Sildenafil Increases Muscle Mass

[Jinzang]

This is an older study (2013) but I haven't seen this result mentioned before. This extract is taken from the text of the study:

Two groups of men were studied over 15 days, including a baseline period (the week preceding the treatment period.) In the subsequent treatment period (days 1–8) they received either daily low‐dose (25 mg) sildenafil (N = 5) or placebo (N = 6) in a randomized, double‐blinded fashion The men were healthy, based on their history and screening results, represented a wide age range, and the majority (4/6 placebo, 4/5 sildenafil) were overweight based on their BMI. Subjects were instructed to continue regular activities of daily living and maintain their usual diet during the study.
In this study we found that short‐term treatment with the phosphodiesterase 5 inhibitor sildenafil reduces skeletal muscle fatigue and stimulates skeletal muscle protein synthesis while altering muscle protein expression and nitrosylation. Our findings thus provide evidence that sildenafil remodels human skeletal muscle in a functionally adaptive manner.
The differences between treatment groups in protein abundance and S‐nitrosylation observed in this study suggest that changes in myofibrillar function and actin dynamics may have contributed to an increase in muscle quality, manifested as increased fatigue resistance, in individuals receiving sildenafil. Notably, the approximate doubling of skeletal muscle protein synthesis observed in response to sildenafil is of similar magnitude to that observed in response to 100–200 mg/week testosterone injection.
Whether the short‐term responses of protein synthesis and expression eventually manifest as a change in muscle mass or simply reflect an adaptive qualitative change in muscle protein composition will be important to determine in future longer‐term studies.

 

[Vince]

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 does not 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.http://www.musculardevelopment.com/...-latest-research-on-exercise-performance.html

 

[Nelson Vergel]

They need to prove it with studies using body composition analysis.

 

[Mountain Man]

They need to prove it with studies using body composition analysis.

I want this to be true, and I take a pde5 daily. I believe this may be true, but the n=5 is simply not enough to substantiate these claims. I will continue daily cialis and occasional viagra. More studies like this would be a great thing.