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Nicolette C. Bishop, Neil P. Walsh, Donna L. Haines, Emily E. Richards, and Michael Gleeson

Ingesting carbohydrate (CHO) beverages during heavy exercise is associated with smaller shifts in numbers of circulating neutrophils and attenuated changes in neutrophil functional responses. The influence of dietary CHO availability on these responses has not been determined. Therefore, the present study investigated the influence of pre-exercise CHO status on circulating neutrophil and lipopolysaccharide (LPS)-stimulated neutrophil degranulation responses to prolonged cycling. Twelve trained male cyclists performed a glycogen-lowering bout of cycling and were randomly assigned to follow a diet ensuring either greater than 70% (HIGH) or less than 10% (LOW) of daily energy intake from CHO for the next 3 days. On day 4, subjects performed an exercise test that comprised cycling for 1 hour at 60% Wmax immediately followed by a time-trial (TT) ensuring an energy expenditure equivalent to cycling for 30 min at 80% Wmax. Subjects repeated the protocol after 7 days, this time following the second diet. The order of the trials was counterbalanced. At TT completion, the HIGH compared with the LOW trial was associated with higher plasma glucose concentration, lower plasma cortisol concentration, and lower circulating neutrophil count. LPS-stimulated neutrophil degranulation per cell fell similarly on both trials. These findings suggest that pre-exercise CHO status influences neutrophil trafficking but not function in response to prolonged cycling.

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Nicolette C. Bishop, Neil P. Walsh, Donna L. Haines, Emily E. Richards, and Michael Gleeson

Ingesting carbohydrate (CHO) beverages during heavy exercise is associated with smaller changes in the plasma concentrations of several cytokines. The influence of dietary CHO availability on these responses has not been determined. Therefore, the present study investigated the influence of pre-exercise CHO status on plasma interleukin (IL)-6, IL-10, and IL-1 receptor antagonist (IL-1ra) responses to prolonged cycling. Seven trained male cyclists performed a glycogen-lowering bout of cycling and were randomly assigned to follow a diet ensuring either greater than 70% (HIGH) or less than 10% (LOW) of daily energy intake from CHO for the next 3 days. On day 4 subjects performed an exercise test that comprised cycling for 1 hour at 60% Wmax immediately followed by a time-trial (TT) ensuring an energy expenditure equivalent to cycling for 30 min at 80% Wmax. Subjects repeated the protocol after 7 days, this time following the second diet. The order of the trials was counterbalanced. At 1 and 2 hours post-TT, plasma concentrations of IL-6 and IL-10 were 2-fold greater on the LOW trial than on the HIGH trial, and peak plasma concentrations of TL-1ra were 9-fold greater on the LOW trial than on the HIGH trial. These findings suggest that pre-exercise CHO status can influence the plasma cytokine response to prolonged cycling.

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Alannah K. A. McKay, Ida A. Heikura, Louise M. Burke, Peter Peeling, David B. Pyne, Rachel P.L. van Swelm, Coby M. Laarakkers, and Gregory R. Cox

). Despite the potential long-term implications to athlete health and performance, studies exploring these effects in elite athletes are lacking. Therefore, we quantified the effect of a sleep-low protocol in the daily training environment on markers of inflammation, iron regulation, and immune function in

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Helen G. Hanstock, Andrew D. Govus, Thomas B. Stenqvist, Anna K. Melin, Øystein Sylta, and Monica K. Torstveit

HIT (4 × 4 min) , despite lower heart rates (HRs), blood lactate concentrations, ratings of perceived exertion (RPE), and a less pronounced steroid hormone response. 3 However, it is unclear how different interval training prescriptions influence athletes’ health and immune status. Training

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Brian W. Timmons

Despite significant advances in exercise immunology over the last two decades, our understanding of immune responses to exercise in children remains sparse. This review outlines and discusses commonly reported aspects of the immune response to exercise, with emphasis on child-adult differences. Compared with adults, children generally experience smaller perturbations to the immune system (e.g., NK cells and IL-6) in response to exercise of the same duration and intensity. Children also demonstrate a faster recovery of immune components (e.g., neutrophil and IL-6) after exercise. The health and clinical relevance of exercise-induced changes in a child’s immune system remain to be determined.

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Shlomit Radom-Aizik

Two papers were selected for this commentary. The first paper (Citation 1) suggests that a 10-week, moderate-intensity exercise program performed early after allogeneic hematopoietic stem cell transplantation is feasible in this fragile population, and might improve cell cytotoxicity by redistributing subpopulations of NK cells. This study adds to the growing evidence that enhancing immune cell surveillance (e.g., NK cells) in response to exercise could benefit cancer patients. The second paper (Citation 2) studied neutrophil-related mediators of oxidative stress and inflammatory cytokines in response to exercise in children compared with adults. The authors found age/maturation-related differences in these responses. The paper provides a valuable introduction to the current knowledge of maturational changes in immune mediators’ response to exercise. Data about leukocyte function in response to exercise in healthy children and in children with clinical conditions is scant. The need for prospective large scale pediatric clinical exercise studies is clear. Molecular approaches to understand the mechanisms through which physical activity can improve health will help to shape guidelines that optimize the mode, frequency, intensity, and duration of the training intervention.

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Bindu P. Gopalan, Mary Dias, Karthika Arumugam, Reena R. D’Souza, Mathew Perumpil, Prasanna Kulkarni, Udaykumar Ranga, and Anita Shet

neuropsychiatric disorders ( 28 ). The pathogenesis of these illnesses is attributable to the accelerated aging and immune senescence due to chronic inflammation and immune activation ( 17 ) resulting from the direct effect of HIV, microbial translocation, coinfections, and other comorbidities ( 19 ). To reduce

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Alexandra A. Avloniti, Helen T. Douda, Savvas P. Tokmakidis, Alexandros H. Kortsaris, Evropi G. Papadopoulou, and Emmanouil G. Spanoudakis

Purpose:

To investigate the acute changes in leukocyte number and cortisol after a single bout of soccer training.

Methods:

Ten elite female national-team soccer players and 8 nonathletes participated in the study. The duration of the exercise was 2 h, and it was performed at an intensity of 75% of maximal heart rate (HRmax). Blood samples were taken before, immediately after, and 4 h after a soccer training session to determine total white blood cells; the subsets of neutrophils, lymphocytes, monocytes, eosinophils, and basophils; and cortisol. At the same time, blood samples were obtained from nonathletes who refrained from exercise.

Results:

Data analysis indicated a significant increase in total white blood cells in the athletes postexercise (P < .001). The leukocytosis was still evident after 4 h of recovery (78% higher than the preexercise values), and there was a significant difference between athletes and nonathletes (P < .001). This leukocytosis was primarily caused by neutrophilia—there were no significant differences in lymphocytes after the end of exercise or between the 2 groups (P > 0.05). In addition, there was a statistically significant difference in cortisol concentration between athletes and nonathletes after the exercise (P < .001).

Conclusion:

These findings revealed that the single bout of soccer training at an intensity of 75% of HRmax induced leukocytosis without affecting the lymphocyte count in elite female athletes and probably the effectiveness of cellular components of adaptive immunity. Coaches should provide adequate time (>4 h) until the next exercise session.

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William A. Braun, Michael G. Flynn, Daniel L. Carl, Kathy K. Carroll, Todd Brickman, and Charlie P. Lambert

Iron deficiency may lead to anemia and may result in compromised endurance exercise performance. Iron deficiency has also been reported to adversely affect the immune system and has been associated with attenuation of natural killer cell (NK) activity. This study was conducted to examine the relationship between iron status and NK activity in highly conditioned female athletes. Ten collegiate female swimmers (SWM) and 9 inactive females (SED) participated in this investigation. Resting blood samples were obtained and analyzed for serum iron and ferritin. NK activity (% lysis) was determined using a whole blood method (51Cr release assay). No significant relationship was found between iron and NK activity (r = 0.55, p = .09), nor between serum ferritin and NK activity (r = 0.33. p = .35) for SWM. ANOVA revealed significantly greater NK activity for SWM (51.63 ± 15.79%) versus SED (30.34 ± 13.67%). Serum ferritin levels were not significantly different between SWM (20.38±8.62Ƞg · ml−1) and SED (16.79±10.53Ƞg · ml−1), nor were iron values different between groups (16.54 ± 2.17 μmol · L−1 SWM; 11.92 ± 2.61 μmol · L−1 SED). A significant relationship between iron status and resting immune function could not be established. Exercise training may affect NK activity; however, the influence of iron status on immune function requires further evaluation.

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Lara A. Carlson, Samuel Headley, Jason DeBruin, Alex P. Tuckow, Alexander J. Koch, and Robert W. Kenefick

This investigation sought to study changes in leukocyte subsets after an acute bout of resistance exercise (ARE) and to determine whether ingestion of carbohydrate (CHO) could attenuate those immune responses. Nine male track-and-field athletes (21.1 ± 1.4 yr, 177.2 ± 5.5 cm, 80.9 ± 9.7 kg, 8.7% ± 3.8% fat) and 10 male ice hockey athletes (21.0 ± 2.2 yr, 174.3 ± 6.2 cm, 79.6 ±11.1 kg, 13.9% ± 3.73% fat) participated in 2 different ARE protocols. Both experiments employed a counterbalanced double-blind research design, wherein participants consumed either a CHO (1 g/kg body weight) or placebo beverage before, during, and after a weight-lifting session. Serum cortisol decreased (p < .05) at 90 min into recovery compared with immediately postexercise. Plasma lactate, total leukocyte, neutrophil, and monocyte concentrations increased (p < .05) from baseline to immediately postexercise. Lymphocytes decreased significantly (p < .05) from baseline to 90 min postexercise. Lymphocytes were lower (p < .05) for the CHO condition than for placebo. The findings of this study indicate the following: ARE appears to evoke changes in immune cells similar to those previously reported during endurance exercise, and CHO ingestion attenuates lymphocytosis after ARE.