The present secondary analysis of a larger study (Zeiger et al. 2019a) examined patterns of cannabis use and subjective effects to cannabis by decade in adult community-based athletes. Significant differences were observed across decades for cannabis use patterns and reported subjective effects to cannabis. Younger athletes significantly used cannabis longer, consumed more THC only and in combination with CBD for recreational and combined medical/recreational purposes than older athletes. Younger athletes endorsed more positive and adverse subjective effects items than older athletes.

The different patterns of use and subjective effects to cannabis by age group in adults are novel findings since few studies have looked at specific age related effects to cannabis. A very small study reported that young adults (n = 20, 24–28 years) reported more acute subjective effects (anxiety and less alertness) of inhaled cannabis than 20 adolescents (16–17 years) (Mokrysz et al. 2016). A cross-sectional study of adult users showed that older adults endorsed fewer positive and adverse subjective effects than younger adults, however older adults and those who used cannabis medically experienced the most acute withdrawal effects (Sexton et al. 2019). The difference in subjective effects to cannabis by age may stem from younger athletes consuming THC and THC/CBD combination more often than older athletes. An analysis of these data that explored the differences in subjective effects to cannabis by cannabinoid type suggested that athletes endorsed more positive and negative subjective effects to THC/CBD combination use (Zeiger et al. 2019c). The age related trends of subjective effects to cannabis may point to a biological difference in response to cannabis exposure in younger athletes or a willingness to use higher doses of THC via edibles or smoking, both of which can lead to a higher preponderance of positive and adverse effects which can sometimes lead to overdose (Meacham et al. 2018; Schauer et al. 2016; Monte et al. 2019). A study of medical cannabis users in California who were aged 18–72 found that younger users reported the highest quantity of use while older participants reported the fewest negative consequences related to cannabis use (Haug et al. 2017). Cohort effects of social acceptability, legal consequences, and legalization all may play a role in cannabis initiation, route of administration, and adoption of medical vs. recreation cannabis use (Haug et al. 2017). Although studies examining brain morphology have been disparate in their results, there is evidence that chronic cannabis users experience changes in brain structure and function, however it is unknown whether these changes are responsible for difference in subjective effects to cannabis by age (Lorenzetti et al. 2010; Batalla et al. 2013). Further studies need to be conducted in a larger replication sample and with clinical trials to better parse out the combined effects of THC and CBD and compare subjective and objective reactions to cannabis use by age. Reassuring of the clinical relevance of subjective effects, a recent trial found a moderate but statistically significant correlation between observed and self-reported subjective effects of intoxication between THC-only and low dose CBD in combination with THC (Solowij et al. 2019).

The use of cannabis to treat pain has been of interest. Less pain associated with cannabis use was reported from about 60 to 70% of athletes in all the age strata in the present study, highlighting that the reported positive effect of cannabis on reducing pain appears independent of age. The 69% frequency of pain relief in the present study across all ages is on the higher end of benefit reported in other studies noting an efficacy ranging from 37 to 86% for pain relief from cannabis (Ware et al. 2005; Brunt et al. 2014; Swift et al. 2005; Whiting et al. 2015).

Adverse effects were reported in this sample; however, at a lower reported rate than positive effects. Respiratory and cardiovascular adverse effects and anxiety showed the highest reporting in the younger age strata. This is possibly due to the route of administration since there was a tendency for the younger ages in this sample to smoke, vaporize, and consume edibles, while older age groups reported mostly using topicals, tinctures, and oils. Additionally, route of administration has been associated with subjective effects to cannabis use (Russell et al. 2018) and the preferred cannabinoids could also play a role in the reporting of adverse (and positive) effects (Niesink and van Laar 2013).

Our findings suggest that adult athletes are using cannabis both similarly and differently than adolescent and university athletes as well as the general population. Twenty-six percent of our overall sample reported current cannabis use, a frequency that is similar to that found in the NCAA, but lower than the overall population past-months use of 8.1% (Chawla et al. 2018). Past month use in a national sample showed lower frequencies of cannabis use across all ages than our sample of adult athletes (Chawla et al. 2018); national sample numbers ranged from 15.9% in 22–25 years old’s to 2.0% for those over 50. In our athlete sample, 33.3% of 21 to 29-year old’s consumed cannabis in the last 2 weeks, and 22.0 and 19.2% of those 50 to 59 and 60 and older used cannabis in the past 2 weeks, respectively.

The older adult athletes reported using cannabis for medical purposes with a preference for oral routes of administration, findings similar to other studies (Haug et al. 2017). Over 30% of this athlete sample reported using topical administration, a rate that is higher than reported in other studies (0.6–5%) (Russell et al. 2018). The frequency of 32.9% medical-only cannabis use was higher in this sample than the 17% reported in the National Survey on Drug Use and Health (Green et al. 2003). Cross-use of medical and recreational cannabis was observed in 38.2% of our athletes, which is lower than the 55% of medical and recreational combination use seen in a survey of 348 medical cannabis users (Zeiger et al. 2012). Furthermore, medical patients use cannabis more frequently than our athlete population, with 75% reporting using cannabis more than once per day in published studies (Zuardi et al. 2017). Studies of cannabis use indicate that past-months use is higher in males than females (Chawla et al. 2018). Our sample skewed male (62.3%), however, there were no significant differences by sex for current use.

It is challenging to put the results of the present study into the context of use in adolescent, university-based, and elite athletes. University athletes are mostly younger than the legal age for cannabis use and elite and university athletes are subjected to drug testing. However, drug testing among athletes is complicated by the fact that cannabis is a threshold drug, meaning athletes can use it out of competition up to a certain detectable blood THC level and THC is entirely banned within competition (Ware et al. 2018). The testing standards among elite athletes are different than occupational drug testing where any presence of cannabis may be grounds for discipline. Indeed, in our sample 20.5% of those who do not currently use cannabis reported they do not use it because it is not legal at their job. These complexities justify the importance of studying adult athletes apart from the traditional groups of adolescent, university, and elites.

Cannabis use concurrently with exercise was lower in this sample than the 81.7% found in a previous report, and unlike that study we did not find a difference by sex (data not shown); however, we did corroborate the finding that younger adults tended to use cannabis before and after exercise more often than older adults (YorkWilliams et al. 2019). In the previous study, the main reasons for cannabis use concurrent with exercise were enhanced performance, enjoyment, motivation, and recovery. In our study, we captured reasons for concurrent cannabis use with exercise separately for pre- and post- exercise; athletes in our study used cannabis for different reasons before exercise (improve focus, enjoyment) than after exercise (pain management, relaxation, aid in sleep). Our sample of athletes is unique in that 86.7% of participants indicated they exercise more than 5 h per week (45.9% reported ≥11 h per week), a number that exceeds the 2.66 h per week of the concurrent cannabis users in the YorkWilliams study and the daily WHO recommendation of 1 h per day (Kahlmeier et al. 2015). Concerns about cannabis mis-use and abuse in athletes maybe overstated with the potential benefits (improved sleep, decreased anxiety, less pain) outweighing the adverse effects (increased anxiety, increased appetite, difficulty concentrating).

Several limitations exist. Questionnaire based studies are always subject to misclassification errors. The internal consistency of the responses lends credibility to the participants answers. A moderate but statistically significant correlation between observed and self-reported subjective effects of intoxication between THC and low dose CBD in combination with THC in a recent trial, results which are encouraging for self-reported data collection. (Solowij et al. 2019). The study did not ask about dosing or ratios of CBD and THC in those who used both CBD and THC which limits the specificity of this combination. The generalizability of this convenience sample drawn from social media outlets is unknown, particularly due to the over-representation of Caucasians. In addition, it is not known whether the age effects observed on cannabis use in athletes will be seen in non-athletes. The study of cannabis users was of moderate size, but confirmation in larger cohorts would be informative. These analyses are exploratory and do not correct for multiple testing; the results, however will inform future analyses with data reduction techniques that will enable multivariate analysis.

The strength of this study is the online recruitment of a relatively large sample in a short amount of time. Community-based adult athletes have been infrequently studied with respect to cannabis use, patterns of use, or subjective effects to cannabis (Campian et al. 2018). Most studies of cannabis use in athletes have been mainly in adolescents, university athletes, and elite athletes (Ware et al. 2018; Buckman et al. 2011; Peretti-Watel et al. 2003a).

These analyses suggest there are age related differences in cannabis patterns of use and subjective effects to cannabis. The younger athletes compared to older athletes in this cohort reported more positive and adverse effects to cannabis, used cannabis longer, and consumed both CBD and THC for medical and recreational purposes. Future directions include examining age by cannabinoid type interactions in relation to subjective effects to cannabis.