Newsletter
HotBod January 99
Welcome All:
Happy New Year! 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: Cardiovascular Intensity/The Right Speed
This myth was given credence when several research studies indicated that low- intensity activities burned a greater percentage of fat calories than high- intensity activities. These studies validated that the body prefers to use fat as its fuel source during low-intensity exercise (equating to roughly 60% of the calories burned, as opposed to about 40% from high-intensity exercise).
However, it is misguided to believe that the selective use of fat for fuel will translate into burning more total fat calories. High-intensity exercise burns more fat calories on an absolute basis than lower intensity activities. Since the most important aspect of training intensity is the total amount of fat calories burned-not the percentage from fat-higher intensity exercise has the decided edge.
Furthermore, when you consider the time related efficiency of training, low- intensity exercise provides a very poor cost/benefit dividend. After all, why would you want to spend an hour running on the treadmill when you can get better results from training for half that time? In final analysis, if fat burning is your aim, performing cardiovascular exercise at a high level of intensity is your best choice.
NUTRITION CORNER: Good Fat/Better Body
For many years, common nutritional wisdom preached that fat was the enemy. "Eat fat and you'll get fat," was the mantra of most dieticians. Recently, however, this view has softened and a more moderate approach has been adopted in respect to fat intake.
Despite what you might have heard, certain fats are vital for basic sustenance. They are involved in cushioning your internal organs for protection, aiding in the absorption of vitamins and facilitating the production of cell membranes, hormones and prostaglandins. Physiologically, it would be impossible to survive without the inclusion of fats in your diet. Consequently, rather than cutting all fats out of your diet, it is advisable to focus on eliminating saturated fats and replace them with unsaturated, essential fatty acids (EFAs).
Saturated fats have virtually no biological purpose. If you don't burn them immediately for fuel, they either are stored in adipose cells throughout your body or become oxidized as fatty deposits in your arteries. But that's not all. These fats tend to make your muscles less responsive to insulin and inhibit your body's ability to store sugars as glycogen. Even worse, because of their chemical make-up, they are prone to clumping together, making your fat deposits more likely to take on the appearance of "cellulite".
On the other hand, EFAs cannot be manufactured by your body and hence, like vitamins, are an "essential" component in food. Due to their lack of saturation, EFAs don't readily bond together (that's why they remain liquid at room temperature) and thereby decrease the potential for clumping into a cellulite-like appearance in areas prone to this phenomenon. In addition, they are extremely biologically active and actually help to increase your metabolic rate while enhancing the ability of your muscles to use insulin. Ultimately, this results in better fat metabolism and improved body composition.
As a rule, limit your fat intake to less than 20% of your total calories with the majority coming from EFAs. The best sources of EFAs are found in soy products and deep-colored, cold-water fish such as salmon, mackerel and tuna. Flaxseed oil also contains high levels of EFAs. It comes in liquid form and either can be mixed into your foods or taken by the spoonful. Look for a brand that has a 3:1 ratio of omega-3 (linolenic acid) to omega-6 EFAs (linoleic acid).
SUPPLEMENT REVIEW: Androstenedione
Androstendione (andro, for short) is the new rage in sports supplementation. After Mark McGwire claimed that it enhanced his athletic performance, sales of the product went through the roof. It was the buzz on every television and radio program in the country and soon became a household name. Now, many women are utilizing this supplement, in hopes of redefining their physique.
Before discussing its efficacy, it is important to understand how andro effects your body. Andro is a precursor to testosterone-a hormone that helps to promote muscular growth. In theory, andro can be converted directly into testosterone, creating an anabolic environment that is conducive to building size and strength. However, andro only stays active in your system for about an hour and there is no evidence that short-term testosterone spikes have a significant impact on increasing muscle mass. At best, studies have only shown minimal gains in training performance. Thus, don't be fooled by the hype: The claims that andro produces "steroid-like" effects are pure fantasy.
Additionally, there are many potential side-effects associated with the use of andro. For one, it has the potential to turn into dihydro-testosterone (DHT), a hormone that produces such unwanted side-effects as acne, clitoral enlargement, decreased breast tissue, deepening of the voice, body hair growth, and menstrual irregularities. While the long-term effects are not yet known, heart and liver disease are distinct possibilities. For a woman who just wants to look better at the beach, these adverse consequences are clearly unacceptable.
In final analysis, andro is far from being a wonder supplement. It has a limited upside with a significant downside, making for a poor risk/reward ratio. Unless you don't care about your health and well being, I would highly advise against its use. Certainly, it would be prudent to wait until better research has been conducted.
SUPPLEMENT GRADE: D
