Guest Writer: Jonny Lisano
In a recent study published in the Journal of Strength and Conditioning Research titled: “Performance and Health Related Characteristics of Male Athletes Using Marijuana” researchers in the Sport and Exercise Science Department at the University of Northern Colorado were assessing if the chronic use of marijuana products had any effects on physical performance or overall health in physically active males using marijuana.
Chronic marijuana users were defined as: using marijuana products at least once a week for at least the past 6-months. For purposes of this study, marijuana users were compared to a healthy, physically active control group that had not used any marijuana products within the past year.
The sample for the study on the effect of cannabis
Study participants were between the ages of 18-40 and had their physical performance assessed throughout multiple study visits assessing their lung function, cardiovascular fitness, power production, and strength. It is important to note that study participants were not under the influence of marijuana at the time of data collection, and were at least 12-hours removed from their last use of marijuana.
Chronic marijuana users showed no impairment in lung function, based on current health standards for either restrictive or obstructive lung disorders. When chronic users were then compared to the non-using control group it was found that there was no difference in lung function. Suggesting that chronic cannabis use has no effects on lung function.
Cardiovascular fitness is roughly defined as the body’s ability do adequately deliver oxygen to tissues, such as muscle, was measured using a state of the art metabolic cart from ParvoMedics. Both groups of subjects were found to have excellent cardiovascular fitness, well above what would be expected to be seen in the average individual. When the two groups were compared it was found that there was no difference in cardiovascular fitness between physically active individuals using marijuana and those that were not.
Muscular power and marijuana use
Muscular power production is a key component to performance in sports such as: weightlifting, football and track. It is defined as the body’s ability to produce force over time, and was measured in study participants using a standardized bike protocol. Participant peddled all out against a predetermined resistance based on their body weight for 30-seconds, and had their power output calculated. While there was no difference in power output across the 30-second bout between the user and non-user groups, it was found that chronic users did show a trend to fatigue to a greater extent over the 30-second period from initial to final power output.
Assessment of muscular strength performance was done by the university’s biomechanics lab, and was measured at the ankle, knee, and hip using a Biodex force meter. Again, it was found that there was no difference in strength performance between chronic users and non-users.
The testosterone in males and cannabis use
Researchers also collected and analyzed blood samples from participants to measure key markers of health. There have been some claims that chronic marijuana use inhibits the production of the male sex hormone testosterone. Testosterone is a key hormone in aiding in lean body mass development in both males and females. Results from this study showed that there was no difference in testosterone levels between physically active males that were chronic users or non-users. Cortisol levels in the blood were also measured. Cortisol is commonly known as a stress hormone that can cause tissue degradation if in excess concentrations in the body. The results from this study showed that there was no effect on resting cortisol levels in chronic marijuana users, and levels were within normal, expected ranges.
The overall findings on The Marijuana use
The overall findings of this study done at the University of Northern Colorado showed that there were no effects on lung function, cardiovascular performance or strength with chronic marijuana use. There was a slight trend for increased fatigue in power production in cannabis users, but no differences in overall power production as compared to a control group. Results from this study also showed that chronic cannabis use did not lower testosterone levels in physically active males, and had no effects on resting cortisol concentration. However, keep in mind that these results only apply to individuals that are chronically using, but not currently under the influence of cannabis products.
This summary was based on the article provided below:
Lisano, J.K., J.D., Mathias, A.B., Christensen M., Smoak, P., Phillips, K.T., Quinn, C.J., Stewart, L.K. (2017) Performance and Health Related Characteristics of Male Athletes Using Marijuana. Journal of Strength and Conditioning Research, E-pub.