A MATTER OF MINERALS
Whether you’re on a treadmill, writing a letter, or even lying in bed at night, your muscles are constantly contracting and relaxing. As a result, they need a lot of nourishment. When they don’t get it, they’ll sometimes contract into tight, painful spasms known as muscle cramps. Cramps are a muscle’s way of telling you it’s tired, hungry, and in need of rest.
Muscle cramps are painful, but they play a protective role, says Leslie Bonci, RD, a dietitian at the University of Pittsburgh Medical Center and a spokesperson for the American Dietetic Association. Essentially, they force the muscle to remain inactive until it has time to recover, usually within a few minutes.
While you can’t prevent muscle cramps entirely, choosing the right foods will make them less likely to return. Here’s how it works.
Muscles don’t move without orders from the brain. Before you can stand up, blink an eye, or turn the pages of this book, the brain sends electrical messages to the appropriate muscles, telling them when (and how much) to contract or relax. Minerals such as calcium, potassium, sodium, and magnesium, which are known as electrolytes, play a role in helping the messages get through, says Joel Press, MD, medical director of the Spine and Sports Rehabilitation Center at the Rehabilitation Institute of Chicago.
If you haven’t been getting enough of these minerals or have sweated them out during vigorous exercise, a muscle may not get the message to relax. This can cause it to contract in a painful cramp.
Of all the electrolytes, magnesium is one of the most important, because it helps other electrolytes do their jobs, says Robert McLean, MD, associate clinical professor of internal medicine and rheumatology at Yale University School of Medicine. When you don’t eat enough magnesium-rich foods, minerals such as calcium and potassium can’t get into muscle-fiber cells. So even if you have an abundance of other electrolytes, without magnesium, they may be locked out and ineffective. “People who are depleted of magnesium tend to have greater irritability of the muscles and nerves,” says Dr. McLean. “This irritability may cause muscle cramping.”
Water will go a long way toward keeping your muscles healthy during exercise, but you’ll need more help if you’re exercising vigorously or for an hour or more. In this case, reach for a sports drink, such as Gatorade. The electrolytes and carbohydrates in such drinks get into the bloodstream quickly and help keep muscles from cramping, says Leslie Bonci, RD, a dietitian at the University of Pittsburgh Medical Center and a spokesperson for the American Dietetic Association.
Here are a few tips for improving your electrolyte balance:
Get magnesium from tofu, spinach, and Spanish mackerel. A serving of tofu has 128 milligrams of magnesium, or 32 percent of the Daily Value (DV). A serving of spinach has about 44 milligrams, or 11 percent of the DV, and a serving of mackerel has 82 milligrams, or 20 percent of the DV.
Include dairy in your diet. Calcium helps regulate the muscles’ ability to contract. Dairy foods are the best sources. A cup of fat-free milk, for example, has nearly 302 milligrams of calcium, or 30 percent of the DV, while a serving of low-fat yogurt has 77 milligrams, or 7 percent of the DV.
Choose potassium-rich bananas and potatoes. Getting enough potassium in your diet may also be helpful for preventing cramps, says Dr. Press. Bananas are a good source of potassium, with one banana supplying 451 milligrams, or 13 percent of the DV. Potatoes are also a good source, with a half-cup containing 114 milligrams, or 3 percent of the DV.
Say no to sodium. For most people, the problem isn’t getting enough sodium, it’s getting too much, since this mineral is found in large amounts in many foods, particularly processed foods. And for those who are sensitive, sodium can lead to fluid retention and high blood pressure. So even if you have been getting cramps, leave the sodium alone—you’re almost certainly getting enough.
Hydrate, hydrate, hydrate. Whenever you perspire, you lose fluids from the muscle cells, which can result in cramping, Bonci says. And you’re more likely to get muscle cramps when you exercise in hot weather because you’ll be sweating more and losing fluid, salt, and minerals that keep your muscles working optimally. Sipping water frequently throughout the day will help keep electrolyte levels in balance. When you’re planning on being active, it’s a good idea to drink at least 16 ounces of water or juice to prime your body with the necessary minerals.
Dodge cramps with carbs. Muscles need more than electrolytes and water to function well. They also need glycogen, a sugar that comes from carbohydrates. Getting plenty of carbohydrates in your diet will help keep muscles working well. Good sources include potatoes, rice, bananas, and bread.