Sports Drinks and Muscle Cramp Prevention

Practically any athlete remembers having suffered a muscle cramp at some point. Months of painstaking preparation can be ruined by this sudden and painful response of the body. In fact, in a study of 82 runners during a marathon, one in five suffered a cramp (1). The same data was observed in another study in 210 triathletes who were participating in an Ironman (2).  And if you have not experienced one yet, it may still happen; A survey of more than 1000 marathoners showed that almost 40% had suffered a cramp at some point in their lives (3). But what causes cramps, and what can we do to avoid them?

Cramps, what is their origin?

The causes of muscle cramps are still not fully understood. Traditionally, the focus has been on dehydration, especially since almost a century ago numerous cases of cramps were reported in soldiers or workers who were subjected to situations of heat and dehydration, such as miners or masons. More importantly, the researchers found that when these subjects drank only water, the incidence of cramps was unchanged, whereas drinking water with mineral salts reduced it (4). In other words, it could be hyponatremia (decreased salt concentration), and not just dehydration, that causes cramps.

It's important to note, however, that hyponatremia is just one of many causes of cramps. In fact, surely many of our readers will remember a case of muscle cramp in which they were neither hot nor dehydrated. This fact has led to the development of other theories about cramps, one of the main ones being the one involving the nervous system. Thus, it has been observed that excessive excitation of the nervous system, sending more signals than necessary to the muscles to contract or not allowing their inhibition correctly (for example, when working in very short ranges of motion), could lead to a muscle cramp. Similarly, excessive muscle fatigue could also interfere with the proper functioning of the contraction-relaxation process, favoring the appearance of cramps. We can see this in numerous sports. For example, in the marathon most cramps occur in the last part of the race (from km 30 onwards), when muscle fatigue lurks, regardless of whether there is no dehydration (3). In addition, it has been observed that the risk of cramps is higher the less trained we are or the higher the intensity at which we compete with respect to the intensity at which we are used to training, which would also support a possible role of fatigue (3).

Sports drinks and cramps

Although when talking about cramps it is normal to think of sports drinks with mineral salts, we often overlook the possible role of carbohydrates. We have already talked on previous occasions about the benefits of carbohydrates on performance. In fact, carbohydrates have been shown to attenuate fatigue during prolonged exercise (what we currently know as durability). Therefore, given the role of muscle fatigue in cramps, it is therefore not surprising that carbohydrate consumption may have some role in preventing cramps. In this sense, in a study in university students, researchers designed a protocol to produce fatigue locally in the calves in hot and humid conditions, in order to promote the appearance of muscle cramps as much as possible (5). The authors observed that regardless of whether they drank a drink with electrolytes and carbohydrates (56 grams), or no drink at all, the number of participants who suffered from cramps was practically the same. However, curiously, the time it took for them to suffer from the cramp was more than halved when drinking the drink with carbohydrates and electrolytes (15 minutes compared to 37 minutes when they did not drink anything) (5).

Therefore, a sports drink composed of carbohydrates and electrolytes was in this case effective in reducing the negative effects of cramps. Unfortunately, we can't know if the benefits were due to electrolytes or carbohydrates. However, the fact that the authors observed minimal dehydration even in the group that did not hydrate (only 1% body weight loss), could suggest that dehydration did not play a major role.

Conclusions

Cramps have a multifactorial origin, and can appear due to dehydration and hyponatremia (loss of electrolytes), but also due to excessive muscle fatigue or hyperactivation at the level of the nervous system. Therefore, looking for a single method of prevention will be counterproductive. However, the use of sports drinks with electrolytes and carbohydrates could partly attenuate both the negative effects of dehydration and those of muscle fatigue, thus reducing the incidence of cramps or at least delaying their onset.

10% DISCOUNT ON THE WEBSITE WITH THE CODE:

CROWN10

*Free shipping on orders over €25

AUTHOR

Pedro Valenzuela
Researcher at the Physiology Unit of the University of Alcalá
Web: www.fissac.com

References

1.          Maughan RJ. Exercise-induced muscle cramp: A prospective biochemical study in marathon runners. J Sports Sci. 1986;4(1):31–4.

2.          Schwellnus MP, Drew N, Collins M. Increased running speed and previous cramps rather than dehydration or serum sodium changes predict exercise-associated muscle cramping: A prospective cohort study in 210 Ironman triathletes. Br J Sports Med. 2011;45(8):650–6.

3.          Schwellnus MS, Noakes TD. Risk Factors for Exercise Associated Muscle Cramping (EAMC) in Marathon Runners. Med Sci Sport Exerc. 1996;28(5):167.

4.          Talbott BYJH, Michelsen J. HEAT CRAMPS. A CLINICAL AND CHEMICAL STUDY. J Clin Inv. 1933;12(9):533–49.

5.          Jung AP, Bishop PA, Al-Nawwas A, Dale RB. Influence of hydration and electrolyte supplementation on incidence and time to onset of exercise-associated muscle cramps. J Athl Train. 2005;40(2):71–5.