A muscle cramp is not great. The system that was working flawlessly has now jammed and what was going to be a personal best is now dragged down by a ghostly grip that will not let go: cramp.
In addition to being not great, muscle cramps can be painful, inhibit mobility and greatly decrease performance.
So why do they happen?
Unfortunately, there is not great science to support an answer. There are two leading theories: electrolyte loss and spinal cord signaling malfunction.
Spinal cord signaling malfunction
Basically, the constant stream of information from your body to your brain goes haywire. Your body stress levels can no longer communicate accurately to your brain what is going on, your brain panics and shuts down the muscles: cramp.
Or, the muscles are screaming fatigue and the brain interprets this information to mean danger, shut it down before there is an injury: cramp.
Electrolyte loss
This theory has been made popular by sports drinks and you already have a good sense for what it is; sweat maintains the body’s temperature below a threshold that keeps the organs from cooking, but sodium is lost through the sweat. The hotter, longer, harder you exercise, the more sweat and the more sodium is removed from the body. Sodium works with potassium in the chain reaction of muscle contractions, without this key electrolyte: cramp
A study involving industrial workers showed a decrease in muscle cramps when the workers were given salt tablets and they experienced less cramps then their coworkers that did not get the tablets.
Maybe, it’s both
Your body is experiencing stress in the form of exercise , there is a loss of sodium so nerve action potential starts misfiring and the brain processes all this as a possible injury so it sends signals to shut it down: cramp
Cramps are notoriously difficult to study because of all the complicated factors involved as well as they are inconsistent. Science likes a simple process with repeatable results, cramps are neither.
How to avoid cramps, hopefully
Drink water. Drink water with salt in it. Drink water while exercising and replace electrolytes during and after exercising.
That is not ground breaking, staying hydrated keeps everything flowing, and nearly everybody knows this. You even have a built in response for when you should drink water: when you are thirsty.
Interestingly, a study demonstrated no difference in performance between cyclists that drank water on a strict schedule and cyclists that drank when they were thirsty. It did show that not hydrating decreases performance.
Also, if eating a mustard packet cures your cramps, eat a mustard packet. If doing yoga keeps you from cramping on long runs, do yoga. If you need 14 hours of sleep at night to not cramp, get to bed early. The best science we have right now suggests: do what is best for you.
Health Insights 