Which exercises give the best workout?

Among exercisers, the "one-up" game is as old as sweat. As modern exercisers continue the "my-workout-is-better-than-yours" debate, researchers have joined the game. Here's a sampling of their findings.

Skating Versus Running

In-line skating at brisk speeds can burn about the same amount of calories as running, says Ed Melanson, a researcher at the University of Massachusetts in Amherst. He evaluated 20 college-age exercisers - 10 men and 10 women. Those who ran six to eight miles in an hour burned about 14.9 calories per minute. Skaters who sped along at 12 or 14 miles can hour - a fairly brisk pace - burned about 14.1 calories per minute.

Last year, Melanson presented the findings of the study, partially funded by a skate manufacturer, at a meeting of the American Alliance for Physical Education, Recreation, and Dance.

But a study published the previous year in the International Journal of Sports Medicine found that skating was not as intense an aerobic workout as running or cycling.

Experts do agree, though, that skating does tone hips, thighs, and buttocks fairly quickly.

Fast Versus Slow Walking

Predictably, walking at a fast pace improves fitness more than walking at slower speeds. But even strollers show improved cholesterol levels, according to research done at the Cooper Institute for Aerobics Research and published in the Journal of the American

Medical Association.

John Duncan and his colleagues evaluated 102 sedentary women, ages 20 to 40, for six months. The women walked five days a week, covering nearly five miles each session. But they walked at three speeds: five, four, or less than three miles per hour. The fastest walkers were more fit than the slow walkers, but the strollers improved their levels of "good" cholesterol just as much as the fast walkers.

Running Versus Walking

When runners and walkers exercise at the same intensity, runners burn a bit more fat, say researchers Tom Thomas and Ben Londeree at the University of Missouri in Columbia. They evaluated nine exercisers who walked and then jogged at the same intensity - enough to raise the heart rate to 65 percent and then 75 percent of the maximum (well within the recommended range).

"The amount of fat burned was greater during jogging than walking," says Londeree, whose study was published in the International Journal of Sports Medicine and in Running and Fit News.

Water Versus Land Aerobics

Water workouts aren't intense enough, critics say, to yield the same benefits as land-based exercise. But Werner Hoeger, Ph.D., an exercise physiologist at Boise State University in Boise, idaho, disagrees.

He evaluated 10 people working out in a pool doing a self-paced routine of standard aquatic exercises and measured their heart rates. Each exerciser reached a heart rate of 75 percent of the maximum.

"The aquatic exercisers were burning roughly 10.5 calories per minute," Hoeger says. That is similar to what is burned in a low-impact aerobics class. He presented his findings at an international Aquatics Association meeting.

High-Impact Versus Low-Impact

Exercise is often recommended to slow the age-related bone loss that can increase the risk of fractures. Low-impact exercise is as good as high-impact if the only goal is to maintain bone density, say University of Missouri researchers Katie Grove and Londeree.

They evaluated 15 postmenopausal women for a year. Those in the control group did not exercise. Those in the exercise groups worked out three times a week. Each session consisted of a 20-minute warm-up, 20-minute active exercise time, and 15-minute cool-down.

At the end of the year, the difference in bone mass density between the low-impact and high-impact exercisers was not significant. But the sedentary control group lost bone mass.

"From the present study it appears that 20 minutes of a low-impact exercise three days a week for one year is effective at maintaining bone mass density," says Londeree, whose study was published in Medicine and Science in Sports and Exercise.