A $252 million contract to play baseball causes "an enormous amount of pressure ... to perform at a high level every day," according to Alex Rodriguez. The New York Yankees' third baseman provided a few more details last week about the anabolic steroids he used from 2001 to 2003 after he had signed a record-setting deal with his former team, the Texas Rangers.

Here is what most of us know about anabolic steroids: they make muscles grow faster, there are harmful side effects to our health, most sports leagues have banned them, and they are illegal without a prescription.

But how do they actually work? Does an athlete just pop a few pills and then wait for the Popeye-spinach effect? Let's dig a little deeper into the science of steroids.

Legal uses
Anabolic steroids, or anabolic-androgenic steroids (AAS), are the synthetic (made in a lab) derivatives of the naturally produced hormone testosterone. They promote the growth of muscle (anabolic effect) and the typical male characteristics of puberty (androgenic effect).

When legally prescribed, they are an option for patients who produce abnormally low levels of testosterone or who suffer from body-wasting diseases such as cancer or AIDS. When used by athletes, the goal is to speed up the body's natural muscle-building process.

When we lift weights heavier than what we're used to, we create tiny micro-tears in muscle fibers. The body's natural repair process repairs the tear and then overcompensates by adding bigger cells to build a stronger fiber — this is called muscular hypertrophy. Over time, this repeated process of teardown and re-build will result in muscle growth.

Natural testosterone is the body's main ingredient for this process, but anabolic steroids can serve as a supplement.

Once ingested, an AAS travels through the blood stream to the muscle tissue. It is drawn into the muscle cell's receiving dock, called an androgen receptor. Once delivered to the muscle cell, the steroid can interact with the cell's DNA and stimulate the protein synthesis process that promotes cell growth.

Different variants and amounts of AAS can cause different reactions producing either massive body-building physiques or more toned athletic muscles (i.e. Barry Bonds vs. A-Rod). Athletes experiment with different combinations (called stacking) or regimens (pyramiding) in an attempt to fine-tune the final result. A-Rod's stack was reportedly straight testosterone and Primobolan.

Beyond bulk
While the focus in the media is on the bulked-up home run hitters, anabolic steroids can also benefit pitchers and others who need a faster turnaround from sore, overused muscles. Intense exercise also releases cortisol, known as the stress hormone, which breaks down muscle tissue, producing sore muscles.

AAS can block cortisol from binding to the muscle cell's receptor sites, which diminishes the breakdown process. Less muscle breakdown means less muscle fatigue which would allow a pitcher to recover more quickly from a nine-inning outing.

Besides all of the known negative side effects of using steroids just for ergogenic reasons, there is also the uncertainty of what exactly you are taking. Last month, federal Drug Enforcement Administration agents arrested the owners of an Alabama-based online pharmacy on charges that they filled hundreds of illegal prescriptions for anabolic steroids for clients across the country.

The worst news for the customers of this pharmacy was delivered by U.S. Attorney Deborah Rhodes: "Each of the pharmacy owners and pharmacists named in the indictment are charged with prescribing and selling veterinary steroids, approved for cattle and livestock only, to humans."

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When Milwaukee Brewers pitcher Chris Capuano reports for spring training in April, he will be anxious to demonstrate the effects of a performance-enhancing off-season. His brain will benefit from a sharper focus while his throwing arm will boast an extra boost that has been missing since 2006. Stimulants? Steroids? Scandal? No need to panic, he just had LASIK surgery for his eyes and "Tommy John" surgery for his injured elbow. Of course, had he chosen amphetamines to improve his focus or steroids to increase his strength, he would have been banned and berated.

Society Decides

There is confusion over the means and methods athletes have available to enhance their performance. Certainly, corrective eye surgery to raise your vision level to 20/20 seems fair, but many athletes go into the procedure hoping to come out with enhanced 20/15 or 20/10 eyesight. Replacing a damaged elbow ligament with a tendon doesn't seem like cheating, but what if its done on a healthy elbow hoping for a few more miles per hour on a fastball that has faded over the years?

Earlier this month, a commentary in the journal Nature recommended a fresh look at cognitive-enhancing drugs and where to draw the line in the sand between natural performance and enhanced performance. The authors, an esteemed group of neuroscientists and ethicists, argued that "enhanced" is only defined by the rules set by society.

Certainly, abuse of prescription drugs, such as Ritalin and Adderall, is illegal because of the potential, harmful side effects. Still, reports of the rising use of these drugs by college students and professionals show the demand for options beyond nutrition, exercise and sleep.

These drugs are just the first generation of possible brain boosting supplements, which is why the Nature commentators are calling for an organized, stigma-free approach to evaluating the risks, benefits and ethics of future products.

Even in Major League Baseball, there is mounting evidence that cognitive-enhancing drugs may be on the rise. Since MLB banned amphetamines in 2006, there has been a dramatic rise in the number of therapeutic use exemptions issued to players for attention-deficit disorder diagnoses, for which drugs like Ritalin and Adderall can be legitimately prescribed. In 2006, 28 players applied for the exemption, while a year later there were 103. There is suspicion that many of these ADD diagnoses are just excuses to get the pills.

Legal Jolt

So, what if there was a cognitive-enhancing, sports supplement that increased alertness, concentration, reaction time and focus while also decreasing the perception of muscle fatigue? Even more encouraging, this supplement is sold in millions of outlets and is socially accepted worldwide. It comes in three sizes, tall, grande or venti – coffee. More specifically, caffeine has been the subject of many recent studies of its effectiveness, both cognitively and physiologically.

Earlier this year, Dr. Carrie Ruxton completed a literature survey to summarize 41 double-blind, placebo-controlled trials published over the past 15 years to establish what range of caffeine consumption would maximize benefits and minimize risk for cognitive function, mood, physical performance and hydration. The studies were divided into two categories, those that looked at the cognitive effects and those that looked at physical performance effects.

The results concluded that there was a significant improvement in cognitive functions like attention, reaction time and mental processing as well as physical benefits described as increased "time to exhaustion" and decreased "perception of fatigue" in cycling and running tests.

Given these results, how exactly does caffeine perform these wonderful tricks? Dr. Ruxton explains from the study, "Caffeine is believed to impact on mood and performance by inhibiting the binding of both adenosine and benzodiazepine receptor ligands to brain membranes. As these neurotransmitters are known to slow down brain activity, a blockade of their receptors lessens this effect."

Bottom line, the chemicals in your brain that would cause you to feel tired are blocked, giving you a feeling of ongoing alertness. This pharmacological process is very similar to that of the ADD drugs.

If caffeine is such a clear cut performance enhancing supplement, why did the World Anti-Doping Agency (WADA) first add caffeine to its banned substance list, only to remove it in 2004? At the time that it was placed on the banned list, the threshold for a positive caffeine test was set to a post-exercise urinary caffeine concentration of about 3-4 cups of strong coffee.

However, more recent research has shown that caffeine has ergogenic effects at levels as low as the equivalent of 1-2 cups of coffee. So, it was hard for WADA to know where to draw the line between athletes just having a few morning cups of coffee/tea and those that were intentionally consuming caffeine to increase their performance level.

So, if Chris Capuano has a double espresso before pitching, his brain, eyes and arm should enhance his performance in the game. Is that an unfair advantage? Science will continue to offer new and improved methods for raising an athlete's game above the competition. Players, league officials and fans will have to decide where to draw the line.

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