Erythrocyte Free Radical Scavenger Enzymes in Bicycle Professional Racers. Adaptation to Training

P, Mena; Maynar, M.; Jm, Gutiérrez; Maynar, J.I.; Timon, Jennifer; Je, Campillo

doi:10.1055/s-2007-1024734

Cited by 134 publications

(94 citation statements)

References 7 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In fact, megadoses of vitamins may even impair immune function in athletes (Prasad, 1980). Although the cellular antioxidant mechanism adapts efficiently to acute and chronic exercise (Mena et al, 1991), extreme physical exercise causes oxidative damage to athletes, which is reflected by increases in plasma levels of malondialdehyde (Marzatico et al, 1997), urine 8-hydroxideoxyguanosine (Radak et al, 2000) and erythrocyte catalase activity (Tauler et al, 1999), which could relate to exercise-induced immunodepression. Vitamin C supplementation augmented the increase in lymphocyte counts after exercise (Petersen et al, 2001;Peters et al, 2001b), attenuated the serum cortisol increase in ultramarathon runners (Peters et al, 2001a, b;Nieman et al, 2002b) and attenuated the increases in inflammatory cytokines (Nieman et al, 1997b(Nieman et al, , 2000bPeters et al, 2001a, b), when ingested in doses greater than or equal to 1000 mg/day, but not on 500 mg/day.…”

Section: Antioxidants and Vitaminsmentioning

confidence: 99%

Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis

et al. 2006

View full text Add to dashboard Cite

Background: Heavy exercise induces marked immunodepression that is multifactorial in origin. Nutrition can modulate normal immune function. Objective: To assess the efficacy of nutritional supplements in exercise-induced immunodepression in athletes. Design: Systematic review. Review methods: Randomised and/or controlled trials of athletes undertaking nutritional supplements to minimise the immunodepression after exercise were retrieved. The primary outcome measure was incidence of upper respiratory tract (URT) illness symptoms after exercise, and secondary outcomes included cortisol, cell counts, plasma cytokine concentration, cell proliferative response, oxidative burst, natural killer cell activity and immunoglobulins. When data were available for a pooled estimate of the effect of intervention, meta-analyses were conducted for direct comparisons. Results: Forty-five studies were included (1603 subjects). The studies were heterogeneous in terms of exercise interventions, selection of athletes, settings and outcomes. The overall methodological quality of most of the trials was poor. Twenty studies addressed carbohydrate supplementation, eight glutamine, 13 vitamin C and four others interventions. Three trials assessed the effect of intervention on prevention of URT infections. The pooled rate ratio for URT infections after vitamin C supplementation against placebo was 0.49 (0.34-0.71). Carbohydrate supplementation attenuated the increase in cortisol and neutrophils after exercise; vitamin C attenuated the decrease in lymphocytes after exercise. No other interventions had significant or consistent effect on any of the studied outcomes. Conclusions: Although the prevention of URT infections by vitamin C was supported by two trials, further studies are needed. The available evidence failed to support a role for other nutritional supplements in preventing exercise-induced immune suppression. Larger trials with clinically relevant and uniform end points are necessary to clarify the role of these nutritional interventions.

show abstract

Section: Antioxidants and Vitaminsmentioning

confidence: 99%

Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis

et al. 2006

View full text Add to dashboard Cite

show abstract

“…Superoxide Dismutase An acute bout of exercise has been shown to increase SOD activity in a number of biological tissues including heart (21,78,99), liver (26,43,74,100,101 ), blood platelets (102), erythrocytes (103), and skeletal muscle (29,74,99,(103)(104)(105). However, reports on the effect of exercise on SOD varies greatly among different studies with many showing no significant effect (see 105 for a review).…”

Section: Antioxidant Enzymesmentioning

confidence: 99%

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Leichtweis

1997

AGE

View full text Add to dashboard Cite

Strenuous exercise is characterized by increased oxygen consumption and the disturbance between intracellular pro-oxidant and antioxidant homeostasis. At lease three biochemical pathways (i.e., mitochondrial electron transport chain, xanthine oxidase, and polymorphoneutrophil) have been identified as potential sources of intracellular free radical generation during exercise. These deleterious reactive oxygen species pose a serious threat to the cellular antioxidant defense system, such as diminished reserves of antioxidant vitamins and glutathione. However, enzymatic and non-enzymatic antioxidants have demonstrated great versitility and adaptability in response to acute and chronic exercise. The delicate balance between pro-oxidants and antioxidants suggests that supplementation with antioxidants may be desirable for physically active individuals under certain physiological conditions by providing a larger protective margin.

show abstract

“…Mena et al 47 showed that highly trained athletes indeed have higher activities of several scavenger enzymes, but the effects of moderate training are apparently much smaller 48 . An increased need for endogenous defence against free radicals might raise the requirements for zinc and copper (in Zn 2 Cu 2 -superoxide dismutase) and selenium (in glutathione peroxidase) in physically active people.…”

Section: Factors Potentially Affecting Micronutrient Requirements In mentioning

confidence: 99%

Micronutrients: interaction between physical activity, intakes and requirements

Fogelholm

1999

Public Health Nutr.

View full text Add to dashboard Cite

The present literature review examines the following questions: (a) What is the evidence that micronutrient requirements are increased in physically active people? (b) Is there an association between physical activity and micronutrient intake? (c) Are there any significant differences between indices of micronutrient status between physically active and inactive people? The available data suggest that micronutrient requirements are increased in physically active people because of increased losses through sweat, urine and faeces, and an increased need for defence against free radicals. However the evidence is controversial, and it is not possible to make any quantitative estimations. Micronutrient requirements in moderately active people are not likely to be very much above the levels recommended for the general population. The intake of micronutrients increases with increasing energy intake. Therefore, physically highly active people (athletes) have higher micronutrient intakes than untrained subjects. However, moderate physical activity does not necessarily affect daily micronutrient intake. The available indices of micronutrient status do not support the belief that micronutrient status is compromised in highly trained athletes, even without use of dietary supplements. Hence, there are no reasons to believe that the situation would be different in people who are only moderately active. The results suggest that micronutrient status is adequate for health and functional performance in physically active people who follow a normal, mixed Western diet.

show abstract

Erythrocyte Free Radical Scavenger Enzymes in Bicycle Professional Racers. Adaptation to Training

Cited by 134 publications

References 7 publications

Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis

Nutritional modulation of exercise-induced immunodepression in athletes: a systematic review and meta-analysis

Exercise and oxidative stress: Sources of free radicals and their impact on antioxidant systems

Micronutrients: interaction between physical activity, intakes and requirements

Contact Info

Product

Resources

About