Can Viagra Make You a Better Athlete?

OK don’t laugh, this is a genuine scientific enquiry. Can Viagra make you run faster?

As a medical representative (when i’m not out running), I am interested in keeping up with industry trends, and what is happening in the world of pharmaceuticals, whether it is in my therapeutic area or not. One area I find particularly interesting is the off-label use of drugs.

Off-label use of a drug is the use of a drug for an indication that has not been approved. Generally speaking, it is legal, but does have certain health risks, as the drug is not being used for its original (and tested) purpose. Usually, there is inadequate evidence supporting the off-label use. It is quite a common practice. Examples of off-label drug use include Zoloft (sertraline) an approved anti-depressant, being used to treat premature ejaculation, and Duromine (phentermine) an appetite suppressant used for treating obesity, used by long-haul truck drivers to stay awake, as it is an amphetamine derivative.

Another off-label use of a drug is the use of Viagra (sildenafil) to improve exercise performance. That is, performance on the playing field/track/road/sporting arena. Just to be clear on the kind of exercise performance I’m talking about.

image

Now, I’m sure we all know what Viagra is approved to be prescribed for. In addition to treating erectile dysfunction, it is also approved to treat pulmonary arterial hypertension, and has been shown to be useful in treating pulmonary oedema associated with altitude sickness.

Viagra’s use in sport is not a new phenomenon. The theory is that Viagra is a vasodilator (opens up blood vessels), which improves blood flow. More blood flow to our muscles means more oxygen, and in theory could lead to greater athletic performance.

So, is there any evidence to support this? And can we actually make athletic gains from this? The answer to both questions is, not really, but maybe a little.

One of the studies that I looked at involved only 16 subjects, so it is hardly overwhelming medical evidence. The results showed that Viagra did indeed increase exercise capacity, but only in acute normobaric hypoxia: at altitude, in low-oxygen condition. Not at sea level. It was concluded that this was a result of improved arterial oxygenation.

Most other studies I looked at had similar findings: Viagra (sildenafil) improves cardiac output and exercise performance in acute hypoxia, but not normoxia. Another study looked at a group of 10 trained cyclists, who performed a time trial at sea level, and again at altitude (3874m). They found 2 different subject groups: sildenafil responders, and sildenafil non-responders. The responders improved their time trial performance by an average of 39%, while the non-responders improved theirs by an average of 1%. (It increased stroke volume, cardiac output, and SaO2.) So it works…. for certain individuals.

Despite these studies, I would still consider the scientific evidence for Viagra very sparse. These studies were performed on only a handful of test subjects. The scientific papers that I review for work are often studies done with over 20 000 patients. In addition, no study has found that it has any benefits at sea level. My conclusion? We need more studies.

So… Can Viagra help me? If I plan on running a marathon up Mt Everest, maybe. But for my next event, the Central Coast half marathon this weekend, It’s not looking good. I guess I’d be better off sticking to the chocolate.

image

REFERENCES:

Faoro, V., et al. Effects of sildenafil on exercise capacity in hypoxic normal subjects. High Alt Med Biol, 8:155-163, 2007.

Hsu, A. R., K. E. Barnholt, N. K. Grundmann, J. H. Lin, S. W. McCallum, and A. L. Friedlander. Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia. J Appl Physiol, 100:2031-2040, 2006.

Advertisements

3 thoughts on “Can Viagra Make You a Better Athlete?

  1. Hey Kirby,

    I came across your blog over google, while looking for running groups in Newcastle. I have just moved to Newcastle and looking for some running groups, and like minded fit outdoor people to tag along on some runs.if you could point me in the right direction that would be great. I’m from Brisbane and have been competing in Ironman racers and a few marathons over the last 3 years. Ive been Enjoying your articles and your pursuit of marathon perfection.

    Have a great day.

    Kind regards Adam

    Sent from my iPad

    1. Welcome to the Region of Runners! There are plenty of running groups here, i do a lot of my runs with a girls group, there are a few social running groups like 5 30 runners, wooters runners, or the newcastle flyers if you are after something more serious. They all have facebook pages. The Flyers run 6 am every sunday from Merewether surfhouse for 20-30km. The best way to meet plenty of runners in Newy would be to head along to Newy Parkrun, every Saturday, 8am. You will meet lots of runners there! Dont forget to register first if you havent done one before… Parkrun.com.au/newy

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out / Change )

Twitter picture

You are commenting using your Twitter account. Log Out / Change )

Facebook photo

You are commenting using your Facebook account. Log Out / Change )

Google+ photo

You are commenting using your Google+ account. Log Out / Change )

Connecting to %s