Sunday, March 2, 2008

February News: Fatigue

1. Low-intensity exercise boosts energy and relieves fatigue.
The NYT has a story on a new study showing what many of us already know. If I feel sleepy at work, I sometimes get out for a 15 minute brisk walk, and voila! I am back in the game. The explanation the researchers give is that "...exercise acts directly on the central nervous system to increase energy and reduce fatigue."
Link to story

2. Muscle fatigue explained: calcium leaks.
The NYT nicely summarizes a study that elucidates why our muscles get tired. For many years, the theory was that the release of lactic acid causes muscle fatigue. However, this theory was discredited a long time ago (see this story), and the mystery remained. Scientists studying congestive heart failure found that muscles get tired because muscle cells leak calcium. These scientists developed a drug that blocks calcium leaks, and they tested it in mice. The little guys were able to run and swim 10-20% longer. The drug is intended to prevent heart failure, but the article mentions that some athletes may be tempted to use it to increase endurance.
Link to story

3. Signs of fatigue due to overtraining.
Another NYT article lists the signs of overtraining, and says that the simple (and obvious) cure is to rest. One of the interesting facts I learned from this article is the reason why our legs feel heavy when we are overtrained: our blood viscosity increases, and thus it weighs more.
Link to story

Finally, while looking for these month's news, I found a couple of interesting sites:
AIMS: Guidelines for fluid replacement.
Science of Sport blog

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