How to Keep Your Muscles While on a Weight Loss Diet Plan

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Bodybuilders who attempt tolose body fat by restricting caloric intake walk a fine line between anabolic and catabolic effects. Simply put, when you severely restrict either energy sources (such as carbohydrates) or calories in general, you risk tapping into vital protein stores in muscle. This tearing down of muscle protein is a catabolic effect. The results of injudicious dieting are often evident in the haggard faces and excessive muscle loss seen in many competitive bodybuilders. To those who use drugs, losing fat while maintaining muscle is even more problematic. Drugs such as anabolic steroids and growth hormone have patent anticatabolic effects: They preserve protein, and hence muscle, while simultaneously tapping into fat stores in the body. Thus, so-coiled natural bodybuilders need to employ every nutritional element to their advantage while dieting.

If caloric intake is too low or protein consumption is insufficient, adding exercise, such as aerobics, in an effort to increase bodyfat loss will potentate the loss of muscle. Bodybuilders who perform hours of aerobics each day while dieting ore often compromising their own objectives by losing large amounts of muscle in addition to burning superfluous fat deposits. The effect is heightened because excessive aerobic training interferes with muscle-protein synthesis. Does this mean that aerobics should be avoided in order to preserve hard- earned muscle? Not necessarily. You must, however, take certain dietary precautions. For example, staying on a near-zero-curb, low-fat diet will lead sooner or later to muscle loss, particularity once you've reduced most of your body fat. The body will then tap into amino acids stored in muscle to provide energy for training, especially aerobics.

The specific amino acids used for this process ore branched-chain amino acids {BCAAs), which can be directly metabolized in muscle for use as energy. This often occurs under conditions of tow-caloric consumption or excessive activity. Losing BCAAs from muscle also promotes the loss of another amino acid predominant in muscle, glutamine. Once that happens, the catabolic process is in full swing and you lose muscle. While it's true that muscle tissue can adapt to using other energy sources, such as metabolic byproducts of fat combustion called ketones, as well as fatty acids themselves, the stress of low-calorie dieting coupled with high- intensity exercise promotes cortisol release from the adrenal glands.

Cortisol, in turn, promotes the release of BCAAs and glutamine from muscle, where they travel to the liver to be converted into glucose. The results of a recent study suggest that taking extra BCAAs while dieting may effectively curtail such catabolic reactions if muscle during exercise. The study reported in the Nutritional Sciences Journal (21:27.36, 1996), examined the effects of a very-low-calorie diet (810 calories a day) combined with aerobic exercise on 8CM levels in muscle, The study consisted of 18 college- aged men divided into two groups: those who only dieted, and those who dieted and performed 30 minutes of aerobic exercise doily. Both groups in the week- long study began losing weight within three days, but BCAA levels were lower in the group whose members combined the diet with aerobic exercise. The researchers noted that when calories ore severely restricted, exercise oxidizes BCAAs derived from muscle breakdown to provide energy, which leads to a loss of muscle mass and strength.

Another study, conducted by Australian researchers, looked at the effect of taking supplemental BCAAs on biochemical indicators of muscle damaged during exercise. The study involved 16 men divided randomly into two groups: a BCAA group, whose members took 12 grams of supplemental BCAAs in addition to their regular diet for 14 days; and a second group, whose members consumed a "regular" diet without supplemental BCAAS. One week before undergoing an exercise lest, subjects were tested for base-line levels of two enzymes creatine kinase and lactate dehydrogenase both of which are released into the blood after muscle damage from intense exercise. The exercise test consisted of cycling for two hours at 70% of maximum oxygen intake, a respectable level of intensity. While all subjects consumed the suggested intake of BCAAs in their diets, only those taking supplemental BCAAs showed less muscle damage after exercise as measured by the aforementioned intramuscular enzymes. This led to the conclusion that BCAAS may reduce muscle damage occurring during exercise.

BCAA supplementation may also preserve muscle through still another mechanism. In a study published in the journal Nutrition (12:485-90, 1996), seven cyclists were supphed either a liquid solution of BCAAS or a placebo. Those consuming the solution with BCAAs showed a 135% increase in BCAAs in blood plasma and a 57% increase of these aminos in muscle tissue during exercise. The placebo group showed an overall decrease of BCAAs in blood and an 18% drop in these aminos in muscle tissue during training. During the exercise test, those athletes taking the BCAA solution also showed a 48% overall increase in the amino acid alanine, and a 70% rise of this amino acid in muscle. In contrast, those taking placebos exhibited only a 31% increase in alanine production in muscle.

This is significant because ala. nine is synthesized from BCAAs in muscle and can be transported to the liver, where it's converted into glucose through a process called gluconeogenesis. This glucose then travels in the blood back to the muscles, where it's used for energy. In doing so, it provides a sparing action for other amino acids in muscle, including all-important glutamine. The BCAA group also showed a 14% increase in argirline levels in blood. Arginine is an amino acid that releases growth hormone, and in- amounts of arginine circulating in the blood during exercise may promote GH release. Perhaps the most important finding of this study was that the increased BCAA intake significantly decreased muscle-glycogen breakdown during exercise. This would not only provide more energy during intense training but also spare muscle protein. This aspect of BCAA intake is particularly vital to those who train more than once a day, since it normally takes a few hours to replen- ish stares of muscle glycogen. These studies underscore the necesity to consume more protein while on low-calorie or low-carbohydrate diets. BCAAs are particularly important in this regard, since they seem to limit the loss of muscle that may occur with intense sessions of aerobic exercise. Taking extra glutamine might also be prudent, since recent research shows that it may block much of the catabol increase effect of cortisol in muscle.

Taking glutamine orally in doses any higher than four grams will usual l lead to either its breakdown in the liver or its use as an energy substrate for intestinal and immune cells. Thus, it may be more effective to consume glutamine in smaller doses (two to four grams) throughout the day and particularly after a workout aid in muscle-protein synthesis.




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