Why, after an intense run or session on the stepmill, is there involuntary twitching in my leg muscles, especially my calves?
Post-exercise twitching, which can be likened to low-grade cramping, is very common, especially in the calves, hamstrings and quadriceps, says Dr. John Su, a sports medicine physician at UCLA. There are several possible explanations.
The twitching could be caused by insufficient energy in the muscles. Muscles need adequate energy for proper contraction and relaxation, and a specific balance of electrolytes (such as sodium, potassium, calcium and magnesium) to regulate electrical signals governing contraction of the muscles. If either of these needs aren't met, "then you may get a cramp or twitching," Su says.
Some suggest there may be a neural component to cramping and twitching, says Joel Stager, a kinesiology professor at Indiana University in Bloomington. After intensive activity, the recovery process takes some time to be complete. Chemical substances that act as neural signals causing the muscles to contract must be recycled. Until they are, the muscle cells remain "irritable" and may spontaneously contract.
Muscles may also be more susceptible to twitching when they're cold or haven't been properly stretched.
To reduce the chance of post-exercise twitching, warm up before working out, gradually increase your workload, drink plenty of fluids, incorporate stretching and keep muscles warm -- tights can help.
Sustained twitching could be caused by an underlying neurological or muscular disorder. So if it persists beyond a few minutes, see your doctor.
-- Janet Cromley
After long weeks of recovery from major surgery, I've lost a lot of my conditioning. What's the best way to start a reconditioning program?
We're going to assume that you've gotten clearance from your doctor to begin exercising again. Though you may be itching to return to your presurgery shape, it will take time for your body to regain muscle strength and cardio endurance, says Bill Case, a Houston physical therapist with a sports medicine specialization. So begin slowly and add activity gradually.
For cardiovascular exercise, Case suggests starting with low-impact or nonimpact activities such as walking, swimming or cycling on a recumbent bike. "Walking is good for increasing circulation to your entire body and working major muscle groups such as thighs, calves and back muscles," Case says.
Swimming imparts no stress to joints, which also makes it a good post-operation workout. In addition to swimming laps, Case recommends using a flotation device that suspends the body vertically in the water, making it easy to "run" under water.
Recumbent bikes also provide good nonimpact exercise that takes stress off the back and can be done indoors.
As a general rule, Case suggests starting slowly, with about 10 to 15 minutes of activity, depending on how you feel, and increasing that by 10% each week. You can do this amount of cardio daily, if you're up to it.
As for strength training, start lifting about 70% of the weight you were doing before surgery and increase that by 10% each week. "It's better to start with light weight and high repetitions," Case says, "because you can fatigue the muscles without straining them." Two sets of 10 reps is a good place to begin. Resistance exercises can be done about three to four days a week, Case says. But with any activity, "Listen to your body. If you're overtraining, stop."
Other tips from Case: You may want to consult a registered dietitian, since the right foods can hasten your recovery. Also, invest in new shoes if your old pair are worn out, and look for ones that offer good shock absorption and stability. If you're having trouble getting back into the exercise groove, consider hiring a certified personal trainer, preferably one experienced in rehabbing injuries or working with post-surgery patients. He or she can set up a program that will get you back on track safely.
-- Jeannine Stein