Tuesday, September 27, 2011

Muscle Cramps and the Endurance Athlete

Check out this recent article I wrote for Zoom Performance on muscle cramps in endurance athletes. May be some information you didn't know about!

Exercise Cramps: how they occur and what can be done to prevent them

Article by Carson Christen, USA Cycling and Swimming Level 3 Coach, Graduate Student at UNI (Exercise Physiology)

Research presented over the previous few years has placed extreme emphasis on hydration with different solutions during events last longer than one hour. These drinks are usually simple sugar (carbohydrate) based and new market products are incorporating protein to prevent muscle degeneration. The evidence is not inaccurate, as it is very important to hydrate with something other than water during longer distance sporting events, such as Ironman, trail running, and RAAM. Recent research is taking a different approach to muscle cramps and have presented some new evidence as to the causes of these un-desired events.

Cramps Defined

An exercise-associate muscle cramp (EAMC) can be defined as “an involuntary painful skeletal muscle spasm that occurs during or immediately after physical exercise” (Schwellnus, Drew, & Collins, 2010, p. 1). I have had these cramps occur during important stages of a race, and they affect an athlete physically and psychologically. This study looked at 210 participants of Ironman South Africa to look at risk factors of EAMC. After this study was conducted, researchers found that factors other than hydration and heat play a factor in muscle cramping. Athletes who responded as getting muscle cramps both predicted they would complete the Ironman faster than the non-cramping group, and also exercised at a greater speed. The kicker is there were no significant differences in training volume or intensity for the two groups. There were also no significant differences in body weight and electrolyte levels from pre- to post-race measurements. Cramping athletes also responded as getting more cramps over their last 10 races then the non-cramping group. Researchers made the observation that muscle fatigue, and a previous history of cramping are more potent risk factors for muscle cramping.

Apply the Knowledge

With evidence suggesting that dehydration and electrolyte balance are not the sole causes of muscle cramps, what does that mean for us as athletes? This doesn’t mean you can ignore your hydration levels during a long distance event such as Ironman, but should also pay close attention to your training. If muscle fatigue is in fact a large part of EAMC, then it is important that an athlete not try to race at a pace much greater than one they train at. This seems like a no-brainer, but it happens about 80% of the time. It takes a lot of hard work and self-discipline to not become overwhelmed by race day or the paces of others, it is important to race your race! If your training for a race at a bike speed of 18.0mph and a run speed of 10:00min/mile, there is no reason you should be racing at 22:00mph and 8:30min/mile on race day. This will likely because the muscle fatigue/cramping towards the end of the event as was found from this scientific study.


So in conclusion, long distance events like Ironman or RAAM are extremely fun and rewarding accomplishments. It is an athlete and coaches’ responsibility to make sure an athlete is training at a level they can accomplish in a race to prevent over-pacing and causing excess muscle fatigue. It is also very important to remember, this study does not say that hydration and electrolyte levels are not key factors to success. You need to make sure you stay properly hydrated and fueled as well. If you can control these key elements to prevent exercise-associated muscle cramps, you will have the opportunity to produce the best race you can, and also have fun!! Make sure to practice these plans prior to race day so you know what works and what does not! Most of all, have fun and race hard!


Schwellnus, M. P., Drew, N., & Collins, M. (2011). 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 athletes. British Journal of Sports Medicine, 45, 650-656.

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