You'll lose more fat faster by doing aerobic exercise than by lifting weights, according to a study published last month in the Journal of Applied Physiology.
Researchers at Duke University divided 234 sedentary adults, who ranged in age from 18 to 70, into three groups, each of which did supervised exercise three times a week for eight months. One group did aerobic exercise only. The second group did resistance exercise only. The third did a combination of aerobic and resistance exercises.
Those who did aerobic exercise only lost slightly more than 1.5 percent of their body weight, on average. Those who did a combination lost slightly less than 1.5 percent. Those who did resistance exercise only actually gained weight, because they built up lean body mass.
Doing both aerobic and resistance exercise was best for losing body fat, the researchers found. Those who did both lost about 2.5 percent of body fat, compared to 1.5 percent for those who did aerobic exercise only, and less than 0.5 percent for those who did resistance training only.
Those who lifted weights only increased their lean body mass by a little more than a percentage point, those who did both increased theirs by a little less than a percent. Those who did aerobic exercise only actually lost a little lean body mass.
Overall, the health benefits were greatest for those who combined aerobic training and resistance training, concluded the authors of the study, "Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults." But that required double the time commitment of those who did aerobics only.
"It appears that AT alone is the optimal mode of exercise for reducing fat mass and total body mass," the study concluded.
Jack Kelly: firstname.lastname@example.org or 412-263-1476. First Published January 14, 2013 12:00 AM