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As anyone who has ever raced a triathlon can attest, quad cramps suck. Cramping is extremely common, occurring in up to 67% in triathletes, with Any muscle can cramp up, but the quadriceps are one of the most commonly affected. These quad ramps can range in severity, from small short-lived spasms to episodes of painful “locking up” that can entirely derail races.
Some athletes seem to be more prone to cramps than others. A large study of runners linked underlying chronic disease, medication use, allergies, prior muscle or tendon injuries, and greater running experience to a greater risk of cramping. Multiple studies of Ironman athletes have shown that cramp risk increases with racing at higher-than-normal intensities and faster race times. Regardless of risk factors, cramps can negatively affect any athlete – so what causes them, and how can we prevent them?
Conventional thinking commonly links nutritional factors to exercise-associated muscle cramps, in particular dehydration and electrolyte depletion, especially sodium. More recently, abnormal spinal reflex activity in tired muscles has been implicated—basically, fatigue makes nerves and muscles to go haywire. In reality, nailing down an exact cause or mechanism that applies to all athletes in all situations is difficult, if not impossible, so let’s take a deeper look at these two main theories.
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Quad cramping: Nutritional factors
Dehydration and electrolyte depletion has been postulated to contribute to muscle cramps. Historically, industrial workers found that sodium depletion provoked cramps, while rehydrating with a saline solution relieved them. Increased cramping has been associated with large fluid and electrolyte losses in tennis and football players, particularly in hot and humid conditions. Dehydration and electrolyte imbalance are theorized to sensitize and increase mechanical pressure on nerves, leading to cramps. But evidence for this theory is mixed. Inducing mild and significant (with moderate electrolyte loss) dehydration did not increase cramp susceptibility in some investigations. Studies of Ironman athletes have failed to demonstrate any clinically significant differences in body mass loss or serum electrolytes between cramping and non-cramping athletes, with similar findings seen in marathon runners. Still, serum electrolyte levels might not reflect what is occurring within muscles and cells, with often normal circulating sodium concentrations post-exercise despite an overall body deficit. So, then, hydration and electrolytes might be part of the story, but perhaps not all of it.
Quad cramping: Fatigue factors
This brings us to the “altered neuromuscular control” theory of muscle cramping. The basis of this theory proposes that an overloaded, fatigued neuromuscular system leads to an imbalance between excitatory impulses and inhibitory impulses, causing involuntary, sustained muscle contractions. Muscles contracting at already shortened lengths are particularly at risk, and this type of cramping tends to be confined to a specific muscle group. This theory is supported by studies showing increased baseline electromyographic activity in runners’ and triathletes’ muscles between or after bouts of cramping, as well as by studies showing altered reflex activity with muscle fatigue in animal models. The findings that cramps tend to occur late in competitions and, as previously mentioned, when triathletes are racing at higher intensities relative to their training, also support neuromuscular fatigue as the cause of cramps. Still, this theory isn’t without its own questions and limitations. Stimulation frequencies used in some research to induce fatigue don’t always match up with what naturally occurs in humans, and the variations in cramp susceptibility between individuals still isn’t explained, either.
How to fix and prevent quad cramps
Well, then, if the science behind the exact causes of cramps isn’t conclusive, how can we stop – or better yet, prevent – them? While the etiology behind cramping may be complicated and multifactorial, the good news is that simple, evidence-based prevention and treatment methods for quad cramps are out there.
Stretching it out is typically the first response to cramping, and for good reason: it works. Stretching reduces muscle activity and induces an inverse stretch reflex, calming down those hyperactive nerves. Just work into the stretch slowly, as a rapid jolt in the opposite direction could cause the affected muscle to clamp down further.
Although evidence for the dehydration/electrolyte depletion theory of cramping is a bit mixed, cramping does appear to respond to fluid and electrolyte (namely, sodium) replacement, particularly at the early stages of cramping. In one study, rehydrating with an electrolyte-containing solution decreased cramp susceptibility after dehydrating downhill running. Plus, we know that determining and meeting hydration and electrolyte needs in all conditions is otherwise crucial for performance.
Don’t discount carbohydrates, either, since anything that increases fatigue, like a lack of fuel, could theoretically increase cramp risk. Nutrition is crucial to triathlon regardless, so focus on it, and eliminate it as even a potential cause of cramping!
In recent years, small amounts of noxious liquids such as pickle juice or spicy formulations such as HOTSHOT have been used to decrease cramping. While one might postulate that pickle juice works due to its sodium content, ingesting small amounts has no effect on plasma electrolyte content. Instead, pickle juice and other noxious substances such as peppers, mustard, cinnamon, and ginger are thought to stimulate nerves in the mouth, esophagus, and stomach that tell the spinal cord to send inhibitory signals to cramping muscles. So, while maybe not-so-great tasting, downing a noxious liquid may help!
Train and pace
Just like with nutrition, you should practice what you’ll be doing on race day as far as duration, intensity, and conditions. When it comes to cramping, the altered neuromuscular control theory is based on fatigued muscles. Be realistic with your pacing plan, as faster early paces in long distance events may increase cramping risk.
Make sure to respect heat and humidity, too. Know what your body can handle in those conditions, as the carnage on a triathlon run course in the heat is real.
Even the best theory out there cannot explain the differences in cramping between athletes, so trying to figure out a one-size-fits-all prevention and treatment strategy is next to impossible. If you find yourself prone to cramping, take note of triggers! Do cramps come on at certain durations or intensities? In hot conditions? Do electrolyte tabs help? What was your diet like in the days leading up to the cramp? Any recent injuries? Identifying any contributing or underlying factors can be invaluable into formulating an individual game plan for cramp prevention.
Talk to your doctor
Medical issues such as thyroid issues, diabetes, vascular issues, and nerve compression all can increase cramp susceptibility, as can certain medications. So, if cramping happens frequently no matter what you do, consult with your doctor to investigate for any potential underlying issues.
Jennie Hansen is a physical therapist, Ironman champion, and USAT Level 1 triathlon coach with QT2 systems. Hansen has a background as a collegiate and professional runner, as well as a number of professional triathlon podiums. She has been in the sport for over a decade.