Nobody can exercise vigorously every day. If you think you can, expect to be injured. All athletic training is done by stressing and recovering. It's called the hard-easy principle. On one day, you exercise vigorously and your muscles feel sore. Then, for the next few workouts you exercise far less intensely until the soreness disappears. Only then should you attempt another hard workout.
There are three different ways to use the hard-easy principle. Athletes in competitive sports have to train specifically in their sports, so a basketball player may scrimmage for four hours on one day and then shoot baskets and run plays on the next.
If you do not compete in sports, it is better to exercise only every other day or play alternate sports that stress different parts of your body. For example, on one day, you could stress your legs by running or dancing. On the next day, you could stress your back and shoulders by pulling on a rowing machine.
The hard-easy principle applies to your skeletal muscles, not your heart. You can exercise hard on consecutive days as long as you do not use the same set of skeletal muscles.
Q: Are tanning lotions safe?
A: Most people now realize that any exposure to sunlight can damage their skin. If you want to look tan, the sunless-tanning lotions are safe, but they have some limitations.
The vast majority darken your skin using a chemical called dihydroxyacetone or DHA. It has been approved by the Food and Drug Administration and is safe, as far as we know, because it darkens only the outside surface of the skin and does not affect the deeper layers.
Your skin contains protein, which is made up of chains of building blocks called amino acids. DHA turns only the amino acids brown, and they are only on the surface of your skin and in your sweat. DHA does not affect intact protein which is in the BTC deeper layers of skin.
If you decide to use DHA creams and lotions, apply them two to four times for the first day and repeat once every few days as the color starts to fade. You can increase the darkening effect by applying DHA after you shower. The water smoothes out the skin and exposes more amino acids to the DHA.
DHA does not protect you from sun damage, so use a sun screen of at least Sun Protection Factor 15 whenever you go into the sun. If you have light skin, I recommend applying sunscreen all year.
Q: Is it true drinking lots of water as you eat will help lose weight?
A: Drinking extra water with meals will not reduce the amount of food you eat. If you drink several glasses of water with your meals, the extra water will distend your stomach and make you feel full and satisfied. Water has no calories and does not satisfy hunger.
Healthy kidneys are so effective in clearing extra fluid from your body that healthy people can take in a lot of extra water safely. Your kidneys can clear 5 gallons of water per day.
Foods high in fiber help you lose weight because they fill you up without a lot of calories. Forget extra water; eat lots of fruits, vegetables, whole grains and beans.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.