Man experiencing a muscle cramp while running

Muscle Cramps During Exercise: Prevention and Treatment

What are muscle cramps?

Exercise-associated muscle cramps are painful, involuntary contractions of muscle, typically lasting one to three minutes, that occur either during or after exercise. They frequently occur in muscle groups used repeatedly during an activity, such as the calf muscles during running or cycling. Cramps can range from mild to severe, but either way, they can be very frustrating for an athlete.

A cramp in the quad muscle is common during exercise

Even more frustrating is the fact that a review of the medical literature doesn’t give us good answers on why they occur and how to prevent them. This post covers what we know and what can be done to help you or someone you know who suffers from exercise-induced muscle cramps.

Is it dehydration?

A common belief is that dehydration causes muscle cramping during exercise. It makes sense that when we exercise, we sweat and lose fluids. While replacing fluids during exercise is vital, modern research has shown that hydration has little to do with cramping. In studies, athletes and exercisers who get cramps are not more dehydrated than those without cramps. There was also a belief that exercising in the heat causes cramping due to increased sweating and fluid loss. However, athletes can also get muscle cramps in the cold, and the term “heat cramps” has been debunked by the research.

Preventing cramps during exercise with hydration

It is crucial to remain hydrated while exercising. The American College of Sports Medicine’s (ACSM) position on fluid replacement is that athletes should consume a volume of fluid that prevents more than a 2% body weight loss from perspiration. You can get a handle on this by weighing yourself before and after an exercise bout.

Too much hydration can actually be dangerous, as it can interfere with fluid and electrolyte balance and result in a condition known as hyponatremia. You can monitor your hydration state by the color of your urine, which should be clear and light yellow, not completely colorless. Drink throughout the day, not in huge amounts at one sitting, to remain hydrated safely.

Is it electrolytes?

When we sweat, we lose more than water; we also lose electrolytes, specifically sodium and chloride. The brain tightly regulates our electrolytes, maintaining balance throughout the body. Similar to hydration, replacing the lost electrolytes is important to allow the brain to maintain balance. However, electrolyte balance affects the entire body. Exercise-induced cramping is localized and only affects specific muscles. The research does not support the theory that electrolyte imbalances cause cramping. However, there may be some people more sensitive to dehydration and electrolyte imbalance, resulting in an increased tendency to experience cramps.

Is it deconditioning?

An athlete exhausted from an exercise bout

Experts agree that an increase in exercise intensity plays a role in cramping. Research shows that poor conditioning and higher-intensity exercise bouts may be risk factors for exercise-associated muscle cramping. Performing an activity at a higher intensity than your body is used to results in fatigue. Fatigue can cause a ‘cramp-prone’ state, which makes the muscles more excitable through various reflexes within the muscle. That higher excitability can lead to muscle cramps. Certain muscles, especially two-joint muscles such as the calves, hamstrings, and quads, more commonly cramp up. Fatigue occurs during endurance activities that use those muscles repeatedly. Cramping is also more likely in early-season athletics, when the athlete may not be as conditioned. Finally, a recently injured or recovering muscle may be more susceptible to cramping.

A cramp in the hamstring muscle is common during exercise

While this theory seems to make the most sense and has the most support in the literature, many contributors and interactions within the body systems likely result in painful muscle cramps during exercise.

How to deal with muscle cramps

We may not know precisely what causes muscles to cramp during exercise, but there is agreement on what to do once it happens. Gentle stretching is the fastest, safest, and most effective treatment to relieve an active muscle cramp. You can stretch on your own or with assistance.

Stretching the foot and calf to relieve a muscle cramp

Stretching a muscle while it is cramping helps to restore the balance between excitability and inhibition in the muscle. It resets the reflexes to shut down the cramp. The cramping threshold may be reduced if you continue with your activity, so the cramp may occur again. After a severe cramp, the muscle may be sore for a day or two.

Stretching the quad muscle can help relieve cramping during exercise

Prevention of muscle cramps

There are many anecdotal remedies for cramps, and you may have your favorite ways to minimize cramping associated with exercise. In addition to fluids and electrolytes, ingesting fluid containing high concentrations of vinegar and brine, such as pickle juice, can act on a reflex in the digestive system, which may reduce cramping. There is some research to back this up, so if you can handle the taste of pickle juice, it may be worth a try. I have found some reduction in cramping while cycling if I take pickle juice before and during a long ride.

Pickle juice can help treat and prevent muscle cramps during exercise

Stretching before a bout of exercise does not appear to reduce cramping. Some evidence suggests that strengthening and corrective exercises to minimize muscle imbalances may be helpful, especially following an injury.

Research on using magnesium supplements or bananas to reduce exercise-associated muscle cramps has had mixed results. Quinine supplementation has shown some positive effects on nighttime cramps. However, due to health risks, it is no longer allowed in the US for muscle cramps. Tonic water contains Quinine at lower concentrations, and there is anecdotal evidence that it can be beneficial.

Bottom line

Cramps can occur in both hot and cold temperature athletic efforts. The longer and more intense the effort is, the more likely a cramp may occur. We may not know precisely why some people are more susceptible to muscle cramping. Still, gradual increases in activity, maintaining the strength of the offending muscles, fully rehabbing injured muscles and tendons, and keeping a healthy level of hydration appear to be the key. When you get a cramp, the quickest way to shut it down is to stretch the offending muscle. Finally, downing a shot of pickle juice may help!

Cycling in the mountains

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Picture of Carol Grgic, PT, OCS, CSCS

Carol Grgic, PT, OCS, CSCS

Carol Grgic is the owner and treating therapist at Elite Bodyworks in the Historic Third Ward, in Milwaukee, Wisconsin. She has extensive experience treating athletes and active people of all levels. She has a particular interest in headache treatment. She also enjoys blogging about health and wellness topics.

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