Aerobic and anaerobic training effects on the antioxidant enzymes of the blood

Biomarkers of post-match recovery in semi-professional and professional football (soccer)

High-level football (soccer) players face intense physical demands that result in acute and residual fatigue, impairing their physical performance in subsequent matches. Further, top-class players are frequently exposed to match-congested periods where sufficient recovery times are not achievable. To evaluate training and recovery strategies, the monitoring of players' recovery profiles is crucial. Along with performance and neuro-mechanical impairments, match-induced fatigue causes metabolic disturbances denoted by changes in chemical analytes that can be quantified in different body fluids such as blood, saliva, and urine, thus acting as biomarkers. The monitoring of these molecules might supplement performance, neuromuscular and cognitive measurements to guide coaches and trainers during the recovery period. The present narrative review aims to comprehensively review the scientific literature on biomarkers of post-match recovery in semi-professional and professional football players as well as provide an outlook on the role that metabolomic studies might play in this field of research. Overall, no single gold-standard biomarker of match-induced fatigue exists, and a range of metabolites are available to assess different aspects of post-match recovery. The use of biomarker panels might be suitable to simultaneously monitoring these broad physiological processes, yet further research on fluctuations of different analytes throughout post-match recovery is warranted. Although important efforts have been made to address the high interindividual heterogeneity of available markers, limitations inherent to these markers might compromise the information they provide to guide recovery protocols. Further research on metabolomics might benefit from evaluating the long-term recovery period from a high-level football match to shed light upon new biomarkers of post-match recovery.

Consumption of Spinacia Oleracea (spinach) and aerobic exercise controls obesity in rats by an inhibitory action on pancreatic lipase

Context: Spinaciaoleracea (spinach) is abundant in antioxidant phytoconstituents, termed as the natural antioxidant mixture (NAO).Objective: This study evaluates the anti-hyperlipidemicand anti-obesity effects of an antioxidant-rich extract of Spinaciaoleracea (NAOE) and aerobic exercise (AE) in rats fed with high fat diet (HFD).Methods: Rats received NAOE (200 and 400 mg/kg), the standard drug orlistat (10 mg/kg), AE and NAOEAE (NAOE 400 mg/kg + AE) daily with HFD for 21 d.Results: Orlistat, NAOE and NAOEAE treatments to HFD-fed rats significantly reduced the HFD-elevated food intake, weight gain, pancreatic lipase activity and lipid peroxidation, and successfully restored the HFD-skewed lipid profile and antioxidant levels.Conclusions: It may be concluded that NAOE exhibited a promising anti-hyperlipidemic effect by its inhibitory action on pancreatic lipase. The combination treatment NAOEAE produced the best results indicating the essential role of exercise along with consumption of antioxidant-rich foods in maintaining a normal lipid profile and controlling obesity.

Effects of different loading exercises on apelin levels and physical and hematologic parameters of swimmers

Background

The purpose of this study was to investigate the effects of different exercise loads (short, medium and long swimming distances) on apelin levels and some physical and hematologic parameters of male professional swimmers.

Materials and methods

Apelin levels, hematologic parameters, whole blood values and physical measurements, including body mass index (BMI), aerobic power values and anaerobic power values, were also obtained.

Results

It was determined that the thrombocyte, erythrocyte and leukocyte values from the hematologic parameters increased after exercise (p < 0.05). According to the results, there were significant differences (p < 0.05) between the pretest apelin level (2090.75 pg/mg) and the apelin levels taken after swimming M 200 m (4260.43 pg/mg) and after swimming L 400 m (3694.4 pg/mg).

Conclusions

The different exercise loads had significant effects on the hematologic parameters and apelin values in the swimmers. The study also determined the relationships between swimming exercises and aerobic and anaerobic capacity and BMI.

The effects of physical activity on cancer prevention, treatment and prognosis: A review of the literature

INTRODUCTION

The World Health Organization has reported that approximately 35% of cancer-related deaths are attributed to modifiable risk factors. Among the most important risk factors amenable to modification are obesity and lack of physical activity. The purpose of this article is to review the current evidence of the benefits of physical activity in various types of cancer.

METHODS

A PubMed search for the key words "physical activity and cancer" as well as "exercise and cancer" was used to identify all indexed publications on this topic for potential utilization in this review. One MET was defined as the amount of oxygen consumed while a person is sitting quietly and is about 3.5 mL O2/kg body weight/min. MET represents the ratio of the working metabolic rate to the resting metabolic rate.

RESULTS

Routine physical activity was found to be associated with a reduced incidence of several of the most common malignancies, including colon, breast, lung, and endometrial cancer as well as many others. Physical activity also appears to reduce all-cause mortality and cancer-related mortality among patients with breast and colon cancer, and may improve the functional status and quality of life for these patients during cancer therapy.

CONCLUSIONS

The benefits of physical activity in the prevention and progression of cancer patients are multiple. However, the strength of the available evidence is limited by the observational nature of most studies. Given the probable improvement in prevention, mortality, and quality of life with structured physical activity in different malignancies, it is important that healthcare providers discuss physical activity programs with their cancer patients. Larger randomized trials are recommended.

Physical Exercise and DNA Injury: Good or Evil?

Regular, low-intensity physical activity is currently advocated for lowering the risk of developing many acute and especially chronic diseases. However, several lines of evidence attest that strenuous exercise may enhance inflammation and trigger the generation of free radical-mediated damage, thus overwhelming the undisputable benefits of regular, medium-intensity physical activity. Since reactive oxygen species are actively generated during high-intensity exercise, and these reactive compounds are known to impact DNA stability, we review here the current evidence about strenuous exercise and DNA injury. Despite the outcome of the various studies cannot be pooled due to considerable variation in design, sample population, outcome, and analytical techniques used to assess DNA damage, it seems reasonable to conclude that medium- to high-volume exercise triggers a certain amount of DNA injury, which appears to be transitory and directly proportional to exercise intensity. This damage, reasonably attributable to direct effect of free radicals on nucleic acids, is efficiently repaired in vivo within 24-72h. Therefore, physical exercise should not bear long-term consequences for athlete's health provided that an appropriate time of recovery between volumes of high-intensity exercise is set. Regular exertion, with a step-by-step increase of exercise load, also seems to be the most safe approach for eluding DNA instability.

Oxidative stress status in elite athletes engaged in different sport disciplines

Exercise training may increase production of free radicals and reactive oxygen species in different ways. The training type and intensity may influence free radicals production, which leads to differences in oxidative stress status between athletes, but the results of the previous studies are incosistent. The aim of our study was to estimate oxidative stress status in elite athletes engaged in different sport disciplines. The study included 39 male highly skilled professional competitors with international experience (2 Olympic players): 12 wrestlers, 14 soccer players and 13 basketball players in whom we determined the levels of advanced oxidation protein products (AOPP) and malondialdehyde (MDA), as markers of oxidative stress and the total antioxidative capacity (ImAnOX) using commercially available assay kits. The mean AOPP concentration was not significantly different between soccer players, wrestler and basketball players (60.0 ± 23.0 vs. 68.5 ± 30.8 and 80.72 ± 29.1 μmol/L respectively). Mean ImAnOX concentration was not different between soccer players (344.8 ± 35.6 μmol/L), wrestlers (342.5 ± 36.2 μmol/L) and basketball players (347.95 ± 31.3 μmol/L). Mean MDA concentration was significantly higher in basketball players (1912.1 ± 667.7 ng/mL) compared to soccer players (1060.1 ± 391.0 ng/mL, p=0.003). In spite of this fact, oxidative stress markers levels were increased compared to referral values provided by the manufacturer. Type of sports (soccer, wrestler or basketball) have no impact on the levels of oxidative stress markers. Elite sports engagement is a potent stimulus of oxidative stress that leads to the large recruitment of antioxidative defense. Oxidative stress status monitoring followed by appropriate use of antioxidants is recommended as a part of training regime.

Oxidative stress and total antioxidant capacity in handball players

Background:

Exercise training increases oxygen consumption, which was associated with the high generation of reactive oxygen species and markers of lipid peroxidation in the blood. The aim of this study was to assess the responses of total antioxidant capacity (TAC), biomarker of oxidative stress and erythrocyte, leukocyte and hematocrit (Hct) levels in plasma in athlete girls (handball players) and non-athlete girls.

Materials and Methods:

We evaluated two groups, which known as athlete and non-athlete women and they were similar in anthropometric characteristics. The athletic women engaged in the regular handball training 3 times a week for at least 6 months. However, non-athletic women didn’t have any regular activity over the last 6 months. Each subject referred to the lab and after 12 h fasting, the blood samples were taken for measuring all variables. Independent sample t-tests were used to identify the differences.

Result:

Significant differences were observed in malondehyde (P = 0.00), red blood (P = 0.00) cell and hemoglobin (P = 0.00). However, other evaluated factors such as of TAC, white blood cell, Hct and the mean corpuscular volume were higher in athletes than in non-athletes, but statistical significant differences weren’t seen in these variables between two groups.

Conclusion:

Regular exercise training for handball players may increase the activity of antioxidant enzymes and blood cells and reduces oxidant production.

The pharmacology of actoprotectors: practical application for improvement of mental and physical performance

Actoprotectors are preparations that enhance body stability against physical loads without increasing oxygen consumption or heat production. Or, in short, actoprotectors are synthetic adaptogens with a significant capacity to improve physical performance. This paper explores the history of actoprotectors’development, their pharmacological properties, mechanism of action, and practical application to the improvement of mental and physical performance. A brief summary of the clinico-pharmacological characteristics of the main representatives of this class (bemitil and bromantane) is provided. Some other synthesized compounds, and even natural ones such as ginseng, also are regarded as potential actoprotectors, and these are treated herein as well. Actoprotectors, owing to their wide-ranging pharmacological activities, high efficiency and safety, can be applied under either normal or extreme conditions.

Exercise is the real polypill

The concept of a "polypill" is receiving growing attention to prevent cardiovascular disease. Yet similar if not overall higher benefits are achievable with regular exercise, a drug-free intervention for which our genome has been haped over evolution. Compared with drugs, exercise is available at low cost and relatively free of adverse effects. We summarize epidemiological evidence on the preventive/therapeutic benefits of exercise and on the main biological mediators involved.

Hematological, oxidative stress, and immune status profiling in elite combat sport athletes

The aim of this study was to profile hematological, oxidative stress, and immunological parameters in male athletes who practiced combat sports and to determine whether the type of combat sport influenced the measured parameters. Eighteen karate professionals, 15 wrestlers, and 14 kickboxers participated in the study. Hematological, iron-related, oxidative stress, and immunological parameters were measured at the beginning of a precompetitive period. The general linear model showed significant differences between the karate professionals, wrestlers, and kickboxers with respect to their hematological and iron status parameters (Wilks' Lambda = 0.270, F = 2.186, p < 0.05) and oxidative stress status (Wilks' Lambda = 0.529, F = 1.940, p < 0.05). The immature reticulocyte fraction was significantly higher in wrestlers (0.30 ± 0.03) compared with kickboxers (0.24 ± 0.04; p < 0.05) and karate professionals (0.26 ± 0.04; p < 0.05). Low hemoglobin density was significantly lower in wrestlers and kickboxers (p < 0.05) compared with karate professionals (karate: 3.51 ± 1.19, wrestlers: 1.95 ± 1.10, and kickboxers: 1.77 ± 0.76). Significant differences were observed between the karate professionals and wrestlers with respect to their pro-oxidant-antioxidant balance (437 ± 103 vs. 323 ± 148, p < 0.05) and superoxide-dismutase activity (SOD) (73 ± 37 vs. 103 ± 30, p < 0.05). All the measured parameters (with the exception of SOD activity) fell within their physiological ranges, indicating that the study participants represented a young and healthy male population. Hematological parameters differed between kickboxers and karate professionals. The low pro-oxidant-antioxidant balance and high SOD activity in wrestlers could be associated with the long-term impact of wrestling as a type of strenuous exercise.

Respostas bioquímicas e físicas ao treinamento realizado dentro e fora da água em atletas de futsal

O objetivo deste estudo foi analisar os efeitos do treinamento físico em quadra e do treinamento físico em piscina (hidroginástica) sobre os índices bioquímicos relativos ao dano muscular e a aptidão física de atletas de futsal. Doze jogadores de futsal foram divididos em dois grupos: 1) grupo de treinamento em quadra (GTQ, n = 6) e 2) grupo de treinamento em piscina (GTP, n =6). Foram verificados os índices de capacidades aeróbicas e aneróbicas pelos testes de RAST e Yo-yo intermitent, o dano muscular pela creatina quinase (CK) e lactato desidrogenase (LDH) e os níveis de stress oxidativo pelos níveis de ácido tiobarbitúrico (TBARS) e atividade da catalase (CAT) antes e após 10 sessões de trainamento (p<0,05). Os resultados mostraram que ambos os grupos melhoraram a condição aeróbica após as 10 sessões de treinamento. Mas o GTP apresentou maior atividade da CAT em repouso e menores níveis de CK ao ser comparado com o GTQ na 10ª sessão de treino. Concluiu-se que o treino com hidroginástica parece ser uma alternativa interessante para a melhoria das capacidades físicas e para a proteção muscular durante a preparação física inicial de atletas de futsal.

Pilot study: Effects of drinking hydrogen-rich water on muscle fatigue caused by acute exercise in elite athletes

Background

Muscle contraction during short intervals of intense exercise causes oxidative stress, which can play a role in the development of overtraining symptoms, including increased fatigue, resulting in muscle microinjury or inflammation. Recently it has been said that hydrogen can function as antioxidant, so we investigated the effect of hydrogen-rich water (HW) on oxidative stress and muscle fatigue in response to acute exercise.

Methods

Ten male soccer players aged 20.9 ± 1.3 years old were subjected to exercise tests and blood sampling. Each subject was examined twice in a crossover double-blind manner; they were given either HW or placebo water (PW) for one week intervals. Subjects were requested to use a cycle ergometer at a 75 % maximal oxygen uptake (VO₂) for 30 min, followed by measurement of peak torque and muscle activity throughout 100 repetitions of maximal isokinetic knee extension. Oxidative stress markers and creatine kinase in the peripheral blood were sequentially measured.

Results

Although acute exercise resulted in an increase in blood lactate levels in the subjects given PW, oral intake of HW prevented an elevation of blood lactate during heavy exercise. Peak torque of PW significantly decreased during maximal isokinetic knee extension, suggesting muscle fatigue, but peak torque of HW didn’t decrease at early phase. There was no significant change in blood oxidative injury markers (d-ROMs and BAP) or creatine kinease after exercise.

Conclusion

Adequate hydration with hydrogen-rich water pre-exercise reduced blood lactate levels and improved exercise-induced decline of muscle function. Although further studies to elucidate the exact mechanisms and the benefits are needed to be confirmed in larger series of studies, these preliminary results may suggest that HW may be suitable hydration for athletes.

Oxidative stress effects on endothelial cells treated with different athletes' sera

PURPOSE

Exercise training is a nonpharmacological intervention that improves cardiovascular function and enhances endothelial homeostasis in patients with cardiovascular diseases. However, the amount of benefit achieved varies widely depending on the type and duration of exercise. Moreover, data about the long-term effects of physical activity are scarce.

METHODS

In this study, endothelial cells, exposed or not to oxidative stress, were conditioned with sera from athletes regularly participating in sports classified as "aerobic" (triathlon), "mixed aerobic-anaerobic" (soccer), and "anaerobic" (sprint running).

RESULTS

Functional and hemodynamic variables did not differ between groups of athletes, whereas there were dramatic changes in serum markers for oxidative stress. Lipid peroxidation assessed by the thiobarbituric acid reactive substances assay and catalase activity were the lowest and nitric oxide availability was the highest in sera of triathletes. Endothelial cells cultured in serum from triathletes (T-endothelial cells) had the highest survival, evaluated by viability assay, BrdU incorporation, and senescence-associated β galactosidase assays, and preserved the endothelial appearance before and after stress in contrast to the cells grown in sera from the other athletes. T-endothelial cells also had the highest catalase messenger RNA expression and, after stress, the highest catalase activity of all the endothelial cells. Moreover, poststress activity of Sirt1, a NAD(+)-dependent deacetylase involved in cellular stress resistance and a key regulator of longevity, was significantly increased in T-endothelial cells.

CONCLUSIONS

Different types of exercise training induced different molecular effects in terms of survival, morphology, and antioxidant system efficiency. The in vitro technique used herein may help to shed light on the molecular basis of effects of long-term physical activity in humans.

Effects of physical activity on cancer prevention

Results of most epidemiological and laboratory studies suggest an inverse relationship between regular exercise and the risk of certain malignancies, such as intestinal, colon, pancreatic, breast, lung, skin, mammary, endometrial, and prostate cancer. However, physical activity can have different influence on carcinogenesis, depending on energy supply and the age of the subject as well as strength, frequency, and length of exercise. The biochemical and molecular basis of the interaction between aerobic physical activity and tumorigenic processes remains poorly understood. Physical activity may generate reactive oxygen species (ROS) to a different extent. Mild oxidative stress caused by moderate physical activity can activate cellular stress response signaling and potentiate cellular antioxidant defense capacity. However, accumulation of relatively large amounts of ROS as a consequence of exhaustive exercise can either directly damage DNA, causing mutation, or promote tumorigenesis by activating proinflammatory signaling. This review highlights the effects of physical activity on various malignancies in the context of redox status modulated during exercise.

Aspectos sobre a relação entre exercício físico, estresse oxidativo e zinco

Este trabalho visa a contribuir com informações sobre a relação entre exercício físico, estresse oxidativo e zinco. A formação de espécies reativas de oxigênio durante o exercício pode contribuir para danos tissulares e celulares, prejudicando o desempenho do atleta. Podem amenizar esses efeitos alguns minerais, como o zinco, que atuam como cofator da enzima superóxido dismutase e na regulação da síntese da metalotioneína, proteínas importantes no sistema de defesa antioxidante. No exercício físico, ocorrem distúrbios na compartimentalização do zinco, com alterações da concentração desse mineral em compartimentos celulares. No entanto, os mecanismos envolvidos no comportamento metabólico do zinco bem como a participação do mineral na melhora do desempenho físico ainda não estão totalmente esclarecidos. Dessa forma, conclui-se que a distribuição do zinco em organismos submetidos ao estresse oxidativo e os efeitos da deficiência desse mineral na capacidade antioxidante durante o exercício ainda devem ser pesquisados mais profundamente.

Oxidative stress and inflammatory parameters after an Ironman race

OBJECTIVE

The aim of the present study was to investigate oxidative stress markers and inflammatory response in triathletes after an Ironman race (IR).

DESIGN

Descriptive research.

PARTICIPANTS

Eighteen well-trained male triathletes (mean age, 34.7 +/- 2.15 years; weight, 69.3 +/- 1.9 kg; height, 1.81 +/- 0.58 cm) participated in the study.

SETTING

Ironman Triathlon (3.8-km swim, 180-km cycle, 42.2-km run). Mean environmental conditions ranged from 20 to 25 degrees C and from 79% to 85% relative humidity.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Before the race and up to 20 minutes after completing the full race, the weights and heights of volunteers were measured and a 10 mL blood sample was drawn from an antecubital vein. Aliquots of washed/lysed red blood cells and plasma/serum samples were stored at -80 degrees C. Lipid peroxidation, protein carbonylation, superoxide dismutase and catalase activities, and cytokines levels [tumor necrosis factor alpha (TNF-alpha), interleukin (IL)-6, IL-10, and IL-1ra] were determined.

RESULTS

After the IR, the results showed a significant increase in TBARS levels (prerace = 1.15 +/- 0.11; postrace = 1.98 +/- 0.27), lipid hydroperoxide content (prerace = 0.75 +/- 0.03; postrace = 1.46 +/- 0.18), protein carbonylation (prerace = 0.67 +/- 0.12; postrace = 2 0.15 +/- 0.60), superoxide dismutase (prerace = 2.67 +/- 0.62; postrace = 3.97 +/- 1.48), and catalase (prerace = 1.48 +/- 0.18; postrace = 2.84 +/- 0.39). TNF-alpha, IL-6, and IL-10 were not detected at basal conditions, but all markers were significantly increased after the IR (TNF-alpha: prerace = ND and postrace = 67.47 +/- 10.34; IL-6: prerace = ND and postrace = 55.41 +/- 3.45; IL-10: prerace = ND and postrace = 122.53 +/- 9.69; IL-1ra: prerace = 127.79 +/- 25.65 and postrace = 259.51 +/- 32.9).

CONCLUSIONS

An Ironman race provokes significant alterations in oxidative stress and inflammatory parameters. Thus, more studies with other markers and different designs are needed to elucidate the cellular alterations induced by an IR.

Vitamin E and aerobic exercise: effects on physical performance in older adults

BACKGROUND AND AIMS

Aerobic endurance exercise enhances antioxidant defenses and improves the physical performance of older adults. However, the combined effect on physical performance of exercise and an antioxidant such as vitamin E has not been investigated. The purpose of this study was to evaluate the effects of six months of vitamin E supplementation and supervised aerobic training on physical performance and body composition in sedentary older adults.

METHODS

Fifty-seven adults, whose average age was 71.5+/-7.5 years, were randomly assigned to an exercise (E), exercise-vitamin (EV), control (C) or vitamin (V) group, and were evaluated before, halfway through, and after training. The dose of vitamin E was 900 IU/day. The training program comprised three sessions of walking exercise per week, at an intensity of 70% of heart rate reserve.

RESULTS

In the E and EV groups, the training program significantly reduced (p<0.016 for each) body weight and body mass index (BMI), and improved performance in the 6- min walk, chair stand, arm curl, and back scratch tests. Performance on the 6-min walk test improved in E and EV, but decreased in the V group. Performance on the chair stand test increased in the EV and E groups, but decreased in the V and C groups. Body weight and BMI decreased more in the EV group than in the C and V groups (p<0.016).

CONCLUSIONS

Six months of vitamin E supplementation has no additive effect beyond that of aerobic training on indices of physical performance and body composition in older sedentary adults.

The effect of methyl sulphonyl methane supplementation on biomarkers of oxidative stress in sport horses following jumping exercise

Background

Exercise induces changes in several organs and tissues, and this process might be due to oxidative damage caused by free radicals and inflammatory mediators. Methyl Sulphonyl Methane, better known as MSM, is a naturally occurring sulphur compound with well-known antioxidant properties. On the other hand, Vitamin C is important in limiting free radical damage in the aqueous phase of the cell, and cellular vitamin C status may be linked to the mechanisms involved in quenching cellular reactive oxygen species. The aim of this study was to determine if supplementation with MSM and vitamin C could alleviate exercise-induced oxidative stress in horses undergoing jumping competition.

Methods

Twenty four jumping horses involved in competition were used. Horses were given the following three treatment diets: control (without supplementation), MSM 8 mg/kg, and combined supplements (MSM 8 mg/kg + Vit-C 5 mg/kg). EDTA blood samples were collected before exercise, upon arrived to the schooling area (control), and each week after last show. Nitric oxide, carbon monoxide, lipid hydroperoxides and the antioxidant enzymes, glutathione peroxidase, glutathione transferase and glutathione reductase, plasma levels were determined.

Results

Competition induced a significant increase in lipid peroxidation, nitric oxide and carbon monoxide. By contrary, reduced glutathione as well as antioxidant enzyme activities, were decreased. MSM administration significantly ameliorated all these exercise-related changes, and this effect was potentiated by Vit C reaching values in some of the parameters similar to those found before competition.

Conclusion

These results suggest that jumping exercise could induce harmful effects on horses, probably due to an increase in oxidative damage and proinflammatory molecules. In addition, we have demonstrated that MSM could exert some protective effect on oxidative and inflammatory exercise-induced injury.

Apoptosis and antioxidant status are influenced by age and exercise training in horses

Eight mature (12 +/- 2 yr; MAT) and 5 older (22 +/- 2 yr; OLD) Standardbred mares were used to test the hypothesis that aging and exercise training would alter apoptosis in white blood cells and antioxidant status. The horses were housed indoors overnight (16 h/d) in 3 m x 3 m stalls and were turned out in a drylot during the day. They were fed a diet consisting of total mixed ration, hay cubes fed ad libitum or an equine senior diet plus grass hay. Horses were trained for 20 to 30 min/d, 3 to 5 d/wk for 8 wk at a submaximal work intensity between 60 to 70% of maximal heart rate. A graded exercise test (GXT; stepwise test until exhaustion) was performed before (GXT1) and after (GXT2) the 8 wk of training. During the GXT, blood samples and heart rate were taken at rest, 6 m/s, fatigue, and at 5 and 60 min postfatigue. Fatigue plasma lactate concentration was greater in MAT (19.3 +/- 1.5 at 10 m/s) compared with the OLD (10.9 +/- 1.2 mmol/L at 9 m/s; P = 0.008) horses. There was no effect of age or training on plasma lipid hydroperoxide (LPO) concentration. However, there was a positive correlation between LPO and plasma lactate concentration (r = 0.27, P = 0.006) during acute exercise. There was a greater concentration of total glutathione after GXT1 than after GXT2 (111.8 +/- 5.0 vs. 98.6 +/- 3.4 microM, respectively; P = 0.0002) for both age groups. Apoptosis was less (P = 0.002) in white blood cells of the MAT vs. the OLD group. These results demonstrate that older horses are under similar amounts of oxidative stress, measured by LPO, and have similar levels of glutathione in their systems compared with mature horses. The observation that more glutathione was needed during GXT1 for both groups of horses indicates that training helps horses adapt their system for the intense post-training exercise tests. The greater level of white blood cell apoptosis also indicates that older horses may be immune-compromised during exercise. However, research still needs to be performed regarding dietary supplementation in the aged horse.

Aspectos atuais sobre estresse oxidativo, exercícios físicos e suplementação

As espécies reativas de oxigênio (ERO) são normalmente produzidas pelo metabolismo corporal. Todavia, ERO apresentam a capacidade de retirar elétrons de outros compostos celulares, sendo capazes de provocar lesões oxidativas em várias moléculas, fato que leva à perda total da função celular. A realização de exercícios físicos aumenta a síntese de ERO, além de promover lesão muscular e inflamação. Após uma sessão de exercícios físicos, inicia-se normalmente a fase de recuperação, quando são observados diversos efeitos positivos à saúde, incluindo o aumento da resistência a novas lesões induzidas ou não por exercícios, fato que é considerado como um processo "adaptativo". Diversos estudos, porém, relatam que essa recuperação não é alcançada por indivíduos que se submetem a exercícios intensos e prolongados, ou, ainda, que possuem elevada freqüência de treinamento. Alternativas nutricionais têm sido muito estudadas, a fim de reduzir os efeitos promovidos pelo exercício extenuante, dentre as quais está a suplementação com vitamina E, vitamina C, creatina e glutamina. Esta revisão tem como objetivo abordar os aspectos atuais envolvendo a formação das ERO, os processos de lesão celular e inflamação, a adaptação aos tipos de exercício aeróbio e anaeróbio e possíveis intervenções nutricionais.

Leptin, superoxide dismutase, and weight loss: initial leptin predicts weight loss

OBJECTIVE

Our goal was to study how plasma leptin concentration, superoxide dismutase (SOD) activity, and weight loss are related in obese adults.

RESEARCH METHODS AND PROCEDURES

Serum leptin concentration, SOD activities, general biochemical data, and body composition measurements were obtained for 62 overweight and obese subjects before and after an 8-week body weight reduction (BWR) regimen. The subjects were on dietary control, performed moderate aerobic and strength training exercises, and attended educational lectures.

RESULTS

The measurement results indicated that the following criteria were significantly reduced: body weight [84.4 +/- 17.0 vs. 79.3 +/- 16.1 (standard error) kg, p < 0.001]; BMI (31.5 +/- 4.3 vs. 29.4 +/- 4.2 kg/m(2), p < 0.001), and fat mass (33.3 +/- 10.0 vs. 29.8 +/- 10.4 kg, p < 0.001). Plasma leptin levels also significantly decreased from 31.5 +/- 17.6 to 26.5 +/- 17.2 ng/mL (p < 0.001). Additionally, SOD activity was significantly increased from 261.4 +/- 66.0 to 302.7 +/- 30.9 U/mL (p < 0.001). Based on linear regression analysis results, a 3.78- to 8.13-kg reduction in weight can be expected after the 8-week BWR regimen when initial leptin concentration was 5 to 30 ng/mL.

DISCUSSION

We found that an 8-week exercise and diet program was effective in reducing weight and fat mass and, notably, had further beneficial effects on leptin resistance and SOD activity. Additionally, this study demonstrated that initial plasma leptin concentration may be used as a predictor for weight loss outcome.

Oxidative stress : relationship with exercise and training

Free radicals are reactive compounds that are naturally produced in the human body. They can exert positive effects (e.g. on the immune system) or negative effects (e.g. lipids, proteins or DNA oxidation). To limit these harmful effects, an organism requires complex protection - the antioxidant system. This system consists of antioxidant enzymes (catalase, glutathione peroxidase, superoxide dismutase) and non-enzymatic antioxidants (e.g. vitamin E [tocopherol], vitamin A [retinol], vitamin C [ascorbic acid], glutathione and uric acid). An imbalance between free radical production and antioxidant defence leads to an oxidative stress state, which may be involved in aging processes and even in some pathology (e.g. cancer and Parkinson's disease). Physical exercise also increases oxidative stress and causes disruptions of the homeostasis. Training can have positive or negative effects on oxidative stress depending on training load, training specificity and the basal level of training. Moreover, oxidative stress seems to be involved in muscular fatigue and may lead to overtraining.

The influence of season on oxidant–antioxidant status in trained and sedentary subjects

The association between oxidative stress and cardiovascular diseases is a widely accepted fact today. Generally, men have a higher risk of cardiovascular incidents and mortality from acute myocardial infarction and strokes. We have examined sport-associated circannual rhythms of oxidant and antioxidant processes by measuring plasma LPO, erythrocyte SOD, CAT, Gpx activity and plasma hormonal status in both sedentary and long-term trained men and women. We have shown seasonal variations in both oxidant and antioxidant status in all examined groups. The largest difference was observed in the oxidant status between sedentary men and women during autumn and winter, which is considered a period of high coronary risk for men. Sport decreased LPO in trained men in autumn, while the same effect in trained women was shifted towards summer. These data state that regular, long-term physical exercise training induces adaptive responses that confer protection against oxidative stress, as well as the beneficial effect of exercise with regard to season, particularly in men during a period of high coronary risk (autumn and winter, respectively) and in women during summer.

Response of blood cell antioxidant enzyme defences to antioxidant diet supplementation and to intense exercise

BACKGROUND

Exhaustive exercise induces oxidative stress. The cellular antioxidant defence systems have demonstrated great adaptation to chronic exercise.

AIM

To establish the influence of the antioxidant diet supplementation on the erythrocyte and lymphocyte antioxidant enzyme activities in athletes at basal and post-exercise levels.

METHODS

Fifteen amateur trained male athletes were randomly distributed in two groups: control and antioxidant supplemented (90 days' diet supplementation with 500 mg/day vitamin E and 30 mg/day beta-carotene, and the last 15 days also with 1 g/day vitamin C). The study was double blind. Maximal and submaximal exercise tests were performed after three months of diet supplementation. The study was developed during the training and competition season.

RESULTS

The sportsmen of the supplemented group presented significantly higher plasmatic final levels of vitamin C, vitamin E and beta-carotene. Erythrocyte glutathione reductase activity significantly decreased in the placebo group but was maintained in the supplemented group after the three months studied. The erythrocyte superoxide dismutase activity increased after the training/competition period in the placebo group. Lymphocyte catalase and glutathione peroxidase activities increased significantly in the supplemented group after the supplementation period but were maintained in the placebo group. No effects of the antioxidant supplementation were observed in the erythrocyte antioxidant enzyme response to the exercise tests. The antioxidant supplementation induced a better adaptation of lymphocyte catalase after submaximal test.

CONCLUSIONS

Lymphocytes showed higher sensibility to antioxidant supplementation, improving the response of antioxidant enzymes to training and to acute exercise. In erythrocytes the training adaptations were more important than the antioxidant supplementation effects.

Soy versus whey protein bars: effects on exercise training impact on lean body mass and antioxidant status

Background

Although soy protein may have many health benefits derived from its associated antioxidants, many male exercisers avoid soy protein. This is due partly to a popular, but untested notion that in males, soy is inferior to whey in promoting muscle weight gain. This study provided a direct comparison between a soy product and a whey product.

Methods

Lean body mass gain was examined in males from a university weight training class given daily servings of micronutrient-fortified protein bars containing soy or whey protein (33 g protein/day, 9 weeks, n = 9 for each protein treatment group). Training used workouts with fairly low repetition numbers per set. A control group from the class (N = 9) did the training, but did not consume either type protein bar.

Results

Both the soy and whey treatment groups showed a gain in lean body mass, but the training-only group did not. The whey and training only groups, but not the soy group, showed a potentially deleterious post-training effect on two antioxidant-related related parameters.

Conclusions

Soy and whey protein bar products both promoted exercise training-induced lean body mass gain, but the soy had the added benefit of preserving two aspects of antioxidant function.

Radicais livres de oxigênio e exercício: mecanismos de formação e adaptação ao treinamento físico

O interesse acerca dos mecanismos de geração e adaptação de radicais livres de oxigênio (RLO) ao exercício aumentou significativamente a partir da demonstração de sua relação com o consumo de oxigênio. Os RLO são formados pela redução incompleta do oxigênio, gerando espécies que apresentam alta reatividade para outras biomoléculas, principalmente lipídios e proteínas das membranas celulares e, até mesmo, o DNA. As injúrias provocadas por estresse oxidativo apresentam efeitos cumulativos e estão relacionadas a uma série de doenças, como o câncer, a aterosclerose e o diabetes. O exercício físico agudo, em função do incremento do consumo de oxigênio, promove o aumento da formação de RLO. No entanto, o treinamento físico é capaz de gerar adaptações capazes de mitigar os efeitos deletérios provocados pelos RLO. Estas adaptações estão relacionadas a uma série de sistemas, dos quais os mais importantes são os sistemas enzimáticos, compostos pela superóxido dismutase, catalase e glutationa peroxidase, e o não enzimático, composto por ceruloplasmina, hormônios sexuais, coenzima Q, ácido úrico, proteínas de choque térmico e outros. Tais adaptações, apesar das controvérsias sobre os mecanismos envolvidos, promovem maior resistência tecidual a desafios oxidativos, como aqueles proporcionados pelo exercício de alta intensidade e longa duração. As técnicas de avaliação de estresse oxidativo, na maioria das vezes, não são capazes de detectar injúria em exercícios de curta duração. Dessa forma, esforços estão sendo feitos para o estudo de esforços físicos realizados por longos períodos de tempo ou efetuados até a exaustão. Novos marcadores de lesão por ação dos RLO estão sendo descobertos e novas técnicas para sua determinação estão sendo criadas. O objetivo deste trabalho é discutir os mecanismos da formação dos RLO e das adaptações ao estresse oxidativo crônico provocado pelo treinamento físico.

Antioxidant enzyme expression in health and disease: effects of exercise and hypertension

Antioxidant enzymes (superoxide dismutases, catalase and glutathione peroxidase) are components of an organism's mechanisms for combating oxidative stress which is generated in normal metabolism and which may also be a reaction in response to external stimuli. This review identifies the general significance of antioxidant enzymes in health and disease, and some of the diseases that are now believed to have oxidative stress as a component. A discussion is then presented of the molecular mechanisms by which antioxidant enzyme expression is controlled at the transcriptional and post-transcriptional levels. The final sections of the review highlight the effects of exercise and hypertension on antioxidant enzyme expression in a number of different tissues, and the possibilities for future studies in these areas are discussed.