Many people swear that a bar of soap under the mattress helps with muscle cramps. Is there any science behind the theory
Nighttime leg cramps are involuntary but often painful muscle contractions that affect one or more muscles. Muscle cramping differs from restless leg syndrome, but the underlying cause is often the same.
Muscle cramping is when a muscle causes a knotted feeling that can immobilize your leg for a few seconds to several minutes. Muscle cramps often respond to massage to loosen the knot that has formed. Restless leg syndrome produces more of a twitching sensation that forces you to want to move your leg to reduce the sensation, and no amount of rubbing of the legs seems to provide relief. Night cramps and restless leg syndrome tend to worsen in the summer, most likely because of increased minerals lost through perspiration.
The Soap Remedy!
Slipping a bar of soap under your sheets before you go to bed is a folk remedy that some people swear by! This treatment may be supported by traditional beliefs or anecdotal evidence, but there is little scientific research to back up the claim. One hypothesis as to how soap might work involves the fragrance limonene, a common component of some soaps. Some research suggests that this volatile compound activates the skin's TRP (transient receptor potential) channels. This may calm hyperexcitable nerves (European Journal of Applied Physiology, Aug. 2017).
Could that be it?
Perhaps but what makes more sense is that one of the ingredients in soap is magnesium! And magnesium is one of the essential minerals in which most people with muscle cramping and restless leg syndrome are deficient. The theory is that as the bed warms up from your body heat, the oils from the soap help the magnesium release and then get absorbed through the skin. The magnesium may then help relax the muscles of the legs, improving some of the symptoms associated with restless legs and cramping.
The caveat is that for you to potentially feel the benefits of the soap remedy, you should have the soap under the bottom sheet, not under the mattress. Under the mattress will release some scents, only partially completing the benefits. Seeing benefits also depends on how much of the soap ails and magnesium actually gets absorbed through the skin
The better choice for Cramping and RLS!
The amount of magnesium in the soap is minimal compared to topical magnesium cream or lotion or taking a magnesium supplement. Magnesium helps to balance the amount of calcium in our cells; too much calcium can disrupt nerve signally. Magnesium also helps increase potassium absorption, which is also critical for proper muscle function. If you want to try magnesium, start by taking one capsule before bed. Work your way up to taking 1000- 2000 mg of magnesium. Don't start at this high dosage, as it could have a laxative effect with some people. Topical Magnesium oil or Magnesium Spray is an excellent option and can be applied before bed to reduce the incidents of cramping and RLS . Or it can be used as needed as a quick and effective way to get things calmed down again so you can get back to sleep.
Other Options for Managing RLS & Muscle Cramping
Increase your electrolytes! Leg cramps can occur if you are low on electrolytes like calcium, magnesium, and potassium. Electrolytes are minerals needed for various body functions, particularly nerve and muscle functions. Mild electrolyte imbalances are more common and can affect anyone. For example, if you are dehydrated or have over-exerted yourself physically, that could bring on a bout of leg cramps. You may also experience frequent leg cramps if you have a condition that affects your fluid and electrolyte balance, such as diabetes, liver disease, or kidney failure that requires dialysis.
Iron supplementation is another option for managing RLS syndrome. Low iron in the brain can affect dopamine levels which not only control our moods but also control the way the body moves.
Restless Leg Syndrome can also occur with peripheral neuropathy, which damages the nerves throughout your body. It's also associated with multiple sclerosis and Parkinson's disease. RLS can also be a problem during pregnancy. It is best to contact your healthcare provider to discuss options for managing RLS and muscle cramping if you have any of these conditions.
There is probably no harm in placing soap in your bed. It's not likely to bring you any relief, though. If your symptoms don't go away, consider your present health conditions and try taking magnesium and potassium before bed or supplement with an electrolyte during the day.