A muscle cramp is any interference in a muscle's ability to expand or contract.
Over-flexing the feet is one cause of leg cramps. It is possible to overextend the tendons and nerves in the feet, and since these lead back into the calf muscles, they can cramp.
Another major cause of leg cramps is the lack of oxygen in the muscles produced by doing too much work too quickly. This prevents the oxidation of lactic acid, a mild muscle toxin that can cause cramps.
An uncommon cause of cramps for swimmers is electrolyte imbalance due to perspiration, but it is still possible in warm, tropical waters. As they are immersed in cool water, swimmers do not perspire as much as a runner making the same effort might, for example.
Leg cramps are so dangerous to swimmers because the loss of the use of one leg seriously impairs the ability to stay afloat. Getting out of trouble means staying calm and trying to massage the cramp out of the muscle.
According to Snopes.com, the old cautionary dictum of waiting an hour after meals before going swimming for fear of stomach or other cramps has little or no medical validity.
Article Written By Edwin Thomas
Edwin Thomas has been writing since 1997. His work has appeared in various online publications, including The Black Table, Proboxing-Fans and others. A travel blogger, editor and writer, Thomas has traveled from Argentina to Vietnam in pursuit of stories. He holds a Master of Arts in international affairs from American University.