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Jeffrey A. Woods and Brandt D. Pence

Exercise immunology is a relatively new discipline in the exercise sciences that seeks to understand how exercise affects the immune system and susceptibility to infectious and chronic diseases. This brief review will focus on three major observations that have driven the field to date including: (1) acute exercise-induced leukocytosis, (2) the observation that intense, prolonged exercise results in upper respiratory tract symptoms, and (3) the paradoxical effect of acute and chronic exercise on inflammation. This framework will be used to examine the mechanisms and implications behind these seminal observations. Data generally support the conclusion that moderate intensity exercise enhances immune function, whereas prolonged, intense exercise diminishes immune function.

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Caterina Pesce, Lucio Cereatti, Rita Casella, Carlo Baldari and Laura Capranica

This study investigated the visual attention of older expert orienteers and older adults not practicing activities with high attentional and psychomotor demands, and considered whether prolonged practice of orienteering may counteract the age-related deterioration of visual attentional performance both at rest and under acute exercise. In two discriminative reaction time experiments, performed both at rest and under submaximal physical workload, visual attention was cued by means of spatial cues of different sizes followed, at different stimulus-onset asynchronies, by compound stimuli with local and global target features. Orienteers, as compared to nonathletes, showed a faster reaction speed and a complex pattern of attentional differences depending on the time constraints of the attentional task, the demands on endogenous attentional control, and the presence or absence of a concomitant effortful motor task. Results suggest that older expert orienteers have developed attentional skills that outweigh, at least at rest, the age-related deficits of visual attentional focusing.

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Brian C. Focht and Heather A. Hausenblas

The primary purpose of the present study was to examine psychological responses of 50 young women following single episodes of aerobic exercise (AE) performed in a naturalistic exercise setting and quiet rest (QR). Given the salience of self-presentational qualities in a naturalistic exercise setting, a secondary purpose was to examine whether psychological responses to acute exercise varied as a function of social physique anxiety (SPA). The dependent measures of state anxiety, positive engagement, revitalization, tranquility, and physical exhaustion were assessed immediately prior to and then at 5 and 30 minutes following each condition. It was found that (a) AE and QR were associated with decreases in state anxiety and increases in tranquility; (b) AE was associated with increases in positive engagement and revitalization; and (c) these changes did not vary as a function of SPA level.

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Margaret Schneider, Andrea Dunn and Daniel Cooper

Many adolescents do not meet public health recommendations for moderate-to-vigorous physical activity (MVPA). In studies of variables influencing adolescent MVPA, one that has been understudied is the affective response to exercise. We hypothesized that adolescents with a more positive affective response to acute exercise would be more active. Adolescents (N = 124; 46% male) completed two 30-min exercise tasks (above and below the ventilatory threshold [VT]), and wore ActiGraph accelerometers for 6.5 ± 0.7 days. Affective valence was assessed before, during, and after each task. A more positive affective response during exercise below the VT was associated with greater participation in MVPA (p < .05). The results are consistent with the hypothesis that individuals who have a more positive affective response to exercise will engage in more MVPA. To promote greater participation in MVPA among adolescents, programs should be designed to facilitate a positive affective experience during exercise.

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Fiona Barnett

Background:

This study examined the self-efficacy and affective responses to an acute exercise bout in sedentary older and younger women to determine whether aging has an effect on affective states.

Methods:

Twenty-five sedentary younger (mean age = 19.9 yrs) and 25 older (mean age = 55.7 yrs) women completed an acute bout of exercise. Affective responses were measured before, during, and immediately following exercise. Self-efficacy responses were measured before and immediately following exercise.

Results:

Positive engagement, revitalization, tranquility, Felt Arousal and Feeling Scale responses, and self-efficacy were all higher immediately following compared with before or during exercise for both groups of women. In addition, older women experienced higher overall positive engagement and lower physical exhaustion compared with younger women as well as higher tranquility and Feeling Scale responses immediately following exercise.

Conclusions:

This investigation found that an acute bout of moderate-intensity exercise produced more positive and fewer negative affective states in both younger and older women.

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Xiaoya Ma, Kaitlyn J. Patterson, Kayla M. Gieschen and Peter F. Bodary

The prevalence of iron deficiency tends to be higher in athletic populations, especially among endurancetrained females. Recent studies have provided evidence that the iron-regulating hormone hepcidin is transiently increased with acute exercise and suggest that this may contribute to iron deficiency anemia in athletes. The purpose of this study was to determine whether resting serum hepcidin is significantly elevated in highly trained female distance runners compared with a low exercise control group. Due to the importance of the monocyte in the process of iron recycling, monocyte expression of hepcidin was also measured. A single fasted blood sample was collected midseason from twenty female distance runners averaging 81.9 ± 14.2 km of running per week. Ten age-, gender-, and BMI-matched low-exercise control subjects provided samples during the same period using identical collection procedures. There was no difference between the runners (RUN) and control subjects (CON) for serum hepcidin levels (p = .159). In addition, monocyte hepcidin gene expression was not different between the two groups (p = .635). Furthermore, no relationship between weekly training volume and serum hepcidin concentration was evident among the trained runners. The results suggest that hepcidin is not chronically elevated with sustained training in competitive collegiate runners. This is an important finding because the current clinical conditions that link hepcidin to anemia include a sustained elevation in serum hepcidin. Nevertheless, additional studies are needed to determine the clinical relevance of the well-documented, transient rise in hepcidin that follows acute sessions of exercise.

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Andrea T. Duran, Erik Gertz, Daniel A. Judelson, Andrea M. Haqq, Susan J. Clark, Kavin W. Tsang and Daniela Rubin

Prader-Willi Syndrome (PWS), the best characterized form of syndromic obesity, presents with abnormally high fat mass. In children, obesity presents with low-grade systemic inflammation. This study evaluated if PWS and/or nonsyndromic obesity affected cytokine responses to intermittent aerobic exercise in children. Eleven children with PWS (11 ± 2 y, 45.4 ± 9.5% body fat), 12 children with obesity (OB) (9 ± 1 y, 39.9 ± 6.8% body fat), and 12 lean (LN) children (9 ± 1 y, 17.5 ± 4.6% body fat) participated. Children completed 10 2-min cycling bouts of vigorous intensity, separated by 1-min rest. Blood samples were collected preexercise (PRE), immediately postexercise (IP), and 15, 30, and 60 min into recovery to analyze possible changes in cytokines. In all groups, IL-6 and IL-8 concentrations were greater during recovery compared with PRE. PWS and OB exhibited higher IL-6 area under the curve (AUC) than LN (p < .01 for both). PWS demonstrated higher IL-8 AUC than LN (p < .04). IL-10, TNF-α, and IFN-γ did not change with exercise (p > .05 for all). Results indicate that children with PWS respond with increased Il-6 and IL-8 concentrations to acute exercise similarly to controls. Excess adiposity and epigenetic modifications may explain the greater integrated IL-6 and IL-8 responses in PWS compared with controls.

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Alfredo Córdova, Antoni Sureda, María L. Albina, Victoria Linares, Montse Bellés and Domènec J. Sánchez

The aim was to determine the levels and activities of the oxidative stress markers in erythrocytes, plasma, and urine after a flat cyclist stage. Eight voluntary male professional trained-cyclists participated in the study. Exercise significantly increased erythrocyte, leukocyte, platelet, and reticulocyte counts. The exercise induced significant increases in the erythrocyte activities of catalase (19.8%) and glutathione reductase (19.2%), while glutathione peroxidase activity decreased significantly (29.3%). Erythrocyte GSSG concentration was significantly increased after exercise (21.4%), whereas GSH was significantly diminished (20.4%). Erythrocyte malondialdehyde levels evidenced a significant decrease 3 h after finishing the stage (44.3%). Plasma malondialdehyde, GSH and GSSG levels significantly decreased after 3 hr recovery (26.8%, 48.6%, and 31.1%, respectively). The exercise significantly increased the F2-isoprostane concentration in urine from 359 ± 71 pg/mg creatinine to 686 ± 139 pg/mg creatinine. In conclusion, a flat cycling stage induced changes in oxidative stress markers in erythrocytes, plasma, and urine of professional cyclists. Urine F2-isoprostane is a more useful biomarker for assessing the effects of acute exercise than the traditional malondialdehyde measurement.

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Rachael C. Gliottoni, John R. Meyers, Sigurbjörn Á. Arngrímsson, Steven P. Broglio and Robert W. Motl

This experiment examined the effect of a moderate dose of caffeine on quadriceps muscle pain during a bout of high-intensity cycling in low- versus high-caffeine-consuming males. College-age men who were low (≤100 mg/day; n = 12) or high (≥400 mg/day; n = 13) habitual caffeine consumers ingested caffeine (5 mg/kg body weight) or a placebo in a counterbalanced order and 1 hr later completed 30 min of cycle ergometry at 75–77% of peak oxygen consumption. Perceptions of quadriceps muscle pain, as well as oxygen consumption, heart rate, and work rate, were recorded during both bouts of exercise. Caffeine ingestion resulted in a statistically significant and moderate reduction in quadriceps muscle-pain-intensity ratings during the 30-min bout of high-intensity cycle ergometry compared with placebo ingestion in both low (d = −0.42) and high (d = −0.55) caffeine consumers. The results suggest that caffeine ingestion is associated with a moderate hypoalgesic effect during high-intensity cycling in college-age men who are low or high habitual caffeine consumers, but future work should consider better defining and differentiating pain and effort when examining the effects of caffeine during acute exercise.

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Amy S. Welch, Angie Hulley and Mark Beauchamp

To investigate the relationship between cognitive and affective responses during acute exercise, 24 low-active females completed two 30-min bouts of cycle ergometer exercise at 90% of the ventilatory threshold. In one condition participants had full knowledge of the exercise duration (KD); in the other, exercise duration was unknown (UD). Affect and self-efficacy were measured before and every 3 min during exercise, and affect was also measured postexercise. Affect declined throughout the first half of both conditions, and continued its decline until the end of the UD condition, when a rebound effect was observed. Self-efficacy during exercise displayed a similar pattern. Hierarchical regression analyses demonstrated that during-exercise self-efficacy was a stronger predictor of during-exercise affect than preexercise self-efficacy, and that this relationship was strongest at the end of exercise when duration was unknown. These results indicate that repetitive cognitive appraisal of self and the task could impact the exercise experiences of low-active women during the adoption phase of an exercise program.