“Why do I get cramps sometimes but not others even though the workouts are the same?” “Why do I get cramps an hour or more after a
workout?” “Why do I cramp when my teammates doing the same workout don’t?” “Why do I get cramps at night hours after doing anything
that might have made my muscles tight ... or even when I’ve done nothing strenuous?” While most athletes and active people realize that
dehydration and electrolytes have something to do with muscle cramps, I get lots of questions like these. To nd some answers, let’s look
at what normally happens in muscular activity using these diagrams of a single muscle cell in which K+ represents a potassium ion1 and
Na+ a sodium ion, two vital electrolytes as we will see. Note that with the relaxed muscle cell there are proportionately more potassium
ions inside the cell than in the uids outside the cell while the opposite is true for sodium ions2).
When a nerve impulse is transmitted to the muscle cell, the cell membrane becomes permeable and the potassium ions can migrate out
of the cell while the sodium ions can diffuse into the cell as the cell contracts. If the conditions are right, the cell will then pump the excess
sodium ions out of the cell and the potassium ions back into the cell. Meanwhile, the cell is also ratcheting the muscle bers in the cell into
the stretched or so-called “relaxed” condition. The conditions are “right” when (1) there is enough water in the uids around the cells for the
ions to move freely, (2) there are enough potassium ions in this extracellular uid to restore the “relaxed” condition, (3) there are enough
sodium ions to maintain the “bridge” across the cell membrane and (4) there is enough energy available in the cell to pump the sodium
and potassium ions back across the membrane and to ratchet the muscle bers into the extended (“relaxed”)3 condition. If any of these
conditions are not right, the cell will not be able to stretch into the extended condition and, the next time you try to extend that muscle, it
will “protest” and “refuse” to extend. If conditions in the muscles are marginal, say, you are a little dehydrated, the muscles involved will
be tight and the next day they’ll be sore from hundreds of “micro-muscle pulls” and the subsequent inammation. If the conditions are
worse yet or you worsen them by trying to “push” yourself even as your muscles are becoming tight, the entire muscle bundle may cramp
up and you can’t continue (your body’s emergency “off” switch). If you still try to keep going or the cramp occurs in mid-stride the muscle
will probably “pull” ... tearing some if not all of the muscle.
As you can see, it takes more than plain water to prevent or relieve muscle cramps: you also need the proper balance of electrolytes and
not just a lot of salt either. For example, too much sodium will pull uids out of circulation into the tissues, depleting blood volume and
increasing stress on your heart. You don’t have to be running a marathon or hiking in the desert to be dehydrated and low on electrolytes;
even daily activities can leave you dehydrated and upset your electrolyte balance. Sometimes you can even have “localized” dehydration,
as when you are on a long plane ight or sitting at a desk or computer and your uids can be pooled in your legs and feet. If you get up
and walk around, you can feel better because your blood is circulating more and your brain is getting rehydrated. This is also a signal
that you are probably at least a little dehydrated and should replace some of that uid. Remember that the rst symptom of dehydration
is diminished mental function. What about “night cramps”? Often people will wake up in the night with leg cramps even though it’s been
hours since they exercised or, for many people, they haven’t bee exercising at all. They are dehydrated and low in electrolytes; in this case
low calcium is usually the culprit and hydrating with a balanced electrolyte drink plus a calcium supplement usually solves the problem ...
and, believe it or not, the isotonic electrolyte drink (VITALYTE) won’t make you get up in the night as much as plain water.
1Ions are atoms or groups of atoms that have become electrically charged, usually when a compound is dissolved in water; for example,
salt or sodium chloride (NaCl) becomes sodium ions (Na+) and chloride ions (Cl-); substances that break up in water to form these electri-
cally charged particles are called electrolytes.
2”Why do they use these symbols instead of P for potassium and S for sodium?” These chemical symbols come from the Latin names
kalium and natrium respectively; P and S were already taken for phosphorus and sulfur when potassium and sodium were discovered.
3Note that the so-called “relaxed” term for the extended muscle is a misnomer; it has taken energy to get it extended and no energy is
needed for it to contract, very much like a rubber band.
DEHYDRATION AND MUSCLE CRAMPS.
By: Bill Gookin, No. 2 in a series of occasional reports on wellness and dehydration ***
* For 40 years athletes have known us as Gookinaid, but we are not just a drink for athletes. Now the world knows
us as Vitalyte™, a drink for everyone. Same fast, effective formula...band new name!
**This article is the opinion, advice and testimonial of the author and your results may vary. If you have a medical
condition involving dehydration or electrolyte imbalance, you should consult a physician before following this advice.
***Documentation on le.