I'll find the craziest stuff. I was just talking about this the other day with two of my clients.
Viagra has moved from the bedroom to the locker room. The buzz on the
street was that Yankee superstar Roger Clemens had a bottle of Viagra
disguised as vitamin pills stashed in his locker. Last May, Italian
cyclist Andrea Moletta was removed from the Giro d'Italia after police
found a cache of Viagra and syringes in his car. Not surprisingly, the
tabloids had a field day following these incidents and charged that
legions of athletes in baseball, football, bodybuilding and Olympic
sports took Viagra to boost endurance and physical performance. The
World Anti-Doping Association (WADA) considered banning Viagra before
the Beijing Olympics, but backed off because it had no evidence that the
drug provided a competitive advantage.
What do firm erections have to do with sports like bodybuilding?
Viagra improves blood flow control. Muscles need plenty of blood to
remove wastes and deliver energy, oxygen, and hormones. Increased blood
flow could speed the delivery of key amino acids to the muscles, which
would promote muscle protein synthesis and growth. It seems reasonable
that Viagra could boost performance and that bodybuilders might take it.
A Stanford University study by Ann Friedlander and colleagues
published in 2006 triggered the Viagra craze among athletes. The
researchers found that Viagra improved cardiovascular capacity during
exercise on a stationary bike at a simulated altitude of 12,710 feet but
not at sea level. Viagra increased cardiac output (blood pumped by the
heart per minute), stroke volume (blood pumped by the heart per
heartbeat), and oxygen saturation (percent of red blood cells carrying
oxygen). Cycling performance at altitude improved by 15 percent. The
drug increased exercise capacity by reducing blood pressure in the
lungs, which increases at high altitude. Not all subjects benefited from
the drug— there were responders and non-responders. Other researchers
confirmed the Stanford results and also showed that Viagra improved
exercise capacity in people suffering from lung disease and heart
failure.
Bodybuilding is an incredibly difficult sport that requires years of
backbreaking work to achieve success. Most athletes will do whatever it
takes to increase muscle mass and win contests. It’s understandable that
they take Viagra: it’s not on any banned substances list; it’s readily
available; it has few side effects; and it might provide a significant
edge. The fact that it only worked in some people above 12,000 feet
altitude and didn’t work at sea level was somehow lost in the shuffle.
Why Viagra Might Be an Effective Bodybuilding Drug
Viagra (sildenafil) is one of three FDA-approved, erection-promoting
drugs called PDE-5 inhibitors that also include tadalafil (Cialis) and
vardenafil (Levitra). They work by inhibiting the PDE-5 enzyme, which
then increases the concentration of a chemical called nitric oxide that
promotes blood flow to the penis and other tissues throughout the body.
Blood vessels, smooth muscle, skeletal muscle, blood platelets, and lung
tissue contain this and similar PDE enzymes. In addition to promoting
erections, PDE-5 inhibitors decrease systemic blood pressure, lung blood
pressure, lung resistance, and promote coronary (heart) blood flow.
Long-term use improves endothelial function, which is critical to blood
flow control.
The drugs reduce stress in pressure-overloaded hearts, which is
important for bodybuilders because large increases in muscle tension
restrict blood flow to working muscles. Increasing muscle blood flow
during training could increase muscle strength, size, and fitness, while
reducing stress on the heart. They also improve lung blood flow and
boost quality of life in patients suffering from lung disease. These
drugs have promising pulmonary and cardiovascular applications that go
beyond firm erections.
To date, no study has found that Viagra improves exercise performance
in athletes at sea level. The drug is helpful in people with blood
pressure limitations that interfere with oxygen transport to the
tissues. For example, lung blood pressure increases substantially in
some people at altitude, which makes it difficult to move oxygen from
the air into the bloodstream. Viagra reduces lung blood pressure, which
enhances oxygen consumption and the capacity to exercise.
A small percentage of elite endurance athletes have a performance
imbalance between the heart and lungs. Their powerful hearts exceed
breathing capacity, which causes a mismatch between the pulmonary and
cardiovascular systems. Viagra might increase lung function to match
their superior heart capacity, which could give them a significant
competitive advantage. However, other athletes might benefit as well.
Physical inactivity, diets high in saturated and trans-fats and
simple sugars, and reduced muscle mass impair the ability of insulin
receptors to regulate carbohydrates, amino acids (building blocks of
proteins) and fats. Insulin sensitivity affects the health of the
endothelium, the cells that line the blood vessels. These cells release
nitric oxide (NO) that opens blood vessels in tissues throughout the
body. Long-term use of Viagra has training-like effects on the
endothelium, which increases its capacity to release NO. While the
Viagra-induced improvements in blood flow control might be greater in
men suffering from poor metabolic health, they might also promote blood
flow in the muscles and nervous systems in bodybuilders and physically
fit adults. Viagra doesn’t appear to increase endurance performance
following short-term use, but it might have long-term benefits in
well-trained athletes.
Long-term use of Viagra might also benefit metabolic capacity by
enhancing blood sugar control and increasing testosterone levels.
Scientists from Vanderbilt University School of Medicine found that the
drug helped restore energy balance and boosted insulin metabolism in
mice fed high-fat diets (compared to a placebo). The animals showed
lower blood sugar and insulin levels and improved blood sugar regulation
after a high-carbohydrate meal. They also lost bodyweight and fat mass
during the 12-week study. In humans, long-term use of Viagra increased
the production of the blood vessel controlling chemical nitric oxide,
which has strong links to insulin metabolism.
Viagra boosts testosterone, which is a critical hormone for
increasing muscle mass, strength, and aggressiveness— all critical for
athletes. Testosterone is linked to sexual arousal and performance.
Middle-aged men who take testosterone supplements improve sex drive,
capacity for erections, self-confidence, and aggressiveness. Italian
researchers found that total and free testosterone levels increased by
50 percent in men treated for erectile dysfunction with Cialis or
Viagra. It’s not clear whether these drugs increased testosterone
directly or if they increased it indirectly through increased sexual
activity. Frequency of sexual intercourse was greatest in men who took
Cialis (a longer-acting PDE-5 inhibitor), which makes it the preferred
drug for men in stable relationships. Men who had the most sex also had
the highest testosterone levels.
Factors affecting testosterone include psychological health, diet,
exercise, and sexual activity. Men who have a lot of sex are happier,
more confident, and have better-functioning sex organs than men who
don’t. The sex organs— like your muscles— function best when you use
them, so Viagra might give them a boost. We don’t know if Viagra
increases testosterone levels in healthy, fit bodybuilders.
Long-term use of Viagra might also increase muscle strength, power,
and size by triggering biochemical pathways that increase protein
synthesis and prevent protein breakdown in muscle cells. As discussed,
Viagra increases nitric oxide (NO) release by the blood vessels. NO
helps turn on protein synthesis in muscles, particularly when the fibers
are under tension or stretch. NO also triggers the formation of
satellite cells that add mass to the muscle fibers. To date, no study
has shown that Viagra and similar drugs have steroid-like effects in
athletes, but we can infer from biochemical studies that they might.
Viagra is on WADA’s Radar
WADA first took notice of Viagra following the Stanford University
study and reports that the drug was given to greyhounds to improve
running performance. They were concerned that Viagra might improve
performance at lower altitudes and provide a competitive advantage at
venues such as Denver, Mexico City, or areas hosting the Winter
Olympics. The margin of victory is often a matter of seconds in
endurance events in cycling and cross-country skiing, so a drug that
provides even a small advantage could be very significant.
WADA is currently funding a series of studies at Marywood University
in Scranton, Pennsylvania and at the University of Miami, to determine
the effects of Viagra on exercise capacity and performance at sea level,
moderate altitudes, and in polluted environments. They also want to
know if the drug has different effects in men and women. The results of
these studies will determine whether Viagra ends up on the banned
substances list.
Will Viagra Make You a Superstar?
Viagra can help make you a sexual Olympian, provided that you have
game, good hygiene, and a reasonably firm body. It definitely won’t get
you a spot on the Yankee’s roster or the Olympic team if you don’t have
the talent. To date, no study has found that Viagra improves exercise
capacity at sea level. However, long-term use of the drug might promote
muscle protein synthesis and improve metabolic fitness enough to have a
small effect on endurance or strength. Viagra and similar drugs have
side effects; so don’t use them without following the advice of a
physician. We need many more studies before we can adequately assess the
effects of these drugs on exercise capacity and athletic performance.
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