Swimming --- whether treading water or doing laps --- is an exercise that puts minimal stress on the body's joints. However, muscle cramping during a workout is common, especially if you aren't preparing your body for the pool by adequately stretching and nourishing your body before hitting the water. The intensity and technique in the water also cause cramps in the legs.
Anaerobic Zone
If your body is working in the anaerobic zone --- quantified by a heart rate of 80 percent to 90 percent of your body's maximum --- you are more likely to suffer from leg cramps. The word "anaerobic" means "without oxygen." During this type of intense swimming workout, your body is working at a very high level on minimal oxygen. When your body has less oxygen in the blood, it is harder for your body to cleanse itself of lactic acid, which is released by your muscles as they break down. High levels of lactic acid in your muscles leads to cramping. To alleviate this issue, take frequent breaks to get your heart rate and breathing down, getting more oxygen into your body.
Poor Technique
Poor technique plays a key role in the development of leg cramps while swimming. While performing three of the four main strokes --- backstroke, freestyle and butterfly --- the legs should be slightly bent at the knee, ankles relaxed and feet slightly turned in. Holding your legs in an unusual position --- for example, keeping the feet turned out --- for long periods of time will prematurely fatigue the muscle, leading to cramps. Ask a friend or a coach to observe your kick to see whether poor technique is to blame.
Improper Stretching
All four of the strokes used in competitive swimming --- freestyle, backstroke, breaststroke and butterfly --- require some degree of flexibility in the ankles. This happens in two ways --- either by flexing the ankle, so the foot and calf form a right angle, or by pointing the toes so the muscles from the calves through the feet form a straight line. The latter, called plantar flexing, is similar to wearing high heels for long periods of time and puts stress on your calf and foot muscles. To solve this issue, stretch your ankles extensively before beginning your workout. Sitting on the ground, stretch both legs out in front of you. Rotate your ankles clockwise and counterclockwise multiple times. If the pain returns during or after your workout, stop what you're doing and repeat the ankle rotations.
Poor Nutrition
Dehydration and electrolyte imbalance also lead to leg cramps in swimmers. When you're dehydrated, your body is less able to recover during and after a strenuous workout. Additionally, too little water in your system can also upset your body's electrolyte balance. Electrolytes include foods rich in calcium, potassium, chlorine, phosphate, magnesium and sodium. Drinking fluids that contain electrolytes --- such as sports drinks --- and eating electrolyte-rich foods such as bananas, which are rich in potassium, can ward off leg cramps before they start.
References
- Better Medicine: Electrolyte Imbalance
- "Extreme Tri Magazine"; Cramping Your Style: Dealing With Cramps In The Pool; Haydn Wooley; August 2001
- "South Pacific Masters Association"; How To Stop Cramping; Dr. Jessica Seaton
