A good example of the effectiveness of resistance training while dieting is found in a study conducted by scientists at West Virginia University, which split 20 men and women into two groups:34 Group one did one hour of cardio four times per week. Group two lifted weights three times per week. Both groups followed the same diet, and after 12 weeks, everyone lost about the same amount of fat, but the cardio group also lost nine pounds of lean body mass, whereas the weightlifting group didn’t lose any.