My friend Jim is beginning to worry about regaining the weight he lost recently. Without any real effort at dieting, he melted away 14 pounds in a summer of cycling 120 miles a week that consisted of a couple of two- or three-hour evening rides, as well as half-day rides on both Saturday and Sunday.
But autumn's early sunsets wiped out the weeknight rides, and the chill air reminds him that bitter winter weather soon will eliminate weekend riding, too. So he's already started working out on his cross-country ski machine 15 minutes every other day but says that's all he can do right now. He hopes to increase to 30 minutes per session by the time winter comes.
Clearly, Jim faces a big drop in activity, at least as far as his time investment goes, and it will affect his calorie needs, but perhaps not as much as he expects. Weight regain is not inevitable, and with a few facts and some careful planning, he can greet the spring just as trim as he is now. Two things will work in his favor: concentrated indoor exercise and changes in appetite.
Jim is a 50-year-old, average-size man, sedentary except for his planned exercise. So he needs only about 2,300 calories a day to maintain his weight.
Cycling burns about 7.5 calories per minute more than just sitting around watching TV. So summer cycling boosted his energy output an average of 600 calories a day for a daily #F 2,900-calorie requirement. That means he could eat normally and drop a pound of body fat each week. Or he could eat 300 calories more each day and still melt away a half-pound of fat weekly. Three hundred extra calories could be a banana, an ounce of pretzels and a carton of fat-free yogurt.
According to the folks at Nordic Track, the ski machine requires about 1,100 calories per hour. That's about 16.5 calories per minute more than TV watching. So the autumn transition to weekend-only cycling and 45 minutes a week on the ski machine will keep his daily energy expenditure at 400 calories above normal. That means he could keep right on eating those extra 300 calories and still continue to lose weight, although very, very slowly. In fact, it would take him about five weeks to lose another pound. (The difference between "calories in" and "calories out" is just 100 per day, and it takes a 3,500-calorie deficit to lose a pound.)
By the time winter arrives, Jim could easily work up to 30 minutes three times a week on his ski machine, for an average 200-calorie/day expenditure above normal. But that won't quite replace the weekend rides. At that exercise level, he'll have to cut back on calories slightly, by about 100 calories per day (by dropping the banana), to maintain his weight. This should be easy to do because a body that burns fewer calories demands less food, and he'll be less hungry.
But if he wants to keep losing, he could cut back by another 100 calories (drop the banana and the yogurt), and he'll continue to lose a pound every five weeks.
Jim could also increase his exercise time if he'd rather keep eating. Thirty minutes on the ski machine, six days a week, would raise his calorie expenditure back to 400/day above normal. That's just about what it was for fall, when he could still lose slowly without changing his eating habits.
As you can see, he's getting a big exercise advantage in a short period of time, because he's spending twice as many calories per minute skiing as he did cycling.
The problem, though, is that he misses the socialization of riding with the group. Maybe he'll just have to round up the gang and go bowling. It doesn't burn many calories, but it's a fun way to get together.
Colleen Pierre, a registered dietitian, is the nutrition consultant at the Union Memorial Sports Medicine Center and Vanderhorst & Associates in Baltimore.