Sports Fitness Training

Walk into any dietary supplement store and you will notice that more products fall into the category of diet or fat loss aids than any other product category. A recent search of an online dietary supplement store indicated that there are close to 400 products that are marketed for fat loss. Fifty-five products contain the dietary supplement, chromium.

Supplements are designed to promote fat loss. The term fat loss will be used rather than weight loss because the latter term does not differentiate between muscle mass and fat mass. Supplements designed to promote fat loss can function on one of a number of different principles. These principles as well as the most commonly used fat loss supplements.

Over the last 20 years, there has been about a 10% increase in the prevalence of overweight individuals. Furthermore, one in five adolescents are considered obese, which is a 45% increase Because of societal pressures, it seems that everyone has used or at least has thought of using a fat loss product at one time or another. This includes adolescents as well as older adults. Just because these supplements are sold in health food and vitamin stores does not guarantee their safety. Some of these supplements may have cross-reactivity with some prescription medications and alcoholic beverages.
Increase in Fat Oxidation

Several factors are involved in the use of lipids as fuel. For muscles to oxidize fatty acids, fat (triacylglycerol) must first be mobilized from the adipose tissue. This is referred to as lipolysis. Once the free fatty acids are lysed and released from adipose tissue, they must be transported by albumin in the blood to the muscle, where uptake occurs via a specific transporter protein called the fatty acid binding protein (FABP) When the free fatty acid (FFA) enters the muscle it is activated, after which the activated fatty acid is transported into the mitochondria where Beeta-oxidation occurs.

Theoretically, an increase in fatty acid oxidation could be achieved at anyone of seven sites. However, the mobilization of free fatty acids from the adipose tissue appears to be the best site because the uptake of FFA by the muscle is dependent on the arterial blood concentration of FFA. The more FFA released by the adipose tissue, the higher the concentration of FFA in the circulation. Therefore, any product that increases lipolysis should increase fatty acid oxidation at the muscle.
Mechanism of Action for Fat Loss Supplements

Supplements marketed to promote fat loss can theoretically function on one of a number of principles, from increasing adipose tissue lipolysis or fat breakdown, to suppressing the appetite or the desire for food to reducing the amount of fat absorbed from food during the digestive process. To better understand how fat loss supplements function, their potential mechanisms of action should first be understood.

While starting a resistance exercise program, remember to consider your age, fnness level, and the personal goals you would like to achieve. Strength training exercises are done in a set, or a single series of multiple repetitions using the same resistance. Current research tells us that for healthy people of all ages(and for many individuals with chronic illnesses), single set resistance programs of up to 15 repetitions per exercise, performed a minimum of two days per week, are recommended. Each of your workout sessions should include 8 to 10 different resistance exercises that involve the major muscle groups of the upper and lower extremities and the trunk. Somewhat surprisingly, single-set resistance programs have been recently recommended by the American College of Sports Medicine 47 for the majority of the United States population because they produce most of the health and fitness benefits associated with much more time consuming, traditional multiple-set programs(e.g., 3 sets of 10 repetitions of each exercise three days per week).

Remember that resistance training exercises cause microscopic damage(tears) to muscle fibers, and the rebuilding process that increases the size and capacity of the muscle takes about 2.4 to 48 hours. Thus resistance training exercise programs should include at least one day of rest and recovery between workouts before overloading the same muscles again.

Resistance Training Program Guidelines

• Resistance training should be an integral part of an adult fitness program and of sufficient intensity to enhance strength, muscular endurance, and maintain fat-free mass(FFM).

• Resistance training should be progressive in nature, individualized, and provide a stimulus(overload) to all major muscle groups in the body

• One set of 8 to 10 different resistance exercises that condition the major muscle groups 2. to 3 days per week is recommended.

• Most healthy individuals should complete one set of 8 to 12 repetitions for each selected exercise; for older(50 to 60 years of age and above) and more frail persons, one set of 10 to 15 repetitions may be more appropriate.

• The goal of this type of resistance training program is to develop and maintain a significant amount of muscle mass, endurance, and strength to contribute to overall fitness and health throughout the life span.

• If sufficient time is available, multiple-set resistance exercise regimens using heavier weights and fewer repetitions will result in greater strength gains and fitness benefits.

Ballistic stretching Techniques that employ the repetitive, rapid stretching of muscles with no holding or the stretch at a terminal position; not recommended because of the risk of injury to muscle and/or tendon

Muscular strength The amount of force that a muscle is capable of exerting.

One repetition maximum(1 RM) The amount of weight/resistance that can be lifted/moved one time, but not twice; a common measure of strength.

Muscular endurance A muscle’s ability to exert force repeatedly without fatiguing

Resistance exercise program A regular program of exercises designed to improve muscular strength and endurance in the major muscle groups.

Hypertrophy Increased size(girth) of a muscle.

What Do You Think?

What types of resistance equipment can you currently access? Based on what you’ve read, what specific actions can you take to increase your muscular strength? Muscular endurance? How would you measure your improvement?

Muscular strength refers to the amount of force a muscle is capable of exerting. The most common way to assess strength in a resistance exercise program is to measure the maximum amount of weight you can lift one time. This value is known as the one repetition maximum, and is written as 1 RM. Muscular endurance is defined as a muscle’s ability to exert force repeatedly without fatiguing. The more repetitions of a certain resistance exercise you can perform successfully(e.g., a bench press of one-half your body weight), the greater your muscular endurance.

Principles of Strength Development

There are three key principles to understand if you intend to maximize muscular strength and endurance benefits from your resistance exercise program. Unless you follow these principles, you are likely to be disappointed in the results of your program.

• The Tension Principle The key to developing strength is to create tension within a muscle. The more tension you can create in a muscle, the greater your strength gain will be. The most common recreational way to create tension in a muscle is by lifting weights. While weight lifting is one method of producing tension in a muscle, any activity that creates muscle tension-for example, riding a bike up a hill-will result in greater strength.

• The Overload Principle The overload principle is the most important of the three key principles for improving muscular strength. Everyone begins a resistance training program with an initial level of strength. To increase that level of strength, you must regularly create a degree of tension in your muscles that is greater than they are accustomed to. This overloading of your muscles will cause your muscles to adapt to the new level of overload. As your muscles respond to a regular program of overloading by getting larger(hyper trophy), they become capable of generating more tension.

Some women avoid resistance exercise because they fear that they’ll develop large “bulky” muscles, while others are frustrated because their weight-lifting efforts in the gym don’t produce the same results as in their male friends. The main reason for this difference is the hormone testosterone. Before puberty, testosterone levels in blood are similar for both boys and girls. During adolescence, testosterone in men increase about tenfold to its adult level; testosterone in women remains at prepubertal levels throughout adulthood. Women’s muscles will hypertrophy from regular exercise but typically not to the same degree as in adult males. The difference in maximum attainable hypertrophy between men and women is not currently known.