More than just cold feet.

Have you ever wondered why we use the term "cold feet" to describe someone experiencing second thoughts before a wedding? You may be surprised to learn that the reason for cold feet is much the same whether you're talking about a reluctant bride or your toes after a winter run.

During times of stress, such as during anxious moments or when exposed to cold temperatures, blood is shunted to our vital organs and away from our extremities. The total volume shift of blood from the periphery to the internal vessels is estimated to be as much as 5% to 10%. Females may be more prone to this since their bodies were designed to protect the reproductive organs.

The medical jargon for the cause of cold feet is vasospacity. This condition results from a higher than normal secretion by the nerves of the hormone adrenalin. Adrenalin is the same wonderful hormone that bungee jumpers crave and drivers in rush hour traffic could do without. The surge of adrenalin in the bloodstream as a result of stress causes constriction in the capillaries and small arteries going to the hands, lips, nose, ears, and the feet where there is a high concentration of nerve endings. This is part of the body's amazing flight or fight response, which allows you to endure in jury with less pain and bleeding when your nervous system perceives a serious threat. The result? You guessed it--cold feet.

Raynaud's disease can cause cold feet associated with cool temperatures. Color changes in the toes and fingers are hallmarks of this condition. (See Running & FitNews, December 1998, page 3.) There are a number of other less common medical conditions that can cause cold feet. Atherosclerosis or hardening of the arteries may cause cold feet. If you have high blood pressure or a family history of heart problems you are at a higher risk of developing vascular problems in the legs and feet.

There are some initial steps that you can take if you are prone to this problem. Wear a hat when exposed to cold weather because you lose over 50% of your body heat through your head. Try fabrics like Gore-Tex, Dacron, and wool for insulation and to stay dry since water on the skin allows freezing to occur 240 times faster than cold air. You may also want to consider waterproofing your running shoes with a water-repellent spray.

Food intake translates into calories and calories equal heat. So eating before braving the cold is helpful as long as you give your food enough time to leave the stomach. A full stomach causes diversion of blood to the gastrointestinal track to aid digestion depriving the feet and hands of their usual supply. That slug of peppermint schnapps at the football game might make your belly feel warm, but alcohol actually lowers your body's core temperature by allowing cold blood from the skin's surface into the blood vessels of our vital organs, essentially overriding the body's normal response to cold. Believe it or not, a cup of hot cocoa has an overall body temperature lowering effect by allowing the skin's surface vessels to dilate, resulting in lost heat. If you are on the ski slope, loosen your boot buckles in between runs to allow more blood flow to the feet. If you have chronically cold feet that seem beyond the scope of normal, it warrants a consultation with your doctor.

(AR&FA Clinic Advisor Aaron Ben Pearl, D.P.M., is a consultant to the National Institutes of Health and practices podiatry in Arlington, VA.)