Preventing Muscle Cramping in Football.

Sodium replenishment and fluid replacement are the keys

WE HAVE ALL SEEN A football player lying on his back with a trainer stretching and massaging his leg cramps.

Or a lineman being transported for I.V. therapy, while writhing in pain and rigid from multiple muscle cramping.

Why do some athletes experience cramps and others do not, while going through the same workouts?

It's the combination of muscle fatigue, dehydration, and salt loss that causes whole-body cramping in football players.

"Athletic Hydrophobia" -- the prohibition of all fluid consumption during practice or competition (Bilik) -- is practically extinct these days. Research has proven that inadequate hydration can produce both poor performance and serious health risks.

Numerous recommendations for optimal fluid-replacement practices, most recently by the National Athletic Trainers' Association (NATA 2000), are available to all athletes. Less recognition has been given to the concept of sodium loss in sweat as the primary factor in muscle cramping.

Experience has proven and current research now supports the theory that sodium replenishment and fluid replacement are the keys to the prevention of cramping.

Chronic Crampers

Whole-body cramping is caused by muscle fatigue created by the large losses of sodium chloride and water in sweat. A study at the University of South Carolina (Davis) revealed that players ranging from 200 to 300 pounds (the weight range of the majority of collegiate football players) perspire the most.

Other research reveals that even when athletes are heat-acclimatized higher sweating rates produce greater sodium losses (Bergeron). A 250-pound fullback can easily lose as much as one gallon of sweat and two to three teaspoons of salt during a game.

Since it is reasonable to assume that an athlete eating in an institutional dining hall is likely to be on a low salt diet, any restriction in his dietary intake of sodium is likely to produce a significant sodium deficit. Loss of appetite in two-a-days (not uncommon) can further restrict sodium intake in the diet.

Empirically, history has long implicated sodium depletion as a factor in muscle cramping. A London doctor, knowing that stokers on ocean liners mixed seawater with their regular drinking water, prevented cramps by prescribing a saline drink (Oswald). Salty milk reduced cramping in the men building the Hoover Dam (Talbott and Michelsen). And in British coal mines, where in one shift a man could sweat out "20 grams of salt," cramps were reduced by "salt in the water, about the composition of sweat" (Brockbank) -- the same theory applied in the formulation of a popular sport chink some 30 years ago (Eichner).

Over the last 50 years, sports generally has gone from an emphasis on salt to the exclusion of water, to an emphasis on water to the exclusion of salt, to a current trend toward a balanced inclusion of both in a replenishment protocol.

Recognize Those at Risk

A key aspect is to recognize and deal directly with those at risk for cramping. Several characteristics can aid in their identification:

1. History of heat cramps. If an athlete has previously experienced cramping, odds are the condition will recur, unless preventative steps are taken.

2. Salt avoider. Family history of hypertension or adherence to general warnings regarding consumption of sodium in the diet.

3. Unacclimatized. May have spent the summer in air-conditioning, trained only in the cool of the day, or recently moved from a home in a mild climate to a school in a harsh environment.

4. Heavy sweater. Sweats early and heavy; will exhibit profuse sweating in a sweat-soaked jersey after merely going through warmups whereas teammates may not yet have broken a sweat or only slightly so.

5. Prone to dehydration. Poor fluid replacement habits; use of diuretics; spends a lot of time in the sun, prone to partying (late nights) and alcohol use; enters a workout already in a dehydrated state.

6. Premonitory twitches in the muscles that cramp the next day

7. Sweat stings their eyes and abrasions, and tastes salty.

8. Visible, white salt residue on their skin and clothes after practice.

9. Intense coach who works players extra hard.

10. Evidence of cystic fibrosis in the family (cystic fibrosis produces a greater than normal salt loss in sweat).

Prevention of Muscle Cramps

Keeping up with fluid and sodium losses during training is a challenge and will only succeed if the athlete, coach, athletic trainer, and physician are attentive to their roles in the steps that will lessen the risk of dehydration and muscle cramping.

1. Educate. Take advantage of the onset of two-a-day drills when the high energy requirement, extreme environmental factors, and concerns about hydration are heightened.

2. Inform athletes on how to monitor their hydration status.

3. Recognize those at risk and convince them to participate in their own drinking schedule based on weight loss and drinking preferences

4. Have a plan to replenish fluid and sodium and foster encouragement from the coaches for athlete compliance.

5. Make sport drinks readily available. The more convenient the fluids, the more likely is the athlete to be compliant.

6. Have a scale accessible for athletes to weigh in before and after activity and to replace fluids at the rate of 150% of weight lost.

7. Pace workouts. Vary the intensity of the practice and provide periods of rest.

8. Have schedule to minimize risks associated with exercise in the heat and provide a period of rest and recovery. For instance, practice early and late. In morning workouts, the temperature tends to increase as the workout progresses and fatigue and dehydration increase. Late-afternoon workouts will gain the potential benefit of increasingly lower temperature.

Take advantage of time scheduled between events for physical rest to combat cumulative fatigue and to promote full body-heat dissipation.

9. Emphasize sodium intake. For most healthy athletes, consuming more salt-containing fluids and food during periods of training or competition in the heat will at worst be harmless and may indeed enhance well-being and performance (Bergeron). Even sport drinks have too little sodium for "salty sweaters." High-sodium electrolyte replacement drinks, adding 1/4 to 1/2 teaspoon of table salt to 32 ounces of a sport drink, or use of a prepackaged electrolyte mix formulated as an adjunct to sports drinks for use by athletes with a history of severe, whole body muscle cramps may be a necessity for cramp prone athletes.

Substandard Solutions

As mentioned, empirical evidence has long implicated sodium loss as a factor for muscle cramps. To that end a myriad of remedies have found cyclical popularity. Among them are mustard, A1ka-Sehzer[R], and pickles.

Undoubtedly, pickle juice is high in sodium content, an ounce is in effect a "liquid salt tablet". Given the large loss of sodium that puts athletes at risk, it is unlikely that one can drink enough pickle juice to offset the amount of sodium loss that puts athletes at risk of cramping. While these "magic potions" do provide sodium, they ignore the balance of fluid loss that becomes equally critical.

Water, as the lone source of replenishment in the working athlete is not the ultimate solution many would assume. Hyponatremia, or water-intoxication, ironically occurs in those endeavoring to avoid dehydration by consuming only water.

Mild cases of hyponatremia may exhibit symptoms of fatigue, apathy, slight nausea and headache that may be misinterpreted as heat exhaustion and be erroneously treated with increased water intake. Consumption is at a higher rate than the kidneys can excrete. Collapse, seizure, coma, and death can result if left untreated. The condition may be avoided if sodium is consumed. Balance between sodium and fluid is the key.

Ten Tips to Sweat Healthy

Salt depletion and dehydration predispose to muscle cramping and increase the risk of heat illness. For optimum performance, athletes must learn to "sweat healthy."

Practical tips:

1. Rely not on thirst. Thirst kicks in too late and shuts off too early. Studies suggest that athletes in the heat voluntarily drink only half of what they need.

2. Drink on schedule. A schedule rate of fluid intake offsets fluid lost in sweating.

3. Favor sports drinks. The formulation should facilitate absorption as fast as plain water along with containing sugars for energy and sodium to replace that lost in sweat.

4. Monitor weight. Fluid replenishment should be based on 150% of weight loss.

5. Watch urine. Urine should be copious, clear, and pale yellow. Small amounts of dark urine mean dehydration.

6. Shun caffeine and alcohol. Both promote urine production and so tend to dehydrate you.

7. Key on meals. Prime opportunity for fluid and sodium intake and replenishment!

8. Stay cool when you can. Minimize sweating off the field. Sleep in air-conditioning.

9. Know other risks -- sleep deprivation; illness that causes fever, vomiting, or diarrhea; sunburn.

10. Know the warning signs of heat stress: dizziness, nausea, vomiting, headache, confusion, and muscle cramping.

Conclusion:

Heavy sweaters mean heavy salt loss. Recognize those at risk and have a ready response -- a planned and balanced replenishment of both fluid and sodium that may prevent susceptible athletes from recurrent cramping and enable their unrestricted participation in sport.

References

* MF Bergeron, Sodium: The Forgotten Nutrient, Sports Science Exchange (Gatorade Sports Science Institute), 2000, 13(3):l-4

* SE Bilik, "The Trainer's Bible", TJ Reed & Co., 1947, p. 96

* EM Brockbank, Miners Cramp, British Medical Journal, 1929; I:65-6

* JM Davis, M Gentry, D Kennedy, D Kleinschmidt, R Walters, C Williams, Helping Athletes Survive Two-A-Day Practices, Sports Science Exchange Roundtable (Gatorade Sports Science Institute), 1999, l0(2):l-4

* ER Eichner. Heat Cramps: Salt is Simplest, Most Effective Antidote, Sports Medicine Digest, 1999, 21:8:88

* National Athletic Trainers' Association Position Statement: Fluid Replacement for Athletes Journal of Athletic Training 2000; 35(2): 212-224)

* RIW Oswald, Saline Drink In Industrial Fatigue, Lancet, 1925; 1:1369

* JH Talbott and 3 Michelsen, Heat Cramps: A Clinical And Chemical Study Journal of Clinical Investigation, 1933; 12:533-49