When it comes to keeping your body weight in check, brisk walking almost every day is proving to be the best exercise.

In an analysis of a large British multiyear survey, men who engaged in brisk walking for 30 minutes or more a day about five days a week weighed about six pounds less—and women about 11 pounds less—than their sedentary counterparts.

By contrast, those who went to the gym or played sports just as frequently as the walkers didn’t fare as well. Compared to the sedentary types, men weighed just 1.8 pounds less and women about six pounds less. Other activities done for the same time/frequency—heavy housework (moving furniture, walking with heavy shopping bags, scrubbing floors) or manual activities (digging, chopping wood, moving heavy loads)—were only weakly linked to a lower body weight.

It’s just an association, not proof, but the research does suggest that the one exercise we can do almost anywhere, almost any time, for free, is a good lifelong defense against weight gain. To get started on your walking program, see Bottom Line’s Why Walking Is the #1 Way to Exercise.