen
A new triaxial accelerometer (AMP 331) provides a novel approach to understanding free-living activity through its ability to measure real time speed, cadence, and step length. This study examined the reliability and accuracy of the AMP 331, along with construction of prediction equations for oxygen consumption and energy cost.
Young adult volunteers (n = 41) wearing two AMP units walked and ran on a treadmill with energy cost data simultaneously collected through indirect calorimetry.
Statistically significant differences exist in inter-AMP unit reliability for speed and step length and in accuracy between the AMP units and criterion measures for speed, oxygen consumption, and energy cost. However, the differences in accuracy for speed were very small during walking (≤ 0.16 km/h) and not clinically relevant. Prediction equations constructed for walking oxygen uptake and energy expenditure demonstrated R 2 between 0.76 to 0.90 and between subject deviations were 1.53 mL O2 · kg-1 · min−1 and 0.43 kcal/min.
In young adults, the AMP 331 is acceptable for monitoring walking speeds and the output can be used in predicting energy cost during walking but not running.
Michael R.M. McGuigan, Roger Bronks, Robert U. Newton, John C. Graham and David V. Cody
Peripheral arterial disease (PAD) is associated with impaired lower extremity function. This study investigated differences in PAD and control participants and the relationship between lower limb strength and clinical measures of PAD severity. Participants were evaluated by 6-min-walk distance, normal and maximal walking speed over 10 m, isometric plantar-flexion strength, and dynamic dorsi-/plantar-flexion strength. Hemodynamic measures of the lower limbs were recorded at rest and after maximal treadmill testing. PAD participants walked significantly less far during the 6-min walk, and there were large differences in normal and maximal walking speeds. Small to moderate differences were found for isometric plantar-flexion strength. In the diseased legs of the PAD participants, resting systolic hallux photoplethysmography was significantly correlated with isokinetic plantar-flexion strength and onset of claudication pain during the 6-min-walk test. In addition to confirming the documented loss of walking endurance, these data suggest that loss of strength of the plantar flexors is associated with increasing PAD impairment.