Runners have long talked about the high they get when a long workout releases enough endorphins to cause euphoria. So does it follow that they would want to get high — on cannabis — before they hit the trail?

Some athletes tout the benefits of cannabis as a performance-enhancing drug that relieves pain and inflammation and even helps restore focus. They generally fall into two camps, split over the two main compounds found in marijuana, CBD and THC. One camp says CBD handles the heavy lifting of recovery and focus and that THC’s psychotropic properties impede workouts. The other argues that THC not only brings greater clarity but also works with CBD to create a synergy among multiple cannabinoids or terpenes known as the entourage effect.

Others, including some in the medical community, caution that THC and CBD have not been adequately studied — certainly not in the United States, where cannabis remains federally banned — and that, depending on the way you take it, it could even harm you, to say nothing of your workout. Getting too high could also lead to injury if you don’t notice that you’re pushing yourself too far.

Even Matthew Hook, a cannabis activist and athlete who posts on Instagram as @runningonreefer, says he once “took an edible, got really high, and went out way too hard on a trail and blew out my knee.”

Yet Hook, a longtime Santa Cruz resident who moved to Arizona last year, still puts dried flower in a Volcano vaporizer before his runs. One day in March, a rainy morning caused his arthritis to flare up, locking his knees. “I had a little bit of cannabis this morning, a bowl of oatmeal and was soon knocking out a sub-one hour 10K,” he says.

Alicia Rose of Napa, who runs Herba Buena, a biodynamic cannabis company that grows cannabis without pesticides or fertilizers, questions whether getting high might actually ruin the runner’s high. “When I smoke or vape, I feel high,” she says. “You won’t feel the additional pop of euphoria” that exercise often brings.

Ali Stoddard, owner of Green Alley, a Lafayette CBD health and wellness company that serves athletes, among others, says there’s a big difference between the two main plants in the cannabis family, hemp and marijuana. These plants each contain THC and CBD, but marijuana has far more THC — cannabis’ psychoactive component — than hemp.

Hemp, which has traditionally had many more industrial uses, including as a fiber for clothes, has only trace amounts of THC. Instead, it’s chock full of CBD, which Stoddard says has anti-inflammatory properties that help the body recover after a workout.

Historically, the only way to get CBD was to smoke marijuana, Stoddard says. “All the football players were smoking pot because that’s the only form they could find,” she says, referring to former NFL players who have been lobbying the league to lift penalties for using cannabis.

But now, when an athlete wants those benefits, “they’re all turning to CBD,” Stoddard says, “especially our weekend warriors, who don’t want to get high. How the hell can you work out in a gym when you’re high?”

Stoddard, a former Cal swimmer and rugby player who still plays soccer at age 57, is a self-described “science geek” with a long career working for medical companies, selling replacement hips, knees and spinal implants to surgeons.

“When I was playing rugby, I was smoking pot recreationally, and I didn’t feel any medicinal benefit,” she says. “The only reason I survived is I was young. But last weekend, at a soccer tournament, I used CBD like candy.”

Rose says the CBD in marijuana works in tandem with the THC. “CBD can be very helpful for recovery,” she says. “CBD has the innate ability to regulate and calm the biological systems of the body. It works on so many different systems. It works on anxiety. It calms the body’s response to stress. It works on pain.”

But, she cautions, “it’s not analgesic. THC is the analgesic. It kills the pain like an aspirin or Tylenol would.”

Stoddard of Green Alley says that some of the supplements derived from cannabis make people feel lousy, whereas those that incorporate a more plant-based approach include the properties that prevent nausea and other side effects. Stoddard says this can be accomplished with hemp CBD, forgoing the THC in marijuana.

“My whole point is, if you’re an athlete, or a sick patient, or elderly, you don’t want to get high,” Stoddard says. “But you do want the anti-inflammatory effect, the antioxidant effect, the focusing effect, the regenerative effect. … You go for hemp.”

Michael Crawford, a cardiologist at UCSF, remains skeptical of claims about the physiological benefits of cannabis, citing a lack of data.

Certainly, Crawford says, one should not smoke anything before working out. “It doesn’t make any sense to inhale burning vegetable matter and then exercise. It doesn’t matter if it has cannabinoids in it.”

Edibles pose a challenge, Crawford says, because it’s difficult to control the dose. “It’s hard to mix it into food and get a consistent product,” he says. “You can easily get overdosed if you’re not careful.

“We know if you take marijuana with a high-fat substance like a brownie, you absorb much more than if you take it with a low-fat food such as rice. There are a lot of variables that are difficult to control for.”

Crawford says it’s hard to control the dose in edibles because growers have been “doing a lot of tweaking with the plant. They’re growing hybrid kinds of marijuana now that are more potent than the old-fashioned weed that people used to smoke. Some of them are tenfold more potent than the older forms of marijuana.”

Another concern is the appeal that cannabis might have to young athletes, whose brains are still developing. Christine Carter, a sociologist and senior fellow at UC Berkeley’s Greater Good Science Center, who has written about the topic, cites studies showing that new strains of marijuana have a much higher THC content, that most teens think cannabis is safe and that marijuana stunts brain development in teens.

“I’m unconcerned about CBD,” Carter says, “but THC presents a huge risk, and if they don’t perceive the risk, they’ll eventually use marijuana. It’s legal. It’s easy to get. If it’s a positive experience, they’ll use a lot, and it can be very addictive.”

Rose of Herba Buena laments the lack of scientific evidence. “Personally I’ve seen a lot of anecdotal evidence as it relates to exercise, both the act of exercising and certainly the recovery of athletes,” she says.

Rose says cannabis heightens sensory awareness, both physical and metaphysical. “If you’re an athlete in training, it can actually get you to a place where you’re aware of the exercise you’re doing and its effect on what you’re doing, more than if you’re not high.”

On the other hand, she says, you risk injury.  “If you’re lowering your inhibitions to a point where you’re not aware of what you’re doing, you’ve over-imbibed,” she says. “You’ve gone over the threshold. For me, that’s where the line in the sand is drawn between therapeutic and recreational.”

Rose says some studies from Israel and other countries that don’t ban marijuana research show that CBD helps people coping with chronic pain, head injuries and post-traumatic stress disorder. She believes that same impact can help repair a body after a strenuous workout.

Efforts to isolate the “good” CBD molecules and administer them in, say, pill form are likely not as beneficial as using the whole plant’s “entourage effect.” “The balance and the ratios of hundreds and hundreds of different compounds that cannabis is made up of actually is what creates the greatest healing and the greatest energy.

“Isolating one or two molecules is so Western of us. It’s like taking the curcumin out of turmeric and expecting the same anti-inflammatory effect.” –Dan Fost