Keen observers of human anatomy have long suggested that, in the vaulted pantheon of sports figures, pound for pound, soccer players have the best bods. Now, researchers in Denmark are suggesting that soccer players get a better brand of exercise as well, at least compared to joggers.

Keen observers of human anatomy have long suggested that, in the vaulted pantheon of sports figures, pound for pound, soccer players have the best bods. Now, researchers in Denmark are suggesting that soccer players get a better brand of exercise as well, at least compared to joggers.

When a group of couch potatoes underwent three months of soccer training, they became leaner, fitter and healthier than a similar group that jogged, according to a study presented last week at the 2007 British Association of Sport and Exercise Sciences Annual Conference.

Led by Peter Krustrup, an associate professor in exercise physiology at the University of Copenhagen and colleagues at the Copenhagen University Hospital and Bispebjerg Hospital, the study evaluated the effects of three hours per week of soccer, jogging or no exercise, among 37 randomly assigned sedentary males. Some of the participants, ranging in age from 20 to 40, had played soccer in the past.

After 12 weeks, subjects in the soccer group had lost 7.3 pounds of fat as measured using specialized X-ray imaging, compared with 4 pounds among joggers (there was no change in the control group). The soccer group also gained 3.7 pounds in muscle, while the joggers did not gain measurably in muscle.

Both groups logged significant improvements in insulin sensitivity, as measured by an oral glucose tolerance test, and in balance, as measured in several ways, including a one-legged balance test. Both groups also experienced significantly lowered heart rate during a treadmill test.

The soccer group posted a significant reduction in so-called "bad" LDL cholesterol, while the jogging group's cholesterol was unchanged (HDL was not significantly changed in any of the groups). And finally, the soccer group's sprint time was significantly better, while the jogging group's scores were unchanged.

The control group showed no changes in any of the measurements.

Krustrup hypothesizes that the intense physical moves required by soccer — quick stops and starts, sprinting and kicks, which are similar to interval training — use more muscle fibers, while working the heart at near-maximal capacity. Jogging, on the other hand, uses fewer muscle fibers while working the heart to a lesser degree.

The researchers found something else of interest. They had assumed that subjects who had played soccer before would reap superior benefits to those who never had played, reasoning that former players would move more efficiently, while the newbies would be stumbling around adapting to the game.

"What was surprising," Krustrup says, "was that the complete beginners achieved the same physical loading and health effects as the former soccer players. Soccer was beneficial to obese and untrained participants."

The study might be open to criticism, though. The problem, says Timothy Church, an exercise researcher and director of preventive medicine research at Pennington Biomedical Research Center in Baton Rouge, La., "is that the two groups were not matched for intensity. The soccer players are going to have to stop and go, speed up, slow down," while the joggers are running at an even pace. Thus, the investigators were comparing apples and oranges, he believes.

Beyond debating the merits of soccer vs . jogging, the most important contribution of this type of study is that it gets people moving, says Jeffrey Edwards, acting chairman of physical education and interim chairman of athletic training at Indiana State University. "When you offer people other possibilities for increased activity, you've increased their chances to get some exercise and get the benefits. I would love to have people playing soccer into their 40s and 50s and 60s."

But couch potatoes who envision themselves as the next Ronaldinho need to think twice before mixing it up on the field, cautions Church.

"Middle-aged, sedentary men who suddenly take up a sport like soccer are every orthopedist's dream," he says.