Why do so many athletes and runners, especially long-distance, suffer from cramps? For many years, the usual recommendation was to refill any electrolyte and sodium deficiencies. But in the past few years, new research has shined fresh light on the subject, suggesting novel theories on what might be causing muscle cramping (other than low electrolyte or sodium levels).
The topic is of interest to most athletes, as a high percentage of sportspeople have been dealing with muscle cramps. Many have tried to solve their cramping issue by addressing their hydration, electrolyte, and sodium intakes. For some, increasing their sodium intake before and during a race solved the problem. But for most runners, drinking enough electrolytes and taking extra sodium tablets did nothing to relieve them of cramping during races.
What Causes Muscle Cramps?
Theory 1: Dehydration, or Electrolyte Deficit
The initial theory about muscle cramping over the past decades focused on dehydration, electrolyte deficits, and sodium loss. The theory is largely based on the fact that a significant disturbance in fluid or electrolyte balance causes a contraction of the fluid compartment around the muscles, leading to a firing of nerve impulses, and effectively causing cramps. If we lose a lot of sodium, and don’t subsequently replace stores, this causes fluid shifts in the body that lead to cramps. And looking at most cases when athletes and long-distance runners suffer cramping, it usually happens towards the end of a race, or after many hours of racing—that’s why ultra runners sometimes replenish their electrolytes by adding salt tablets to their nutrition plan. But when the weather is not too hot and when we hydrate plenty, what other factor can cause cramping?
Theory 2: Neuromuscular Theory
This is the most recent theory regarding muscle cramping in athletes. After realizing that most athletes were suffering from cramps during races even when properly hydrating, new research proposed that a cramp was the result of dysfunctional reflex control of the motor nerve as a result of fatigue—meaning that muscle overload and neuromuscular fatigue are the root of exercise-related muscle cramps. The theory is that fatigue contributes to an imbalance between excitatory impulses from muscle spindles and inhibitory impulses from Golgi tendon organs—as such, muscles tend to cramp specifically when they are overworked and fatigued due to electrical misfiring.
What Happens When We Cramp?
• Muscle contraction is initiated by a nerve called the alpha motor neuron. This nerve receives inputs from the higher brain areas (when you make conscious movements), as well as from the spinal reflexes.
• The reflexes are responsible for protecting the muscle against either excessive stretching or loading—they are called muscle spindles and Golgi tendon organs.
• There is evidence that fatigue causes increased firing from the muscle spindles and decreased activity from the Golgi tendon organs.
• The result of this change in the activity of these reflexes is that the alpha motor neuron activity is increased, and the muscle contracts involuntarily.
• Fatigue causes: 1) spindle activity increases, leading to alpha-motor increases, causing muscle contraction; 2) Golgi-tendon-organ activity decreases, leading to an increase in alpha-motor activity, causing muscle contraction.
If dehydration and electrolyte depletion was actually the main factor for muscle cramps, then a lack of electrolytes or sodium would not cause a specific muscle group to cramp every time. We would expect generalized cramping. However, the muscles that are more likely to cramp tend to be the calves, quadriceps, and hamstrings.
Another factor supporting the neuromuscular theory is that stopping and stretching the affected muscles is a very effective method for fixing a cramp as it is occurring. This is because stretching puts the muscle under tension, invoking a specific reaction from the Golgi tendons and causing the cramp to dissipate. Adding validity to the theory is the fact that with 20 seconds of passive stretching the electrical activity of muscles significantly decreases.
Drink Pickle Juice
Aside from making sure we are well hydrated and loaded up on electrolytes and sodium, pickle juice’s popularity has been rising alongside neuromuscular theory’s. Another important factor in muscle cramping is the use of compounds that can stimulate something in the mouth called “transient receptor potential” channels that have possible effects on cramping muscles. These channels connect the mouth to the central nervous system, and the hypothesis is that stimulating these receptors somehow sends a “spike” reaction down the nerves, disrupting the signals that are causing a cramp in the first place.
Some substances that stimulate TRP channels include wasabi, mustard oil, and pickle juice. Pickle juice contains acetic acid, which stimulates the TRP receptors and helps relieve cramps. Among athletes who have tried drinking pickle juice during races, as soon as the substance was ingested the cramps almost instantly dissipated (that’s because the nerve stimulation is instantaneous, whereas the delivery of sodium to your blood takes several minutes). Pickle juice is a great food supplement for ultra runners—easy to swallow and digest.
How to Reduce Muscle Fatigue?
• Train specifically for the event that might induce cramping. Aim for the right volume, intensity, and elevation to prepare the muscles for that specific race.
• Pace yourself appropriately according to your fitness level and environmental conditions to avoid overloading the muscles.
• Make sure you taper before the race so that you are well rested and fresh at the start.
• Make sure you focus on proper race nutrition and hydration to avoid premature fatigue.
• Get regular sports massages and stretches of the affected muscles.
• Use acupuncture treatments.
• Warm up properly before training and racing.
• Try to include some mental-relaxation techniques to use while racing.
Luckily, muscle cramps can be resolved easily once the cause and issues are determined.
By Katia Kutcher
Katia, owner of d.BeFit, is a NASM-certified personal trainer, is a NASM Sports Nutrition Specialist, is PT Global-certified, and is TRX-certified.