This article was originally featured on Triathlete. 

Weed, marijuana, pot—whatever you call it, cannabis is a hot topic in the endurance community. Some steer clear completely, considering cannabis to be a performance-enhancing (or illegal recreational) drug. Some athletes swear by it for a variety of uses, from helping the time fly by on long runs to relieving aches and pains after a hard race. Some use it to stay alert and focused, and others use it to sleep. And almost always, the near-evangelical proponents of training with cannabis take great pains to point out that it’s “all natural,” implying that it’s without risk.

But is it really? Proponents say that cannabis has helped a lot of people with various ailments, but it is also woefully under-researched in endurance sport applications. Though an increasing number of state and federal governments have passed laws allowing cannabis for medical and/or recreational use within their borders, THC, the psychoactive component of cannabis, is still listed as a Schedule I substance under the U.S. Controlled Substances Act. In other words, cannabis is in the same category as heroin or LSD in the eyes of the federal government, making it nearly impossible for researchers to legally conduct quality research on human subjects. The passing of the 2018 Farm Bill legalized hemp, which is defined as cannabis with <0.3% THC, which means that CBD, another component of the cannabis plant, is legal federally. Unlike THC, CBD is not psychoactive, and is being studied in clinical trials throughout the country.

RELATED: Runner’s High: Can Cannabis Help Runners?

Adding to the complications of cannabis are the widely varying legalities of the substance from state to state. Some states allow cannabis to be sold legally for medical purposes, others allow it for recreational use, and some ban it altogether. The water becomes even murkier when it comes to using cannabis for training: The World Anti-Doping Agency has banned the use of cannabis in-competition. Also, most places have age restrictions on its purchase, and laws about what you can and cannot do while under the influence.

If the topic sounds messy, that’s because it is. But there are some who are trying to cut through the red tape and complexities in an effort to get answers about training with cannabis. Olympian and Ironman 70.3 World Champion Joanna Zeiger is one of them. As the CEO of the Canna Research Foundation, Zeiger has leveraged her PhD in epidemiology into a post-triathlon career studying the use of cannabis in endurance sport. She is joined by Dr. Jordan Tishler, faculty at Harvard Medical School, president of the Association of Cannabinoid Specialists, and CEO/CMO at inhaleMD, a patient-focused clinical practice for cannabis therapeutics. Though the information in this article should not be taken as medical advice, this primer can help athletes better understand what cannabis is, how it works (and doesn’t work), and arm them with the knowledge to make their own decisions about taking a trip to their local dispensary.

How cannabis works in the body

The human body is equipped with something called the endocannabinoid system—a network of receptors in the central and peripheral nervous systems that controls functions like sleep, temperature control, inflammatory responses, and food intake. There are two types of receptors in the endocannabinoid system:

• CB1 Receptors – Found primarily in the brain and central nervous system, regulate learning, memory, pain perception, and appetite.
• CB2 Receptors – Found in peripheral cells, serve as a “traffic cop” of sorts for information flowing to and from the bones, muscles, skin, cardiovascular system, and immune system, among others, to maintain homeostasis in the body. For example, if the body falls out of the normal temperature range, CB2 receptors help it return to optimal range.

The molecules that stimulate these receptors, called endocannabinoids, are produced naturally by the body (“endo” is short for “endogenous”) every single day. This usually takes place through exercise; if you’ve experienced a “runner’s high,” that’s your endocannabinoid system at work (not endorphins, as was once believed). The endocannabinoid system can also be stimulated by eating chocolate, drinking green tea, or being exposed to the cold.

The CB1 and CB2 receptors can also be turned on by exogenous cannabinoids, or sources outside the body. To distinguish these from endocannabinoids, exogenous cannabinoids are referred to as phytocannabinoids. These phytocannabinoids are delivered through the use of products derived from certain plants under the Cannabaceae family—specifically, those that fall under the Cannabis genus. Though an exact number is unknown, some experts suggest there are over 700 strains of the cannabis plant, each with their own makeup of phytocannabinoids that mimic endocannabinoids in the way that they interact with receptors.

“Cannabis is a plant, so it contains many different chemicals that all work in different ways,” Tishler said. “Our understanding of which chemicals are important and what they do is just beginning.”

Cannabinoids and their effects

The main difference between endocannabinoids and phytocannabinoids is that phytocannabinoids are often more potent than what the body naturally produces. This can cause much stronger effects than a natural runner’s high, especially at high doses.

“The most abundant cannabinoid from the cannabis plant is THC [tetrahydrocannabinol], which can make you feel impaired,” Zeiger said. “CBD [cannabidiol] is another cannabinoid that seems to have some medicinal purposes, but does not make you impaired. And then there are many other cannabinoids with varying effects we don’t yet understand. Plus, the plant has terpenes and flavonoids that may contribute to some of the benefits that people who use cannabis experience.”

THC

Cannabis plants contain varying levels of THC, the psychoactive compound that produces the “high” sensation. In the United States, a cannabis plant that contains more than 0.3 percent delta-9-tetrahydrocannabinol, more commonly known as THC, is illegal under federal law. Some states and federal governments have laws legalizing medical and/or recreational use.

THC is molecularly similar to naturally-produced endocannabinoids, but with a more potent punch. When THC is introduced to the body, it binds with both the CB1 and CB2 receptors, flooding the endocannabinoid system to the point where it overrides normal neural function. This is where the “high” comes in – cannabis-induced feelings of euphoria, fascination, intense focus or high energy (or, on the other end of the spectrum, anxiety and panic) are the result of THC overriding the regularly-scheduled programming of the naturally-occuring endocannabinoid system. By binding to CB1 and CB2 receptors in the brain and body, THC causes certain executive functions to relax and others to rev up. As the amount of THC increases in the body, muscles become less tense and short-term memory more impaired, while the heart may beat faster or hunger signals in the body light up for the onset of the most infamous side effect of cannabis: a ravenous hunger colloquially known as “the munchies.” Because of this, THC has been instrumental in aiding medical patients, such as those fighting cancer, who rely on THC for appetite, pain control, reducing spasticity, and sleep.

Because of the potent effects of THC, WADA has an in-competition ban on THC, saying athletes under the influence could “potentially endanger themselves and others because of increased risk taking, slower reaction times and poor executive function or decision making,” which are vitally important during, say, the late stages of an ultramarathon. WADA also believes cannabis violates the spirit of sport, saying the drug “can be performance enhancing for some athletes and sports disciplines.” In sports like ultrarunning, for example, THC can numb pain, alleviate fatigue, or decrease nausea – ailments that historically have been part and parcel of ultra-distance racing, where the person who suffers best wins.

The ban on THC is in-competition only, which means technically athletes can use cannabis out of competition. But that doesn’t exactly mean you can light up a joint to deal with pre-race nerves. Even though under WADA rules THC is considered a threshold drug, meaning it is allowed in your system up to a certain level, THC can stay in the body for weeks. In other words, an athlete who uses cannabis leading up to the race, but abstains during a competition, can still test positive in a urine test collected on race day. The amount of THC an athlete needs to consume to reach the threshold is unknown because the metabolism of THC varies greatly from person to person, meaning the clearance time from their system cannot be specifically defined.

CBD

Cannabis plants that contain 0.3% THC or less are classified as hemp, a legal plant used for nutrition and textile applications. These plants are also usually the source of products marketed as CBD supplements, which is legal under federal law and for in-competition use during races, because it does not have psychoactive effects.

CBD has a more roundabout way of impacting the brain and body than its THC counterpart. Instead of a perfect, direct bind with CB1 and CB2 receptors, CBD stimulates the endocannabinoid system to produce its own natural cannabinoids with its own loose bind to the CB receptors. It can also enhance or inhibit how a receptor transmits a signal, yielding a more-optimized system for regulating mood, sleep, or pain relief. When CBD is combined with THC, the intoxicating effects of THC are often lessened. CBD has been shown to help with seizure disorders, anxiety, and symptoms of inflammatory bowel disease.

Because CBD is not intoxicating, products containing CBD are federally legal as long as they don’t contain more than 0.3% THC. CBD is also the only cannabinoid exempt from the WADA ban on cannabinoids in-competition and does not show up on the drug screen administered for in-competition drug testing.

RELATED: Is CBD Trail Running’s Wonder Drug?

CBN, THC-V, and other cannabinoids

Though THC and CBD are the two most common cannabinoids found in the cannabis plant, they’re not the only ones. To date, 120 distinct phytocannabinoids have been identified in the cannabis plant, with more being discovered every year and hyped as the next big thing in cannabis dispensaries.

But identification and understanding are not the same thing, warned Tishler: “There are a raft of other chemicals – CBN, THCV, CBC, CBG, Delta-8-THC – that are available from the plant material, but that we know very little about. Any products containing these should be viewed with great suspicion and generally avoided until better safety and efficacy data are found.”

Delta-8 THC is a particular cannabinoid that has recently received a lot of attention because of its growing use in states where THC is not legal. This synthetic cannabinoid, made by a chemical conversion of CBD from the hemp plant, can have psychoactive effects, though it’s thought to be less potent than Delta-9 (what is typically referred to as THC). Because of a loophole in the 2018 Farm Bill, which specifies Delta-9 THC limits for legality and not Delta-8, some argue that Delta 8 is federally legal. However, more states are cracking down on Delta-8, and it’s recommended a customer checks their own state’s laws on Delta-8 before purchasing such a product. As for advice for athletes using such products? It’s hard to say – even less research exists on Delta-8 than Delta-9.

These cannabinoids all fall under the WADA blanket ban on cannabinoids, with CBD being the only exception.

The best cannabis strain for exercise isn’t what you think

All of these endocannabinoids combine in various configurations, each with its own marker, or strain.

“A ‘strain’ is a made-up word in the cannabis world to mean different varieties of cannabis, which are actually called cultivars in science,” Tishler said. “This is like roses are all roses, but there are versions, or cultivars, which are red, pink, or yellow.”

“Strains are typically classified into indicas or sativas,” Zeiger said. “Historically, sativa was thought to make you more active or more alert, awake, while indica makes you more mellow, tired, sleepy.”

Many cannabis dispensaries still use the indica-sativa classification system as a shortcut with customers, knowing that someone looking for an indica is likely looking for a certain type of experience. But most strains today don’t fit neatly into the either-or classification; instead, they’re what’s known as “hybrid” strains.

“Because of crossbreeding and how things have changed over the years, there’s less and less distinction between the sativa and indica,” Zeiger said.

What’s more, even the specific strain itself may not carry as much meaning as one might assume. “It turns out that strains have no predictable differences, and that all the marketing around different strains is hype,” Tishler added.

So if strain doesn’t matter, what does? When shopping for cannabis products to use during a long run or gym workout—more on that below—Tishler suggests ignoring the buzzwords and clever strain names and instead focusing on the factors that actually matter.

“What is important to outcomes is method of use, dose, timing, and frequency of use,” Tishler advised. “This is where athletes and others should focus their attention.”

Uses, benefits, and side effects of training with cannabis

In a 2019 study of 1,161 athletes – mostly triathletes, runners, and cyclists – 26 percent indicated they had used cannabis in some form in the past two weeks, be it a CBD-only product or one containing THC. The effects they reported from cannabis use included:

• Increased energy
• Improved athletic performance
• Less pain
• Fewer muscle spasms
• Decreased nausea
• Help with sleep
• Calming nerves and anxiety

In another study of 600 cannabis users living in states where cannabis is legal, four out of five respondents said they use marijuana right before or after exercising. The majority of those studied reported cannabis:

• Enhanced exercise performance
• Increased enjoyment during exercised
• Increased motivation to exercise
• Improved recovery

With that said, to date, there’s no conclusive evidence that has found a causal link between cannabis use and any health or performance benefit in endurance athletes. Most of what we know for sure about cannabis comes from studies done in medical settings, such as decreasing nausea in cancer patients undergoing chemotherapy, but even that should not be extrapolated to athletes, as cancer treatment and a race are not even close to being the same physiological or psychological experience.

Though anecdotal evidence is exciting, it shouldn’t be a substitute for rigorous scientific investigation. This can help us ascertain what’s true and what’s a placebo effect. For example, Tishler notes that despite what many people believe, cannabis is not an anti-inflammatory drug.

“THC is a pain reliever. There is no human evidence that it is an anti-inflammatory,” Tishler said. “Similarly, CBD has no human data to support use as either a pain reliever or an anti-inflammatory. More data to come.”

Side effects

In that same study of endurance athletes, subjects noted side effects of cannabis use, which included:

• Cardiovascular effects (wheezing, coughing itchy eyes, nasal symptoms)
• Anxiety, paranoia, feeling uneasy
• Difficulty concentrating
• Worse athletic performance
• Increased appetite
• Vomiting (also known as cannabinoid hyperemesis syndrome)

In medical settings, side effects of drugs are common, and cannabis is no different. Just like a patient needs to find the right formulation and dosage of a new anti-anxiety medication, so too might there be a period of trial and error with cannabis. “All medications have side effects,” Tishler warned. “As a physician, I’m used to managing and minimizing side effects for my patients.

Though addiction is more common in drugs like alcohol or cocaine, it’s possible to get hooked on cannabis. Cannabis use disorder (CUD), a term describing the continued use of cannabis despite impairment in psychological, physical, or social functioning, may affect up to 30% of users, according to the Centers for Disease Control. In studies, the likelihood of CUD was found to increase with high-dosage and high-frequency use.

The entourage effect

In choosing the best cannabis product for your athletic ambitions, consider the makeup of cannabinoids present and your overall goals. A CBD-only product is likely a good place to start, since it is both federally legal and acceptable under WADA rules.

If that CBD-only product doesn’t work for you, however, it might be that your unique endocannabinoid system doesn’t respond to that particular formulation. In order to feel the effects of the CBD, you might need to pair it with a little THC. This is what is known in cannabis research as the “entourage effect,” a fancy way of saying that all the cannabinoids seem to perform at their best when they’re in synergy with each other. If CBD is Captain America, then THC is Iron Man – they can each do a fine job solo, but when the Avengers assemble, they can do a whole lot more.

“The entourage effect basically means that you’re getting the benefit of the whole plant, and not just one part of the plant itself. So when you buy something like a CBD isolate, it means all you’re getting is CBD, and you’re not getting other parts of the plant that may provide some medical purpose to alleviate some kind of symptom that the person is trying to treat,” Zeiger said.

An athlete’s guide to choosing the best cannabis for workouts & recovery

There is no one-size-fits-all approach when making recommendations for the best weed gummies for running, or the best marijuana to help you with post-workout soreness. That’s because every single person reacts to cannabis in a different way. Each person is going to store cannabis differently, and each person’s going to metabolize it differently. Two people can consume the exact same dose and strain, with one going for a run while the other takes a nap. It’s not completely understood why this is, but Zeiger says it’s not out of the ordinary:

“It’s no different than ibuprofen. Some people need 200 milligrams to feel better; for somebody else, 200 milligrams is nothing and they need 600 milligrams. So we see this with other medications, not just with cannabis.”

Because of this, choosing the right cannabis product is a matter of careful, slow experimentation, noting what works for you as an individual and what doesn’t. The mantra in the cannabis world is “Start low, go slow,” meaning start at a low dose and titrate up to the dose that works for you very slowly. (More on dosing below.)

How to buy cannabis for athletes

It’s important to preface this section with a reminder that as of this writing, cannabis is only legal for adult use in 19 states and for medical use in 36 states. Check your state’s laws regarding cannabis before proceeding. (CBD-only products are federally legal, but some states only allow the sale of CBD for specific medical purposes; again, check your state’s laws.)

In states where cannabis is legal only for medical use, users will have to follow state laws for obtaining a special license typically known as a “medical marijuana card.” The process of approval for this card varies from state to state, but usually entails a letter from a health care provider who can certify patients for medical marijuana, a hefty fee, and enrolling as part of a statewide registry of medical marijuana users. From there, cardholders can visit licensed dispensaries to purchase cannabis products. Even in states where recreational adult-use cannabis is allowed, obtaining a medical card can be beneficial, as the products that are available to medical patients can differ from those on offer to recreational users.

In states where recreational use is allowed, customers can visit any recreational dispensary, where they will be required to show their ID (such as a driver’s license or passport) in order to verify they are over the minimum age of 21. They may also be required to have their ID scanned and recorded into a government database before being allowed to make a purchase – this is to ensure a dispensary doesn’t sell more to an individual than the state allows in one day (this maximum number varies from state to state).

Inside the dispensary, you will be assigned to a salesperson – sometimes known as a “budtender” – who can listen to what outcomes you’re looking for and make recommendations based on your goals, history of cannabis use (or lack thereof), and personal preferences. But don’t mistake their recommendations for prescriptions or medical advice: Most people who work at a dispensary are not medical professionals, the same way a bartender is not a licensed therapist.

“Generally, don’t listen to the advice of the sales clerk at the dispensary and be wary of articles that promote cannabis or cannabinoids as a self-medication,” said Tishler, who advises users to “get your advice from physicians who spend their lives working with these substances.” For athletes looking for a medically-informed approach to cannabis use, the Association of Cannabinoid Specialists is a good place to start their search for a healthcare provider. An appointment with such a provider is no different than any other standard healthcare appointment – the only difference is that your doctor’s prescription will be filled at a dispensary, rather than a pharmacy.

Method of use

Cannabis products, whether they contain THC, CBD, or both, can be consumed in many forms. When choosing the best method for using cannabis during training, it’s best to consider your goals:

Dose

Again, it cannot be overstated that the most important rule for new cannabis users is “Start low and go slow.” Most new users find edibles to be the best way to control the dosage of their cannabis, as inhalation and topicals are not typically portioned out in metered “doses” with set amounts of THC and CBD. However, edibles can take much longer to provide an effect than inhalation methods, which work almost immediately. If you are using an edible product, it can take 30 minutes or longer to feel the effects. It is easy to take too high a dose of edibles if you are expecting an immediate effect, so wait at least 60 minutes before taking another dose.

In 2021, a global team of experts on cannabis developed a dosing protocol for introducing CBD and THC to the body. The recommendations are as follows:

What CBD dose should I take?

Start with 5 mg CBD twice daily, titrating by 10 mg every 2 to 3 days until the patient reaches their desired outcome, or up to 40 mg/day. If relief is not found at 40 mg/day, consider adding THC.

What THC dose should I take?

Start with 2.5 milligrams per day, and you increase 2.5 milligrams every two to seven days until desired outcome or a maximum dose of 40 milligrams per day of THC is reached.

So how much cannabis should an athlete take for a workout? The lowest dose possible to get the effect you’re looking for, said Zeiger.

“Don’t take so much that you’re so impaired that you’re going to fall, or you’re not going to be aware of your surroundings. You want to take ‘just enough’ – if you’re having pain, or you’re taking it for anxiety, or for workout enjoyment, you really want to take the lowest possible dose to give you the benefit that you’re looking for. You don’t want to go into a workout severely impaired.”

It’s also important to note that it’s illegal and punishable in all 50 states to drive under the influence of THC, just like it’s illegal to drive a vehicle under the influence of alcohol. If you eat a gummy before a run on your favorite trail, but drive home from the trailhead while the THC is still in your system, that could end in arrest, fines, or even jail time.

Timing

Athletes should time their cannabis ingestion to coincide with when they want to experience peak effects. Cannabis use is not a cannon shot, with effects felt immediately and felt with the same intensity until the it leaves your system. Rather, it’s shaped like a bell curve, with onset of effects beginning gradually, growing into a peak, and then tapering off gradually. This can vary from person to person, but in general, the timeline for each method is as follows:

Frequency of use

Most athletes who use cannabis do so on an as-needed basis: to treat muscle soreness the day after a race, or if they know they typically have trouble sleeping after a hard workout. Some experts recommend people who use cannabis space out their doses to avoid the risk of dependence or cannabis use disorder. Sporadic dosing (spaced out at least every 48-72 hours) can also keep one’s tolerance down, allowing the body to remain sensitive to the effects of cannabis instead of requiring a higher dose to achieve the desired effect.

Some people who experience chronic issues may use cannabis daily in “microdoses,” or low doses metered throughout the day. However, it’s recommended daily cannabis consumption only be used as a part of (not in lieu of) a comprehensive treatment plan with a medical health professional; when possible the ultimate goal should be treating any underlying causes of pain, anxiety, or insomnia, not simply masking the symptoms with cannabis.

How to start exercising with cannabis

So you’ve bought the pot gummies for your run – now what? Though it may be tempting to just jump right in, it’s best to gradually ease into training with cannabis, following a few dos and don’ts from the experts.

DO check with your doctor or pharmacist to ensure any medications you are taking will not react with cannabis products. A 2020 advisory paper published in the Canadian Medical Association Journal warns CBD and THC can interfere with many common over-the-counter and prescription medications, including Claritin and Warfarin.

DO follow the package instructions. Some products, especially edibles, need to be portioned into servings. One cannabis-infused chocolate bar or cookie for example, may have up to 20 servings. Eat the smallest serving possible – remember, you can always take more, but you can’t undo taking too much.

DON’T draw conclusions too quickly. “The onset of action with an edible can take 45 minutes to 60 minutes, and people often forget that,” Zeiger said. “So they will take an edible and 15 minutes later assume it’s not working, then they take more, and assume it’s still not working, so they take more – and all of a sudden, they’re way too high. So if you are going to use edibles, please wait 45 to 60 minutes before you decide to take more.”

DO conduct your testing safely at home, but recognize that you’re putting yourself at risk any time you’re potentially impaired and lifting heavy things or using moving objects. “I would never recommend trying THC for the first time and then try to do anything else,” Tishler said, “I would try it in the safety and calm of your home to learn what to expect. Only after you feel you have a handle on the experience and the optimal dose would I then try to exercise.” For your first workout sessions under the influence of cannabis, do a strength workout, run on a treadmill, or ride on your indoor trainer, but know there are still inherent dangers even with those activities. Once you know how you respond to cannabis and you’ve locked in your lowest possible dose to get the effect you need (while remaining aware of your surroundings), then head outside if you wish.

DON’T ever drive, ride your bike on the street, or explore new routes and trails while under the influence. You may feel like you’re fine, but remember – impaired judgment, delayed reaction time, and lack of coordination are common effects of cannabis, even at low doses. DUI laws apply to cannabis just as they do alcohol, in all 50 states.

DO hydrate as needed. “Dry mouth is common with cannabis use, and does not mean you’re dehydrated,” Tishler said. “You should hydrate as you would for the exercise, but only sips are needed for the actual dry mouth.”

DO have a healthy post-workout snack at the ready. Both CBD and THC have been found to increase appetite, so your post-run hunger might be particularly intense by the time you get home.

DON’T have unrealistic expectations. Though many like to tout cannabis as a miracle drug, there isn’t always enough (or any) research to back up these claims. Every athlete who chooses to use cannabis is a science experiment of one. Cannabis is not a substitute for bad habits, like lack of sleep or a poor diet. Cannabis should be used as part of a multi-modal approach to health and wellness.

DO abstain from cannabis before your competition with ample time to allow it to clear from your body. (For more on this, see the FAQs below.)

DO know that by using cannabis, you could potentially be breaking either laws or the rules of your sport. Whether or not you believe these laws and rules are justified, they’re still in place, and if you’re caught breaking the rules, you’ll still have to face the consequences.