Why Do I Get Calf Cramps at Night?

Do you experience uncomfortable cramps in your legs at night?  Do your calf muscles cramp up when you’re least expecting it?  Calf cramps and other leg muscle cramps can have various causes.  This article will examine some of the most common reasons for getting calf cramps, and then discuss some options for prevention and treatment.

 

What Are Calf Cramps?

A cramp, also known as a charley horse is a sudden spasm or tightness in a muscle.  They can last anywhere from one second to several minutes.  On a microscopic level, the actin-myosin fiber segments that are involved in shortening and lengthening a muscle, to put it technically, “go totally wonky”.  When the myosin fibers are unable to break free from the actin filaments during muscle contraction, a prolonged contraction occurs and the person may experience a cramp.

Actin_myosin_filaments pic

Sodium (Na), Magnesium (Mg), and Potassium (K) are necessary to drive this process, so if we are deficient in either of these minerals, we are leaving our muscles susceptible to cramps.

There is one other mineral we need to think about with respect to this process, and that is calcium (Ca). Keep in mind for now that potassium can inhibit calcium (not let poor calcium do it’s job).

There is also one other microscopic miracle we need to know about, so let’s go back to microbiology class!  Our cell membranes contain little pumps called Sodium-Potassium pumps (Na-K pumps) that shuttle those two minerals in and out of cells as necessary to maintain proper mineral balance.  As that “put on the brakes” potassium flows out of the cell, it eventually wipes out all the calcium in the cell, which is a trigger to closes the Na-K pump.  When we don’t have enough potassium in the body, the calcium builds and builds and builds and basically the muscle contraction builds up and never shuts off, thus a cramp!

na-k pump pic

So in summary, we need:

Calcium, to drive the actin-myosin contraction process.

Magnesium, to allow for muscle relaxation in the actin-myosin process.

Sodium, to maintain mineral balance with respect to the Na-K pump.

Potassium, to assure that we don’t use too much calcium.

 

Why Do I Get Calf Cramps?

Cramps may occur due to various causes, such as:

  • Repetitive motion or overuse injuries to the calves (running or even standing for too long).
  • Exposure to cold temperatures, especially to cold water.
  • Specific medical conditions, such as blood flow problems, MS, or kidney or thyroid dysfunction.
  • Pregnancy (in late stages of pregnancy the mother’s calcium and magnesium stores may be low).
  • Mineral imbalance in the blood (lack of sodium, calcium, potassium, or magnesium).
  • Dehydration (not enough fluid in the body).
  • Exposure to cold water.
  • Taking certain medications such as steroids, diuretics, and birth control pills

Calf cramps, and other leg and foot muscle cramps tend to happen at night because that is when your muscles are resting.

 

How To Prevent Calf Cramps?

Cramps may be prevented or decreased if you can take in adequate Na, Ca, K, and Mg and drink enough water throughout the day to stay hydrated.  Whole foods sources of these minerals are as follows:

leafy greens chard pic

Calcium: Leafy greens, legumes, seafood, and fruit.

Magnesium: Leafy greens, nuts and seeds, fish, beans, avocados, yogurt, bananas, dried fruit, dark chocolate,

Potassium, Leafy greens, fish, squash, yogurt, white beans, avocados, mushrooms.

Sodium:  Many foods contain sodium and most americans get enough sodium.  It’s important to note however, that clean eaters who exercise frequently may need to add sea salt into their diet to make sure not too much sodium is lost through sweat.

To prevent calf cramps at night, you can take a warm bath, do some gentle exercise, and drink some fluids before bedtime.

 

Treatment of Calf Cramps

Once a cramp is happening, there are two ways to break it.  The first way is to gently stretch the muscle.  If it’s a calf cramp, stretch the calf muscle by pulling your toes towards your shin.  One easy way to do this is to stand facing a wall with one foot behind you, and then do a basic runner’s calf stretch.

If this method doesn’t work, the second, slightly more aggressive method, is to manually affect the actin-myosin bridging.  No, you don’t need to pull out a microscope for that.  All you need to know is in which direction the muscle fibers run.  In the example of the calf muscle, the fibers run vertically from the knee to the foot.  You are basically going to quickly pinch the middle of the muscle.  Place your hands in the center of the muscle, fingers facing each other and about two inches apart.  Then perform a quick pinch motion, going deep into the muscle and bringing your hands towards each other.  It doesn’t feel great, but it is effective!