Cramping is one of those issues that can ruin an entire session or competition, even when you're in top shape. We explore what research says about why cramping occurs, which factors seem most significant, and why the old explanation of fluids and salts isn't sufficient on its own. The main question is simple: what is most likely to trigger cramps, and what can you actually do about it? The conclusion is that muscle fatigue and (often) too high competition intensity are the clearest risk factors, while fluid/salt can matter for some but rarely explain everything. You can reduce the risk, but you need to work with both training and strategy.

Cramps are a major issue for many. In certain groups, up to 37% of those who train experience cramping, which causes many to hesitate to push themselves, resulting in poorer training outcomes. But why do we cramp? Several theories exist, but research has never pinpointed a single factor as the sole culprit, despite numerous studies over the past hundred years. Perhaps this isn't surprising. Cramps likely occur as a result of multiple interacting factors.

An article in the Journal of Strength and Conditioning provides a good overview, but if you want a shorter version, there's also a four-minute video here. Feel it's too advanced? Read on for a good summary. 

To avoid cramps during physical activity, we first need to try to understand why they occur. Several factors are strongly associated with cramps, but the two main ones are:

• Competing at a higher intensity/speed than you're trained for
• Frequent cramping (genetic influence, lower threshold for cramps)

One of the more likely theories is that the interaction between the Golgi tendon organ (see image below) and the muscle spindles fails. Several studies show that muscle spindle activity increases during muscle fatigue. The muscle spindle acts like a watchdog in the muscle—the more tired you get, the more prepared it becomes for something to go wrong (you step awkwardly, twist incorrectly, etc.).

At the same time, the activity in the Golgi tendon organ is inhibited during fatigue. The constant stretching of the tendon tires the Golgi, which would otherwise help the muscle to relax when the tension becomes too great. The result is an imbalance: the muscle spindle becomes overactive and tenses the muscle, while the Golgi cannot dampen the tension. This is what gives you that intense, involuntary, and painful contraction we call cramp. This theory has been around in the research world for about 20 years but doesn't always reach us athletes as quickly.

When you stretch the muscle, you're essentially doing a manual reset of the Golgi tendon organ. By increasing the tension in the tendon, the Golgi gets reactivated and the system is reset, which causes the cramping muscle to relax. It's similar to using another car and a pair of jumper cables when your own car has died.

Dehydration and mineral/salt balance have been extensively studied, but they are likely not the primary causes of cramps.

The idea that cramps are caused by dehydration was conceived over 100 years ago when it was noted that many who cramp also sweat a lot. Simultaneously, the theory arose that mineral and salt balance was crucial because sweat contains minerals and salts.

In modern times, with better measuring equipment and controlled experiments, it has not been shown that fluid balance affects the risk of cramps. For instance, 210 participants were tested during an Ironman, an additional 49 participants during a 56 km ultramarathon, and over 200 participants in a 100-mile race. Many cramp during these races, but there was never any difference in either salt/mineral balance or fluid balance between those who cramped and those who didn't. More such studies have similar results. Even in clinically controlled trials where participants lose as much as 5 percent of body weight (over 4 liters of fluid loss), the occurrence of cramps is not affected.

One study looked at how sports drinks with carbohydrates and salts affected cramps. The researchers found that the sports drink extended the time to cramps in participants. But the drink was complex, so it's not possible to pinpoint carbohydrates, salts, or fluids as the specific help. Who hasn't tried that pickle during a race? It tastes extra good because we have an increased craving for salt when we sweat. As far as we know, there's no clear connection between consuming pickle juice and reduced cramping, although one study compared pickle juice with deionized water and found that pickle juice reduced cramp duration. Maybe it's also that you stop, take the pickle, and rest for a few seconds, and the cramp subsides.

Our recommendation is to go for a sports drink that contains both salt and carbohydrates to help with fluid balance. The goal should be to replenish well enough that you don't feel the need to stop for a pickle during the race.

This year, exciting developments have occurred in cramp research. Two labs, one in the USA and one in Germany, have published studies that enhance our understanding of how cramps occur.

Since the exact cause of cramps isn't fully understood, we try to treat them using various methods. Pickle juice has become popular and has shown cramp-relieving effects in studies. The issue is that the cramp-relieving effect occurs very quickly (within a few minutes), long before the time it takes for salts to be absorbed in the small intestine. One hypothesis is that the vinegar in pickle juice may have a neurological effect that influences the cramp.

Many also believe that stretching helps significantly, which aligns with what's mentioned earlier in the article. However, if cramps were due to dehydration or mineral deficiency, stretching alone wouldn't supply water or minerals, so there's no logical connection that stretching directly affects the supposed cause (fluid/mineral deficiency).

This is where new research comes in: TRP channels, specifically TRPC – Transient Receptor Potential Canonical channels – are special ion channels located in the cell's plasma membrane (the outer cell membrane). There are nearly 30 variants of these channels, divided into groups with different functions. They serve as sensory messengers. For example, when you place your hand on a hot surface, a nerve signal is sent that quickly makes the muscle pull the hand away. The signal doesn't need to reach the brain for interpretation; it reacts faster locally. Through this process, TRP channels are activated and pass on information.

Some TRP channels are activated by specific molecules, such as capsaicin (the substance that gives spice its heat). When capsaicin activates a TRP channel, information is transmitted, which we later interpret, and we start to sweat, for example.

There are TRP channels that react to changes in osmotic pressure, cell volume, stretch, heat, cold, vibration, spices, and various other substances. In a study, researchers provided a substance that inhibited activity in TRPC; those who received this inhibitory substance could sustain an isometric muscle contraction 25 percent longer before cramps began (37 vs. 28 seconds). Participants who received inhibitors could also exert 28 percent more force before cramps (13.8 vs. 9.9 kg) and reported less perceived pain after cramps compared to the control group.

In another study conducted in Germany, the opposite was done: they activated TRPC and were able to induce short-term muscle cramps. If an inhibitor delays cramps and an activator induces them, then we've found an important clue. Since different TRPCs respond to different stimuli, this can also explain why some people experience more cramps in cold, heat, after consuming too much or too little carbohydrates, during salt replenishment, etc.

The explanation involving Golgi tendon organs and muscle spindles remains a significant cause of cramps. But the knowledge of TRPC provides deeper insight into how cramps can occur and potentially offers ways to alleviate them.

A few quick tips that might help:

• Occasionally train at a higher speed/intensity than you're used to.
• Try some longer distances/sessions before the race to help your body adjust.
• Hydrate properly beforehand with both water and a bit of extra salts/minerals.
• Use sports drinks during training and competitions.
• Menthol in some form. Peppermint, for instance, activates the TRPM8 ion channel, providing a cooling sensation even if it's not cold.
• Chili shot or other spicy options. For example, a pinch of cayenne pepper in a homemade start shot. Why not mix peppermint + cayenne pepper + stevia (steviol glycosides)—each activates different ion channels.
• There's actually a ready-made anti-cramp shot called HotShot (no, not Galliano, coffee, cream) that might be worth trying. It contains active ingredients to influence TRP channels, and there is some specific research on the ingredients and on the shot itself.

The advice on fluid, salt, and carbohydrate intake is described by the article's author as:

“nothing to lose if you do, possibly something to lose if you don’t”

We know it sounds boring, but if you always suffer from cramps despite training as much as your neighbor, it might partly be genetic. If you’ve tried mineral supplements (calcium, magnesium) and experimented with extra salt and fluids without improvement, the likely cause is simply that you pushed your muscles harder than they’re used to.