You may be exercising to improve your health, your memory, your strength, your endurance, or for the pure pleasure of it all. By now, there’s a mountain of research to show the best ways to achieve these goals while minimizing the chance of injuries. Gretchen Reynolds, who writes the “Phys Ed” column for the New York Times Well Blog, has distilled it all for her new book, “The First 20 Minutes.” Many myths were busted along the way.
The book’s title refers to the latest research that shows the greatest health and fitness benefits from exercise are conferred within the first 20 minutes of a routine that combines low- and high-intensity exercise, alternating at about one-minute intervals. This type of workout, called “high-intensity fitness training,” can be applied to different forms of aerobic exercise—cycling, walking, etc.
Runners, for example, would start out with a slow jog and then alternate jogging at a normal speed with running at the fastest speed possible. This, says Reynolds, will prolong your life and provide the greatest reductions your chances of developing heart disease, diabetes 2, osteoarthritis. You continue to get benefit with longer workout, but at a slower rate. (You will also get the same benefits from walking, but it will take longer —20 to 30 minutes, five times a week.)
Actually, high-intensity fitness training was the least appealing part of an excellent book that is aimed at everyone from marathon runners to people like me who don’t want to move at high speed. Each chapter addresses a single topic like endurance, the brain, avoiding injury, nutrition, and ends with a bullet list summary that allows readers to skip whole sections and cut to the chase.
Reynolds is at her most enjoyable when debunking the myths that surround exercise, nutrition, and injury prevention. By now, most of us have probably heard that stretching before vigorous exercise is useless and perhaps even counterproductive. It lives on, of course, because it takes time for the word to get out. And regular exercise will not result in much weight loss. Many of us can’t let go of that one, either. “Why exercise doesn’t inevitably make people skinny is one of the more intriguing and vexing issues in physiology,” writes Gretchen Reynolds.
Here’s a sampling of gems from “The First 20 Minutes:”
-Unless you have a congenital defect, running is not bad for your knees. What’s more, the incidence of knee arthritis in “not necessarily high,” according to a study of longtime runners who were followed for two decades when most were in their fifties or sixties.
-The squat is extremely effective as a body strengthener. It activates the body’s biggest muscles, those in the buttocks, back, and legs. And doesn’t require a gym, a coach or equipment.
-Running for a half-hour doubles the number of brain cells involved in memory, but running has an extremely high injury rate.
-Any kind of movement can improve memory, even everyday activities—cooking, gardening, cleaning, walking around the block—performed by sedentary elderly people showed improvements in memory compared to elderly people who were completely sedentary.
-The importance of improving the body’s core strength has been disproven.
-Healthy people who eat eggs for breakfast consume fewer calories the rest of the day than people who eat bagels or other high-carbohydrate foods.
-Despite the popular notion that slow exercise burns more fat than longer, more rigorous exercise, it doesn’t.
-If you need an alternative to stretching before vigorous exercise (and many people don’t), warm up for a few minutes with an easy version of your planned exercise.
-Massage after strenuous exercise may feel good, but it impairs removal of lactic acid from tired muscles following exercise and interferes temporarily with blood flow to the sore muscles.
-Forget the sugary sports drinks and water. Low-fat chocolate milk provides the ideal ratio of carbohydrates and protein to boost fuel replenishment after a hard workout.
The book ends with a description of a term coined by exercise physiologists, “active couch potatoes,” which probably describes most people who exercise regularly. Their day might include an hour at the gym or a run in the park, but most of the other waking hours are spent sitting—in front of a computer, watching TV, driving, etc. The body is not meant to be so physically inert. Reynolds’s final message is call to arms: Just “Move it!” Stand up from the computer every now and then; pace around the room while talking on the phone. Simply standing up for two minutes every 20 minutes will counter the negative health effects of sitting for prolonged periods.
Maryann Napoli, Center for Medical Consumers©
You can be fat and fit