You needn't worry about cold air damaging your lungs when you exercise in cold weather. The only reports of lung damage from cold air are in people who were unable to get out of the cold, such as American gunners who lay unconscious in the frozen turrets of high-flying World War II bombers or people who were injured in automobile accidents and lay unconscious for hours in the cold.
During exercise, your muscles produce so much heat that air inhaled at 40 degrees below zero will be warmed more than 100 degrees before it reaches your lungs. Air that cold will burn your nose, throat and mouth so badly that only the worst masochist would even think of exercising in minus 40-degree weather.
There is no need to try to breathe through your nose when you exercise in cold weather. Your nostrils have only one-tenth the surface area of your throat, so they are too small to allow you to get adequate amounts of air during vigorous exercise.
If you cough, wheeze or become short of breath when you exercise in cold weather, you may have exercise-induced asthma. This condition affects one in 10 Americans and is caused by breathing dry, cold air. It can be prevented by warming the air with a cold-weather mask that goes over your nose and mouth or by wrapping a scarf over your mouth. Or, have your doctor prescribe an inhaler such as Ventolyn, Proventyl or Tornulate, and use it just prior to exercising.
Q: I'm training for my first marathon. How many miles per week should I run?
A: You should train for speed, not mileage. When I competed in marathons, I thought that the best way to train for competition was to run asmany miles as I could. I didn't become a great runner, but I did become an expert on injuries. I've had them all.
Top marathon runners can run more than 100 miles a week because their bodies have the genetic ability to resist injuries when they run many miles. For most of us, the odds are overwhelming that we will become injured if we try to run more than 100 miles a week.
Running a lot of miles slowly won't help you in races. The ability to run fast in races depends more on how fast you run in practice than on how many miles you run each week. The faster that you run in practice, the faster you will be able to run in races.
However, every time you run fast, your muscles are damaged. It takes at least 48 hours for your muscles to heal enough to allow you to run comfortably again at a very fast pace. If you try to run fast on the day after a fast workout, you are likely to injure yourself.
You should take the next day off, or at least run at a much slower pace. You probably won't be able to run very far, either.
Running fast limits the number of miles you can run each week. Most top athletes plan their workouts so they run very fast only two times a week.
Q: Will protein supplements make me a better athlete?
A: It is illegal in this country for a manufacturer to claim that protein supplements will make you stronger, give you larger muscles or make you a better athlete. To support this position, the Food and Drug Administration recently commissioned a study by the Federation of American Societies for Experimental Biology (FASEB). The FASEB found no scientific reason for healthy people to take protein supplements.
Protein supplement manufacturers make pills and powders from foods such as tuna fish and milk powder and sell them for much higher prices than you would pay for the food. They also sell free amino acids, claiming that they break protein down into its building blocks, which are called amino acids. This is unnecessary because your stomach and intestinal enzymes are so effective in breaking down protein into amino acids that they need no help whatever. Supplement promoters claim that the individual amino acids, arginine and lysine, make your muscles larger than just protein.
This claim is not supported by any controlled scientific studies. Besides, meat, fish and chicken, eggs and dairy products are loaded with these two amino acids.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.