Marihuana and human physical activity

Cannabinoids, Insomnia, and Other Sleep Disorders

Sleep disturbances are often cited as a primary reason for medicinal cannabis use, and there is increasing clinical interest in the therapeutic potential of cannabinoids in treating sleep disorders. Burgeoning evidence suggests a role of the endocannabinoid system in regulating the circadian sleep-wake cycle, highlighting a potential avenue for developing novel therapeutics. Despite widespread use of cannabis products as sleep aids globally, robustly designed studies verifying efficacy in sleep-disordered populations are limited. Although some study outcomes have suggested cannabinoid utility in insomnia disorder and sleep apnea, most studies to date are limited by small sample sizes, lack of rigorously controlled study designs, and high risk of bias. This critical review summarizes the current evidence for the use of cannabinoids as a treatment for sleep disorders and provides an overview of endocannabinoid modulation of sleep-wake cycles, as well as the sleep-modulating effects of plant-derived cannabinoids such as delta-9-tetrahydrocannbinol, cannabidiol, and cannabinol. The review also discusses practical considerations for clinicians regarding cannabinoid formulations, routes of administration, respiratory concerns, dosing, potential side effects, drug interactions, and effects relevant to driving, tolerance, and withdrawal. Although current interest in, and uptake of, medicinal cannabis use for sleep disorders may have surpassed the evidence base, there is a strong rationale for continued investigation into the therapeutic potential of cannabinoids.

Endocannabinoids as Therapeutic Targets

Most of the drugs of abuse affect the brain by interacting with naturally expressed molecular receptors. Marihuana affects a series of receptors including cannabinoid receptor 1 (CB1R) and CB2R, among others. Endogenous molecules with cannabinoid activity interact with these receptors naturally. Receptors, ligands, synthesizing and degrading enzymes, as well as transporters, have been described. This endocannabinoid system modulates behaviors and physiological processes, i.e. food intake, the sleep-waking cycle, learning and memory, motivation, and pain perception, among others. The rather broad distribution of endocannabinoids in the brain explains the different effects marihuana induces in its users. However, this very same anatomical and physiological distribution makes this system a useful target for therapeutic endeavors. In this review, we briefly discuss the potential of small molecules that target the endocannabinoids as therapeutic tools to improve behaviors and treat illnesses. We believe that under medical supervision, endocannabinoid targets offer new advantages for patients for controlling multiple medical disorders.

Marijuana and Its Effects on Athletic Performance: A Systematic Review

OBJECTIVE

To determine the effects of marijuana on athletic performance.

DESIGN

We searched MEDLINE, EMBASE, CINAHL, PsycINFO, AMED, and SPORTDiscus from their beginning to September 2016. Study quality was assessed using the Cochrane collaboration tool for assessing risk of bias and the Cochrane GRADE scale. No meta-analyses were performed for this review.

SETTING

Subjects in a track, gym, or recreational ward.

PARTICIPANTS

Any primary study which included male and female adults of any athletic background between ages 18 and 65, with no other comorbid conditions.

INTERVENTIONS

Any primary study which used marijuana cigarettes and included a control group.

MAIN OUTCOME MEASURES

Vital signs, pulmonary measures, physical work capacity, grip strength, and exercise duration were determined to be relevant outcomes.

RESULTS

Three trials examined marijuana and its effects on athletic performance. Two trials had a high risk of bias and 1 trial had an unclear risk of bias. The effect of marijuana on outcomes including heart rate, blood pressure, and exercise duration remains unclear. Low quality evidence suggests that treatment, sham, and inactive control groups do not have a significant difference for grip strength. Low quality evidence suggests that there is an ergogenic effect of treatment demonstrated by increased bronchodilation and FEV1 compared with inactive control and that there is an ergolytic effect of treatment demonstrated by decreased physical work capacity compared with sham and inactive control groups.

CONCLUSION

Because the number and quality of studies was low, the effects of marijuana on athletic performance remain unclear.

Effects of smoked marijuana on food intake and body weight of humans living in a residential laboratory

Six adult male research volunteers, in two groups of three subjects each, lived in a residential laboratory for 13 days. All contact with the experimenter was through a networked computer system and subjects' behaviors, including food intake, were continuously recorded. During the first part of the day, subjects remained in continuously recorded. During the first part of the day, subjects remained in their private rooms doing planned work activities, and during the remainder of the day, they were allowed to socialize. Two cigarettes containing active marijuana (2.3% delta 9 THC) or placebo were smoked during both the private work period and the period of access to social activities. Smoked active marijuana significantly increased total daily caloric intake by 40%. Increased food intake was evident during both private and social periods. The increase in caloric intake was due to an increased consumption of snack foods as a consequence of an increase in the number of snacking occasions. There was no significant change in caloric consumption during meals. The principal increase within the category of snack foods was in the intake of sweet solid items, e.g., candy bars, compared to sweet fluid, e.g., soda, or savory solid items, e.g., potato chips. Increases in body weight during periods of active marijuana smoking were greater than predicted by caloric intake alone.

Behavioral effects of hashish in mice. I. Social interactions and nest-building behavior of males

The acute and subchronic effects of hashish extract (20 mg delta 9-THC/kg) on the behavior of male mice encountering a control partner was studied by ethological methods. A single administration of the extract resulted in general sedation, suppressing all the individual and social activities with the exception of some submissive elements. The locomotive and the overall activity of drugged males was drastically reduced and immobility occurred frequently. After four applications, tolerance to the sedative effects had developed and behavioral drug effects were recognizable. Drugged males showed an increase in nonsocial activities as well as in submissive behavior and flight, whereas social investigation was less frequent. Sexual and aggressive behavior was not significantly affected by the drug and immobility no longer occurred. In spite of behavioral changes after a single or repeated drug treatment, drugged males became dominant in about half the experiments. The nest-building behavior of males was disturbed in the same way after one or four drug applications. Drugged males generally refrained from carrying and working up the nesting material. The acute behavioral effects of hashish extract are compared to those described in previous papers and the difference between acute and subchronic drug effects is discussed.