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Standing in line at the super market, wedged between carts full of TV dinners, processed cheese and improved varieties of dish soap, waiting shoppers are bombarded with magazine-rack hype.
Packaged in a variety of covers, one topic is guaranteed to grab our attention: “Diet Your Way to Happiness,” “Lose Thirty Pounds by Summer,” “Fabulous Thighs in Nine Minutes a Week,” and “Diet of the Stars: Grapefruit and Garlic” — they vie not only for our attention, but our dollars. Weight may be the great American obsession.
Not surprisingly, the reason most new exercisers give for launching an exercise routing is the desire to lose weight. Of course exercise is not the only way to reduce surplus body weight – an attempt to control food consumption is the more usual approach. Dieting is, after all, a big business. Americans reportedly spend some 30 billion dollars annually on weight loss products and programs.
It’s a lot when you consider that losing fat is not hard to do – in principle. If we eat more calories than we need for our daily energy expenditure then we store the excess calories as body fat. Conversely, if we eat fewer calories than we require for our daily energy expenditure, we use up some of our stored body fat to provide the necessary calories.
The Diet Strategy
The most popular and straightforward way to produce a negative calorie balance is to diet. Eating 500 fewer calories per day results in a pound of fat loss per week. Still, even though dieting works reasonably well as a weight loss strategy, it has serious drawbacks.
Here’s one of them. When we reduce our calorie consumption most of the additional energy comes from stored fat, however, some of the additional energy comes from protein stores which results in muscle loss! Very low calorie diets (600-900 calories per day) may produce almost as much muscle loss as fat loss, which generates an additional problem. The reduction in muscle mass causes a corresponding decrease in metabolic rate, making further fat loss even more difficult.
Numerous follow-up studies of dieters reveal that lost weight is typically regained within several months after the diet is over. Intolerant of change, our bodies tend to counter adjust for any shift. For example, after a few nights of little sleep, we may end up sleeping several hours longer than normal. In the same way, after finishing a reduced calorie diet we may tend to overeat in a somewhat compensatory manner.
The Aerobic Strategy
A better approach to weight loss is via aerobic exercise, that is, exercise characterized by continuous large muscle activity such as running, cycling, and swimming. Take cycling, for example. Depending on the level of intensity, 500 calories could be consumed by a rider on a thirty to fifty minute ride.
In addition to burning calories, aerobic exercise stimulates a variety of beneficial cardiovascular adaptations: the heart becomes a stronger pump, the circulatory network becomes more efficient, and the blood becomes a better transporter.
Unlike dieting, which often leaves us feeling deprived, aerobic exercise adds something positive to our lives – physical activity. An unlike dieting, aerobic exercise need not be a short-term phenomenon. When integrated into our regular routine, aerobic exercise actually permits greater calorie consumption to meet the extra energy requirements.
The Strength-Building Strategy
Developing muscle is one of the best ways to control weight because it causes a double reducing effect. First, resistance training is vigorous physical activity: a significant number of calories are burned during exercise. Second, the additional muscle tissue produced by resistance training increases resting metabolism: calories are burned at a higher rate all day long – regardless of activity or inactivity.
For years people have associated resistance training with bodybuilding and weightlifting. Yet only a small percentage of men and women possess the genetic capacity to develop relatively large muscles; most of us do not. On the contrary, those of us who don’t do regular resistance training should be concerned about losing too much muscle.
After we reach physical maturity in our early twenties, our bodies begin a long and gradual degenerative process. Our maximum heart rate decreases by about one beat per year throughout our lives. Another effect of the aging process is a reduction in muscle mass, which decreases by about one-half pound a year throughout our lives.
In the absence of regular resistance training, our muscle fibers simply become smaller and weaker at a slow but consistent rate. It’s a phenomenon called disuse atrophy – essentially the same thing that occurs to an arm that has been immobilized in a cast. And aerobic exercise, even though it’s extremely beneficial for our cardiovascular system, does not prevent disuse atrophy in muscles. Only regular resistance training can maintain (or increase) muscle mass.
This has important weight loss and dieting implications because muscle mass directly affects metabolic rate. A very active tissue, muscle utilizes energy continually for protein synthesis, maintenance, and rebuilding processes. Even when we sleep our skeletal muscles are responsible for over 25 percent of our total energy expenditure. In fact, exercise physiologists believe that every pound of muscle we add or lose as an adult is worth about 350 calories per week!
Let’s look at muscle mass loss as it might effect an ordinary man. At twenty-five, Chris had seventy-five pounds of skeletal muscle and required 2500 calories per day to maintain his weight. Over the next twenty years Chris did not perform regular resistance training and so relinquished ten pounds of muscle tissue as a result of disuse atrophy.
Consequently at forty-five, Chris has only sixty-five pounds of skeletal muscle and needs only 2000 calories per day to maintain his weight. This is where Chris runs into trouble. Like most of us, he’s not aware of the gradual decrease in muscle mass and metabolic rate, and eats more calories than he requires. The result? Chris experiences the slow steady increase in weight (fat) typical of middle age – a gradual accumulation known as creeping obesity.
Every pound of muscle we add or lose as an adult is worth about fifty calories per day. It doesn’t have to be this way. If Chris had performed regular resistance training he could have maintained his previous muscle mass and metabolic function, considerably reducing the likelihood of unwanted weight gain.
Fortunately, the extra weight isn’t cast in cement. It’s possible to increase muscle mass and metabolic rate at any age through a sensible resistance training program.
Resistance training should be part of every weight loss program. Like aerobic exercise, it burns a considerable number of calories. More importantly, the increased muscle tissue requires a higher daily calorie burn making it easier to maintain your weight.
Dieting your way to happiness is as unlikely as the prospect of developing fabulous thighs in nine minutes a week. But developing stronger, firmer muscles is a realistic and workable exercise objective – one that can enhance your physical appearance, physical capacity, and ultimately your self-esteem.
Developing Muscle – Training Tips
So what do you need to know to start an effective resistance training program? First, rest assured that developing muscle needn’t be either tedious or time-consuming. Set aside a regular time to exercise and then follow these basic guidelines to establish a sensible strength training program.
– Selection: Address all major muscle groups – the quadriceps, hamstrings, lower back, abdominals, chest, upper back, shoulders, biceps and triceps. Each group can be trained individually using rotary exercises or in combination with other groups.
– Speed: Slow movement reduces the risk of injury and enhances the training stimulus. Perform all resistance training in a carefully controlled manner.
– Range: Muscles develop strength only in the exercised positions, so perform each exercise through a complete range of movement. Whenever possible, work from a position of full muscle extension to full muscle contraction.
– Resistance: Always train at about 75 percent of maximum resistance. For most practical purposes, this corresponds to a resistance that can be performed at least eight times, but not more than twelve.
– Sets: One, two, or three sets of exercises are equally effective for promoting strength development. Thus, personal preference (or time constraints) should be the determining factor with regards to the number of sets.
– Progression: Resistance training must be progressive for continued muscle development. One highly effective approach to exercise progression is to use a given resistance until twelve repetitions can be completed, at which time you should increase resistance by approximately 5 percent.
– Frequency: Muscles respond to the training stimulus during the recovery period following an exercise session. Most people require about forty-eight hours for the muscle rebuilding process to reach its peak. It is therefore not advisable to perform strength training more frequently than every other day.
About the author:
Wayne L. Westcott, Ph.D., C.S.C.S, is Fitness Research Director at the South Shore YMCA in Quincy, MA. He is strength training consultant for numerous national organizations, such as the American Council on Exercise, the American Senior Fitness Association, and the National Youth Sports Safety Foundation, and editorial advisor for many publications, including Prevention, Shape, and Club Industry magazines.