Data supporting the physiological effects of cannabidiol (CBD) ingestion in humans are conflicting. Differences between CBD preparations and bioavailability may contribute to these discrepancies. Further, an influence of body composition on CBD bioavailability is feasible, but currently undocumented. The aims of this study were to: (1) compare the pharmacokinetics of five oral CBD preparations over 4 h; (2) examine the relationship between body composition and CBD pharmacokinetics; and, (3) explore the influence of CBD on heart rate variability. In total, five preparations of CBD, standardized to 30 mg, were orally administered to 15 healthy men and women (21–62 years) in a randomized, crossover design. Prior to and 60 min following CBD ingestion, heart rate variability was determined. Body composition was assessed using dual energy X-ray absorptiometry. Peak circulating CBD concentration, time to peak concentration, and area under the curve was superior in a preparation comprising 5% CBD concentration liquid. Fat free mass was a significant predictor (R2 = 0.365, p = 0.017) of time to peak concentration for this preparation. Several heart rate variability parameters, including peak frequency of the high frequency band, were favorably, but modestly modified following CBD ingestion. These data confirm an influence of CBD preparation and body composition on CBD bioavailability, and suggest that acute CBD ingestion may have a modest influence on autonomic regulation of heart rate.

Cannabidiol (CBD) is widely available and marketed as having therapeutic properties. Over-the-counter CBD is unregulated, many of the therapeutic claims lack scientific support, and controversy exists as to the safety of CBD-liver interaction. The study aims were to compare the pharmacokinetics of commercial CBD and CBD metabolites following the ingestion of five different CBD formulations, determine the influence of CBD on food induced thermogenesis, determine the influence of food on CBD pharmacokinetics, and determine the influence of CBD on markers of liver function. Fourteen males (body mass index ³ 25 kg/m2) were studied in a placebo-controlled, randomized, crossover design. On five occasions, different CBD formulations were ingested (one per visit). On two additional occasions, CBD or placebo was ingested following a meal. CBD servings were standardized to 30 mg. Considerable pharmacokinetic variability existed between formulations; this pharmacokinetic variability transferred to several of the metabolites. CBD did not influence food induced thermogenesis but did favorably modify early insulin and triglyceride responses. Food appreciably altered the pharmacokinetics of CBD. Finally, CBD did not evoke physiologically relevant changes in markers of liver function. Collectively, these data suggest that consumers should be aware of the appreciable pharmacokinetic differences between commercial CBD formulations, CBD is unlikely to influence the caloric cost of eating but may prove to be of some benefit to initial metabolic responses, consuming CBD with food alters the dynamics of CBD metabolism and increases systemic availability, and low-dose CBD probably does not represent a risk to normal liver function.

Sedentary obesity is associated with increased risk of many cardio-metabolic diseases, including type 2 diabetes. Weight loss is therefore a desirable goal for sedentary adults with obesity. Weight loss is also a well-documented side effect of sodium glucose co-transporter 2 (SGLT2) inhibition, a pharmaceutical strategy for diabetes treatment. We hypothesized that, compared with placebo, SGLT2 inhibition as an adjunct to out-patient dietary counselling for weight loss would lead to more favorable modification of body mass and composition, and greater improvement in glucose regulation and lipid profile. Using a randomized, double-blind, repeated measures parallel design, 50 sedentary men and women (body mass index: 33.4 ± 4.7 kg/m2; mean ± SD) were assigned to 12 weeks of dietary counselling, supplemented with daily ingestion of either a placebo or SGLT2 inhibitor (dapagliflozin: up to 10 mg/day). Dietary counselling favorably modified body mass, body fat, glucose regulation, and fasting concentrations of triglyceride and very low-density lipoprotein cholesterol (main effects of counselling: p < 0.05); SGLT2 inhibition did not influence any of these adaptations (counselling × medication interactions: p > 0.05). However, SGLT2 inhibition when combined with dietary counselling led to greater loss of fat-free mass (counselling × medication interaction: p = 0.047) and attenuated the rise in high-density lipoprotein cholesterol (counselling × medication interaction: p = 0.028). In light of these data and the health implications of decreased fat-free mass, we recommend careful consideration before implementing SGLT2 inhibition as an adjunct to dietary counselling for weight loss in sedentary adults with obesity.

The purpose of the study was to describe and compare the pharmacokinetics of five commercial edible marijuana products, determine the influence of body composition on pharmacokinetics, and, in light of epidemiology suggesting marijuana may offer diabetes protection, explore the influence of edible marijuana on glucose tolerance. Seven regular users of marijuana self-administered five edible products in a randomized crossover design; each product contained 10 mg of delta-9-tetrahydrocannabinol (THC). Thirty minutes following marijuana ingestion, participants imbibed a 75 g glucose beverage. Time-to-peak plasma THC concentration ranged between 35 and 90 min; maximal plasma THC concentration (Cmax) ranged between 3.2 and 5.5 ng/mL. Differences between products in plasma THC concentration during the first 20–30 min were detected (p = 0.019). Relations were identified between body composition and pharmacokinetic parameters for some products; however, none of these body composition characteristics were consistently related to pharmacokinetics across all five of the products. Edible marijuana had no effect on oral glucose tolerance compared with a marijuana-free control (Matsuda Index; p > 0.395). Commercially available edible marijuana products evoke different plasma THC concentrations shortly after ingestion, but do not appear to influence acute glucose regulation. These data may allow recreational marijuana users to make informed decisions pertaining to rates of edible marijuana ingestion and avoid overdose.

No abstract

In light of the many demands competing for our attention in today’s modern lifestyle, scheduling healthy behaviors, such as daily exercise, at or around the same time of day can be difficult. Accordingly, the purpose of this study was to compare the endurance benefits of short‐term sprint interval training (SIT) when SIT was completed at a constant or variable time of day. The influence of the time of day of assessment relative to the time of day of training was also examined. SIT consisted of six sessions of 4‐to‐7 x 30‐second sprints on a stationary cycle ergometer completed over two weeks. Endurance exercise performance was assessed via a laboratory‐based cycle ergometer time trial equivalent to 10‐km. Two habituation time trials were completed prior to pre‐SIT assessment. Twenty healthy adults (age: 23 ± 7 years, body mass index: 24.7 ± 3.0 kg/m2, maximal oxygen uptake: 44 ± 9 ml/kg/min (mean ± SD)) were randomly assigned to one of two training conditions: (1) Constant (6 males, 3 females), in which all training and pre/post time‐trials occurred at a fixed time of day that was not necessarily the same time for each participant; or, (2) Variable (7 males, 4 females), in which all training was scheduled such that each session never occurred within 6‐hours of the time of day of the previous session; post‐SIT time trials for the Variable group were completed at the same time of day as pre‐SIT time trials. A second post‐SIT time trial (Post2) was scheduled for all participants to occur at a time of day a minimum of 6‐hours earlier/later than the time of day of the first post‐SIT time trial. SIT improved time trial performance (main effect P=0.019) but only when the time trial did not occur at the same time of day as training (i.e. Post2); the magnitude of improvement was not influenced by whether the training was completed at a constant or variable time of day (Constant: Pre 1153 ± 173, Post 1136 ± 179, & Post2 1123 ± 154 s vs. Variable: Pre 1186 ± 159, Post 1166 ± 158, & Post2 1149 ± 130 s; group x training interaction P=0.646). SIT did not influence body mass or composition, as determined by dual energy X‐ray absorptiometry (all P>0.34). At the start of each SIT session, oral temperature was measured. The co‐efficient of variation appeared lower for the Constant compared with the Variable group (0.6 ± 0.3 vs. 1.1 ± 0.7%; P=0.099). Our preliminary data suggest that SIT improves endurance exercise performance when assessed at a variable time of day, irrespective of whether training is scheduled at a constant or variable time of day. From a public health perspective, scheduling regular exercise at or around the same time of day does not appear to be important for obtaining endurance benefits.

The purpose of the study was to describe and compare the pharmacokinetics of five commercial edible marijuana products, determine the influence of body composition on pharmacokinetics, and, in light of epidemiology suggesting marijuana may offer diabetes protection, explore the influence of edible marijuana on glucose tolerance. Seven regular users of marijuana self-administered five edible products in a randomized crossover design; each product contained 10mg of delta-9-tetrahydrocannabinol (THC). 30-minutes following marijuana ingestion, participants imbibed a 75g glucose beverage. Time-to-peak plasma THC concentration ranged between 35 and 90 minutes; maximal plasma THC concentration (Cmax) ranged between 3.2 and 5.5 ng/mL. Differences between products in plasma THC concentration during the first 20-to-30 minutes were detected (P=0.019). Relations were identified between body composition and pharmacokinetic parameters for some products; however, none of these body composition characteristics were consistently related to pharmacokinetics across all five of the products. Edible marijuana had no effect on oral glucose tolerance compared with a marijuana-free control (Matsuda Index; P&gt;0.395). Commercially available edible marijuana products evoke different plasma THC concentrations shortly after ingestion, but do not appear to influence acute glucose regulation. These data may allow marijuana users to make informed decisions pertaining to rates of edible marijuana ingestion and avoid overdose.

Purpose: There is extensive public and scientific interest in the influence of cannabis and the psychoactive cannabinoid, delta-9-tetrahydrocannabinol (THC), on exercise performance. Unfortunately, recent, up-to-date studies are lacking. The aim of the current study was to address the hypothesis that ingestion of edible marijuana, prior to exercise, would have unfavorable effects on the physiological response to exercise and on exercise performance.Methods: 17 Healthy adult male and female habitual exercisers, who were regular users of cannabis products, were screened for study participation. 10 were enrolled, and data from 9 [8 males, 1 female, aged 25±3 years, with peak oxygen uptake of 56.5±11.7 ml/kg/min (mean ± SD)] were retained. Participation included two exercise sessions, each preceded by self-administration and ingestion of either edible marijuana (containing 10 mg THC) or placebo. Cardio-respiratory responses (via indirect calorimetry) to stationary cycle ergometer exercise (8 min at 50, 100 and 150 W) were recorded before completion of a 20-min Functional Threshold Power test (FTP20) and a sprint test involving maximal effort until volitional fatigue.Results: Edible marijuana increased the concentration of circulating THC and THC metabolites, and evoked sensations of intoxication and altered psychoactive state. Cardio-respiratory responses to staged cycle ergometer exercise were normal and were unaffected by edible marijuana. Compared with placebo, edible marijuana did not influence FTP20 (Placebo 253±75 vs THC: 251±72 W (mean±SD); p &gt; 0.45) or peak power output during the sprint test (Placebo: 710±201 vs. THC: 732±136 W; p = 0.864).Conclusion: 10 mg of THC, when ingested prior to exercise by regular exercisers and habitual users of cannabis, had little effect on the physiological response to standardized cycle ergometer exercise, and was neither ergogenic nor ergolytic.