Latest revision as of 16:26, 30 January 2017

Running on Manali Leh Highway, average elevation 4,000 m (13,000 feet) , rising to 5,328 m (17,480 feet). Image by TheHellRace.

Viagra can improve exercise at altitude, though it is not clear if a single dose is sufficient, or if it needs to be taken regularly. It is also not clear if everyone responds to Viagra in high altitude exercise the same way. In addition, Viagra may be a treatment for altitude sickness.

1 Viagra and Performance

Viagra (the brand name for Sildenafil) has been shown to help with the effects of altitude. Some studies^[1][2][3] have shown that Viagra increases the maximum exercise capacity at altitude. One study^[4] showed that for some trained cyclists a single dose of Viagra 1 hour before exercise produced a significant improvement (39%) in sub-maximal performance in altitude (12,700 ft) while others did not experience a worthwhile improvement (1%). However, another study^[5] supplied Viagra for 6 days, and the benefits took several days to kick in. Other studies^[1] have shown benefits from a single dose 2 hours before exercise. A study of 20 male and 15 female trained athletes performing a 6 Km time trial at a simulated 12,700ft altitude showed only a single male athlete with improved performance, so individuality may be a factor^[6].

2 Altitude Sickness

Long term use of Viagra has been shown^[7] reduce the impact of altitude. Subjects were given Viagra every 8 hours for 12 weeks inhibited a particular type of altitude sickness (high altitude pulmonary arterial hypertension or HAPH). Viagra also improved the distance the subjects could walk in 6 minutes. Altitude sickness can lead to a potentially lethal condition called "High-Altitude Pulmonary Edema" (HAPE). Viagra is considered^[8] a viable treatment for HAPE, and is being used in some situations^[9]. A review of 5 studies found that Viagra reduced pulmonary systolic arterial pressure, but did not improve oxygen saturation or Acute Mountain Sickness scores^[10]. The use of Viagra as a preventative in healthy subjects with no history of HAPE may not be justified^[11]. The best treatment for Altitude Sickness is decent, but in the event that decent is dangerous, Viagra may be useful.

3 Side Effects of Viagra

Viagra can cause headaches^[7] at altitude or at sea level^[4]. No other side effects were noted in any of the altitude studies. Viagra is a vasodilator which can cause systemic hypotension (low blood pressure), especially given with nifedipine, but a review of 56 subjects administered Viagra for altitude sickness did not have this problem^[12].The primary use of Viagra for Erectile Dysfunction does raise some questions about other possible side effects, as well as being a source of endless jokes. However, background reading suggests that Viagra does not result in unwanted erections and requires physical or mental stimulation. In the treatment of ED, noted side effects included headache, flushing, dyspepsia, nasal congestion and impaired vision, including photophobia and blurred vision^[13].

4 Viagra and Doping

At the time of writing, the World Anti-Doping Agency has not banned Viagra (Sildenafil), but you should check before using Viagra (or any other medication) before taking it. World Anti-Doping Agency web site.

5 What this means

Viagra is a prescription medication and should only be taken under medical supervision. I believe that self-medication is foolish and I urge you to talk to your doctor if you think Viagra would help. The performance benefits of Viagra at altitude might be significant enough to warrant further investigation, but personally I would only use Viagra as a treatment for altitude sickness.

6 See Also

• Altitude Training
• The Science of Altitude Training
• Altitude Training Approaches
• Comparison of Altitude Training Systems
• Book Review - Altitude Training and Athletic Performance
• Intermittent Hypoxic Exposure and The Science of Intermittent Hypoxic Exposure
• Chronic Mountain Sickness

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7 References

1. ↑ ^{1.0 1.1} HA. Ghofrani, F. Reichenberger, MG. Kohstall, EH. Mrosek, T. Seeger, H. Olschewski, W. Seeger, F. Grimminger, Sildenafil increased exercise capacity during hypoxia at low altitudes and at Mount Everest base camp: a randomized, double-blind, placebo-controlled crossover trial., Ann Intern Med, volume 141, issue 3, pages 169-77, Aug 2004, PMID 15289213
2. ↑ Vitalie Faoro, Michel Lamotte, Gael Deboeck, Adriana Pavelescu, Sandrine Huez, Hervé Guenard, Jean-Benoît Martinot, Robert Naeije, Effects of Sildenafil on Exercise Capacity in Hypoxic Normal Subjects, High Altitude Medicine & Biology, volume 8, issue 2, 2007, pages 155–163, ISSN 1527-0297, doi 10.1089/ham.2007.1058
3. ↑ Petros Perimenis, Sildenafil for the treatment of altitude-induced hypoxaemia, Expert Opinion on Pharmacotherapy, volume 6, issue 5, 2005, pages 835–837, ISSN 1465-6566, doi 10.1517/14656566.6.5.835
4. ↑ ^{4.0 4.1} AR. Hsu, KE. Barnholt, NK. Grundmann, JH. Lin, SW. McCallum, AL. Friedlander, Sildenafil improves cardiac output and exercise performance during acute hypoxia, but not normoxia., J Appl Physiol (1985), volume 100, issue 6, pages 2031-40, Jun 2006, doi 10.1152/japplphysiol.00806.2005, PMID 16455814
5. ↑ JP. Richalet, P. Gratadour, P. Robach, I. Pham, M. Déchaux, A. Joncquiert-Latarjet, P. Mollard, J. Brugniaux, J. Cornolo, Sildenafil inhibits altitude-induced hypoxemia and pulmonary hypertension., Am J Respir Crit Care Med, volume 171, issue 3, pages 275-81, Feb 2005, doi 10.1164/rccm.200406-804OC, PMID 15516532
6. ↑ Kevin A. Jacobs, Jochen Kressler, Mark Stoutenberg, Bernard A. Roos, Anne L. Friedlander, Sildenafil Has Little Influence on Cardiovascular Hemodynamics or 6-km Time Trial Performance in Trained Men and Women at Simulated High Altitude, High Altitude Medicine & Biology, volume 12, issue 3, 2011, pages 215–222, ISSN 1527-0297, doi 10.1089/ham.2011.0011
7. ↑ ^{7.0 7.1} AA. Aldashev, BK. Kojonazarov, TA. Amatov, TM. Sooronbaev, MM. Mirrakhimov, NW. Morrell, J. Wharton, MR. Wilkins, Phosphodiesterase type 5 and high altitude pulmonary hypertension., Thorax, volume 60, issue 8, pages 683-7, Aug 2005, doi 10.1136/thx.2005.041954, PMID 16061711
8. ↑ A. Kleinsasser, A. Loeckinger, Are sildenafil and theophylline effective in the prevention of high-altitude pulmonary edema?, Med Hypotheses, volume 59, issue 2, pages 223-5, Aug 2002, PMID 12208214
9. ↑ Peter J. Fagenholz, Jonathan A. Gutman, Alice F. Murray, N. Stuart Harris, Treatment of High Altitude Pulmonary Edema at 4240 m in Nepal, High Altitude Medicine & Biology, volume 8, issue 2, 2007, pages 139–146, ISSN 1527-0297, doi 10.1089/ham.2007.3055
10. ↑ Yu Xu, Yuliang Liu, Junze Liu, Guisheng Qian, Meta-Analysis of Clinical Efficacy of Sildenafil, a Phosphodiesterase Type-5 Inhibitor on High Altitude Hypoxia and Its Complications, High Altitude Medicine & Biology, volume 15, issue 1, 2014, pages 46–51, ISSN 1527-0297, doi 10.1089/ham.2013.1110
11. ↑ Matthew G.D. Bates, A.A. Roger Thompson, J. Kenneth Baillie, Andrew I. Sutherland, John B. Irving, Nikhil Hirani, David J. Webb, Sildenafil Citrate for the Prevention of High Altitude Hypoxic Pulmonary Hypertension: Double Blind, Randomized, Placebo-Controlled Trial, High Altitude Medicine & Biology, volume 12, issue 3, 2011, pages 207–214, ISSN 1527-0297, doi 10.1089/ham.2011.0007
12. ↑ Barbara E. Jones, Suzy Stokes, Suzi McKenzie, Eric Nilles, Gregory J. Stoddard, Management of High Altitude Pulmonary Edema in the Himalaya: A Review of 56 Cases Presenting at Pheriche Medical Aid Post (4240 m), Wilderness & Environmental Medicine, volume 24, issue 1, 2013, pages 32–36, ISSN 10806032, doi 10.1016/j.wem.2012.07.004
13. ↑ Viagra Prescribing Information http://www.pfizer.com/files/products/uspi_viagra.pdf