Hydration Series - Why Do People Cramp?

Anyone who has woken up in the middle of the night with a cramp has wondered… what the heck happened?!


Ironically there is no set consensus from the research about exactly what causes cramps and how to stop them. There are 2 major theories behind why humans cramp;


Theory #1 – Dehydration / electrolyte depletion theory

This theory stems from research all the way back in the mid 1900’s, specifically observing factory workers, soldiers and day laborers. At this time there were not many professional or collegiate athletes to study, so most of it was based on people who sweat profusely in hot environments for long periods of time.


Researchers subscribing to this theorize that the loss of water and Na, without replacement, leads to fluid moving out of the muscles and into the blood to maintain balance. This lack of sodium in the muscles leads to the inability of the muscles to work and thus a cramp happens.


The literature states that “Abnormal loss of Na and Cl (sodium and chloride which together = salt) will lead to cramps, fatigue and collapse if not replaced at an appropriate rate”. This highlights the need to begin events already hydrated and continue to replace fluids and sodium appropriately for the event, environment, and individual.


If you’ve been reading our other articles in our Powell Performance Hydration Series, you’re already well aware of this.


While it seems simple and certainly has a lot of empirical evidence behind it, the research has been less conclusive. One reason it is hard to do any research on this topic is the randomness at which it happens. It is very hard to pin point when during an event someone is going to cramp, so it’s hard to study it before, during and after the event to show exactly what happened to cause it and what was done to correct it.


So, if it’s not hydration and sodium related, what causes cramps?


Theory #2 – Neuromuscular theory

Some researchers believe hydration has little to do with cramping. They point to the central nervous system (CNS) and say that cramping is not due to sodium loss, but that the nerve innervating that area is too excited (hyperexcitable). That leads to electrical misfiring and causes that area of the body to cramp.


They also point to these cramps happening more commonly when the body is over stimulated and fatigued. That supports their idea that the nervous system is causing the cramps. From a performance standpoint, this fatigue and over stimulations can be seen when someone tries overreaching their fitness level, specifically training or competing too intensely or for too long. This is often when you’ll see an athlete go down with a cramp in competition.


This theory definitely has more research and publications to support it than the depletion theory. This is due to the ability to manipulate the CNS in a lab so that the researchers can cause a cramp and then try different protocols to relieve it.


This has led to some researchers figuring out why things like pickle juice and other high sodium and electrolyte drinks can have an immediate effect on the person’s muscle cramp in lab settings. More research on specific drinks and how they specifically impact the CNS at the mouth and throat came out and even led to specific products being created.


Which of the Theories is right?

This is where both sides of the aisle agree for once. It doesn’t matter which one you believe is causing the issue. It’s all about how to solve the issue!


So, what advice from each theory can we can use?


Even those who agree that sodium depletion is not a main cause for muscle cramps, still recommends that you go into the training events hydrated and consume fluids and sodium during them at an appropriate amount.


Cool Theories… how do I not get cramps?!


Acutely –

  • Stretch the affected areas – if your hamstring cramps, STRETCH IT!


  • Sports massage, rolling, soft tissue release – specifically 3-5 days before contest to avoid any soreness that may occur from the massage/ rolling. *NOTE - this is based on empirical evidence to help with hyperexcitability and soft tissue recovery, but no way of seeing progress / results since we don't know when cramps will happen.



  • Continue to hydrate and meet needs for activity completed – work to have the fluids necessary available for during and after the event


  • Taper into events – feel fresh going into it – our coaches here at Powell Performance can DEFINITELY help you with this one



Chronically –

  • Reduce training volume and intensity (do less at a slower rate to get acclimated)


  • Train in the environment you’ll be competing, but again, do it slowly to acclimate (if you’re going to play in Arizona in summer, it doesn’t help to train in an Alaskan winter…)



  • Hydrate and fuel for your goals and training – specifically working to make sure you glycogen stores are appropriately filled for your training, this means eating correctly BEFORE, during and after the event/competition



Any recommendations for older athletes?

With our masters athletes, usually at around 35-40 years old, we start to make small adjustments to their hydration plans. We do this because older athletes tend to suffer cramps more frequently than younger athletes.


This happens for a three reasons; older athletes typically lose muscle mass (which holds a lot of water), kidney function decreases and thirst is often blunted compared to when the athlete was younger. These all add up to dehydration.



Wrapping it up

As you can tell, cramping is not a perfect science, so neither is preventing it. So the goal now is to put all the information together in order to give us the best chance to prevent them while also optimizing your performance.


We here at Powell Performance know how to calculate your sweat rate, your fueling needs and adjust for your training and environment. Then we can decide whether to drinking to a plan or drinking to thirst both have merit, and with the guidance our dietitians and coaches, we can help you figure out which one would work better for you and your goals.


Want to learn more? Reach out for a FREE CONSULTATION with our staff!


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