Immune Responses to Exercise and Training: A Comparison of Children and Young Adults

Shore, Susan; Shephard, Roy J.

doi:10.1123/pes.10.3.210

Cited by 12 publications

(18 citation statements)

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“…In contrast, boys’ total neutrophil counts increased in adult males post-exercise but not in boys suggesting that exercise elicits a greater recruitment of leukocytes in men compared to boys [45]. These findings coincide with previous reports of a smaller neutrophil response in children compared to adults post-exercise [60,61]. It has also been speculated that that in boys, neutrophil mobilization in response to exercise may originate from the bone marrow and not from the circulation [45].…”

Section: Responses To Acute Exercisesupporting

confidence: 89%

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

et al. 2017

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Adults demonstrate an upregulation of their pro- and anti-oxidant mechanisms in response to acute exercise while systematic exercise training enhances their antioxidant capacity, thereby leading to a reduced generation of free radicals both at rest and in response to exercise stress. However, less information exists regarding oxidative stress responses and the underlying mechanisms in the pediatric population. Evidence suggests that exercise-induced redox perturbations may be valuable in order to monitor exercise-induced inflammatory responses and as such training overload in children and adolescents as well as monitor optimal growth and development. The purpose of this review was to provide an update on oxidative stress responses to acute and chronic exercise in youth. It has been documented that acute exercise induces age-specific transient alterations in both oxidant and antioxidant markers in children and adolescents. However, these responses seem to be affected by factors such as training phase, training load, fitness level, mode of exercise etc. In relation to chronic adaptation, the role of training on oxidative stress adaptation has not been adequately investigated. The two studies performed so far indicate that children and adolescents exhibit positive adaptations of their antioxidant system, as adults do. More studies are needed in order to shed light on oxidative stress and antioxidant responses, following acute exercise and training adaptations in youth. Available evidence suggests that small amounts of oxidative stress may be necessary for growth whereas the transition to adolescence from childhood may promote maturation of pro- and anti-oxidant mechanisms. Available evidence also suggests that obesity may negatively affect basal and exercise-related antioxidant responses in the peripubertal period during pre- and early-puberty.

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Section: Responses To Acute Exercisesupporting

confidence: 89%

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

et al. 2017

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“…The latter suggestion may appear somewhat extreme, nevertheless, a number of training studies indicate that the weak association between physical activity and aerobic fitness in children may be related to physiological processes associated with puberty (Ignico and Mahon 1995;Mandigout et al 2001;Mobert et al 1997;Rowland et al 1996;Rowland 2005;Rowland and Boyajian 1995;Shore and Shephard 1998;Tolfrey et al 1998;Welsman et al 1997;Williams et al 2000;Williford et al 1996;Yoshizawa et al 1997). In these training studies, previously untrained children exercised at a documented, appropriate intensity (heart rate 160-170 bpm), frequency and duration.…”

Section: Introductionmentioning

confidence: 94%

The association between aerobic fitness and physical activity in children and adolescents: the European youth heart study

et al. 2010

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The link between aerobic fitness and physical activity in children has been studied in a number of earlier studies and the results have generally shown weak to moderate correlations. This overall finding has been widely questioned partly because of the difficulty in obtaining valid estimates of physical activity. This study investigated the cross-sectional and longitudinal relationship between aerobic fitness and physical activity in a representative sample of 9 and 15-year-old children (n = 1260 cross-sectional, n = 153 longitudinal). The specific goal was to improve past studies using an objective method of activity assessment and taking into account a number of major sources of error. Data came from the Danish part of the European youth heart study, 1997-2003. The cross-sectional results generally showed a weak to moderate association between aerobic fitness and physical activity with standardized regression coefficients ranging from 0.14 to 0.33. The longitudinal results revealed a tendency towards an interaction effect of baseline physical activity on the relationship between changes in physical activity and aerobic fitness. Moderate to moderately strong regression effect sizes were observed in the lower quadrant of baseline physical activity compared to weak effect sizes in the remaining quadrants. In conclusion, the present study confirms earlier findings of a weak to moderate association between aerobic fitness and physical activity in total population of children. However, the study also indicates that inactive children can achieve notable increase in aerobic fitness by increasing their habitual physical activity level. A potential physiological explanation for these results is highlighted.

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“…It is possible that we simply missed any suppression either before or after the 60-min sampling time. Although we cannot completely discount this possibility, it is noteworthy that Shore and Shephard (16) did not find suppression of lymphocytes or T cells in their children 30 min after a 30-min bout of exercise performed at an intensity corresponding to their ventilatory threshold. Even if suppression occurred earlier (i.e.…”

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confidence: 91%

Immune Responses to Strenuous Exercise and Carbohydrate Intake in Boys and Men

2004

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Few studies describe immune responses to exercise in children, compared with adults, and none have investigated the influence of carbohydrate (CHO) intake. We hypothesized less perturbation and a faster recovery of the immune system with exercise in children, regardless of supplemental energy. Twelve boys (9.8 Ϯ 0.1 y) and 10 men (22.1 Ϯ 0.5 y) cycled for 60 min at 70% V O 2max while drinking 6% CHO (CHO-T) or flavored water (FW-T). Blood samples were collected before (PRE), immediately after (POST), and 60 min after (REC) exercise. Boys, compared with men, had smaller (p Ͻ 0.05) increases in total leukocytes (28% versus 38%), natural killer (NK) cells (78% versus 236%), and NK T cells (42% versus 128%) at POST, averaged across beverage trials. Exercise did not increase tumor necrosis factor-␣ (TNF-␣), but significantly (p Ͻ 0.05) increased IL-6 in men (189%), but not in boys (11%). In both trials, lymphocytes and T cells at REC were suppressed (p Ͻ 0.05), relative to PRE, in men (Ϫ21%), but not in boys (4%).IL-6 remained elevated ( pϽ 0.001) in men at REC, with no change from POST in boys. In boys, but not in men, CHO significantly (p Ͻ 0.05) attenuated increases in neutrophil, lymphocyte, and NK cell counts at POST. Neutrophils at REC in CHO-T were lower (p Ͻ 0.05) than in FW-T in men ‫)%52ف(‬ and in boys ‫.)%71ف(‬ CHO had no effect on TNF-␣ or IL-6 in either group. Our results indicate a distinct pattern of the immune response to exercise and CHO intake in boys, compared with men. Strenuous exercise can significantly influence several elements of the human immune system. The magnitude and direction of changes in immune cell counts, for example, are mediated by the intensity of the activity (1, 2), the nutritional status of the subject (3, 4), and changes in stress hormones, in particular epinephrine during exercise (5) and cortisol after exercise (6). Although most immune cells increase in concentration during exercise, a brief period of immunosuppression, termed the "open window," occurs during recovery from strenuous exercise and may increase susceptibility to infection (7). Another component of the immune system response to exercise is cytokines. Cytokines serve in a network to help regulate signaling of innate and specific immune responses (8). Traditionally, cytokine responses to exercise, in particular IL-6 and TNF-␣, have been interpreted in the context of immunemediated host defense (9). However, exercise-induced increases in plasma levels of IL-6 and TNF-␣ are not always associated with simultaneous increases in their intracellular production or excretion from immune cells (10 -13). Therefore, changes in these low-molecular-weight proteins with exercise likely serve roles in addition to their control of inflammation.It is important to note, however, that our current understanding of exercise-induced changes in components of the human immune system is derived primarily from adults, and there is a paucity of data on children. With respect to immune cell counts, a few studies have reported similar respo...

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Immune Responses to Exercise and Training: A Comparison of Children and Young Adults

Cited by 12 publications

References 0 publications

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

Exercise-Induced Oxidative Stress Responses in the Pediatric Population

The association between aerobic fitness and physical activity in children and adolescents: the European youth heart study

Immune Responses to Strenuous Exercise and Carbohydrate Intake in Boys and Men

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