Case: My calves ache
Case Study: The Case of the Cramping Tennis Player
Print This Post
“My calves ache so badly that I can barely stand up. It’s to a point that I’m afraid to get out on the tennis court any more.”
Case: Tim is a 21-year-old college senior who comes into the office complaining of intermittent severe and debilitating bilateral cramping in his calves during competitive tennis matches. The cramping usually starts as a ‘twitch’ or fasciculation and proceeds to a full-blown cramping within 20 minutes. The cramps occur whether he plays tennis indoors or outside, on clay or on grass. He believes that the initial onset of the cramping was about 6 months ago.
Patient has lived in Florida all his life. He is training to join a semiprofessional tennis team when he graduates and plays multiple tennis matches 5 days per week. He denies taking any new medications since the onset of the cramping problem. Eats 3 meals per day most days as well as snacks on the days he plays. He drinks plenty of water during his matches. His last tennis match was one day ago.
Past medical history is unremarkable for any known food, medication, or environmental allergies.
Medications: occasional NSAIDs for post-tennis aches and pains and antihistamines for seasonal allergies. Over the past 4 months, he has been taking a creatine monohydrate performance supplement 1000 mg twice daily.
Family history is positive for congenital heart disease (father). Mother is vigilant about maintaining a very low-salt diet for the family. No other family history of note.
Physical examination:
Fit, athletic young man.
Weight 179 lbs. Height 6’0”. BP 126/60, P 81.
Cardiac: Regular rate and rhythm, no murmur. Patient reports no dizziness or lightheadedness.
Lungs: Clear to auscultation.
The remainder of the physical examination is normal, without any twitching, cramping, or pain noted in the calves, upper legs, or back.
Blood chemistries taken on the day of his visit were within normal limits.
How would you proceed?
Published on July 13. 2010
Updated on July 19, 2010
Discussion
Tim’s symptoms are likely due to exertional muscle cramps caused by heat, sweating, and a resulting sodium deficiency. The cramping may also be aggravated by his use of creatine supplements. Data suggest that exertional muscle cramps are prompted by excessive sweating and a significant sweat-induced whole-body sodium deficit,[1] and that adequate sodium levels can prevent cramping. In addition, anecdotal reports of muscle cramps in athletes who supplement with creatine—widely used as a performance enhancer—have been reported in the medical literature.[2]
Adult and older adolescent tennis players generally lose between 1.0 and 2.5 liters of fluid as sweat during each hour of competitive singles play in warm to hot environments, such as Florida. This fluid loss is accompanied by significant sodium losses (2000-5000 mg/hour). Tim’s low-salt diet is an additional risk factor. Tim’s lab tests reveal normal electrolytes because a whole-body sodium deficit will usually not be detectable from a serum electrolyte measurement; in fact, many athletes who suffer exertional heat cramps may present with normal or slightly elevated plasma or serum sodium levels.[3]
Tim should be encouraged to drink plenty of fluids (water, juice, sport drinks, etc) throughout the day—and especially during a match—but he should be careful not to over-hydrate and become bloated.* To minimize cramping, he can drink 16 to 20 oz of water or a sport beverage with a half-teaspoon of salt at the first sign of muscle ‘twitching.’ Match-time snacks such as pretzels or peanut butter crackers will provide additional sodium. Off the court, Tim should concentrate on remaining well hydrated 24 hours before his matches and consume enough sodium to compensate for his losses.
You might also speak with Tim about his creatine use. While data are inconclusive as to whether creatine causes heat cramps, it likely doesn’t help. If he is unreceptive to eliminating the creatine, you might recommend that he institute a 3 to 4 week wash-out phase every 20 to 25 days. If Tim’s cramps persist, he should be worked up for potential other causes related to medications, an underlying metabolic disorder, or other predisposing factors.
*Guidelines for Hydration Based on the American College of Sports Medicine Recommendations[4]
Hydration Before Exercise
- Drink about 15-20 fl oz, 2-3 hours before exercise
- Drink 8-10 fl oz, 10-15 min before exercise
Hydration During Exercise
- Drink 8-10 fl oz every 10-15 min during exercise
- If exercising longer than 90 minutes, drink 8-10 fl oz of a sports drink (with no more than 8 percent carbohydrate) every 15-30 minutes
Hydration After Exercise
- Weigh yourself before and after exercise and replace fluid losses
- Drink 20-24 fl oz water for every 1 lb lost
References
- Palmer MS, Spriet LL. Sweat rate, salt loss, and fluid intake during an intense on-ice practice in elite Canadian male junior hockey players. Appl Physiol Nutr Metab. 2008;33(2):263-271.
- Poortmans JR, Francaux M. Adverse effects of creatine supplementation: fact or fiction? Sports Med. 2000;30(3):155-170.
- Bergeron MF. Heat cramps: fluid and electrolyte challenges during tennis in the heat. J Sci Med Sport. 2003;6(1):19-27.
- Sawka MN, Burke LM, Eichner R, et al. Exercise and fluid replacement. Med Sci Sports Exerc. 2007;39(2):377-390.
Recent Comments