Muscle Cramps, Dehydration and Running

In the past I have addressed side-cramps or “side stitches” in runners. The bottom-line on stitches: There are as many possible causes as cures. No single approach remedies all stitches for all runners. The topic I will address this time is whether non-side-stitch muscle cramps (typically in legs) are any different in cause and cure.

There has been both formal research and of course a plethora of anecdotal accounts on both causes and cures for cramping. Some runners seem prone to muscle cramps more than others (as is the case with side-stitches). Some runners are virtually immune to them (as is the case with side-stitches).

Like so many others I have recommended guidelines along the lines of keeping hydrated to above a 3% body weight loss to help decrease chances of cramping. And some studies had shown that over 3% body weight loss also tended to meet with a gradual decrease in actual performance (slow down). And it is widely quoted that at 2% loss you often will not even feel the urge to drink yet. But, like everything, more research, better research, more controlled research instead of mere correlational studies reveal clearer evidence of what is happening.

Dehydration alarmists are bolstered by hydration studies like the one presented to the American College of Sports Medicine Conference: “The runners underestimated their sweat losses by an average of 46 percent and their fluid intake by an average of 15 percent, resulting in the runners replacing only 30 percent of their fluids lost through sweat.” (But don’t swallow this one that easily. It was conducted by Gatorade Sports Science Institute (GSSI). They have a stake in your intake!) But, it did not address if cramping occurred or if performances dropped off as a result. In other words, it is an observation – not necessarily a need for alarm.

3% dehydration is accepted as mild; while moderate dehydration is 3-5% weight loss and greater than 5% is considered severe dehydration.

Yet researchers like the renowned Dr. Tim Noakes found that things like elevated body temperatures are not correlated to dehydration status; and dehydration was not an indicator for increased medical tent likelihoods.

It also is widely written about that an imbalance or great loss of electrolytes (potassium and sodium most often) via sweat loss is the cause of cramping and performance decrement. Electrolytes are essential to muscle contraction and performance. It all makes sense. Or does it?

Several correlational studies have now shown that many of the most dehydrated individuals are among the fastest finishers in marathons. This of course flies in the face of the dehydration-cramping connection theory; if the most dehydrated were the fastest and in fact did not suffer from cramping. It also flies in the face of dehydration-performance decrement theory. Best performers were most dehydrated. It has also been noted that hyponatremia (low sodium – at least low in the places you need it due to over-hydration) most often afflicts the slowest of marathoners and who demonstrate minimal dehydration.

Studies on cramping now show when muscles are examined after workouts (cramped and non-cramped conditions) it reveals no significant difference in electrolyte content in the blood between the cramped and non-cramped states.

One guy who is conducting research on the topic is Kevin C. Miller, Ph.D. One of his study results show that “pickle juice relieved the cramps about 45 percent faster than if the men drank no fluids and about 37 percent faster than those who drank water.” The acidity of the juice appears to be the reason – but he’s studying that more. (By the way, the amount of pickle juice fluid or sodium content is irrelevant because it did not have time to be absorbed to effect dehydration or electrolyte replacement itself.)

His conclusion at this time is that cramps are the result of a muscular exhaustion is the issue not dehydration or electrolyte loss issues.

The point here is that they now believe it is a neuromuscular fatigue. “Misfires” occur in a muscle when exhausted. That is a conditioning issue – a training issue. We train muscles and nerves to work together in a coordinated effort to get us from point A to point B in the fastest time possible. Nerves tell muscles when to fire and how hard to explode. Muscles respond to what they are told – up to the point that they have been conditioned to respond.

The message to runners is to evaluate when cramps take place. Evaluate pace, distance, stride, terrain, pattern of training days, goal paced runs, hard days and rest days. For instance a cramp may indeed show up in mile 20 of a marathon and not in training because the terrain is different (i.e. slant in road side you run on), the surface is different (i.e. train on trails race on roads) you are unaccustomed to pace (i.e. not enough goal pace miles in your training program) or you are under-conditioned (i.e. insufficient goal paced long runs). Dr. Martin Schwellnus from South Africa states that “cramps are best avoided through proper training at race intensities.” Interestingly of course is that all this suggests that faster running – quality running – race intensity running – is a recipe for cramp prevention in races – not more long slow miles.

Current expert advice on hydration is – drink when you are thirsty.

And if you like, have a swig of pickle juice instead of Gatorade.