Effects of a Supplementation during Exercise and Recovery

High-Intensity Exercise and Mitochondrial Biogenesis: Current Controversies and Future Research Directions

It is well established that different types of exercise can provide a powerful stimulus for mitochondrial biogenesis. However, there are conflicting findings in the literature, and a consensus has not been reached regarding the efficacy of high-intensity exercise to promote mitochondrial biogenesis in humans. The purpose of this review is to examine current controversies in the field and to highlight some important methodological issues that need to be addressed to resolve existing conflicts.

Hydrolyzed protein supplementation improves protein content and peroxidation of skeletal muscle by adjusting the plasma amino acid spectrums in rats after exhaustive swimming exercise: a pilot study

Background

This study was designed to evaluate the effects of hydrolyzed protein supplementation upon skeletal muscle total protein and peroxidation in rats following exhaustive swimming exercise.

Methods

Twenty-four rats were randomized to 4 experimental groups (n = 6 per group): control group fed standard diet without exercise (SD), exercise (EX), exercise plus standard diet for 72 hours (EX + SD), and exercise plus standard diet supplemented with hydrolyzed protein (2 g/kg/d) for 72 hours (EX + HP). Immediately following exercise, the EX group was euthanized for collecting plasma and skeletal muscle samples. The EX + SD and EX + HP groups were fed their respective diets for 72 hour still plasma and skeletal muscle collection. Skeletal muscle samples were used to measure levels of total protein (TP), malondialdehyde (MDA), and protein carbonyl (PC). Plasma samples were used to analyze the amino acids spectrum.

Results

Compared with the EX + SD, EX + HP presented the significantly increased TP (P = 0.02) and decreased MDA and PC levels (P = 0.035). MDA was negatively correlated with the methionine levels. Moreover, EX + HP maintained higher levels of plasmaleucine, isoleucine, and methionine than EX + SD, which may be associated with the increased skeletal muscle TP levels observed (P < 0.05).

Conclusions

These results collectively suggest that hydrolyzed protein supplementation can improve skeletal muscle TP and ameliorate peroxidation damage in rats subjected to exhaustive exercise stress, which may be, at least in part, related with the maintenance of plasma leucine, isoleucine, and methionine levels.

Acute exercise and oxidative stress: a 30 year history

The topic of exercise-induced oxidative stress has received considerable attention in recent years, with close to 300 original investigations published since the early work of Dillard and colleagues in 1978. Single bouts of aerobic and anaerobic exercise can induce an acute state of oxidative stress. This is indicated by an increased presence of oxidized molecules in a variety of tissues. Exercise mode, intensity, and duration, as well as the subject population tested, all can impact the extent of oxidation. Moreover, the use of antioxidant supplements can impact the findings. Although a single bout of exercise often leads to an acute oxidative stress, in accordance with the principle of hormesis, such an increase appears necessary to allow for an up-regulation in endogenous antioxidant defenses. This review presents a comprehensive summary of original investigations focused on exercise-induced oxidative stress. This should provide the reader with a well-documented account of the research done within this area of science over the past 30 years.

Aplicação da escala de conhecimento nutricional em atletas profissionais e amadores de atletismo

Uma alimentação adequada é necessária para suprir a demanda energética requerida pelo exercício tanto para esportistas como para atletas. Porém, muito mais do que o rendimento no esporte, o conhecimento sobre nutrição para prevenção de doenças é fundamental para ambas as populações. Muitas intervenções centradas na educação nutricional têm sido conduzidas com o intuito de aumentar o conhecimento nutricional da população e, conseqüentemente, melhorar seus hábitos alimentares. O presente estudo tem por objetivo avaliar o conhecimento nutricional de atletas profissionais e amadores de atletismo por meio da aplicação de uma escala previamente validada no Brasil. A amostra foi composta por 26 atletas profissionais e 41 atletas amadores de atletismo de diversas modalidades em fase de treinamento contínuo. Os resultados mostraram que atletas profissionais e amadores de atletismo apresentaram, de modo geral, conhecimento nutricional moderado, sendo que este último apresentou pontuação significativamente maior que o grupo de profissionais, fato este associado ao maior grau de instrução/escolaridade. Conclui-se que atletas profissionais de atletismo apresentam conhecimento nutricional inferior a amadores, o que pode ser atribuído, em parte, ao fato destes vivenciarem a ciência da nutrição com o objetivo primário de rendimento esportivo. Na continuidade deste estudo, novas aplicações da escala em atletas profissionais e amadores devem ser realizadas para possível afirmação do nível de conhecimento nutricional desta população.