The Science of Cannabis and Sports

While cannabis use is widespread in the general community, you might be surprised to hear that it’s also readily used in sports.

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.

While cannabis use is widespread in the general community, it is also readily used in sports²³⁴. Athletes have reported using cannabis to assist with pain relief and to enhance mental performance⁵.

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.

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.

Cannabis for Athletes
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.

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 pain⁹¹⁰. 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 diseases¹⁵¹⁶, 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.