New Research May Help Demystify the Science of Bodybuilding

Demystify Bodybuilding Science

We're able to share the in-depth facts and fiction related to this popular sport.

fitFLEX Articles - Learn, Share and Discover

With all the claims and counter-claims made today concerning proper exercise and nutrition, it's easy for the average bodybuilder to become confused. Many articles published in bodybuilding magazines that purport to be factually accurate are, in fact, commercially biased. The ulterior motive behind many of them is simply to increase the sales of a product.

If the product works, there's no harm done. All too often, however, bodybuilders are assaulted with technical mumbo jumbo that sounds right but really doesn't add up. Those who promulgate such claims are often self-appointed experts, some of whom even possess advanced educational degrees, including doctorates. Unfortunately, some of those degrees are from mail-order diploma mills.

The medical community takes a generally dim view of bodybuilding. Many doctors assume the worst when dealing with bodybuilders. Rather than ask about nutrition, bodybuilders often request some kind of pharmaceutical aid, such as anabolic steroids. The recent crackdown by the federal government on steroid distribution has made physicians highly reluctant to prescribe these drugs.

Because of the stigma associated with bodybuilding-that it lacks scientific credibility-legitimate scientific experts have refused to become even obliquely involved with the sport, fearing that they would be rebuked by their colleagues. Due to the nature of bodybuilding and its unique effects on the body, though, some scientists are making tentative forays into the world of sweat and barbells.

One such expert is Scott Connelly, M.D., a successful California-based physician who specializes in the area of nutritional life support. Trained in internal medicine and anesthesiology, the tall, slender Connelly also completed advanced studies in critical care medicine. Today he maintains a brutal schedule as a "life support expert," one of the few now working in mainstream medicine. He monitors patients after they have experienced extensive trauma or surgery and literally keeps them alive through nutrition and other means, a system called "metabolic regulatory control."

Connelly initially became interested in metabolism while on a fellowship in Boston as part of his medical training, and he became gradually more involved in the field. He worked with researchers studying protein economy under conditions of physiologic stress, such as occurs in patients after surgery and in others who have severe systemic illnesses that are characterized by marked tissue catabolism where protein retention is often a major determinant of the patient's survival.

The researchers that Connelly worked with were investigating the interrelationships between intakes of protein and energy that could offset the large-scale losses of muscle protein that occur under the aforementioned catabolic conditions. His principal interest eventually evolved to the precise relationship between the delivery of dietary energy and the control of the lean body compartment, or muscle, as it relates to a phenomenon known as "nutrient partition." Connelly's later studies involved normal, rather than sick, people who were interested in increasing their muscle-to-fat ratios. This group, of course, included bodybuilders.

Connelly looked at weight training as a means of regulating the content of muscle tissue. The reason for using healthy people in these experiments was so that the confounding factors associated with extreme catabolic states wouldn't influence the results. What Connelly was searching for was a means to ideally influence an anabolic, or building, state while minimizing catabolic, or tearing-down, reactions in the muscle.

Building Up and Tearing Down

The generally accepted theory of muscular hypertrophy, or growth, states that muscles increase in size through a thickening process in the individual muscle fibers, or myofibrils. But do such fibers increase in size as a result of increased protein synthesis alone or because they reduce the normal catabolic processes that constantly occur in the muscle? Or is it a combination of the two processes?

Using radioisotope studies to determine the fate of amino acids in muscle, Connelly discovered that muscle protein synthesis wasn't the whole story: You also had to consider the degradation of muscle protein. In fact, these studies suggested that protein breakdown represented a very important nutritional target in the growth response. Eight years ago Connelly studied mature adults-mostly men-who were involved in weight training, and he developed a theory that control of muscle size relates to the ability of the diet to support a small component of new tissue synthesis and simultaneously promote anticatabolic effects at the intracellular level.

Purveyors of food supplements frequently make the claim that "to get big, you must eat big." Connelly disagrees with this line of thinking. "Muscle size isn't dependent on energy intake," he said. "All the biochemical elements necessary to produce the growth response are already in the muscle."

Many of the suggestions concerning protein metabolism and work-induced muscle growth are based on rat studies. According to Connelly, however, there are many problems with using rats to determine human amino acid needs. For example, human muscle has a much greater ability to oxidize branched-chain amino acids than rat muscle has. Branched-chain aminos are important in controlling the catabolic response in muscle tissue.

The best type of resistance to induce muscle growth, Connelly said, involves a prominent eccentric component and relatively heavy training loads. Eccentric contractions involve the lengthening of activated muscle-i.e., the lowering of a weight to its starting position. They are also known as negative reps. Connelly said that to make a muscle grow you must induce a tissue-remodeling process by causing micro-injuries to the muscle fibers and offsetting further damage. This translates into muscular growth. The best type of exercise to induce this controlled damage is movements that emphasize a strong eccentric component.

You would think that a muscle is stronger when it's in the process of growth, but this isn't always the case. Hypertrophied muscle is actually relatively weaker than the original tissue because a host of non-muscle elements are insinuated into the remodeling process. In fact, the first type of protein synthesized after induced damage, or exercise, is collagen, better known as scar tissue. Since this is a non-contractile protein, it lacks the versatility and strength of the original muscle protein.

Are Aerobics Best for Fat Loss?

Connelly also offers heretical opinions concerning the best kind of exercise for losing fat. He cites recent studies that show that the reputed metabolic-raising capacity of aerobics has been greatly overestimated. Yes, you burn calories while engaged in aerobics, but as soon as you stop the exercises, the calorie burn returns to normal levels after a short recovery period. Connelly disputes the idea of an increased caloric afterburn from typical aerobic programs and shows as evidence recent studies using a human calorimeter that indicated no difference in 24-hour energy expenditure between elite endurance athletes and a group of untrained controls.

What really controls your resting metabolic rate is the amount and composition of your muscle mass. That accounts for the frequently observed fact that most males have a higher resting metabolism than females do. The males just have more muscle. Muscle is active tissue, and the higher the oxidative capacity of muscle, the less chance of obesity. As Connelly sees it, you have two choices if you want to effectively reduce fat: You can go on a Spartan diet or you can take up weight training to increase the total oxidative capacity of the body's muscle mass.

Connelly believes that weight training may offer a natural means of increasing thermogenesis, or the conversion of excess calories into heat. The mechanism involves increased adrenergic sensitivity-increased body sensitivity to thermogenesis-inducing substances such as norepinephrine.

The underlying reason for obesity may involve a metabolic defect caused by reduced functioning of the sympathetic nervous system coupled with an abnormal component of Cortisol metabolism. Hormones of the sympathetic nervous system, such as epinephrine and norepinephrine, are known to stimulate fat release from fat cells through activation of beta receptors on the fat cell surface.

Cortisol, on the other hand, is a potent fat-inducing hormone that is released in increased amounts under stress conditions. When the adrenal glands are removed from genetically obese animals, the animals become lean. The importance of Cortisol in this phenomenon is shown by the fact that the rats become obese again when they are given methadone, a synthetic cortisol-like drug, after the surgery to remove the adrenal gland.

Nutritional dogma says that you get fat if your caloric intake exceeds your expenditure, but that doesn't explain the existence of obese people who eat less than their leaner counterparts. This points to an inherent metabolic defect in the obese-most likely the lack of ability to induce futile energy cycles, which involve the conversion of excess calories into heat when no work is done. In the obese these excess calories take an express route to fat cells.

The Most Effective Training Program

Since weight training is clearly the most effective route to increasing lean tissue and so raising the levels of oxidative tissue as a means of controlling obesity, the question is, What's the best way to train?

According to Connelly, you should use heavy loads in workouts that feature sets in the five-to-six-reps range, with three-minute rest periods between sets. He suggests using compound, multi-joint exercises, such as bench presses, squats and barbell rows. Free weights are generally better than machines for adding muscle size because of the increased eccentric component associated with free-weight movements.

On alternate days use a program that emphasizes eight-to-10-rep sets with only one-minute rest intervals between sets. Connelly says such programs are effective because they appear to induce metabolic responses that favor increased levels of insulinlike growth factors (IGF) in the muscle, which stimulates a biochemical cascade that results in increased growth. Specialized cells called satellite cells, which direct the tissue remodeling in the muscles, and fibroblasts produce IGF and are exquisitely sensitive to the levels of certain nutrients.

Connelly also says that fewer training sessions combined with high-intensity levels are the key stimuli to increased muscular growth. He notes that beginners, who haven't yet developed the requisite muscle repair mechanisms, often need up to two weeks to recover biochemically after a workout that emphasizes a strong eccentric component.

Problems With Steroids

Anabolic steroid activity depends on how many cellular androgen receptors are available to usher the steroids into the nuclei of the cells. When you use steroids, however, your body senses the excess amounts of hormone and begins to close down androgen cell receptors as a protective device.

After five to six weeks muscle protein synthesis induced by steroids ends because the cellular receptors are completely saturated. The steroids then continue to exert muscle-building effects through a different mechanism: blockage of Cortisol receptors. By blocking Cortisol, you minimize catabolic reactions in muscle, thus opening the door to increased anabolic reactions.

After a while, however, the Cortisol cellular receptors increase, and the steroids do stop working. One way around this is to increase steroid dosages to block the newer Cortisol receptors. The frequently observed loss of muscle seen when a bodybuilder gets off steroids relates to this increased sensitivity to Cortisol.

Connelly explains that steroid users experience a mild case of Cushing's syndrome, which is excess Cortisol production. This leads to a regression of hypertrophy induced by steroid use, which offsets the removal of active anticatabolic mechanisms, a reaction that differs from muscular atrophy, in which catabolism itself increases.

What all of this means is that many of the effects of steroids are due to an anticatabolic function rather than an increased level of protein synthesis, as is commonly believed. While steroids do exert an increased rate of protein synthesis, this effect is shortlived. Any effect steroids have after that comes from their anticatabolic effect. When you get off steroids, you are left with an increased sensitivity to Cortisol because of the preponderance of Cortisol receptors brought on by steroid use. This increased sensitivity removes the "brakes" and results in muscle-size regression.

A similar scenario occurs when you don't exercise. Exercise itself creates an anticatabolic effect. This accounts for the observed ability of weight training to maintain lean tissue under dieting conditions. Maintenance of this lean tissue prevents the usual metabolic slowdown seen in people who diet without exercising. If you stop exercising, the catabolic effect of Cortisol and other substances increases. But, Connelly says, you never quite return to baseline level. Muscle memory, or neurological adaptations to exercise, remains, allowing you to return to previous levels of development once you commence training.

Connelly says that athletes who resort to using growth hormone alone as an anabolic stimulus will not see effects as apparent as they would get with steroids. While growth hormone promotes increased muscle protein synthesis, it exerts little or no anticatabolic effect in muscle the way steroids do. Remember that the important increases in muscle size that come with steroid use are the result of decreased muscle catabolism.

The Perfect Food

Connelly has discovered that virtually 100 percent of the subjects he's worked with in a muscle-building, fat-loss protocol have an immense amount of "untapped potential," even though many feel that they've gone as far as they can naturally. By studying specific areas of the endogenous mechanisms by which muscle growth occurs, he has identified a number of targets as being nutritionally sensitive. After nearly 10 years of experiments Connelly uncovered two novel substrates that, when combined with a total nutrient array, have been demonstrated to "hit those targets." This extensively up-regulates the nutritional adaptations that occur naturally within cells of the body in conjunction with the appropriate weight-training stimulus. Connelly calls his new substrate array MET-Rx.

It is inappropriate to call MET-Rx a "supplement"- more accurately it is an "engineered food." The concept of engineered foods stems from the fact that it is possible to isolate various constituents of naturally occurring foodstuffs that have important biochemical effects. Connelly's development of MET-Rx is similar to the National Cancer Institute's recent efforts to develop engineered foods that have potent anticancer activity. Connelly's research efforts have been virtually identical-the systematic identification and isolation of individual constituents of dietary supply that are known to exert control over various aspects of the body's metabolism.

Although these constituents are found in various whole foods, the amounts contained in these natural sources vary considerably. Because the absolute levels of individual constituents, as well as their quantitative relationships to one another, are critical to their efficacy, it is virtually impossible for individuals to seek out similar profiles in whole foods.

Do Nutrients Affect Muscle Growth and Fat Loss?

The right nutrients in the right quantities delivered consistently to an appropriately trained bodybuilder will result in muscle growth and fat loss, Connelly contends. He has clearly demonstrated this point in a number of studies at his Human Performance Institute in Menlo Park, California.

One highly controlled study explicitly demonstrated the effects that nutrients play on muscle building and fat loss. A group of 32 male subjects of similar heights, weights and ages were the subjects. A control group and an experimental group were established. All took part in an identical training program that lasted 56 days, and both groups consumed identical caloric intakes; however, only one of the groups used the engineered food MET-Rx as its nutrient source. As a testament to the effectiveness of weight training, all 32 subjects gained muscle mass and lost bodyfat; but the experimental group-those who used MET-Rx-gained 500 percent more fat-free weight than the group that didn't use MET-Rx. They also experienced fat losses that were 350 percent greater than those of the control group.

Another study that was performed by Colorado sports medicine researcher Bill Phillips confirmed Connelly's findings. Phillips procured enough MET-Rx to support 68 weight-training athletes for a period of six weeks. The participants were given specific directions on how to use the product and how to train, but they were uncontrolled for the entire test period. At the end of the six weeks Phillips sent out an extensive survey form to the field study participants. After quantifying the results, he discovered extraordinary uniformity in the feedback-91 percent of the field study participants reported substantial bodyfat reductions, increases in strength and greater muscularity. Phillips, who regularly performs such uncontrolled empirical studies, reported that he has never collected a positive response to any food product or supplement that exceeded 65 percent-until now.

These findings have important implications for bodybuilders who wish to eschew drug use. Although no food or supplement can build muscle comparable to steroids, it does seem that the calculated, consistent intake of specific nutrient combinations can accelerate muscle building and fat loss in disciplined, weight-trained athletes.

Related Articles