Achieving muscular fitness through resistance training has yet another benefit: A stronger body is more resistant to fatigue, moves more quickly, and recovers more quickly from illness or injury. All of these traits contribute to better performance in sports, recreational activities, and other fitness pursuits. Resistance training is often the common denominator among training programs for different sports and activities. Because of these benefits, physically active adults often incorporate some form of resistance training that builds strength and endurance in the muscle groups most crucial to their sport.
WHAT PRECAUTIONS SHOULD YOU TAKE TO AVOID
RESISTANCE-TRAINING INJURIES?
The greater muscular fitness achieved through resistance training helps prevent general injury during sports or daily activity. However, weight training itself can cause injuries such as muscle or tendon strains, ligament sprains, fractures, dislocations, and other joint problems. This is especially true if the lifter pushes for an unrealistic overload. Injuries tend to occur while using free weights, but you can prevent them by getting proper instruction and guidance, and by heeding a few basic suggestions.
IS IT RISKY TO USE SUPPLEMENTS FOR
MUSCULAR FITNESS?
Many people are satisfied with the muscle changes and health-related benefits they realize from resistance training. Others, however, set expectations that their bodies can’t meet without taking supplements and/or steroids. These individuals are unsatisfied with their genetic limitations and the results they have gotten from exercise training alone. Their solution is often to use performanceaid supplements to improve muscle size, muscular fitness, and muscular performance. Is this safe, and do common muscular fitness supplements actually work?
Dietary supplements marketed as promoters of muscle conditioning are called performance aids or dietary ergogenic aids. Some supplements are safe but ineffective; some are both unsafe and ineffective. Few, if any, are worth the risk, making this an area to tread lightly into, if at all. Manufacturers of nutritional supplements need not prove their products are safe or effective before offering them on the open market. The FDA may remove unsafe products, but this occurs after the product is “tested” on the buying public. To avoid being an inadvertent subject in an uncontrolled experiment, look into the risks of any supplement very carefully before considering its use. Some ergogenic aids, such as anabolic steroids, are also controlled substances. This means they require a prescription for legal use and should not be used for nonprescription purposes. In addition, their use can get you banned from athletic competitions.
ANABOLIC STEROIDS
Anabolic steroids are synthetic drugs that are chemically related to the hormone testosterone. Physicians sometimes prescribe small doses within a medical setting for people with muscle diseases,
burns, some cancers, and pituitary disorders. However, some athletes and recreational weight trainers take anabolic steroids—illegally, outside of a medical setting, without a prescription—to increase muscle mass, strength, and power. Anabolic steroids can produce some of these results in some users—but not without overwhelmingly negative side effects that far outweigh the benefits. Besides being illegal, steroids increase the risk of liver and heart disease, cancer, acne, breast development in men, and masculinization in women. Anabolic steroid use can also promote connective tissue and bone injuries because dramatically stronger muscles may exert more force than the body can handle. Steroid use can also be habit forming, lead to other drug addictions, and
even cause death, as explained in the box Spotlight: Behind the Steroid Warnings. Steroid use is relatively high among young athletes in certain sports. Public awareness is continuing to increase along with media coverage of steroid scandals in the sports world. In 2005, for example, a series of congressional hearings investigated steroid usage in major league baseball. Members of Congress examined the adequacy of drug testing and the impact of steroid use by professional sports figures on impressionable teenagers. Most of the baseball players called before the committee denied using steroids, but popular player José Canseco stated that steroids were “as prevalent in . . . the late 1980s and 1990s as a cup of coffee.” A 2005 survey of drug use among U.S. adolescents reported that steroid use is down significantly among 8th and 10th graders from its peak in 2000 and has declined among 12th graders from its peak in 2004.9
CREATINE
Creatine is a legal nutritional supplement containing amino acids. It is most often sold as creatine monohydrate in powder, tablet, capsule, or liquid form. The body’s natural form of creatine (phosphocreatine) is generated by the kidneys and stored in muscle cells. You can also consume creatine in the diet by eating meat products.
Creatine taken at recommended levels can improve performance by temporarily increasing the body’s normal muscle stores of phosphocreatine. Since this natural energy substance powers bursts of activity lasting less than 60 seconds, creatine users sometimes find they can train more effectively in power activities and may be able to maintain higher forces during lifting. This can result in increased training adaptations such as strength and muscle size. Creatine intake also causes a temporary retention of water in muscle tissue that produces a small temporary increase in size, strength, and ability to generate power. Creatine has no effect on performance of aerobic endurance exercise.
So far, there have been few serious side effects reported in studies of people using creatine for up to 4 years. Minor issues are water retention in muscles, muscle cramping, and overall body dehydration. Once a person stops taking creatine, water retention and temporary muscle enlargement due to that retention disappear. Since the long-term effects of creatine use are unknown, however, potential users should proceed with caution.
ADRENAL ANDROGENS (DHEA, ANDROSTENEDIONE)
Dehydroepiandrosterone (DHEA) is the body’s most common hormone and acts as a weak steroid chemical messenger (a conveyor of internal control signals and information). Although DHEA occurs naturally in the body, manufacturers produce and sell it as a supplement in a synthetic concentrated form despite no definitive proof of its safety or effectiveness. DHEA proponents claim that it increases muscle mass and strength, lowers body fat, alters natural hormone levels, slows aging, and boosts immune functions. Despite manufacturers’ claims, research studies have produced some conflicting results on DHEA but overall do not provide strong evidence of a large positive effect on muscle mass and strength, or on body fat levels.
Androstenedione (nickname “andro”) is another naturally occurring steroid hormone with a structure related to both DHEA and testosterone. It is found naturally in meats and some plants. Even
though manufacturers claim “andro” will increase testosterone levels, one pivotal study found that it actually lowers the body’s natural production of testosterone, did not increase the body’s adaptations to resistance training, and increased heart disease risk in men.10 Androstenedione was ordered off the market by the FDA in 2004, and its use is dwindling. Both DHEA and androstenedione appear to decrease HDL or “good” cholesterol,11 which helps explain why these substances increase heart attack risks and other cardiovascular problems. Both also increase the risk of developing certain cancers and accelerating the growth of existing cancers. These serious side effects strongly argue against the use of DHEA or “andro.”
GROWTH HORMONE (GH)
Your body’s pituitary gland produces human growth hormone (GH), which promotes bone growth and muscle growth and decreases fat stores. Drug manufacturers produce GH synthetically for medical use in children and young adults with abnormally slow or reduced growth and related disorders. Although the FDA regulates growth hormone, athletes wanting to gain an edge over their competitors sometimes obtain and use it illegally. Marketers claim that growth hormone supplementation will counteract the muscle mass lost with disuse and aging, among other alleged benefits. However, GH side effects include irreversible bone growth (acromegaly/ gigantism); increased risk of cardiovascular disease and diabetes; and decreased sexual desire, among others.
Marketers of oral GH supplements (GH promoters, not actual GH) claim the same positive benefits to lean muscle mass and fat mass, but this is not borne out in tests or actual use. Oral GH, in fact, cannot even be absorbed from your digestive tract into your bloodstream! A far better way to increase natural levels of growth hormone is to perform regular exercise. In a study of women who ran for exercise, baseline resting GH levels increased by 50 percent in those training at higher compared to lower intensities.12
AMINO ACID AND PROTEIN SUPPLEMENTS
Many bodybuilders and weight lifters take amino acid supplements because they believe that consuming protein or its building blocks (amino acids) will lead to enhanced muscle development. However, evidence is mixed that high intake of protein or taking proteinbased supplements will improve training, exercise performance, or build muscle mass beyond the levels achieved through normal dietary protein. When combined with resistance training, moderate increases in protein intake may lead to small increases in lean muscle mass and strength beyond resistance training alone.13 In contrast, supplementation with the amino acid glutamine produced no beneficial effect above and beyond resistance training itself.14 Taking moderate doses of these supplements has no dramatic side effects, but large doses of either the supplements or protein itself can create amino acid imbalances, alter protein and bone metabolism, and be dangerous to individuals with liver or kidney disease.15
Add Comment