THE CLINIC

Potassium Keeps Muscle Cramps Away

I have been experiencing foot and leg spasms (charlie horses) at night. I’m 63 and exercise regularly, about five times a week. I lift weights and use a glider two to three times a week and jog five to eight miles on the other days.

I started the South Beach Diet in early February and have since lost 25 pounds. I drink water, coffee, tea or diet drinks during the day and sometimes milk or wine in the evening. I take a senior multivitamin, a calcium supplement, plus vitamins E, C, B6 and B12 (my mother had troubles due to B vitamin deficiencies). Any advice about the spasms would be greatly appreciated.

Francis Jordan
Fayetteville, IN

Nocturnal leg cramps, as this condition is formally known, are sometimes the result of low potassium. There is a fair amount of potassium in several of the foods that are decreased on the South Beach Diet—bananas in particular, at least in its early phase. If you also happen to take a diuretic such as furosemide (Lasix) or hydrocholorothiazide, the problem may be exacerbated. Sometimes nocturnal leg cramps can occur when recently-exercised muscles that aren’t accustomed to physical activity are at rest, but it doesn’t sound like you’ve changed your activity levels as of late. If it isn’t new activity or low potassium causing these cramps, a trial of 325 mg of quinine at bedtime may help, even if the cause remains unknown.

William M. Simpson, Jr., MD
Charleston, SC

Congratulations on the terrific commitment to improved health. I wish I had more patients come to me with leg cramps after exercising five days a week. I hope your active lifestyle infects a few friends; keep up the good work.

A person in a catabolic state such as yourself, i.e., one who is losing weight or breaking themselves down as opposed to gaining weight, can sometimes experience subtle electrolyte aberrations. (I can’t recall ever seeing a patient who suffered muscle spasms and at the same time was gaining weight.) Also, when people diet they often drink more, and since you mentioned tea, soda and coffee, it may be that you are now consuming too much caffeine, which can cause muscle spasms.

I recommend, then, that you try limiting your caffeine intake and substitute several glasses of electrolyte-rich sports drink per day. If these steps don’t help, have your doctor check your electrolytes and thyroid. You may also try exercising every other day for longer periods at a time. Quinine sulfate is indeed a well known (and ancient) remedy for nocturnal leg cramps, and it is relatively benign, though it can (infrequently) cause blood-related side effects. People with liver problems or those who are pregnant should avoid quinine.

Peter Mendel, MD
Fairfax, VA

Another possible source of the cramps could be statin drugs, if you happen to be taking them. In any case, I have often seen results with 600 to 1,200 mg daily of calcium (without phosphorus), in split doses.

Sarah Harding Laidlaw, MS, RD, MPA
Mesquite, NV

Why Train Long and Slow?

Many marathon training guides recommend that runners perform their long runs at a pace about two minutes slower than you could have run that day. I'm skeptical. How are you going to develop a good pace by running slow, and how are you going to all of a sudden run two minutes faster per mile on race day?

Robert Huntz
Santa Cruz, CA

Many people have questioned this recommendation. There is a S.A.I.D. principle in training: Specific Adaptations to Imposed Demands. That is to say, if you want to run fast, you have to train fast. However, not all the time! Most marathoners do run their long training runs slower than their expected pace the day of the marathon (LSD is short for long, slow distance).

One of the primary reasons for this is injury prevention. You want to step to the start healthy and injury-free. You need to have easy days and hard days to maximize your training adaptations. And remember, on marathon day, the roar of the crowd and the energy of all those people stampeding through the streets will almost certainly help you go faster than a solo training run.

Tom Holland, MS, CSCS
Darien, CT

Running a time goal in a marathon requires the synthesis of a number of components: a realistic goal; a long, slow run that builds endurance but, because it is paced slower than your realistic goal pace, allows you to recover quickly; and speed work. The logic behind the recommendation is that you won't be able to do the speed work if you take too long to recover from the long run because you started out too quickly.

Jeff Galloway
Atlanta, GA

My belief is that in training for the marathon, long runs are the most important session followed closely by tempo runs. The runner should go into the long run relatively fresh and have one or two recovery days afterward. If the long run is done slowly it provides a reduced training stimulus, so it's more effective to do the long run a bit harder and allow the appropriate recovery afterward than to do a slower long run so speed work (which is less specific to the marathon) can be done earlier in the week.

Pete Pfitzinger
Hamilton, New Zealand

Groin Pain Starts When I Stop

Several hours after running, I have been experiencing pain on the inside of my upper right leg or groin area. I usually run five times a week, totaling 25 or 30 miles. I’m a 62-year-old male, 155 pounds, 5' 11", and have been running for 25 years. I usually run on asphalt. I’m a slight pronator with a heavy heel strike. The pain is usually gone by the next day.

Distance appears to cause more discomfort than intensity does. Though my left leg is not affected, the right leg has nagged me for several years, and lately seems to be getting worse.

Rick Greene
Corpus Christi, TX

The pain you describe sounds like it may be a thinning of the cartilage that protects the ball and socket in the hip. A thorough evaluation, either by a certified chiropractic sports provider or an orthopedic surgeon, is called for. In addition to a physical evaluation, I would have them take x-rays of both hips; you can get a pretty comprehensive understanding of your hip health with these assessment tools. You and your doctor can then decide what is the best fitness plan for you going forward, including shoe and running surface changes, crosstraining, and gentle flexibility work.

Chris Sorenson, DC, CCSP
St. Cloud, MN

Groin pain is not very common among runners, but it can be due to stress fractures of the pelvis, which in this area can be caused by excessive tension on a muscle. Your complaint of long-standing pain in the area might be due to excessive tension on the muscle, and only now as you are getting older has this become a problem for the bone. However, stress fractures usually cause increasing pain on the run that resolves afterward.

The increasing symptoms after the run are more suggestive to me of muscle strain. Again, this is not common in runners, but here are a few scenarios that might cause it. When running, the groin muscles of the leg that is swinging through the air contract to help elevate the pelvis as the leg swings. Facing traffic, the right side of the road is higher than the left. If you always run facing traffic, your right groin muscles (and left hip muscles) will have to work harder to lift your pelvis enough for your right leg to clear the road. A second scenario is that you turn your right leg either inward or outward too much. In either case, the abnormal orientation of the leg forces the muscles to take on slightly different functions than they were designed for.

Try running facing the other direction on the road if you’ve been running against traffic. In the other scenario, you can try to consciously rotate your leg inward or outward—or try a corrective shoe—to counteract the undesired rotation.

Stephen Perle, DC
Bridgeport, CT

The Young Runner's Diet

My 14-year-old daughter has started participating in high school cross country racing. What would you suggest for a young runner's diet both before a meet and in general to sustain her good health? We are new at this, so any information would be greatly appreciated.

Phyllis Meriwether
Glen Cove, NY

You are absolutely right to focus on your fledgling athlete’s diet. Active children and adolescents do have special nutritional needs and most people ignore this. Your body won’t perform well without the proper nutrition. Malnourishment can be a concern in particular with teenage girls; running is one of the sports where eating disorders are common. I tell my young patients that thinness does not equal better performance.

The American Academy of Pediatrics writes that females ages 11 to 18 need 2,200 calories per day. The average kid needs 44 to 46 grams of protein a day as well. For athletes, as you might expect, the calorie requirement goes up based on activity. If your daughter is 100 lbs, she will need at least 54 grams of protein daily.

A training diet should consist of about 55 to 60% carbohydrates, 12 to 15% protein and 25 to 40% fat. In heavy training you might increase protein intake to 15 or 20%. Make sure your daughter also gets adequate iron. Good food sources include meat, beans, peas, spinach and iron-enriched breads. Your daughter should eat before practice and meets. The amount of time for eating prior to running varies depending on the individual, but one to four hours is an appropriate range.

These days carbohydrates have been given a bad name, which is a shame. No-carb diets are not for kids. Chronically omitting carbohydrate-rich foods will decrease muscle glycogen stores (the fuel for running). Common high-carb foods include: beans, rice, spaghetti, flour tortillas, waffles, bagels, whole wheat bread, oatmeal, shredded wheat, graham crackers and popcorn—as well as apples, bananas, cantaloupe, oranges, peaches, pears, raisins, potatoes, corn and carrots.

Terry Adirim, MD
Washington, DC

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