Re-Examining the Value of Aerobic Exercise

By Charles I. Staley, B.Sc., MSS

PART I

Ever since the "jogging craze" of the '70's, aerobic exercise has been the method of choice for those attempting to "lose weight." Gradually, the resistance training area of most gyms and clubs is being scaled back to accommodate all manner of equipment designed to elevate the heart rate. With the aerobic revolution in full gear, I feel compelled to ask, "Why are people getting fatter and fatter?"

For those who have critically studied sport training and exercise physiology, this is a rhetorical question. A quick look at any national level track meet speaks volumes about the effects of aerobic versus anaerobic training. Compare the physiques of 100 meter sprinters against long distance runners, such as marathoners. Although sprinters do little or no aerobic exercise (it's not specific to their events), they are just as lean (if not leaner) than their aerobic counterparts. They also have more attractive physiques, which is a by-product of the muscle they've gained from hours in the weight room and short-term, intensive running. By contrast, the marathoner's lack of muscle gives him a "flat" physique. His extensive and frequent forays into the aerobic zone have caused his body to lose muscle (since muscle weighs more than fat, it is the body's preferred tissue to cannibalize in the interest in lightening the load).

If you've been trying (unsuccessfully) to lose 10 to 20 pounds of unwanted fat, despite spending hours upon hours on the stairclimber, read on. Anaerobic exercise may not be politically correct, but it IS physiologically correct- if fat loss is your objective.

Since our language affects the way we think, let's begin by revising our vocabulary for a moment. I'd like to encourage you to delete a few words from your personal dictionary. Words like tone, shape, contour, sculpt, and all the rest of the vague descriptions you hear on late night infomercials. These terms are irrelevant with respect to the adaptations you can expect from any form of exercise. In reality, there are only two bodily tissues that you have aesthetic control over- muscle, and fat. These tissues can be affected in only two ways: You can gain, or lose. (By the way: tone simply refers to a state of partial, involuntary contraction, a result of muscular work. Even the most rotund can have muscle tone, and the thinnest people sometimes have no tone.) So the goal is to gain muscle and lose fat. When you do so, let everyone else call you toned and sculpted.

Of course, many people, influenced by the exceedingly massive (and rare) physiques adorning the covers of muscle magazines, shirk at the prospect of gaining muscle. It's a shame- myophobia keeps more people from achieving their fitness goals than any other single factor. Just a few pounds of added muscle can make a dramatic difference in your physique, not to mention your health and well-being. Muscle (unlike fat) needs calories to survive. The more muscle you have, the higher your metabolism will be. Bigger muscles burn more calories than smaller ones, even during sleep!

Personal trainers- people who earn their living by making substantial changes in their client's bodies- regard resistance training as the most important item in their professional "toolbox." Dave Sinnot, trainer of many top Hollywood stars, including Sean Penn and Angela Bassett, is amazed at people's avoidance of weight training: "People who think that aerobic training is the ultimate fat loss method are totally missing the boat. I've worked with people who spend half their waking hours doing some form of aerobics. They complain that they aren't getting results anymore. As soon as we shift emphasis to weight training and nutritional modifications, they always start improving immediately. It's like their body was begging for it!" Dave related to me that Angela Bassett (star of "What's Love Got To Do With It") was not blessed with great genetics as many people assume, and was actually "pudgy" when he started working with her.

What's the best approach for people wishing to improve their body composition? First, don't eliminate your aerobic sessions. It's a good practice to do a handful (three or four) of 20 to 40 minute sessions a week. More than that, and your body starts to drop valuable muscle in an effort to adapt. Second, take another look at your resistance training program. Most people simply don't spend adequate time and effort in the weight room, and those that do make one or more of the following four mistakes:

Too many exercises: One exercise per muscle group per workout is plenty. The key is to pick the right exercises, and work them hard. Forget about "hitting the muscle from different angles" and "shaping" exercises - this is all propaganda stemming from bodybuilding circles.
Ineffective exercises: Don't avoid so-called "hard core" exercises for fear of getting a result. Choose multi-joint exercises, such as squats and their variations, bench presses and their variations, lat pulldowns, and shoulder presses. Smaller muscles such as biceps, triceps, and calves will receive adequate exercise when you do the multi-joint movements mentioned above.
Insufficient intensity level: High reps DO NOT "tone" a muscle! For beginners, high reps are important to strengthen connective tissues, and to allow for technique mastery. But for optimum muscle building, stay in the 6 to 12 range for the majority of your workouts. If and when you get to the point where you don't want additional muscle, just cut back on the volume and frequency of training.
Lack of progression and variety: If you don't seek increases in strength, your body will stop responding. Similarly, if you train in exactly the same manner for extensive periods of time, your body will adapt to the monotony, and stop responding, no matter how good the training program is. For this reason, there is no perfect training program. Most successful trainers use several programs, which they rotate as needed.
As a final suggestion, remember that the entire personal training profession was founded upon the fact that resistance training works! Don't make the mistake of thinking that you're beyond benefiting from one. Personal trainers make their living by getting fast results for people. For information on finding a certified trainer in your area, please call the ISSA at  (800) 892-ISSA  .
Consider These Facts:

According to a recent study presented in IDEA magazine, the average female aerobics instructor has 18% bodyfat. This is higher than the average female competitive weightlifter (16%).
According to a recent study published in Muscular Development magazine, muscle necrosis (tissue death) and inflammation can be observed in the calves of marathon runners 7 days after a race.
According to Dr. Marc Breehl, a leading anesthesiologist specializing in cardiac surgery, the enlarged hearts of aerobic athletes are weaker, not stronger than those with anaerobic backgrounds.
Resistance training has numerous benefits to the heart and vascular system, including improved ejection fraction of the left ventricle, and improved elasticity of the arterial walls. This from Power: A Scientific Approach, by Dr Fred Hatfield.
Virtually everything we do in life is anaerobic. Aerobic activity is an artificial state which the human organism is not well adapted to. For the majority of individuals, loss of function associated with aging is due to lack of strength, not aerobic capacity.
 

PART II

Recently, I questioned the obsession most Americans have with aerobic exercise - particularly when done for the purpose of improving physical appearance (which, of course, is why 99.5% of all people exercise in the first place). This article prompted several letters and phone calls, most of which were critical. Therefore, I'd like to clarify my position in this month's article

Obviously, compared to a sedentary lifestyle, aerobic exercise is quite beneficial. The people I'm trying to reach with this message are those individuals who are not competitive aerobic athletes, but who nevertheless spend between 5 and 10 hours a week in the aerobic zone, for the purpose of improving their appearance. These individuals (and there are legions of them) would benefit by reducing their volume of aerobic exercise, and incorporating resistance training into their program.

Even aerobics instructors have intuitively known this for quite some time. Every time I walk past an "aerobics" class in a health club, or if I happen upon one on TV, they're lifting weights. Small ones, of course - they need to guard against gaining too much muscle. Funny how most men have a tremendously difficult time gaining muscle, despite grueling weight lifting programs, while women claim that they grow like weeds just thinking about lifting! Why is this?

One of my "detractors' wrote that (I paraphrase) beginners can benefit from 30 minutes of brisk walking, for which they need no instruction. I couldn't agree more. But walking is a VERY beginning form of exercise. In fact, I consider walking a form of locomotion, not exercise. When the simplest of life's requirements, such as walking, climbing stairs, and carrying groceries are exercise, I'd say you're in pathetic (perhaps pathologic) shape. In this case, walking is in fact an ideal form of exercise. Once you get beyond this point, however, more strenuous forms of activity should be explored, in order to respect the principle of progressive overload (i.e., "If you keep doing what you've always done, you'll keep getting what you've always gotten.")

Resistance training does have a few down-sides, depending on your perspective. It does require a certain amount of supervision, at least in the beginning. And of course, it demands hard, physical work, which most people disdain. Info-mercial companies know this well- selling their exercise gimmicks with phrases like "You can do it while you watch TV," and "It only takes 10 minutes a day!"

Regardless of what your exercise regime consists of, your success will largely depend upon the degree to which you really enjoy exercising. You do best what you do most, and you do most what you enjoy doing. How many times have you heard this exchange in your health club?: "Hey Bob- how's it 'goin?" "Well, it'll be goin better when I get outta here!" In my experience, Bob is very unlikely to make progress, unless he can find a way to enjoy and appreciate physical activity.

What the Research Literature Has to Say About Strength Versus Aerobic Exercise

From Pollack, in the Southern Medical Journal, Volume 87, No. 5, 588

Low levels of aerobics yield the same health benefits as higher levels
Master runners show a 2 kg. average lean body mass (LBM) loss
Higher intensity resistive training may be necessary for a large percentage of the healthy elderly population.
From Ketelhut, in American Heart Journal, 127 (3): 567-71, March, 1994

"We conclude that the gradual decrease in arterial pressure seen with prolonged aerobic exercise (60 min.) is the result of a fall in cardiac pump function (as measured by cardiac output, ejection fraction, fractional fiber shortenings and contractility index), possibly indicating cardiac fatigue."
From Todd, in Sports Medicine, 14(4): 243-59, October, 1992

Circuit weight training has been shown to improve aerobic endurance and muscle strength and to have additional benefits of improved treadmill time compared with traditional aerobics programs.
From Boyden, in Archives of Internal Medicine, 153(1):97-100, January 11, 1993

In healthy pre-menopausal women with normal baseline lipids, 5 months of resistive exercise training reduced) total CHO and the LDL fraction.
From Campbell, in American Journal of Clinical Nutrition, 60(2): 167-175, August, 1994

Resistance training is an effective way to increase energy requirements, decrease body fat mass, and maintain metabolically active tissue mass in healthy older people and may be useful in weight control.
From McCartney, et al:, in American Journal of Cardiology, May, 1991

There is a much better adaptation to life activity with weight training.
From Thomas, in Southern medical Journal, Vol. 87, No. 5

"Because of the correlation between bone mass and muscle mass, an increase in muscle mass isd a desired effect of exercise."

[Articles used with permission.]