Sports medicine doctor, fitness guru and long-time radio host Gabe Mirkin, M.D., and his wife, nutritionist Diana Mirkin bring you news and tips for your healthful lifestyle. A practicing physician for 50 years more
The Good Food Book
FREE! The Good Food Book: Live Better and Longer with Nature’s Best Foods, by Dr. Gabe Mirkin. With 100 of Diana Mirkin’s delicious, healthful recipes and lists of foods you can eat anytime.
Sit-ups will not get rid of belly fat because you cannot get rid of fat in a certain area just by exercising the muscles underneath that fat. You will lose the most belly fat by exercising intensely in any sport (Medicine and Science in Sports and Exercise, November 2008). Three groups of overweight, middle-aged women who suffered from Metabolic Syndrome completed 16-week programs of: (1) continuing their existing levels of activity with no change; (2) low-intensity exercise training five times a week at a level that did not cause breathing hard; and (3) high-intensity exercise training with three days a week hard enough to become short of breath and two days a week at an intensity not becoming short of breath. Cat scan X rays and air displacement plethysmography studies showed that the high intensity exercisers lost belly fat, both underneath their skin and inside their bellies. The low-intensity exercisers lost no measurable belly fat.
Storing extra fat in the belly causes people to become diabetic. Full fat cells produce hormones that prevent the body from responding to insulin so that blood sugar rises too high, causing sugar to stick to cells and damaging cells anywhere in the body. Those who store fat primarily in the belly are the ones most likely to suffer high rises in blood sugar. If you store fat primarily in your belly, have high blood levels of triglycerides and sugar, and low levels of the good HDL cholesterol, you meet the definition of Metabolic Syndrome and the odds are that you are diabetic, or will become diabetic soon. You are likely to suffer a premature death unless you make major lifestyle changes: lose weight, exercise, avoid refined carbohydrates (except during exercise), and make sure you get enough vitamin D.
Exercise can cause heart attacks in people with blocked arteries, and intense exercise increases the risk. Almost 80 percent of diabetics die of heart attacks. Check with your doctor before starting a new exercise program or increasing the intensity of your existing program.
Dear Dr. Mirkin: Should a 65-year-old man who gets weaker every year take testosterone?
Testosterone lowers body fat and increases muscle size and strength in older men (The Journal of Clinical Endocrinology and Metabolism, June 2009). Men in their seventies received a skin patch containing 5 or 10 grams per day of testosterone for 16 weeks. Their muscles enlarged, they became stronger and had greater endurance and lost a lot of whole-body and trunk fat. However, I do not recommend using testosterone because all of the research on the subject to date fails to tell if taking testosterone increases risk for arteriosclerosis, heart attacks or prostate cancer. We do know that it can raise blood pressure and cholesterol; in this study blood pressures rose 12mm systolic and 8mm diastolic.
Dear Dr. Mirkin: My job requires a lot of heavy labor; is there anything I can take to keep from feeling exhausted?
In one study, fire-fighters did far more work when they snacked frequently on a sugar and caffeine field pack. Those who took sugar and 665 mg of caffeine (the amount in six cups of coffee) had more energy and did more work than those who took sugar and only 100 mg of caffeine (Medicine and Science in Sports and Exercise, November 2008).
Athletes have known this for more than 60 years. Virtually all of the bicycle racers in the Tour de France take caffeine and sugar. Low sugar stores in muscles cause you to feel tired and your muscles to hurt. Caffeine causes muscles to burn more fat and preserve muscle sugar stores. Sugar provides immediate energy for your muscles. However, taking sugar when your muscles are not contracting increases risk for diabetes and heart attacks. Contracting muscles remove sugar rapidly from the bloodstream to use it for energy. This effect lasts maximally for 30 minutes after you stop exercising and tapers off completely after about 17 hours. When your muscles are not contracting, your cells are far less sensitive to insulin and blood sugar levels rise much higher, so it is never a good idea to take sugared foods or drinks more than a half hour after you stop exercising. See the July 12 issue for more on caffeine.