Add Free Radicals to The List of Factors That Cause Muscle Fatigue
Most athletes know that the muscles generate free radicals--particularly free radicals known as reactive oxygen species (ROS)--during exercise. Many athletes also know that these free radicals contribute to the muscle damage that normally occurs during exercise and to the muscle soreness and weakness that follow particular tough workouts. But most athletes are not aware that ROS also contribute to muscle fatigue occuring exercise. That's because scientists discovered this link only recently.
In a new review published in Free Radical Biology and Medicine, researchers from the Univeristy of Kentucky summarize the current state of scientific knowledge in this area. Apparently, ROS cause fatigue by reducing calcium sensitivity in muscle cell proteins. Calcium ions play a key role in transmitting motor nerve impulses within muscle cells. When the muscle cell proteins become less calcium sensitive, the muscle fiber is no longer able to contract as forcefully.
The authors of the review also note that "Studies in humans, quadrupeds, and isolated muscle preparations indicate that antioxidant pretreatment can delay muscle fatigue." This reality raises important questions, such as whether certain types of antioxidant pretreatments should be made illegal in sport, and if so, which ones. |
