Muscle cramps that result from exercise -- and muscle cramps in general -- are not a clearly understood phenomenon. Dehydration, eating habits and fatigue have been found to be contributing factors to cramping. Holding muscles in one place for too long can also contribute to cramping, and the abdominal muscles are particularly prone to this because they are short and tend to stay contracted longer than other muscles. Following some simple preventative steps can help avoid cramping when doing crunches.
Cramps are painful, involuntary contractions muscle groups. More severe cramps are felt as a sharp, stabbing pain and milder versions feel like a pulling sensation or mild ache. Cramps can happen at any time but you could be more predisposed to getting cramps, according to the American Academy of Orthopaedic Surgeons -- particularly when you exercise. Cramps that occur on the side of the abdomen are referred to as side stitches, and occur more frequently in runners, cyclists, horseback riders and when working the abdominal muscles, notes certified trainer Stew Smith at Military.com.
The exact mechanism that causes muscle cramps isn't clear, but fatigue, heat, dehydration, and lack of conditioning play a role. If you are overexerting yourself or your muscles are tired, cramps are more likely to occur because the muscles are fatigued and can't function properly. Eating too much or gassy foods before doing crunches can affect the digestive process, which can lead to cramps as well. Another common cause of stomach cramps, which can be related to dehydration, is lack of electrolytes. If you sweat profusely, you can deplete your supply of electrolytes, including calcium, potassium and magnesium, all of which contribute to muscle function. Too little of any of these in your body can cause cramping. In less-common instances an underlying medical disorder, such as thyroid disease, can cause abdominal muscle cramps.
Taking some simple preventative steps may help avoid cramping. To avoid dehydration, start drinking water the day before you do your crunches. Drink 1 to 3 cups of water before you start your routine, and sip water liberally during your workout. Drinking a sports drink or water enhanced with electrolytes can help if you have been sweating a lot. Avoid drinking too much water, which can lead to over-hydration and possibly cramps. To fuel your body properly, eat a smaller meal no less than two to four hours before you work out or a small snack no fewer than 30 minutes beforehand. Perform a warm-up before you do your crunches, and gently stretch the muscles of the abdomen by slowly twisting from side to side or bending backward at the waist. Mix up your routine by adding other abdominal exercises or doing exercises for other parts of the body between sets of crunches.
As soon as you start to feel your muscles cramp, stop doing your crunches and gently stretch the abdominal muscles. Grab the muscles the are cramped and either massage them or put pressure on them until the cramp goes away. If you are dehydrated, drink some water, preferably with added electrolytes. Focus on your breathing and push your abdomen out when you inhale and relax it when you exhale. If the muscles are tense or tight, apply heat -- and if they are sore or tender apply ice for 20 minutes at a time. If they continue to cramp or feel sore, seek medical attention as you may have strained a muscle. Consult a doctor if you continually cramp up doing crunches despite taking preventative measures.