Muscle cramps are sudden, severe, involuntary spasms or contractions in all or part of a muscle. They are often painful and can affect one or multiple muscles. During a muscle spasm, your muscle may be temporarily immobilized.
After exertion, common places to experience muscle cramps are the calf and thigh muscles. You may also notice them in your abdominal muscles, hands, and feet. Sometimes, muscle cramps can be so intense that they wake you at night.
Muscle cramps are not unusual, with 35-60% of participants in one study reporting muscle cramps and 40% reporting that they had muscle cramps more than three times per week.1
Muscle cramps differ from sore muscles in the following ways:
There are two common hypotheses for why muscle cramps occur:
According to this theory, muscle cramps occur after you sweat a lot and don’t replenish water and electrolytes.
Challenges to this theory:
It is more likely that a change in electrolyte levels, when combined with significant dehydration, could set the stage for muscle cramping, especially when environmental conditions are hot and humid or the athlete is deconditioned.
The neuromuscular hypothesis is based on the hypothesis that a change in the central or peripheral nervous system causes a cramp. This could result from a change in electrolyte concentration at the nerve terminal.
This theory is more consistent with the observation that some people seem to be more prone to muscle cramping than others.
Muscle cramps can be divided into three types:2
The first step to preventing muscle cramps is to try to identify the potential causes. While the research is unclear on what causes muscle cramps, you can do a few things to reduce your risk, especially if you are more prone to getting them.
Researchers did not notice a difference in electrolyte levels between people suffering from a cramp and those who were not. Marathon runners and inactive people did not have a difference in blood electrolyte levels, even after a run. However, the research did suggest that the combination of dehydration and electrolyte changes may predispose to muscle cramping.
When exercising in a hot, humid environment, you can sweat 3-4 liters per hour. It is important to replenish these lost fluids. Losing more than 2% of your body weight due to sweating while exercising could also impact athletic performance.
Drink water throughout the day. Thirst is an indicator that your body is low in fluids. However, it is a late indicator. To prevent dehydration-induced muscle cramps, drink water throughout the day.
When you exercise with cold muscles, they are more likely to sustain an injury. Even minor muscle fiber damage can cause a cramp as the muscle tries to protect itself from injury.
Research suggests that stretching muscle cramps can help relieve the pain and restore mobility. It seems to follow that stretching in advance would loosen tight muscles and could prevent cramping.
Football players suffer muscle cramps more frequently when the heat index is high and they are in the initial weeks of the season after a long rest. No matter what your age, there are many benefits to exercise, and reducing your risk of muscle cramps is one of them.
Football players suffer muscle cramps more frequently when the heat index is high. To decrease the risk of heat-related illnesses, including muscle cramps, the National Collegiate Athletic Association instituted a mandatory 5-day acclimatization period. Some research suggests that an even longer period may be needed.3
Acclimate yourself to your environment and protect yourself from heat-related illness.
Choosing a whole-food diet high in nutrients and antioxidants is good for overall health and may reduce muscle cramps. Eat a wide variety of foods. Avoid unhealthy sources of fat and protein and highly processed foods.
An easy rule to follow to ensure your muscles get a wide range of vitamins and minerals is to eat foods across the rainbow. Low-fat dairy products are an excellent source of calcium. Pair foods high in vitamin C with low-fat protein sources to ensure maximum iron absorption. Fruits, vegetables, seafood, and dairy products are high in potassium. Most people get plenty of sodium in their diet.
Depending on the cause of your muscle cramps, medications, and supplements may be helpful, including:
The best treatment strategy for muscle cramps is to prevent them, and if that doesn’t work, try stretching. Do dynamic stretches before your workout and a full range of motion stretches during and after your workout.
Cold decreases blood supply to a muscle and reduces swelling. It is most helpful right after an injury.
Warm increases blood flow. This can reduce pain and speed healing growth factors to the injury.
Massaging a muscle cramp can help relieve it. However, if you massage a cramp too vigorously, you may cause damage to the muscle fibers.
According to the American Academy of Neurology, quinine is effective at treating muscle cramps, but the risks and benefits should be carefully considered. Quinine should only be considered when the cramps are disabling and nothing relieves them and after monitoring for side effects.
There is some evidence that diltiazem and vitamin B complex may treat muscle cramps.
While electrolyte loss alone does not seem to cause cramps, it could contribute. Consume a well-balanced diet high in fruits and vegetables to restore electrolytes after sweating.
While we strive to always provide accurate, current, and safe advice in all of our articles and guides, it’s important to stress that they are no substitute for medical advice from a doctor or healthcare provider. You should always consult a practicing professional who can diagnose your specific case. The content we’ve included in this guide is merely meant to be informational and does not constitute medical advice.
1. Naylor, Jr., and Young, J.B., A General Population Survey of Rest Cramps. Age and Ageing. 1994;23(5):418-420. doi:10.1093/ageing/23.5.418
2. Giuriato G, Pedrinolla A, Schena F, Venturelli M. Muscle cramps: A comparison of the two-leading hypothesis. Journal of Electromyography and Kinesiology. 2018/08/01/ 2018;41:89-95. doi:https://doi.org/10.1016/j.jelekin.2018.05.006
3. Cooper ER, Ferrara MS, Broglio SP. Exertional heat illness and environmental conditions during a single football season in the southeast. J Athl Train. Jul-Sep 2006;41(3):332-6.
4. Miller TM, Layzer RB. Muscle cramps. https://doi.org/10.1002/mus.20341. Muscle & Nerve. 2005/10/01 2005;32(4):431-442. doi:https://doi.org/10.1002/mus.20341