Muscle cramps are part of sports. But what can you do to minimize the risk of cramps? And how can you get rid of a cramp once it occurs?
Most endurance athletes have probably experienced it themselves: towards the end of a long, intense effort, muscles can sometimes go out of control and contract involuntarily. The range of cramps varies from a slight muscle flutter to a very painful complete muscle blockage. Cramps are a widespread phenomenon.
Studies involving 2600 endurance athletes found that two-thirds of triathletes and marathon runners experience cramps. The study indicated that the calf muscles are most frequently affected. However, while cycling, the main working muscles, both the front and rear thigh muscles, often cramp. More exotic cramps can occur in the feet, hands, or arms while cycling, but these are also reported.
What causes muscle cramps?
There are numerous theories, often debated among sports scientists and doctors. The most well-known theory is that of electrolyte deficiency due to significant water loss. However, this is increasingly being replaced by a fatigue theory first published by South African Professor Dr. Martin Schwellnus in 1997. The core of the fatigue theory is a malfunction of fatigued nerve cells that control the muscles. An American meta-study on cramp causes categorizes cramps into two types: fatigue cramps and heat cramps.
Pickles, the rescue!
Recent studies have shown that to combat a cramp, you need to treat the nerve, not the muscle. The idea stems from the theory that cramps occur when nerves are destabilized. In other words, cramps are caused by destabilized, irritated nerves acting up. This occurs when motor neurons in the spinal cord fire excessively.
There were rumors that some athletes consumed pickle juice or a mixture of mustard and warm water to combat cramps. Inspired by these rumors, scientists investigated further and found that both substances activate TRP channels in the mouth.
Stimulation of sensory nerves in the mouth, esophagus, and stomach triggers a nervous system response that calms the motor neurons in the spinal cord. But what does this mean for our next competition if we want to avoid cramps? The solution seems simple and inexpensive! Just tuck a few slices of pickles into your jersey, and when your muscles start twitching, suck on a piece briefly—it should be enough. If interested, there are also commercially available solutions.
Salt is essential
How do you determine the cause of a cramp? Heat cramps affect multiple muscles simultaneously and often come on gradually. The term “heat cramps” is somewhat misleading, as it’s not the heat itself but excessive sweating that is the trigger.
Are you a “salty” sweater? Do visible salt stains form on your sportswear, not only after a long competition but also during training? If so, you should increase your salt intake during periods of significant sweat loss. If heat cramps are imminent, an immediate intake of a concentrated salt solution can help: mix 3 g of salt (about 3 pinches) in half a liter of a carbohydrate drink (Int. J. Sport Nutr. 6, 1996).
It is also possible to drink too much. Those who drink pure water or large amounts of beverages with very low mineral concentration dilute the body’s salt concentration. This must be kept within narrow limits. Some marathon runners have even died from excessive water consumption.
The role of magnesium
In addition to common table salt, which contains essential sodium, magnesium also plays a role in preventing cramps. However, 2PEAK nutrition expert Benoit Nave advises against concentrated magnesium intake during competition: “Under stress, especially during competition, magnesium supplements unnecessarily burden the stomach and should therefore be avoided.”
Roman Gruber, a certified vital substance therapist and advisor to many professional athletes, agrees. Gruber recommends filling electrolyte stores before races similarly to carbohydrate stores, as many athletes cannot tolerate electrolyte drinks and therefore prefer pure water during long competitions, knowing it may lead to deficiency. Gruber’s prevention tip: “Two handfuls of nuts per day cover the need for essential magnesium.”
During races, Gruber, who also advises the Milram team, recommends two pinches of salt per liter of drink (2 g). An alternative is salt capsules taken with water. Energy gel manufacturers have also started adding more salt to their products. Check the sodium content on the packaging.
Sometimes, cramps are mistaken for muscle pain. Roman Gruber notes that especially women often suffer from iron deficiency, which prevents the body from producing enough L-carnitine. In such cases, the expert recommends a daily intake of 5 g of L-carnitine on competition days and 2 g on training days. All supplements and race nutrition must be tested during training! Everyone reacts differently. So, no experiments during competitions!
Tired muscles act up
Although the electrolyte theory is very old and often studied, it does not fit many cases. For instance, musicians’ fingers cramp without much sweating. Additionally, targeted movements can quickly and precisely induce cramps. But even during long endurance efforts with significant sweat loss, the electrolyte theory falters: several studies on cyclists, runners, and triathletes in long competitions found no difference in fluid loss or electrolyte concentration between those who experienced cramps and those who did not!
Schwellnus’ fatigue theory provides more coherent explanations for cramps. It is based on the observation that nerve activity changes with fatigue. A brief excursion into neurophysiology explains how things are connected: muscle activity is controlled and monitored by two sensors built into the muscles. These are muscle spindles, which are arranged parallel to the muscle fibers in bundles, and Golgi tendon organs, located at the transition between muscle and tendon, measuring the force with which the muscle pulls on the tendon.
The spindles’ nerves activate the working muscles, thus tensing the muscle. Golgi organs prevent excessive tension by sending relaxation signals when needed, ensuring the muscle does not overload. When fatigued, the balance of these sensors shifts. The spindles become more excited, sending too many signals, while the Golgi organs send too few. This overexcitation leads to cramps.
But not only muscle fatigue disrupts the balance of muscle activation and relaxation. This mechanism also loses effectiveness when the muscle is tensed in a significantly shortened position. As tendons become slack, Golgi organs cannot detect tension and do not send signals. Muscles spanning two joints are particularly susceptible, as they can be brought into a shorter working position than single-joint muscles.
Examples of two-joint muscles prone to cramps include the calf muscles (flexing the knee and extending the ankle) and the long head of the biceps femoris, which attaches to the prominent tendon on the outside of the knee (extending the hip and flexing the knee). Contracting the biceps femoris in a significantly shortened position (lying flat on the stomach, bending the knee, touching the feet to the buttocks) quickly induces a severe cramp without prior muscle fatigue. The trickery of the Golgi organs is enough to provoke a cramp.
How to relieve a cramp
A local cramp can be relieved mechanically by stretching the affected muscle. Stretching activates the Golgi organs, sending relaxation signals to the muscle. You don’t even have to get off the bike to stretch the muscles. However, proper, slow stretching is essential, as rapid stretching triggers a reflex contraction. You might recognize this from the reflex test at the doctor’s office: a hammer tap on the knee tendon causes the thigh to contract reflexively, swinging the lower leg forward.
After relieving the cramp, continue with reduced intensity. For a thigh cramp, initially contract the muscle only between 12 and 2 o’clock, then gradually expand the range. If the calf is affected, reduce ankle movement and keep the heel down.
Other cramp triggers
Despite the mechanical clarity of cramp theories, biological systems are very complex. Causes of cramps can be more diverse than simple theories suggest. Nutrition plays a crucial role. Nutrition expert Benoit Nave attributes symmetrical cramps to excessive consumption of dairy products, which burden the liver and venous blood system, hindering blood return from the muscles. For unilateral cramps, Nave repeatedly diagnosed and resolved blocked foot or hip joints through osteopathic treatment.
Sometimes, small factors can trigger cramps. Ronald Andraczek, a cyclist from Dresden, identified caffeine-added gel as the culprit for his race cramps through trial and error. After switching to the same gel without caffeine, the cramps disappeared. Literature suggests this is not an isolated case but also not a definitive link.
Carbohydrate deficiency is also critical. When muscle glycogen stores are depleted, the risk of cramps increases. In a lab study where subjects consumed carbohydrate-rich electrolyte drinks, the onset of cramps was significantly delayed. Amateur cyclists who believe training without food and drink is more efficient should not be surprised by cramp attacks.
Measures against cramps
The number one measure to prevent cramps under stress is appropriate training. Overloading will almost certainly lead to cramps eventually. Both exceptionally long and hard or unusual stresses affect the muscles. The exact mechanism of fatigue is unknown, but observations show that even a few unusual peak loads can set the stage for a later cramp. If muscles are pushed into the red zone early in a marathon without practice, the likelihood of cramps increases. Under very hard conditions, like time trials with maximum effort and an unusual position, cramps can develop quickly—sometimes in under 20 minutes.
Our advice: train specifically, stretch after training, eat a balanced diet, and replace fluids and salt under heavy stress. This will significantly reduce the risk of cramps. If you still get cramps, it’s a sign that you have successfully tested your physical limits.
Tips to prevent cramps
- Train specifically for a competition
- Stretch muscles after training
- Eat two handfuls of nuts daily
In training and competition
- Carbohydrate-rich drinks with a pinch of salt per ¾ liter
If a cramp occurs
- Stretch the affected muscle
- Add salt if you have cramps in several muscles