You've just gorged yourself over the holidays. Your New Year's resolution is to lose weight. Great! But how you go about your weight-loss will largely determine whether your resolution leads to a more fit "you" or to more disappointment down the road.

I'm a big proponent of strength training and Pilates, both have many benefits, particularly for middle age and senior citizens. Among them are stopping or even reversing age-related muscles loss, improved posture, improved flexibility, better cardiovascular fitness and increased resistance to injury. Strength training can benefit everyone, particularly those looking to shed holiday pounds. In fact, it is essential for maximum weight loss and to avoid the "yo-yo syndrome," in which fat loss is followed by even greater fat gain.

To understand why this is the case, consider that your look is determined by your bones, muscle and fat. Of these three, only fat and muscle can be influenced by diet or exercise. Your skeletal structure is largely determined by genetics and for the most part cannot be altered.

Most dieters typically cut their caloric intake and engage in some form of aerobic activity to "burn that fat off." While that sounds great, the strategy doesn't work in the long term. Studies show that on a reduced calorie diet, almost as much muscle as fat will be lost. The real solution is to improve your muscle-to fat ratio. This is a permanent solution.

One pound of skeletal muscle requires almost 40 calories a day to maintain. One pound of fat requires only two. Muscle, therefore, is 20 times more metabolically active than fat. There is a difference between fat loss and weight loss. A scale shows only total weight loss, not fat loss. And therein lies the problem for those who rely solely on a scale to gauge their progress.

Stephanie (and yes, men yo-yo, too) is 5-foot-3, 160 pounds and has 35 percent body fat. That translates to 56 lbs of fat. Full of enthusiasm, she starts jogging or walking and cuts out junk food. She has so many salads, she feels like a rabbit. Finally, after four months and by sheer force of will, she reaches her target weight of 135 pounds. She lost the 25 pounds and is proud of herself - and rightly so, since she has made a difficult lifestyle change.

But let's look closely at what Stephanie has really done to herself. Assume Stephanie lost 13 pounds of fat and 12 pounds of muscle. This is a realistic estimate, especially if she was doing lots of aerobic training. Her original body fat percentage was 35 percent. So of her starting weight of 160, 56 pounds was fat. Her lean body mass was 104 pounds. Now, if you subtract the 13 pounds of fat lost from the original 56 pounds, you have 43 pounds of body fat, which Stephanie still carries. Dividing 43 by her current weight of 135 shows that her new body fat percentage is just under 32 percent. Yes, her body fat has dropped ... slightly. But her ratio of muscle to fat has not changed significantly. Stephanie is simply a smaller version of her old self.

While that might satisfy her for now, will those 12 pounds of muscle that she lost come back to haunt her? And this is where dieters set themselves up to yo-yo.

Stephanie has unwittingly reduced her daily metabolic rate by almost 500 calories because of muscle loss. The 12 pounds of muscle loss translates to a reduction in her metabolism of 12 X 40 = 480 calories a day. She struggled during her diet to stick to her reduced caloric intake, but now she'll be forced to eat at those levels if she wants to maintain her new weight. Any higher caloric intake will result in fat weight gain.

If Stephanie is like most people, within a few weeks she'll find this impossible to do, cave in to cravings and begin consuming calories at pre-diet levels. At that point, her metabolism is overwhelmed ... and back come the pounds until she has surpassed her original starting weight of 160 pounds. On top of that, her body fat percentage zooms past the original 35 percent.

Stephanie could have avoided this with an hour of strength training twice each week to reduce the loss of muscle mass and possibly to add muscle mass. By coupling strength training with a reduced caloric intake, you send a strong message to your body. If you strength train as you should, always in proper form. -- and if you give yourself time to recover from your workouts, your body will compensate and improve its metabolic condition. Your body does this to protect itself against further exposure to the stress.

This is the essence of progressive strength training. So let's look at what Stephanie might have accomplished by adding strength training twice a week to her program of aerobic exercise and diet. A realistic estimate, given Stephanie's starting point, would be to lose 22 pounds of fat and lose 3 pounds of muscle. (Muscle is almost always lost as a result of aggressive dieting, but without strength training, muscle loss can be extreme.) That would lower her body fat to 25 percent, and her ratio of muscle-to-fat would have improved greatly. Stephanie now weighs 135 and her fat weight is 34 lbs.

Since one pound of muscle is smaller and denser than one pound of fat, Stephanie would, in fact, be much smaller - she would literally take up less space. She also would have the bonus of underlying muscles that are firm and conditioned - in other words; she would have a more attractive body and better posture. Best of all, Stephanie will be able to increase her food intake a bit without losing these effects because she kept her metabolism high through strength training. As long as she continues to strength train, maintaining muscle, she will avoid the yo-yo syndrome.

Summary:

                        Total Body Weight       Fat Weight     Body Fat Percentage

Original                       160               56               35%
Diet and Aerobic Only          135               43               32%
Diet and Strength Training     135               34               25%