When you think of resistance training, you probably think of some muscle-bound guy over in the corner of the gym doing bicep curls trying to grunt and groan out that last rep to make his arms another inch bigger. Rarely do you think of a middle-aged soccer mom performing leg press to improve her body composition, but resistance training is just as (if not more) important to someone who is looking to reduce body fat and tone up as it is for someone who is looking to bulk up.
Resistance training, although underutilized in weight reduction programs, is one of the most critically important modes of exercise that can be performed for improving body composition. Resistance training increases metabolic rate, enhances muscle mass, and leads to a more toned or firmed appearance. We’ll talk more about this later, but before we get to all the great benefits of resistance training for weight reduction, we must discuss body composition versus scale weight.
When most people engage in an exercise program to lose weight, it is assumed they are looking to lose body fat mass and not lean muscle tissue, as it is the loss of unsightly fat that makes us look better. The problem is that most people judge their success or failure in this process with a measurement device that only measures weight (the scale), not fat, and in doing so they never have a clear idea of exactly what is happening with their body composition (the ratio of fat mass to total mass, otherwise known as percent body fat). Successful weight loss programs focus on reducing percent body fat both by decreasing fat mass and by increasing muscle mass. By focusing on both sides of the body fat fraction (fat mass/total mass), you will see a much more dramatic improvement in percent body fat (and appearance) than if you just focus on fat mass. This is where resistance training comes in.
Above all else, performing a basic resistance training workout ensures that your muscle mass is preserved during a period of extended caloric restriction (like that which occurs during dieting). Resistance training stimulates muscle regeneration and growth, allowing damaged fibers to repair themselves (this damage can occur by either resistance training or extreme caloric restriction). Furthermore, resistance training can stimulate the growth of existing muscle fibers, making your muscles denser and your body more tone. Indeed, it is resistance training that distinguishes the people who look tone and firm following weight reduction from the people who have lost weight but still look flabby and unfit.
Just as important as the preservation of muscle mass is the increase in resting metabolic rate that occurs with resistance training and subsequent muscle gain. Since muscle mass is very metabolically active (requiring a significant amount of energy to survive), the more of it you have, the higher your metabolism will be. In fact, differences in muscle mass account for the majority of differences in metabolism and rate of weight reduction between men and women (with men being able to lose weight at a faster rate as a result of their higher metabolism, due in large part to their greater muscle mass). So, in short, the more muscle you have, the higher your metabolism will be, the more calories you can burn, and the more fat you can lose (and keep off). The best part about the increased metabolism associated with resistance training-induced muscle gain is that it elevates your metabolic rate all the time (not just when you’re lifting weights), so you are always burning more calories.
Since your resistance training program should be part of a much more comprehensive nutrition and exercise program focused on weight reduction, it need not take up a lot of your training time. Your best bet, if possible, is to combine resistance training with continuous movement, which we call circuit training (see this article for more information: Interval Training Accelerates Fat Loss). If circuit training is not something that you’d like to do, and you’re looking to go the more conventional route, then a standard set/rep resistance training workout is your other option. For this type of workout, perform resistance training 2-3 non-consecutive days per week, and in each workout perform one exercise (1-3 sets) for all the major muscle groups of the body (legs, chest, back, arms, abs, and lower back), performing 10-15 reps/set and resting 45-75 seconds in between sets.