The most common muscles that undergo cramps are the hamstrings at the back of your thighs, the quadriceps on the front of your thighs and the gastrocnemius muscles in your calves or lower legs. Muscle spasms also can occur in your eyelids or thumbs. Your muscles begin twitching when they first start to cramp, which feels like tight, sometimes painful spasms. The spasms often stop once you rest the muscle group. Spasms may be so light that you hardly notice them and can continue with your activity.
Muscle spasms are more common in the summer or when you sweat profusely because your body loses significant electrolytes in your perspiration. Minerals also are lost in sweat. Spasms and cramps also appear when your diet lacks sufficient calories that contain minerals such as potassium, calcium and magnesium. Sports drinks that contain electrolytes and the essential nutrients can relieve minor spasms. Effective food sources of minerals needed to prevent spasms include dairy products, fruits, vegetables, meat and nuts.
According to the University of Maryland Medical Center, adults and teenagers need about 2,000mg per day of potassium to supply muscles with the necessary minerals for proper functioning. Do not take potassium supplements unless directed to by your doctor because they can cause serious side effects. Women need between 1,200 mg and 1,300 mg of calcium per day and men require between 1,000 and 1,300 mg of calcium. Healthy balanced diets ranging from 1,500 to 2,000 calories per day provide the necessary minerals. Adults over 30 need between 320 mg and 420 mg per day of magnesium.
Sugar in your system provides fuel to your muscles that keeps them moving without cramping. According to Dr. Clyde Wilson's Nutrition website, adults need an average of 20 calories of sugar in their blood to sustain healthy exercise. Natural sugars from fruits and vegetables are the most effective sources to maintain important blood sugar levels. Blood sugar levels also can be stabilized with sports drinks while you're working out. Unfortunately, too much sugar in the blood also can cause blood sugar levels to drop and lead to spasms and fatigue. When in training, consume about 100 calories every 15 minutes to make sure your blood sugar remains stable.