Muscle Cramping

I recently listened to a very good podcast (https://soundcloud.com/user-562497687/fast-talk-ep-26-busting-myths-about-cramping) on muscle cramping. From the website, “For decades (almost a century, in fact), we’ve been told that cramping is caused by electrolyte imbalance or bad hydration. But new science suggests that this probably isn’t why you cramp during exercise. So why do you cramp? It all comes down to something called altered neuromuscular control.” Briefly, fatigue is the main component. However, it’s more complex than that (as with most things).

The podcast is long, 70 minutes, but is both informative and entertaining. It gets deep and technical at times, but they do a good job at bringing it back to an easily understandable lay level. I encourage you to listen. However, it you don’t want to, or as a preview, here’s a synopsis and my take-aways.

Muscle cramps defined – A muscle that contracts without relaxing. Cramping is a syndrome that can have multiple causes.

Altered Neuromuscular Control

Historically, the theory that cramping is due to electrolyte imbalance and dehydration, comes out of observations from workers on the Hoover dam, and coal shovelers in old steamships. That became the predominate belief for endurance athletes too. It wasn’t until the 1980s that scientists started to look at cramping.

Ironically, it was attempts to prove the electrolyte/hydration theory that led to the altered neuromuscular control theory. Sampling of athletes in competitions found no difference in electrolyte balances or plasma levels between cramping and non-cramping athletes. Cramping almost always happens at the latter stages of races, often just before or after the finish, another strong sign that fatigue is the key factor. Also, questions of athletes showed that those who were injured, sick, or fatigued (i.e., not adequately tapered) going into the events were more likely to get cramps.

These types of observational studies seem to be the best for studying cramping. It’s hard to study cramping in the lab because electrically induced cramps are not the same as cramping during exercise.

There are two key organs that control the contraction and relaxation of muscles. The muscle spindle organ excites, or contracts the muscle. The golgi tendon organ relaxes the muscle. Muscle fatigue can cause the spindle to send excess signals, and the golgi tendon to send fewer. This imbalance can cause twitching or cramping.

Not all fatigue is equal. Cramping tends to happen when competing at a higher level, or in different conditions (e.g., racing in a hot spring race when you’ve trained in the cold, or racing hills when you’ve trained mostly flats) than which you are trained. Cramping tends to happen at the latter stages or after the race. Intensity. It’s also more likely in the early season, when you are racing at intensity before you have adequately trained at intensity.

Other factors that contribute to cramping:

  • Pre race muscle damage, such as from an injury or inadequate taper. This can be tested with high creatine kinase (CK) levels, which indicate muscle damage.
  • Not feeling well, which can lead to early fatigue.
  • Heat and humidity may be a factor, but only because they lead to early fatigue. There are no studies that show a correlation between heat and cramping. Cramping can happen in cold too.
  • Males are more likely to cramp than females. Older athletes are more likely to cramp than younger ones. The reasons are unknown.
  • Certain medications can contribute to cramping, e.g., statins and Beta2Agonists. Also, some underlying medical conditions, e.g., hypothyroidism.
  • Weakness in supporting muscles; e.g., lower back, core, abductors and adductors.
  • Family history of cramping. People tend to have different cramping thresholds. There may be a genetic component.

Other interesting info on cramping. Camping is more common on muscles that cross two joints; e.g., calf, hamstring. Cramping happens when muscles are in a shortened, contracted state; i.e., when the spindles are engaged. So, cramping can occur after a race, for example, when you bend your leg while sitting.

Repeated cramping may indicate some underlying medical or physical issues. In that case, it might be worth getting a CBC blood test and consulting a physician, one who is familiar with endurance athletes.

How to Prevent Cramping

The best way to avoid cramping is to train, to be adequately trained for the race and intensity you are planning to do. There are not magic bullets. While most speed workouts are done when relatively fresh, you should also add Intensity when you are fatigued. This will prepare you to push through the latter stages of a marathon, or to make that finishing kick without cramping.

Back in the day, one of my favorite ultra workouts was to run up Waterton Canyon to the Platte and back, ~31mi, along the northern end of the Colorado Trail. Towards the end of the run, coming back down the canyon, I would run progressively harder the last few miles, sometimes hitting 6:00 for the final almost flat mile.

Add strength training. Stronger muscles better resist fatigue and cramping. Strength training doesn’t necessarily have to involve weights or a gym. Plyometrics, or quick, explosive moves, such as box jumps, jumping rope, or 6-10 second hill sprints.

Don’t make your first race of the season your key race. Do some earlier, shorter, high intensity races, to prepare you for your big race.

Vary your stride. This is, perhaps, the biggest reason why trail running is easier on your body than road running.

What to do if you cramp

If you do get a muscle cramp, don’t try to run through it. That is likely to make it worse. Instead, you should slow down or stop. Muscle twitching may be an early warning sign of impending cramping.

Stretch, longer stretches. The initial stretch may activate the spindle, making it feel worse. If you hold it, typically longer than 10-20 seconds, the golgi tendons will activate allowing the muscle to relax and lengthen; i.e., settling into a stretch.

Put pressure on the golgi tendon cluster, jam your thumb into and vigorously massage. This is a theory, it hasn’t been shown in studies, but seems to be effective for some athletes.

Eat something sharp, pungent, and spicy. There seems to be something in the neural pathways in the mouth that can affect the whole body. The mechanism for this isn’t known, but it may be because sharp tastes overwhelm the neuromuscular signals elsewhere. Related, studies have shown that a sports drink rinse, not ingesting, can increase time to fatigue, meaning that just the sensation of taste can effect muscle control. Many of you may have seen ads for the product Hot Shot. The key ingredients in that product are capsaicin (the chemical in peppers that makes them hot) and cinnamon. You may able to get the same effect from biting on a jalapeno pepper.

Hyperventilating or drinking pickle juice. Studies have shown that increasing blood acidosis can relieve cramping. There is no evidence that electrolyte supplements help. The reason pickle juice may work is because of its acidity or pungent taste, not the electrolytes.

These may fix the immediate problem, but don’t address the underlying causes. Long term, better fitness reduces the likelihood of cramping.

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