There are many ways athletes use CBD to improve endurance. Over the past few years, numerous athletes have opened up about their use of CBD and other cannabinoids.
This is partly due to a positive shift in the societal perception of cannabis and hemp products, as well as the people who consume them. It’s also because the World Anti-Doping Agency removed CBD from the list of banned substances starting in 2018.  Being able to consume CBD without penalty has increased the number of athletes being open about its consumption.
There is also a movement within the athletic and sports community where athletes are advocating for the right to consume cannabis for CBD and other medically beneficial compounds. These accounts are well documented in the book, Runner’s High, written by investigative journalist and marathon runner, Josiah Hesse. 
Research on CBD for Athletic Endurance
As for research on CBD for athletic endurance, it is somewhat limited. Although there is a lot of anecdotical evidence from athletes in the media and research surveys, there are no specific studies on how CBD helps athletic endurance.
In a published narrative review, researchers have examined and compared the current scientific evidence of how CBD affects athletes. Their conclusion noted, “Evidence supporting the potential use of CBD as an ergogenic aid to improve the efficacy and efficiency of recovery processes during exercise and sport-related fatigue seems promising”. They go on to add, “CBD appears to have some properties that could boost exercise recovery as an anti-inflammatory, neuroprotective, analgesic, anxiolytic, and pain reliever”. 
Two of the biggest battles endurance athletes face are fatigue and recovery. The researchers do suggest more research to be conducted, but the initial results indicate a positive impact of CBD on human body to face endurance sports.
References: 2018 Prohibited List: Summary of Major Changes. WADA. 2017. https://www.usada.org/spirit-of-sport/education/2018-prohibited-list-summary-of-major-changes/
 Hesse, J. Runner’s High. (New York: G.P Putnam’s Sons, 2021) https://www.penguinrandomhouse.com/books/653009/runners-high-by-josiah-hesse/
 Rojas-Valverde, D. Potential Role of Cannabidiol on Sports Recovery: A Narrative Review. Front. Physiol., 03 August 2021 | https://doi.org/10.3389/fphys.2021.722550 [Times Cited: 4] [Journal Impact Factor: 4.134]
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