Marijuana, or Cannabis sativa, is one of the oldest and most popular illicit plants. The Canadian Alcohol and Drug Use Monitoring Survey data report that 40.7% of the Canadian population aged 15 to 64 have used cannabis at least once in their lifetime1.
Former Canadian Olympic snowboarder Ross Rebagliati was stripped of his 1998 Olympic gold medal after trace amounts of THC—the most significant compound in cannabis—were found in his blood. His medal was later reinstated, mainly on the basis that cannabis was not yet a banned substance.
Learn More: An Introduction to Cannabinoids
With cannabis becoming legalized in Canada on October 17, 2018, and global laws related to cannabis becoming increasingly tolerant, the role of this substance in sports will probably expand. We should learn as much as we can about how it may help or hinder athletic performance and recovery.
Officially a Banned Substance
The World-Anti Doping Agency (WADA) was established as an independent international agency to coordinate the fight against performance-enhancing drugs in sport. One of the critical activities of WADA is to monitor the World Anti-Doping Code. As mandated by the Anti-Doping Code, WADA publishes an annual list of prohibited substances that are banned from regulated sports.
In 1999, WADA included cannabis on the list of banned substances for all sports during competition but did not ban cannabis outside of competition. The in-competition ban includes THC and its synthetic analogs, nabilone and dronabinol, both of which are used for medicinal purposes, such as anti-nausea, anti-seizure, and anti-anxiety treatments. The only cannabis-derived compound that was specifically not banned is cannabidiol (CBD), the major non-intoxicating component of cannabis6. With WADA making an explicit exception for CBD at the start of 2018, several sports organizations are now allowing athletes to use CBD oil, and many use it to replace other pharmaceuticals7.
Learn More: The Medical Science of CBD
Is Cannabis Performance Enhancing?
The inclusion of cannabinoids on the prohibited list remains controversial. Proponents argue that cannabis isn't performance enhancing in any sport and should remain a social issue. Conversely, opponents claim that cannabis can improve performance, and since it's illegal in many countries and athletes are considered role models, it should be prohibited at all times, in and out of competition8.
Among other reasons, athletes report using cannabis to help reduce stress and anxiety, enhance sleep, reduce inflammation, and relieve pain9 10. All of these effects could be considered to enhance athletic performance.
There are currently only a few scientific studies that have directly tested the effects of cannabis on athletic performance. The results so far suggest cannabis may somewhat hinder an athlete’s physical abilities.
Some studies show that THC and its synthetic analogs can significantly raise a user's heart rate and can cause dangerous cardiac events, such as a stroke or heart attack11. These effects could pose a risk to older athletes, or those with undiagnosed cardiac disease.
THC also affects blood pressure and can impair steadiness, reaction time and movement12. All of these effects could impair an athlete's performance, especially in sports requiring a high level of coordination. Also, THC doesn't appear to enhance aerobic exercise or strength. In fact, the small number of studies that exist show that cannabis decreases aerobic performance or has no effect at all13.
There is some indirect evidence that suggests cannabis may be helpful by reducing pain and inflammation associated with sports injuries, as well as helping to reduce anxiety in athletes. Clinical studies using the oral spray, Sativex, which contains both THC and CBD, demonstrate this formulation can treat chronic pain14. There is also considerable evidence for CBD as an anti-inflammatory to treat a variety of diseases15 16, as well as a potential treatment for anxiety disorders17. The effects of Sativex and CBD on pain, injury and mental performance for athletes specifically, however, have not been assessed in a clinical trial.
An online search of "CBD" and "sport," shows ample use of CBD products. Athletes report using CBD to manage chronic pain, inflammation, and mental stress with few side effects18. With CBD now removed for WADA’s list, and a growing interest in the use of CBD in sport, clinical studies are needed to determine the direct benefits of cannabis, specifically CBD, on athletic performance and for injury recovery.
 Bonner WIA, Andkhoie M, Thompson C, Farag M, Szafron M. Patterns and factors of problematic marijuana use in the Canadian population: Evidence from three cross-sectional surveys. Can J Public Health. 2017;108(2):e110-e116.
 Lorente FO, Peretti-Watel P, Grelot L. Cannabis use to enhance sportive and non-sportive performances among French sport students. Addict Behav. 2005;30(7):1382-1391.
 Spence JC, Gauvin L. Drug and alcohol use by Canadian university athletes: a national survey. J Drug Educ. 1996;26(3):275-287.
 Brisola-Santos MB, Gallinaro JG, Gil F, et al. Prevalence and correlates of cannabis use among athletes-A systematic review. Am J Addict. 2016;25(7):518-528.
 Ricketts A. 7 Ways Athletes Use Cannabis. In. High Times. New York 2018.
 Agency WA-D. The World Anti-Doping Code International Standard: Prohibited List. January 2018 2018.
 Leadville Fso. Organized sports that allow athletes the use of cannabinoid oil. In. Floyd's of Leadville. Leadville, Colorado2018.
 Huestis MA, Mazzoni I, Rabin O. Cannabis in sport: anti-doping perspective. Sports Med. 2011;41(11):949-966.
 Ashton CH. Pharmacology and effects of cannabis: a brief review. Br J Psychiatry. 2001;178:101-106.
 Deligiannis A, Bjornstad H, Carre F, et al. ESC study group of sports cardiology position paper on adverse cardiovascular effects of doping in athletes. Eur J Cardiovasc Prev Rehabil. 2006;13(5):687-694.
 Campos DR, Yonamine M, de Moraes Moreau RL. Marijuana as doping in sports. Sports Med. 2003;33(6):395-399.
 Kennedy MC. Cannabis: Exercise performance and sport. A systematic review. J Sci Med Sport. 2017;20(9):825-829.
 Pesta DH, Angadi SS, Burtscher M, Roberts CK. The effects of caffeine, nicotine, ethanol, and tetrahydrocannabinol on exercise performance. Nutr Metab (Lond). 2013;10(1):71.
 Abrams DI. The therapeutic effects of Cannabis and cannabinoids: An update from the National Academies of Sciences, Engineering and Medicine report. Eur J Intern Med. 2018;49:7-11.
 Pisanti S, Malfitano AM, Ciaglia E, et al. Cannabidiol: State of the art and new challenges for therapeutic applications. Pharmacol Ther. 2017;175:133-150.
 Burstein S. Cannabidiol (CBD) and its analogs: a review of their effects on inflammation. Bioorg Med Chem. 2015;23(7):1377-1385.
 Blessing EM, Steenkamp MM, Manzanares J, Marmar CR. Cannabidiol as a Potential Treatment for Anxiety Disorders. Neurotherapeutics. 2015;12(4):825-836.
 Kemp A. Exploring CBD to treat chronic pain and sport injuries. In. Ministry of Hemp: Ministry of Hemp; 2018.