Additionally, both groups increased their flexibility, with the 2x group reaching an average of 1.7 inches farther and the 3x subjects reaching 1.2 inches farther. All subjects increased their upper body strength by at least 15 percent, with some experiencing up to 45 percent improvement. Increases in lower body strength ranged from 15 to 35 percent. Unfortunately, building stronger muscles did not result in either group losing weight. Both groups lost just a smidgen, one or two pounds, but they saw at least a two percent decrease in body fat.
Muscle weighs more than fat, but it's also more efficient at burning calories.
DiBrezzo believes the duration of the study limited weight loss results. After only eight weeks, subjects were already noticing that their clothes fit more loosely, she said. Had the experiment gone on longer, the women would have continued to firm up and would have shed more pounds. Weight training leads to greater muscle fitness, which in turn boosts metabolism. But DiBrezzo cautions that this type of exercise represents only one facet of a complete fitness regimen.