Muscle cramps are never fun and they can hit anyone at any
time. Lying in bed, your foot can seize up and threaten to implode. Walking up
a hill, your calf might begin to contract. When running, just about any muscle
can succumb to a cramp and the reasons for these cramps vary wildly.
The most common theory for explaining muscle cramps during exercise states that
cramps originate from a lack of electrolytes or dehydration. This theory has its
limitations, though. Namely, an athlete need not be dehydrated to experience a
muscle cramp. Marathoners, for example, often suffered from muscle cramps even
at temperatures that made dehydration unlikely.
Another theory as to the cause
of muscle cramps has to do with the neuromuscular system. This theory proposes
that neuromuscular fatigue can lead to an imbalance in inhibitory and
excitatory drives to alpha motor neurons. This in turn leads to an increase in
alpha motor neuron discharge which causes localized muscle cramps. Essentially,
a fatigued neuromuscular system sends neurons to signal muscles to cramp.
So how does one prevent cramping? Well, obviously making
sure to stay hydrated will prevent any cramp due to dehydration. But what about
cramps brought on by neuromuscular imbalances?
Incredibly, one answer is to
drink pickle juice. It may seem at first that pickle juice could prevent cramps
by increasing electrolyte levels in the body, but one study by Miller et al found that this was not the reason that pickle juice inhibits
cramping. This study electrically induced foot cramps in test subjects and
compared the effects of drinking pickle juice to drinking water.
The result was
that 2.5 oz. of pickle juice caused the cramp to stop after 85 seconds vs. the
water which took 134 seconds. Both sets of subjects were equally hydrated and
plasma compositions after the test were found to be the same. This shows that
neither dehydration nor differences in electrolyte levels explain the results. The
authors of this study theorize that the reason pickle juice inhibits the cramp
quicker than water is because when the juice hits the oropharyngeal region (the
back of the mouth), it inhibits the firing of the alpha motor neurons that
signal muscle cramps.
But how does the practical runner use this information? Well,
first, make sure that you are properly hydrated before each run so muscle
cramps are never caused by dehydration. If you do still experience cramps on
runs, try throwing a little bottle of pickle juice (around 2.5 oz) in your
backpack or running belt. When a cramp strikes, stop your run, take a shot of
pickle juice and lightly stretch out the cramp. The combination of light
stretching and pickle juice, which inhibits cramp-causing neurons, will usually
solve your problem.