Newsletter
Spring 04
Welcome to all the new subscribers to the HotBod newsletter as well as those who have been with us from the beginning. Each month we'll explore issues relating to the three major areas of fitness: exercise, nutrition and supplementation. As always, your comments, questions and suggestions are always appreciated.
TRAINING CORNER: Does the Stairmaster Increase Butt Size
In a recent infomercial, a so-called fitness expert cautioned that "pear-shaped" women shouldn't use the Stairmaster because it will make their butt the size of a movie screen. In truth, this claim has no validity. It's virtually impossible to significantly increase muscle mass through the performance of any endurance-related cardiovascular activity, including the Stair Master. The reason for this is simple: There are two basic types of muscle fibers, slow twitch (Type I) and fast twitch (Type II), and each respond to different stimuli.
Fast twitch fibers are strength-related fibers that contract rapidly but are quick to fatigue. Most of their energy is derived from burning carbohydrates (glucose), rather than fat, as a fuel source. These factors make them more sensitive to anaerobic exercise (push-ups, squats, etc.), where short, intense periods of training are employed. In order to accommodate the demands of these types of activities, fast twitch fibers respond by growing larger and stronger. Consequently, they are the only fibers that have the ability to substantially increase in size and promote muscular bulk.
Slow twitch fibers, on the other hand, are endurance-related fibers that have only a limited ability to increase in size. These fibers get much of their energy by burning fat for fuel, contracting very slowly but having the ability to endure extended periods of activity. They are predominantly utilized during the performance of aerobic exercise lasting more than several minutes in length. As opposed to anaerobic activities, aerobics require minimal activation of fast-twitch fibers and, henceforth, promote little, if any, muscular growth. Accordingly, since stair climbing is aerobically oriented, it simply can't contribute to building an appreciable amount of muscle tissue in your butt - or anywhere else, for that matter.
Moreover, in order for a muscle to increase in size, it must be taxed beyond its present capacity. This is called the Overload Principle and is a universally accepted tenet of modern exercise physiology. By nature, the human body strives to maintain stability-a phenomenon known as homeostasis. If an activity doesn't sufficiently tax your body's resources, there won't be enough of a stimulus to force your body from its homeostatic state. Only by progressively overloading your muscles will they be compelled to produce an adaptive response and grow beyond their normal potential.
Clearly, stair climbing doesn't subject your muscles to a taxing stimulus. It is performed at a relaxed, consistent pace over prolonged periods of time. The limiting factor during performance is your cardiovascular capacity-not your muscular strength. Provided you are aerobically fit, the activity can be continued for hours on end. Thus, since your muscles aren't challenged to any great degree, they have no impetus to enlarge. Bottom line: Don't be afraid of the Stair Master, regardless of your body type - if anything, it will help to strip away fat from your derriere (as well as everywhere else on your body) and ultimately make your butt appear smaller and firmer.
NUTRITION CORNER: Meal Replacement Shakes
They go by many names: Myoplex, Rx-Fuel, Met-Rx…Look through any fitness magazine and you're likely to see ads for these products. The claims range from reduced body fat storage to increased muscle development to more energy. But do these assertions have any credence?
In order to evaluate the efficacy of meal replacements, it's necessary to understand their nutritional composition. Essentially, these products are a high protein, low fat, moderate carbohydrate food source that is rich in vitamins and minerals. They are designed to provide a maximal amount of nutrients in a format that is not inclined to promote significant body fat storage.
As a rule, meal replacements are best utilized as an adjunct to a well-balanced nutritional regimen - not as a substitute for natural foods. They fill a specific dietary niche, but by no means are a complete source of nutrition. Hence, their overuse can lead to a disparity in dietary ratios as well as a deficiency in vital nutrients. Combining meal replacements with natural foods is the best way to satisfy all of your nutritional requirements, ensuring an optimal intake of nutrients.
In practice, it is best to eat a hearty breakfast, lunch and dinner, using shakes as "interim" meals. It is widely recognized that a diet consisting of small, frequent meals (five or six a day) spaced out every two to three hours provides optimal nutritional utility. Eating in this fashion increases metabolic function, regulates blood sugar levels and stabilizes various hormonal processes, allowing your body to operate at peak efficiency. Furthermore, it helps to suppress hunger and thus prevent the temptation to snack on "empty calorie" foods that are high in saturated fat and sugar. Since meal replacements are convenient and easy to prepare, they facilitate your ability to consume quality nutrients at regular intervals without expending a great deal of effort.
On the other hand, meal replacements will not directly build your muscles or make you stronger. There is a prevailing misconception that they have powerful, "steroid-like effects" that will miraculously transform your body from fat to fit. However, despite the hype, muscular development can only be achieved through intense strength training. Although consuming adequate dietary protein will aid in the muscle building process when combined with a dedicated weight-training regimen, simply adding meal replacements to your diet will have no effect on building better muscles!
SUPPLEMENT REVIEW: Garlic
What it is: DHEA is an intermediary hormone produced in the adrenal glands.
What it does: Through various processes, DHEA converts into a variety of hormones including testosterone, estrogen and progesterone. Proponents claim that supplementation can help to slow aging, boost energy, increase weight loss and improve muscularity.
The verdict: There is some evidence that, in people over 40, DHEA supplementation can have some positive benefits. Several studies have shown an increase in lean muscle tissue and improved immune function. However, the studies had small sample sizes and additional research is necessary before any definitive conclusions can be made. What's more, younger people would probably see no benefit from supplementation (DHEA levels decline with age). On the negative side, DHEA supplementation can have detrimental side effects. Remember, DHEA is a hormone and any time you alter natural hormonal levels in the body, you are playing with fire. Hypothetically, this could lead to liver abnormalities, increased facial hair, acne, and other disorders. In sum, unless taken under a physician's supervision, I would caution against DHEA supplementation. For those with diagnosed reductions in DHEA production, supplementation might be effective when taken properly.
Supplement Grade: C
