The Effect of Cannabis on Fitness

What influence does weed from the cannabis plant have on your fitness performance, such as muscle strength and muscle mass? What does it do, for example, to testosterone, cortisol and growth hormone?

Weed in fitness

Often a question in the gym is the reason to write an article. A while ago, for example, I was asked about the influence of cannabis use on building muscle mass. Besides this question, it also seemed useful to me to discuss what influence the even more popular recreational substance alcohol has on muscle growth. Finally, I will also discuss the influence of sex on muscle growth so we can cover all the pleasures at once. In this first part I cover cannabis.

Cannabis: ergolytic or ergogenic?

Cannabis, marijuana, weed, jonko, wierie, ganja, etc. is, funnily enough, on the list of substances prohibited by WADA (World Anti-Doping Agency) and the IOC [1]. I say "funnily" because the substances on this list normally enhance performance and are therefore not allowed as doping. Cannabis, however, tends to reduce performance rather than improve it.

It is not for nothing that in the States you often see employees being checked by their employer for drug use, including cannabis use, because it would lower productivity and, through poorer motor skills and concentration, could lead to unsafe situations. Convenient for African Americans, because apparently in states where there is no testing, they are less likely to get hired because of the assumption that they use drugs [2].

In this respect, it is therefore an 'ergolytic' substance, meaning that it worsens performance, and not an ergogenic, performance-enhancing one. The only benefits mentioned from a sporting perspective are the extent to which it can lead to relaxation and can provide a better night's sleep (sleep promotes muscle growth). However, research has never shown whether and to what extent this would improve athletic performance.

Still, on the list of athletes suspended for doping use, you will find several athletes who were suspended for months to years because a metabolite (a substance into which another substance can change) of THC, the active substance, was found in their blood [3]. Not because this would improve performance, but simply because it is on the list of illegal substances. It is therefore mainly prohibited because it would be contrary to "the spirit of sport". Personally, I think that is nonsense.

Am I not allowed to decide for myself whether I smoke a joint to relax instead of drinking a beer if neither unfairly improves my performance compared with others? I would not be allowed to calmly light up a spliff and chill on the couch because this can still be found in my blood months later, but I can celebrate my participation in an Olympic tournament on a boat while completely drunk and cause half a million euros in damage [4]? Okay, of course the German hockey team is blamed for the damage, but the IOC has no problem with drinking itself. As long as you do not have an unfair advantage over other athletes, drug use, just like alcohol use, seems to me to be a personal choice.

Smoking weed and muscles

But anyway, weed and muscles. When you talk about the influence of cannabis on the human body, you have to distinguish a few things. First, the active component THC (delta-9-tetrahydrocannabinol) from the other components of cannabis (about 460 in total, of which 60 are cannabinoids).

In addition, you have to distinguish between smoking marijuana and eating or drinking it. This is because of the difference in bioavailability. Of smoked cannabis, a maximum of 50% of the THC ultimately reaches the bloodstream, while for orally ingested THC this is a maximum of 20% [5,6,7]. And when you look at the effects of smoking, you also have to take into account the effects of the tobacco with which it is mixed when it is not smoked pure. I will discuss these latter effects later in an article about the influence of cigarettes on muscle growth. Here I will mainly look at the influence of THC.

THC and testosterone

There are many different opinions about the effect of THC on testosterone. In some studies you read as a result that it has no influence, while other studies show a drop of as much as 65% in testosterone levels after administration of THC.

Before I go into this, I first want to mention two studies that indicate that testosterone, because of THC, at least cannot do its job properly. In 1975, researchers already saw that muscle growth in rats caused by administration of testosterone did not occur when they were also given THC [9].

Cannabis extract administration in combination with testosterone propionate (TP) inhibited growth stimulation produced by TP alone. Anti-androgenic nature of the compound is suggested.

P.V. Dixit

Later research from 1980 found a cause for this in the fact that THC and cannabinol (another component of cannabis) bind to the cell receptors for testosterone [10]. As a result, testosterone can no longer do its work in the cells. In fact, breakdown products of THC (metabolites) are said to have an antagonistic effect on these receptors.

In addition, other metabolites of Δ⁹-THC were also androgen antagonists. This data suggests that the anti-androgenic effects associated with marihuana use result, at least in part, from inhibition of androgen action at the receptor level.

V. Purohit -Walter Reed Army Medical Center

One explanation for this difference is that in some cases researchers look at the acute influence, meaning directly after intake, while in other studies they looked at the effects of long-term use and therefore did not necessarily look at testosterone levels directly after intake. For example, in a study by the University of Freiburg in Germany, the testosterone levels of 66 Pakistani men who smoked or drank marijuana for a long time and daily were compared with those of a control group of 41 men who did not use cannabis [9]. They found no difference in testosterone. American researchers came to the same conclusion when they looked at the testosterone levels of 12 "casual users" and 15 "heavy users" before, during and after use over a period of 21 days [mendelson]. They found no differences.

No statistically significant changes in plasma testosterone levels were observed during and after the smoking period as compared with the pre-smoking base-line levels.

J.H.. Mendelson, Harvard

Good news, then, for the guys with a loyalty card for the coffee shop. Yet another study from 1983 showed that smoking 1 joint can lower testosterone in men for up to 24 hours. A study from 1984 showed not only a decrease in testosterone, but also in prolactin and growth hormone. These conclusions were contradicted again, however, by a 1989 study among 17 young men that showed no reduction in testosterone.

Another study looked at what happens immediately after administration in rats [11]. Here the researchers saw a 65% decrease that lasted one hour. The same researchers could not see clear effects with chronic use. They took into account the possibility that this was due to habituation to the substance. It is therefore unfortunate that, in the case of the German study among Pakistani users, it is unclear within what time frame after the last use testosterone was measured. It would be very interesting to know whether in their case testosterone levels also drop so much within an hour after use, or whether this does not happen, or happens to a lesser extent, because of habituation.

In general, what stands out is that it is mainly animal studies that show a drop in testosterone, while this has not been shown, or has been shown less clearly, in humans, and that there is often a difference between acute effects and effects of chronic use. This does not make things any clearer. I have now mentioned only a few of the studies. If you were to throw all the studies onto one pile, the most common conclusion would be that the influence of THC on humans is not significant, certainly not in chronic users. Based on the above, however, it is advisable not to smoke a joint shortly before training.

THC and growth hormone

Growth hormone (Human Growth Hormone, HGH or GH) stimulates growth and therefore also muscle growth and the release of growth factors (which also stimulate growth). Growth hormone is produced in the anterior pituitary gland (adenohypophysis). It is stimulated by Growth hormone releasing hormone (GHRH) and inhibited by somatostatin. More GHRH therefore means more growth hormone, while more somatostatin causes a decrease in growth hormone. Research into the direct effect of THC on growth hormone in rats has shown that the amount of growth hormone decreases because THC stimulates the production of somatostatin. It is a pity that the chronic effects in humans have not yet been studied, because there can clearly be differences between research into acute use and chronic use, and between animals and humans, when it comes to the influence of THC.

THC and increased conversion of testosterone into estradiol

Here too there is no clear answer. The reason it has often been assumed that THC causes the male hormone testosterone to be converted into the female hormone estradiol is partly due to cases of gynecomastia ("bitch tits", female breast formation in men) among cannabis users. Gynecomastia is often caused by high levels of estradiol that lead to tumor formation in the breast. A very small study among three men with gynecomastia, however, showed that in these cases the testosterone levels, estradiol levels and the ratio between them were normal [12]. There was therefore no (increased) aromatization, the conversion of testosterone into estradiol. There are even studies showing that THC lowers conversion into estradiol. This does not automatically mean that cannabis use cannot lead to gynecomastia. The structure of the THC molecule is very similar to that of estradiol, so the possibility is considered that it is THC itself that can cause gynecomastia. In practice, however, known cases of gynecomastia caused by cannabis use are hardly seen.

Cannabis and cortisol

Another reason that is put forward for bodybuilders not to use cannabis is its catabolic effect. Catabolic means that it converts nutrients from tissue, both from muscle and fat, into glucose in order to provide energy. As a bodybuilder, you want to create an anabolic process in which you supply your body with nutrients with which you can build tissue. An important driver of the catabolic process is the "stress hormone" cortisol, which sends a signal to break down fat and proteins and convert them into glucose. The aforementioned 1989 study is interesting here too, because it showed that not only testosterone, but also the amount of cortisol remained unchanged. This would therefore not contribute to muscle breakdown. Here too, however, there is no clear answer. A 1986 study showed an acute rise in cortisol [13]. This difference, however, was again not seen with chronic use in another 1989 study [14].

Psychological effects of cannabis on training and nutrition

Building muscle mass is a matter of nutrition, training and rest. While many people use cannabis for better rest, its influence on training and nutrition can be negative. Especially irregular users, for example, experience "the munchies" after using cannabis. Unfortunately, for most people this does not mean they start cooking pasta with fish and broccoli or throw back a protein shake, but more often that they attack the candy and cookie jar for fast, simple sugars that usually do not fit the diet in that amount and at that moment. In fact, eating all those sweets can come at the expense of the good food for which you no longer have an appetite later. This food craving is probably caused by the influence of THC on the hypothalamus, the part of the limbic system of the brain that regulates hunger, among other things. Regular users often no longer experience the feeling of "getting high" at all, let alone still get the munchies. About the effect of the munchies (the munchies) people, you guessed it, do not always agree either. There are studies showing that total calorie intake is increased by this, while other studies actually see a decrease.

As far as training is concerned, the drowsy feeling after smoking a joint can make you completely unmotivated to train at full intensity. This so-called "amotivational syndrome", however, also mainly occurs in people who do not use cannabis often. Studies among chronic "heavy users" in Costa Rica and Jamaica did not show this amotivational syndrome [15].

How you react to cannabis differs from person to person and can change over time. In addition, THC can amplify your state of mind. If you are completely ready to train hard in the gym, you may feel like it even more, while someone else thinks "nah, not right now". It is also possible that you function well this way for years and then develop a severe psychosis.

The effect of cannabis on the lungs

Perhaps not a direct influence on muscle mass, but since oxygen is one of the important suppliers of energy, it is useful if you can breathe. Apart from one point, people clearly agree that this influence is negative.

The point of discussion is the influence on the airways. One study shows that cannabis causes the airways to widen, while another study actually shows an increase in airway obstructions. There is agreement, however, about the negative influence of tar and carbon monoxide. According to research from the University of California, one joint produces 5 times as much carbon monoxide as a cigarette [16]. As a result, less oxygen is available. The same study showed that smoking cannabis produces 3 times as much tar as cigarettes. Another study indicated that one joint causes 5 to 6 times as much lung damage as one cigarette.

We conclude that smoking marijuana, regardless of tetrahydrocannabinol content, results in a substantially greater respiratory burden of carbon monoxide and tar than smoking a similar quantity of tobacco.

T.C. Wu, University of California

Finally, yet another study showed that 1 joint lowers lung capacity as much as 16 cigarettes. The fact that weed smokers inhale 40% more deeply does not help here.

Conclusion

What keeps recurring in the studies on the various effects of THC is the difference in effect between sporadic use and chronic use. In all cases, except for the influence on the lungs, the effect on chronic smokers is not significant. Put very simply, you could therefore say that the influence of THC on muscle mass is small because the effect is large (but temporary) when you use little, so on balance it does not matter much, while the effect with frequent, regular use is again small, so on balance it also has little influence.

To improve your results in the gym and in front of the mirror, you will therefore probably achieve much more by paying better attention to things such as nutrition and training than by skipping that social weekend joint or stopping use in the case of an addiction.

Still, it is of course wiser (and believe me, I am not a woolly-socks-wearing tree hugger when I say this) simply not to do it, because of the effect on the lungs but also for all the reasons I have not discussed here (influence on chromosomes, fertility, infection by fungi, etc.).

But then of course, the choice is yours

Black Sheep

References

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