Tim just completed the White Rock Marathon in Dallas this weekend. Weather was warm and extremely windy, but he was feeling good and managing to keep his pace through the half way mark. The race was going perfect and pacing was exactly as planned all the way until about mile 18. As he passed the 18 mile marker, he started feeling small cramps in his calves. He tried to slow down a bit to make them go away, but by mile 19 they hit so hard if felt like a ball bearing digging into his calf muscle and the pain literally brought him to the ground in the middle of an intersection. (Much to the traffic cop’s surprise) He had to stop, stretch and hobble along until they stopped. He had to walk for awhile, until they went away and then slowly started to run the last few miles. The cramps did not disappear and he had to stop again and stretch once or twice every mile. So much for his time goal!! 

Question is, why do cramps happen and how can you prevent them? They have never occurred during his extensive training, so why in the middle of a race? 

Muscle cramping usually occurs due to a depletion of "The Big 4":

  • Sodium
  • Potassium
  • Magnesium
  • Calcium

If an athlete is dehydrated, even slightly, going into a race, muscle cramps can be common (no matter how spot-on race day hydration is). Cramping can occur due to the depletion of one or a combination of these four minerals. One area that I would first examine is your everyday fueling. I realize that conventional thinking says that if an athlete cramps up during a race, then it must have been something nutritionally that went awry during the race. This may be the case, but actually the answer usually lies in one’s everyday nutrition and hydration. 

The first thing I would suggest is to monitor your hydration levels before and after training (especially long training days). This can easily be done with a body fat scale that also measures body water percentage. Take this reading each night before bed for 7 days straight so you can determine an average body water percentage; then, after training sessions, re-measure your water percentage. You will probably notice a reduction in your water percentage, as this is normal. Your goal now is to refuel and rehydrate in order to get this water percentage back to its ‘normal’ level. Another easy way to monitor your hydration level is to pay close attention to your urine color. The goal is to keep your urine color in a range from clear to a very light yellow. If one’s urine color is a darker yellow, this can be a sign of dehydration (be aware, that if you take a multiple vitamin, the B-vitamins will turn your urine color yellow, and this is normal; not a sign of dehydration). Following a long training run or race…get your urine clear and keep it clear throughout the day, as this will ensure proper hydration. 

In regards to the Big 4, try to consume a fluid replacement drink that contains all four of these minerals, and be sure to consume this fluid replacement drink during training and racing. Also, be sure to use your “sodium capsule” of choice during training, and not just on race day (you may already be doing this). If you find yourself avoiding sodium in your daily nutrition, try to lightly salt your foods with sea salt. Also, drinking vegetable juice is a great source of sodium and potassium (be sure to check with your physician that there are no blood pressure issues that would contraindicate the use of additional sodium). 

So, in summary, my advice to Tim would make everyday hydration and fueling your focus as this will get you to the start line in a state of optimal hydration. This should help avert any nasty cramps in your next race! 


Run Happy! And cramp free!