Fantasy No. 2 that is probably more commonly believed by men than women is that you shouldn’t weight train when trying to lose weight, because it will make you “bulk up.”

Again, I hate to disrupt your fantasy, but this one comes down to that old energy equation: calories in versus calories out. If you’re consuming fewer calories than you’re expending, it’s impossible to “bulk up,” even if you’re pushing it hard on the weights. You can gain some muscle when losing weight, but not much. In one study, subjects on weight-loss diets were put on a weight training program involving 8-12 repetitions per set. After eight weeks, the subjects gained less than a pound of muscle.

Weight training is critical in helping to maintain your muscle and strength while you lose weight. In one study, researchers compared dieting men who only did aerobic exercise to dieting men who did a combination of aerobic exercise and weight training. In the men who only did aerobics, 78% of the weight they lost was fat, while 22% was lean weight. In the men who did the combination, 97% of the weight they lost was fat and only 3% was lean weight.

At our clinic we always make sure that our patients have a program that combines both cardio and resistant training when actively losing weight. Resistant training helps to preserve the lean body mass you do have when embarking on weight loss. When you create a caloric deficit, you want the majority of your weight loss to be from fat and not your lean body mass. We recommend two to three days a week of resistant training for the best results in maintaining your lean body mass and remaining lean while still losing weight.

In my next blog, I will blow one last fantasy out of the water: you can spot-reduce fat off of your body. I have a feeling this is the fantasy of them all that might hit the ground the hardest.