SHAPE UP
Myths about fitness exposed
By Charles Stuart Platkin
Working in the fields of nutrition and fitness can be disheartening at times — just imagine what it's like to find out that many ideas you hold dear are simply myths. After careful investigation, I discovered a select few that need to be exposed once and for all.
Not eating at night: My parents have a friend who is always on the latest diet — and this time, it was no eating after 8 p.m. Well, it sounded pretty silly, yet sure enough he lost a few pounds. But the reality is that he was simply restricting his calories. Not eating after 8 p.m. helped him to lower his caloric intake, since he typically consumed excess calories during this time — thus, he lost weight.
"It doesn't matter what time of day you eat — it's how much you eat throughout the whole day and how active you are that determines whether or not you'll lose weight," says New York City nutritionist Carey Clifford. That said, Clifford is careful to point out that eating at certain times of day — especially in the middle of the night — can be dangerous to your waistline. "People tend to consume additional high-calorie, high-fat foods that exceed their calorie needs when eating late at night — so not eating after a certain time can be helpful for some."
Exercise in the morning burns more calories: I always thought that if you exercised in the morning, your body had the most energy so you could work out harder and burn more calories. Or at the very least, I thought it gave you a metabolic boost that would last throughout the day. But experts agree that the best time for working out is whenever you're able to do so consistently. "It doesn't matter when you exercise — as long as you do it," says Walter Thompson, director of the Center for Sports Medicine, Science and Technology at Georgia State University. In fact, he says, exercising in the morning is not even the optimal time to do your workout, because you haven't eaten anything. "The last time you ate something was probably eight to 10 hours earlier — which is not optimal for exercising efficiently." Experts recommend eating at least 30 minutes before working out so that your body has the fuel to keep moving.
Sweating means you're exercising and losing weight: I have a friend who believes that if he isn't sweating, he's not getting the exercise he needs and not losing weight. Unfortunately, sweating doesn't mean that you're burning calories. "Sweating is the way your body cools itself. Postexercise weight loss often represents a loss of fluids from the body, not a reduction of fat," says Thompson. "People sweat because their body temperature increases — often times when you work out, your body temperature goes up and that's why sweating is associated with exercise. But that's where the relationship ends."
Actually, if you are just beginning an exercise program and you're sweating excessively, you should be very concerned. "It's a real mistake to monitor your level of exercise by how much you're sweating because excessive sweating can bring on heat exhaustion, followed by heat stroke," cautions Thompson. Experts suggest focusing on replacement of fluids rather than focusing on the alleged pounds lost. For every pound you lose following exercise, you should drink at least 24 ounces of fluid.
Running a mile burns the same calories as walking a mile: This was an interesting topic, because many experts I consulted and articles I read claimed that running and walking for a mile burn the same amount of calories. The reasoning is that walking a mile takes more time than jogging a mile. Therefore, you'll burn the equivalent calories, but it just takes longer. It makes sense.
Unfortunately it's not completely accurate. "You will burn up to 20 percent more calories per mile by running at 6 to 7 mph versus walking at a pace of 3 to 4 mph. The primary reason for the additional calories burned is the vertical movement required by the body to propel both feet off the ground while running," explains William Haskell, professor of medicine at the Stanford University Center for Research in Disease Prevention.
In fact, if you are a 154-pound person, walking one mile at 4 mph will take you 15 minutes, and you will burn 89 calories. But if you run at 5 mph, it will take you 12 minutes to run a mile, and you will burn 113 calories. That's about a 27 percent increase in caloric expenditure. Keep in mind that going from walking to running results in the biggest jump in caloric expenditure. Increasing your running pace from 5 mph to 6 has a negligible increase in caloric expenditure.
The good news is that although walking three miles doesn't burn exactly the same number of calories as running — well, it's close enough for me.
Running outdoors burns more calories than a treadmill: "You burn about the same number of calories whether you're running outside or on a treadmill. The energy required to propel a person forward when running outside is about the same as the energy required to keep your body from going backward on a treadmill," says Haskell.
In fact, a recent study tested eight distance runners, at three different speeds on a treadmill and outdoors, and from a practical standpoint there were no measurable differences in aerobic requirements — going at the same speed on the treadmill and on the ground burns the same energy.
That said, you should be aware that there can be a 3 percent to 5 percent variance in caloric expenditure in favor of outdoor running based on wind resistance and varying terrain. Treadmill runners do not encounter grass or uneven surfaces. Both ground forces and terrain will increase your energy expenditure outside. You can make up for the wind resistance and terrain on a treadmill by setting a minimum of 1 percent to 2 percent incline.
Charles Stuart Platkin is a syndicated health, nutrition and fitness columnist.
