Some bodybuilding magazines urge readers to eat high-protein foods and take special vitamin and mineral supplements in order to give them gorgeous physiques that will make them champion bodybuilders.
But that won't work. Champion bodybuilders are born, not made. Genetic factors are what determine whether or not you have the potential to become a top bodybuilder. The best bodybuilders have the largest muscles and the least body fat.
Muscles attach to bones via tendons, and the potential for having large muscles comes from having long muscles and short tendons.
Look at the calf muscles in the back of your lower legs. The muscles probably extend halfway down the back of your lower legs. Then, the tendons take over and extend to the bottom of your heels. If your calf muscles look like this, you can't possibly become a champion bodybuilder, no matter how hard you train. People with calf muscles that extend all the way to their ankles have the best potential for becoming top body builders; this is what catches the attention of judges.
Many bodybuilders spend several hours every day lifting light weights numerous times. Yet, while hours spent lifting lighter weights can help bodybuilders lose extra body fat, it won't help them increase their muscle size. Large, strong muscles develop when very heavy weights are lifted at fewer repetitions.
If bodybuilders want larger muscles and less fat, they should lift heavier weights fewer times, eat a low-fat diet and get involved in an aerobic exercise to lose fat.
Q: Why do men consistently run faster in races than women do?
A: The world records for all running events from 800 meters to the marathon are 11 percent faster for men. The male advantage is mainly caused by the masculinizing hormone, testosterone.
Testosterone increases the number of red blood cells in the body, and a major factor regarding how fast you can run is the amount of oxygen supplied to your muscles by red blood cells. A hemoglobin blood test
measures the concentration of red blood cells in your bloodstream.
The average female runner has a hemoglobin of 13 grams; the average male runner, 15 grams. That's an 11-percent difference. In tests in which male runners had 11 percent of their blood removed (to make their hemoglobins equal to those of women), the men still ran faster. Therefore, another factor is involved.
The female hormone, estrogen, causes fat to be deposited in the body. Twenty percent of the weight of the average female runner is fat, compared with only 11 percent for the average male runner. Yet when men ran with weights equivalent to 9 percent of their body fat -- thereby carrying as much extra weight as women do -- they still ran faster.
The average male completes a 10-km race in 44 minutes while the average female crosses the finish line in 50 minutes. But if you correct for differences in hemoglobin and body fat at the same time, men and women should run at the same pace.
Dr. Mirkin is a practicing physician in Silver Spring specializing in sports medicine and nutrition.