Marijuana and Its Effects on Athletic Performance: A Systematic Review

Performance-Enhancing Drugs in Healthy Athletes: An Umbrella Review of Systematic Reviews and Meta-analyses

CONTEXT

Many clinicians, trainers, and athletes do not have a true understanding of the effects of commonly used performance-enhancing drugs (PEDs) on performance and health.

OBJECTIVE

To provide an evidence-based review of 7 commonly used pharmacological interventions for performance enhancement in athletes.

DATA SOURCES

PubMed and Scopus databases were searched on April 8, 2022.

STUDY SELECTION

Systematic reviews (SRs) and meta-analyses (MAs) assessing the performance-enhancing effects of the following interventions were included: androgenic anabolic steroids (AAS), growth hormone (GH), selective androgen receptor modulators (SARMs), creatine, angiotensin-converting enzyme (ACE)-inhibitors, recombinant human erythropoietin (rHuEPO), and cannabis.

STUDY DESIGN

Umbrella review of SRs and MAs.

LEVEL OF EVIDENCE

Level 4.

DATA EXTRACTION

Primary outcomes collected were (1) body mass, (2) muscle strength, (3) performance, and (4) recovery. Adverse effects were also noted.

RESULTS

A total of 27 papers evaluating 5 pharmacological interventions met inclusion criteria. No studies evaluating SARMs or ACE-inhibitors were included. AAS lead to a 5% to 52% increase in strength and a 0.62 standard mean difference in lean body mass with subsequent lipid derangements. GH alters body composition, without providing a strength or performance benefit, but potential risks include soft tissue edema, fatigue, arthralgias, and carpel tunnel syndrome. Creatine use during resistance training can safely increase total and lean body mass, strength, and performance in high-intensity, short-duration, repetitive tasks. Limited evidence supports rHuEPO benefit on performance despite increases in both VO2max and maximal power output, and severe cardiovascular risks are documented. Cannabis provides no performance benefit and may even impair athletic performance.

CONCLUSION

In young healthy persons and athletes, creatine can safely provide a performance-enhancing benefit when taken in controlled doses. AAS, GH, and rHuEPO are associated with severe adverse events and do not support a performance benefit, despite showing the ability to change bodily composition, strength, and/or physiologic measures. Cannabis may have an ergolytic, instead of ergogenic, effect.

Cannabis Is Not Doping

The World Anti-Doping Agency (WADA) classifies cannabis, all phytocannabinoids, and synthetics as doping, except for CBD. For agency, a method for doping substance must meet two criteria: performance enhancement (ergogenicity), health risk, or violation of the spirit of sports. Cannabis is neither ergogenic nor ergolytic (performance worsens), and the health risks for athletes are overestimated after 20 years of research. The significant problem remains in the complex (and difficult interpretation) definition of the spirit of sports, which transcends the objectives of sports excellence (performance and injury prevention) for moral policing. This perspective presents an evidence-based counterargument recommending the removal of cannabis and phytocannabinoids from the WADA Prohibited List.

Investigation of hand functions in individuals with cannabis and its derivatives use disorder

BACKGROUND

The present study was aimed to compare the grip/pinch strengths and manual dexterity of individuals with and without the use of cannabis and its derivatives.

METHODS

A cross-sectional prospective study was conducted with 66 individuals, including 33 cases with the use of cannabis (and its derivatives) and 33 age- and sex-matched controls. Grip and pinch strengths were evaluated with a dynamometer. The Nine-Hole Peg Test (9HPT), Minnesota Manual Dexterity Test (MMDT), and Michigan Hand Outcomes Questionnaire (MHQ) were used to assess the hand function.

RESULTS

The hand grip strength and dominant hand 2-point pinch (2PP) grip strength were less in individuals with substance use disorder (SUD) (p < 0.05). The 9HPT duration of the SUD patients was higher (p < 0.05). On the other hand, the MMDT insertion and rotation test results were different between the groups (p < 0.05). Grip strength was related with the MMDT insertion and rotation tests (r =  -0.411 to -0.480). There was significant correlation between grip strength with dominant hand 9HPT (r =  -0.370) and between dominant hand 3-point pinch (3PP) strength with MMDT insertion (r =  -0.378). In addition, dominant hand 2PP strength was correlated with overall hand function of MHQ (r = 0.382).

CONCLUSION

The individuals with cannabis use disorder showed reduced grip strength on both sides and decreased 2PP strength on the dominant side compared to healthy individuals. In addition, there is a decrease in the hand skills of individuals with cannabis use disorder. Decreased grip strength of individuals with cannabis use disorder affected their hand skills negatively.

Cannabis, cannabidiol and tetrahydrocannabinol in sport: An overview

The World Antidoping Agency now allows cannabidiol (CBD) to be taken in elite sport but has retained all other cannabinoids on its banned list. This, together with liberalisation of cannabis laws have led to an increasing interest in its use in sport. This includes commercial sponsorship of sporting events and highlights the need for accurate information to be readily available to athletes and their advisers. This narrative review confirms that CBD and tetrahydrocannabinol (THC) do not enhance performance. CBD possesses anti-inflammatory and analgesic properties which have not been adequately evaluated in the area of sport. Some formulations of CBD contain THC or other cannabinoids that may result in a positive drug test. This article is protected by copyright. All rights reserved.

Chronic cannabis consumption and physical exercise performance in healthy adults: a systematic review

OBJECTIVE

The effects of chronic cannabis consumption on physiological parameters of athletic performance are investigated to determine whether chronic cannabis consumption negatively affects athletic performance; improves performance, potentially via enhanced recovery; or has no effect at all.

METHODS

A systematic review of the literature (cross-sectional, longitudinal, and intervention studies) concerning the effects of cannabis consumption on sports performance outcomes, e.g. VO2Max (maximal oxygen uptake), PWC (physical work capacity) up to January 2020 was conducted using the PubMed, CINAHL, Medline, PsycArticles, PsycInfo, SPORTDiscus, Psychology and Behavioural Sciences Collection, and Health Source: Nursing/Academic Edition databases. After screening and additional forward searching, four articles were found to fit the inclusion criteria.

RESULTS

Resting heart rate was the only physiological measure that significantly differed between groups, and only in one of the four studies included herein. The strongest predictors of athletic performance (VO2Max and PWC) were not found to be significantly different between groups in any of the included studies. Chronic cannabis consumption had no significant effect on athletic performance. The included studies did not assess other elements, such as recovery or endurance.

CONCLUSION

No evidence exists for ergogenic or ergolytic effects from chronic cannabis consumption. In some sports, advantages may plausibly be conveyed by psychotropic enhancement or pain reduction. Further research (particularly longitudinal or interventional studies) is required to determine whether cannabis, or constituents thereof, may provide indirect supplemental benefits to athletes.

Acute effects of cannabis consumption on exercise performance: a systematic and umbrella review

INTRODUCTION

The goal of this systematic and umbrella review was to regroup all systematic reviews, non-systematic reviews and all original articles into one convenient publication that would facilitate the theoretical and applied scientific investigations directed on cannabis consumption and exercise performance, to update current findings on the matters, and assess evidence quality.

EVIDENCE ACQUISITION

The systematic review was conducted following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) method. A computer-based systematic search was conducted in September 2019 through the Pubmed, Scopus and SPORTDiscus databases. The reliability of the systematic search was assured by having the article selection process entirely repeated by a second author. Strength of evidence of the selected articles was assesses using a modified version of the Downs and Black Checklist.

EVIDENCE SYNTHESIS

The systematic search yielded a total of 8 peer-reviewed publications as well as 10 literature reviews. Results show that cannabis consumption prior to exercise induces decrements in performance (reduced ability to maintain effort, physical/maximal work capacity), undesired physiological responses (increased heart and breathing rate as well as myocardial oxygen demand) and neurological effects on balance (increased sway).

CONCLUSIONS

Based on the articles included in this review, the authors conclude that cannabis consumption has an ergolytic effect on exercise performance and therefore does not act as a sport performance enhancing agent as raised by popular beliefs. Thus, cannabis consumption prior to exercise should be avoided in order to maximize performance in sports. Further research should mimic modern THC dosage (150 mg).

Cannabidiol and Sports Performance: a Narrative Review of Relevant Evidence and Recommendations for Future Research

Cannabidiol (CBD) is a non-intoxicating cannabinoid derived from Cannabis sativa. CBD initially drew scientific interest due to its anticonvulsant properties but increasing evidence of other therapeutic effects has attracted the attention of additional clinical and non-clinical populations, including athletes. Unlike the intoxicating cannabinoid, Δ9-tetrahydrocannabinol (Δ9-THC), CBD is no longer prohibited by the World Anti-Doping Agency and appears to be safe and well-tolerated in humans. It has also become readily available in many countries with the introduction of over-the-counter "nutraceutical" products. The aim of this narrative review was to explore various physiological and psychological effects of CBD that may be relevant to the sport and/or exercise context and to identify key areas for future research. As direct studies of CBD and sports performance are is currently lacking, evidence for this narrative review was sourced from preclinical studies and a limited number of clinical trials in non-athlete populations. Preclinical studies have observed robust anti-inflammatory, neuroprotective and analgesic effects of CBD in animal models. Preliminary preclinical evidence also suggests that CBD may protect against gastrointestinal damage associated with inflammation and promote healing of traumatic skeletal injuries. However, further research is required to confirm these observations. Early stage clinical studies suggest that CBD may be anxiolytic in "stress-inducing" situations and in individuals with anxiety disorders. While some case reports indicate that CBD improves sleep, robust evidence is currently lacking. Cognitive function and thermoregulation appear to be unaffected by CBD while effects on food intake, metabolic function, cardiovascular function, and infection require further study. CBD may exert a number of physiological, biochemical, and psychological effects with the potential to benefit athletes. However, well controlled, studies in athlete populations are required before definitive conclusions can be reached regarding the utility of CBD in supporting athletic performance.

Current Trends in Ultramarathon Running

Exercise is universally recognized for its health benefits and distance running has long been a popular form of exercise and sport. Ultramarathons, defined as races longer than a marathon, have become increasingly popular in recent years. The diverse ultramarathon distances and courses provide additional challenges in race performance and medical coverage for these events. As the sport grows in popularity, more literature has become available regarding ultramarathon-specific illnesses and injuries, nutrition guidelines, psychology, physiologic changes, and equipment. This review focuses on recent findings and trends in ultramarathon running.

Review of WADA Prohibited Substances: Limited Evidence for Performance-Enhancing Effects

The World Anti-Doping Agency is responsible for maintaining a Prohibited List that describes the use of substances and methods that are prohibited for athletes. The list currently contains 23 substance classes, and an important reason for the existence of this list is to prevent unfair competition due to pharmacologically enhanced performance. The aim of this review was to give an overview of the available evidence for performance enhancement of these substance classes. We searched the scientific literature through PubMed for studies and reviews evaluating the effects of substance classes on performance. Findings from double-blind, randomized controlled trials were considered as evidence for (the absence of) effects if they were performed in trained subjects measuring relevant performance outcomes. Only 5 of 23 substance classes show evidence of having the ability to enhance actual sports performance, i.e. anabolic agents, β2-agonists, stimulants, glucocorticoids and β-blockers. One additional class, growth hormone, has similar evidence but only in untrained subjects. The observed effects all relate to strength or sprint performance (and accuracy for β-blockers); there are no studies showing positive effects on reliable markers of endurance performance. For 11 classes, no well-designed studies are available, and, for the remaining six classes, there is evidence of an absence of a positive effect. In conclusion, for the majority of substance classes, no convincing evidence for performance enhancement is available, while, for the remaining classes, the evidence is based on a total of only 266 subjects from 11 studies.