Muscle Cramps and Other Injuries Two Studies

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This article was edited and updated on April 22, 2017.

Several questions arise when we find ourselves injured or putting up with frequent muscle cramps:

It’s never easy to know the answer, and every single person faces different problems and therefore different solutions. Two studies have caught my eye as interesting for those of us in the “older adult” category who often find ourselves suffering from minor aches and pains — and muscles cramps — and wondering what we should do about it. As well, there is a brief discussion here about magnesium deficiency which is often considered a "cause" of muscle cramps.

Study #1: Why do we get muscle cramps?

How many times have you been told that “most likely” if you take calcium you won’t get muscle cramps? Or have you ever been told that if you got more electrolytes in your system, or if you drank more water, you’d be less likely to suffer from cramps? In my own experience, I get muscle cramps often, usually during every single fitness session. And I take plenty of calcium and drink plenty of water. So what’s happening?

The researchers of a study published online in the British Journal of Sports Medicine on 9 December 2010, wanted to find out of triathletes who were in excellent condition suffered from muscle cramps during or after high performance. If they did, was there any correlation between cramps and dehydration or serum sodium changes? Or might they find a different explanation?

Martin P. Schwellnus, Nichola Drew, and Malcolm Collins — all associated with exercise and medical research clinics in Cape Town, South Africa — began with the premise that there is a “high prevalence of exercise-associated muscle cramping in endurance athletes.” But, they felt, the “etiology and risk factors for this condition are not fully understood.”

They decided to look at 210 triathletes who were competing in an Ironman triathalon. “Prior to the race, subjects completed a detailed...questionnaire.” As well, “blood samples for serum electrolyte concentrations were taken...and body weight was obtained.”

This was repeated immediately after the race: a questionnaire, blood samples, body weight. As well, the researchers took information from the athletes on when they experienced cramping during or immediately after the race.

Forty-three triathletes reported cramping experiences in the past, and these were compared to the 166 triathletes who did not report cramping during or after the event.

The conclusions were:

The researchers also concluded that “...dehydration and altered serum electrolyte balance are not causes for [muscle cramps]. Rather, endurance runners competing at a fast pace...[and] high intensity are at risk for [muscle cramping].

Although not a large study, there was no money coming from companies with a vested interest, and studying 210 triathletes makes the study more credible than if they had just chosen 210 people off the street.2

How do we extrapolate from this study — which looked at well-trained athletes — and know how it relates to us? My feeling is that the conclusion suggests that we may have a muscle cramp when we are moving fast or at high intensity. That would not be the same speed or intensity of a trained athlete, but something that is faster or more intense than we usually do.

Study #2: Should I exercise when part of my body hurts?

The second study was published in the European Journal of Applied Physiology. The researchers — Chelsea Starbuck and Roger G. Eston — wanted to know if a person exercised the elbow flexors in one arm, might it “protect against exercise-induced muscle damage in the other arm.”

Only fifteen young men were used in this study, making the results less than overwhelming, but still interesting.

The men were randomly assigned to two groups and each performed two repetitions of 60 eccentric contractions separated by two weeks. Measurements were taken of the strength, muscle soreness and rest arm angle for both arms as baseline measures at 1, 24 and 48 hours after exercise.

The results of this study, though small, are interesting. I’m always telling my participants that, even if one arm is sore, they can exercise the other one. This study seems to agree with me: The results showed that “the repeated...effect transfers to the opposite (untrained) limb.” Check that out again: While you exercise one arm, the other one apparently benefits, as well.

The researchers add: This seems to “provide evidence for a centrally mediated, neural adaptation.” In case that is still confusing: The untrained arm appears to also improve, possibly because something is going on neurologically in a “centrally mediated area.”

Clearly, this needs more research. But isn’t it a fascinating idea?3

And, finally, what about magnesium deficiency?

There are some studies on magnesium deficiency, but they are limited and tend to focus on particular conditions. So there will be no study to discuss here; however, it is believed that magnesium deficiency may cause muscle cramps. Research on this is sparse and some controversy exists. Supplements are always problematic (how much to take, when to take it, what kind to take) and getting magnesium from your food, while possible, is also limited.

What do we know? Here are 16 possible signs of a magnesium deficiency:

If you feel that it's worth trying to increase magnesium in your diet, here are a few foods that contain higher levels of magnesium than other foods:

Remember: Before deciding if you have a magnesium deficiency, check with your doctor.

See also:

I am a BCRPA-certified fitness instructor in Vancouver, BC. I teach four classes at the West End Community Centre in Vancouver, BC, mostly designed for the older adult. The Inevitable Disclaimer: Everything published here expresses only my opinion, based on my training and research. What you do with the information is entirely your own responsibility. I am not liable for any injury you suffer that seems to be related to anything you read here. Always consult your doctor before beginning an exercise program. For other articles, return to the table of contents.

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  1. These three dots behave exactly like a footnote. Click on them and you will get more information about the topic. 

  2. Read here for more information about the study 

  3. This research is complex and certainly not complete. More needs to be done. For further details, you can read the full abstract yourself.