Muscle Fatigue May Be Caused By Calcium Loss

New research from Columbia University in New York shows that muscle fatigue during and after exercise may be caused by loss of calcium from muscle cells and that drugs that block the release of calcium from muscle cells may prolong endurance (Proceedings of the National Academy of Sciences, February 11, 2008).

When you exercise, your cells use food to generate electricity that causes nerves to send messages and muscles to contract. The energy from food generates electricity by driving minerals inside and outside of the cells, creating an imbalance of the minerals between the outside and inside of cells that causes electrons (electricity) to flow. A major source of this flow of electrons is from muscle cells pushing calcium outside their cell walls. This paper shows that muscles lose calcium continuously during exercise, and eventually do not have enough calcium to continue pumping calcium outside of cells, and therefore cannot generate as much electricity. This causes the muscles to weaken, hurt, lose coordination and feel tired.

The authors timed mice exercising to the point of exhaustion. Then they gave the mice an experimental drug that blocks the loss of calcium from muscle cells, and they were able to exercise longer. The researchers demonstrated the same process of calcium loss in the muscles of trained cyclists. However, they have not taken the next step of testing the drug to see if it improved endurance, because the drug has not been approved for use in humans. More fitness reports