Weight-bearing activities that work against gravity — aerobic activities like walking, running, cross-country skiing, dancing, skating and stair-climbing — use proportionately more calories at a given level of effort than swimming, cycling or water aerobics.
The more muscle groups involved in your activities, the more calories you are likely to burn. That is why working out against gravity uses more calories than non-weight-bearing activities. On the other hand, because activities like swimming put less stress on weight-bearing joints, many people can do them for longer periods, making up for the lower caloric burn.
If your workout includes hills (real ones or on exercise equipment), you will use more calories per minute than doing the same activity on level ground. But if you engage in resistance exercises — working out with weights or on machines that strengthen various muscle groups — you may gain several pounds of muscle that partly offset the loss of body fat.
In other words, you may lose fewer pounds than if you expended the same number of calories on an aerobic activity (cardio) like brisk walking or swimming, but you will be stronger and better toned. With greater muscle mass, your basic metabolic rate will rise and you will burn more calories all day and night. And since muscle holds less water and takes up less room than the equivalent weight of fat, by shedding fat and gaining muscle you can lose inches and sizes without losing actual pounds on the scale.
Keep in mind, though, that the time spent doing resistance exercise burns fewer calories than if the same time were spent on aerobic activities (cardio).
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