A large study finds that resistance training is not as effective for reducing body weight as aerobic training.
A recent study conducted by researchers at Duke University looked at the weight loss efficiency of aerobic training, resistance training and a combination of the two (Effects of aerobic and/or resistance training on body mass and fat mass in overweight or obese adults, 2012. Leslie Willis, et al.). As expected, the study found that the training strategies have very different affects on the body.
Resistance training involves any type of exercise where the joint performs a full motion with a force opposed to that motion. With elastic bands the opposing force increases as the motion is extended. In hydraulic resistance training the opposing force increases as the speed of motion increases. Aerobic training includes repetitive motions such as cycling, swimming and running. For this particular study weight lifting was used for resistance training. A cycling machine, elliptical machine and treadmill were used for the aerobic training.
Those subjects participating strictly in resistance training saw no decrease in body mass. However, this was because any decrease in fat was offset by an increase in lean body mass. The fat composition was reduced by resistance training participants. On the other hand, aerobic training participants saw a significant drop in both fat composition and total body mass. When time is considered, the aerobic training is even more efficient. Aerobic training in this study took 133 minutes a week compared to the 180 minutes a week spent by the resistance training group.
Interestingly, no increase in weight loss was observed when resistance training was added to aerobic training, but there was a significant drop in fat percent. Waist circumference has been found by some studies to be a better predictor of cardiovascular health than BMI. Although resistance training by itself did not decrease waist circumference, it created a significant drop when added to aerobic training relative to aerobic training by itself.
In conclusion, despite what resistance bands manufacturers or resellers claim, resistance training does not burn fat or decrease body weight according to this study. From this study it appears that the best method of losing fat is aerobic training. If time allows, resistance training can be added on.