Athletes use a variety of nutritional ergogenic aids to enhance performance. Most nutritional aids can be categorized as a potential energy source, an anabolic enhancer, a cellular component, or a recovery aid. Studies have consistently shown that carbohydrates consumed immediately before or after exercise enhance performance by increasing glycogen stores and delaying fatigue. Protein and amino acid supplementation may serve an anabolic role by optimizing body composition crucial in strength-related sports. Dietary antioxidants, such as vitamins C and E and carotenes, may prevent oxidative stress that occurs with intense exercise. Performance during high-intensity exercise, such as sprinting, may be improved with short-term creatine loading, and high-effort exercise lasting 1-7 min may be improved through bicarbonate loading immediately prior to activity. Caffeine dosing before exercise delays fatigue and may enhance performance of high-intensity exercise.
The DOI for the article “Can High-Intensity Exercise Be More Pleasant? Attentional Dissociation Using Music and Video,” by Leighton Jones, Costas I. Karageorghis, and Panteleimon Ekkekakis, in the Journal of Sport and Exercise Psychology 36(5), was incorrectly printed. The correct DOI for this article is http://dx.doi.org/10.1123/jsep.2013-0251. The online version of this article has been corrected.
Charles J. Hardy and Robert G. McMerray
Ten Type A's and 10 Type B's, as measured by the student version of the JAS and the TASRI, exercised on a cycle ergometer for 20 minutes at light (40% V02max), moderate (60% V02max), and high (80% V02max) intensity exercise to determine A/B differences in psychophysiological responses. The norepinephrine and epinephrine responses of A/B types were similar at the light and moderate intensities. However, at the high intensity, norepmephrine response of Type A's was significantly greater than that of Type B's. Epinephrine responses (p=.ll) evidenced the same, albeit nonsignificant, trend. Oxygen uptake and heart rate data indicated that this amine difference was not a function of differential workloads, suggesting that Type A's had a greater psychophysiological reactivity to high intensity exercise than Type B's. Ratings of perceived exertion were similar for Type A's and B's at all intensities. However, a significant interaction between behavioral pattern and intensity emerged for affect. Interpretation of this interaction indicated that Type A's were more positive than B's at light and moderate intensities, yet at the high intensity exercise A's were more negative than B's. The results of this study suggest that A and B types do differ in their psychophysiological responses during exercise, with A's evidencing more positive affect during light and moderate intensities, yet more negative affect and greater neuroendocrine responses during high intensity exercise than B's.
Emily M. Haymes
Muscle glycogen is the primary source of energy during high intensity exercise. Increasing the carbohydrate content of the diet allows more glycogen to be stored. Some adolescent female athletes (gymnasts, dancers) do not consume adequate amounts of vitamin B6, folacin, and E. Many women have low dietary intakes of calcium and iron. Low calcium intake and physical inactivity are factors associated with the development of osteoporosis. Low iron intake is associated with the development of iron deficiency and anemia. Low ferritin levels (an index of body iron stores) are commonly observed in female athletes.
Carl M. Maresh, Catherine L. Gabaree, Jay R. Hoffman, Daniel R. Hannon, Michael R. Deschenes, Lawrence E. Armstrong, Avron Abraham, Frederick E. Bailey and William J. Kraemer
To examine the effect of a nutritional supplement (ATP-E™) on high intensity exercise performance, 23 physically active males volunteered to perform six Wingate Anaerobic Power tests. Tests were performed prior to and at 14 and 21 days during ATP-E~o~r placebo ingestion. f i e experiment followed a double-blind and random-order design. Twelve subjects (responders, R) showed an increase in preexercise blood ATP on Day 14 of ATP-E™ ingestion compared to control measures. The remaining 11 subjects (nonresponders, NR) had no change in pree~e~cibselo od ATP. Peak power and mean power were unchanged for both R and NR subjects across the exercise tests, but R experienced a decrease (p < 0.05) in immediate postexercise plasma lactate on Day 14 of ATP-E™ testing compared to their control measures. NR had no change in peak plasma lactate at any time during the study. The results suggest that short-term high intensity exercise performance was maintained in R with less reliance on anaerobic metabolism, and that response was evident following 14 days of ATP-E™ ingestion.
Walter R. Bixby, Thomas W. Spalding and Bradley D. Hatfield
Electroencephalographic (EEG) and self-report measures of affect were obtained from 27 participants (14 F, 13 M) before, during, and following 30 min of continuous exercise at low and high intensities to determine the respective temporal courses of affective response. Mood was measured via a visual analog mood scale (VAMS), the Positive and Negative Affect Schedules (PANAS-PA and -NA), and EEG hemispheric asymmetry as obtained from three electrode pairs: F4-F3, F8-F7, and P4-P3. Participants reported higher VAMS and lower PANAS-NA scores during low-intensity exercise relative to baseline, and the higher scores were maintained during recovery. In contrast, they reported lower scores on the VAMS during high-intensity exercise relative to baseline that were subsequently elevated during recovery. Also, during high-intensity exercise the PANAS-NA scores were similar to baseline, but they were lower during recovery. Both the VAMS and PANAS-NA scores observed after exercise were similar regardless of intensity. Additionally, participants had higher PANAS-PA and EEG hemispheric asymmetry scores (i.e., F8-F7) during exercise at both intensities relative to baseline, then reported values similar to baseline levels on cessation of work. The magnitude of change from baseline for the PANAS-PA and EEG scores during exercise was similar regardless of exercise intensity.
Lori D. Wilson, Frank P. Zaldivar, Christina D. Schwindt, Jessica Wang-Rodriguez and Dan M. Cooper
Brief high intensity exercise induces peripheral leukocytosis possibly leading to a higher incidence of allergic symptoms in athletes undergoing excessive training. We studied the exercise-induced alternation of circulating Tregs and FoxP3+ Tregs due to acute intense swim exercise in elite swimmers (n = 22, 12 males, age = 15.4 yrs). Twelve had prior or current rhinitis or asthma and 10 had no current or prior allergy or asthma. Circulating Tregs increased significantly (p < .001) following exercise (pre = 133 ± 11.2, post = 196 ± 17.6) as did FoxP3+ cells (pre = 44, post = 64 cells/μl). Increases in Tregs and FoxP3+ Tregs occurred to the same extent in both groups of adolescent swimmers.
Stéphane Nottin, Agnès Vinet, Anne-Marie Lecoq, Patrick Guenon and Philippe Obert
The aim of this study was to examine the reproducibility of cardiac output (Q) measured by Doppler echocardiography and CO2-rebreathing in prepubertal children during exercise. Fourteen healthy children (8 girls and 6 boys aged 10.9 ± 0.9 years) underwent a progressive maximum upright cycle test until exhaustion on two separate occasions (1 week apart). Q was determined successively by the two methods at rest and during the final minutes of each workload. The reproducibility of the Doppler method was higher than the reproducibility of the CO2-rebreathing method, both at rest and during exercise. Moreover, this reproducibility was lower during high intensity exercise whatever the method used. On account of its high reproducibility, Doppler echocardiography should be preferentially used to detect changes in Q as a result of an exercise training intervention in prepubertal children.
Chun-Chih Wang, Chien-Heng Chu, I-Hua Chu, Kuei-Hui Chan and Yu-Kai Chang
This study was designed to examine the modulation of executive functions during acute exercise and to determine whether exercise intensity moderates this relationship. Eighty college-aged adults were recruited and randomly assigned into one of the four following groups: control, 30%, 50%, and 80% heart rate reserve. The Wisconsin Card Sorting Test (WCST) was administered during each intervention. The results indicated that the majority of the WCST performances were impaired in the high exercise intensity group relative to those of the other three groups, whereas similar performance rates were maintained in the low- and moderate-intensity groups. These findings suggest that transient hypofrontality occurs during high-intensity exercise, but not during low- and moderate-intensity exercises. Future research aimed at employing the dual-mode theory, and applying the reticular-activating hypofrontality model is recommended to further the current knowledge.
Christopher J. Brush, Ryan L. Olson, Peter J. Ehmann, Steven Osovsky and Brandon L. Alderman
The purpose of this study was to examine possible dose–response and time course effects of an acute bout of resistance exercise on the core executive functions of inhibition, working memory, and cognitive flexibility. Twenty-eight participants (14 female; M age = 20.5 ± 2.1 years) completed a control condition and resistance exercise bouts performed at 40%, 70%, and 100% of their individual 10-repetition maximum. An executive function test battery was administered at 15 min and 180 min postexercise to assess immediate and delayed effects of exercise on executive functioning. At 15 min postexercise, high-intensity exercise resulted in less interference and improved reaction time (RT) for the Stroop task, while at 180 min low- and moderate-intensity exercise resulted in improved performance on plus–minus and Simon tasks, respectively. These findings suggest a limited and task-specific influence of acute resistance exercise on executive function in healthy young adults.