If you have a tendency to cramp during exercise, it’s probably because your dehydrated or need to have more electrolytes right? Well that’s the doctrine that’s been preached for decades when it comes to exercise-associated muscle cramping. Who are we to question the likes of Gatorade and Powerade and their impecable science on muscle cramping and dehydration? Could it be possible that electrolyte levels in blood and the degree of fluid loss have very little relation to an individual’s likelihood of cramping?
That’s the essence of the message conveyed in a recently published review on the subject called ‘Cramping in Sports: Beyond Dehydration’ in the October 2014 issue of the Strength and Conditioning Journal. Written by Andrew Buskard (a PhD student in exercise physiology from the University of Miami) the review article highlights the distinct lack of direct evidence implicating low serum electrolytes and/or dehydration as principal causes of muscle cramps associated with exercise.
Buskard is careful to delineate that while there is very little evidence directly linking lower electrolyte and fluid levels with increased risk of cramping, likewise, there is no direct evidence disproving the theoretical link. Concerning the lack of evidence between low electrolytes/fluid and cramping, Buskard highlights two key studies in his review.
The first involved an Ironman triathlon and the second an 56-km ultra-marathon. In both studies, competitors who experienced cramps during or immediately after the race showed no significant differences in final serum electrolyte concentration compared with participants who did not experience cramping. Similarly, the average body-weight loss for a competitor over the course of the race (an indicator of dehydration) was not significantly different between individuals who did experience exercise-associated muscle cramps from those who did not.
So what are the primary causes of exercise-associated muscle cramping if it’s not electrolytes or fluid loss? Buskard is quick to point out that it is largely multi-factorial but most evidence points to cramping being primarily caused by neurological factors related to abnormal functioning of feedback mechanisms from within a working muscle as a result of fatigue. So if the muscle is more tired/unconditioned – then it is more likely to cramp.
In support of this, studies have found individuals that cramp during long endurance events tend to compete at a faster race pace than training pace. Which basically means if you push yourself too deep, you increase the likelihood of muscle cramping.
Muscle damage itself is also a risk factor for increased risk of cramping. In this sense, nutritional supplementation strategies associated with reduced muscle damage (i.e. branched-chain amino acids and l-carnitine) may be helpful in reducing the risk of cramping.
Buskard also highlights the utility of static stretching as a means of reducing the likelihood of cramping in individuals prone to exercise-associated muscle cramping.
In conclusion, Buskard asserts that exercise-associated muscle cramping is generally related to muscle fatigue. As such, any endurance athlete partaking in extreme endurance events like Ironman’s and marathons would be wise to adhere to a conservative tapering program in the week before competition and to be cautious about pushing the pace much beyond that which was obtained in training. Additionally, judicious use of static-stretching techniques used separately from training is advisable. In the event exercise-associated muscle cramping does occur, athletes are advised to stretch the affected muscle.
Buskard ANL. Cramping in Sports: Beyond Dehydration. Strength and Conditioning Journal. 2014;36(5):44-52.