High Intensity Exercise: Why Does It Make Us Feel So Good…?

Exploring Intensity

High Intensity Exercise: Why Does It Make Us Feel So Good…?

Everybody assumes we feel great after exercise because of our endorphins, the naturally occurring opiates in the body. But it turns out we feel good due to our endocannabinoids (our body’s own naturally occurring marijuana) which kick in after we ramp up the heart rate. Gretchen Reynolds of the NYT just reported on a new study to prove that endocannabinoids were more of a factor than endorphins. 

Scientists were skeptical of endorphins as the main factor in exercise-induced euphoria because they do not cross the blood-brain barrier, but endocannabinoids do cross. In a recent study, volunteer runners were split into two group: one received a drug that blocked the opiate receptors, and the other group received a placebo. Both groups ran for 45 minutes, and equally reported feeling a buzz after the run; meaning the group with opiate blockers still felt the same high. The groups repeated the exercise tests by walking and not running for 45 minutes. In that case, none of the people experienced an exercise high. 

Dr. John Ratey writes in his book Spark that there are a few chemicals in the brain that lift mood and reduce anxiety. He’s not writing specifically about feeling high, but just feeling better. Exercise increases the levels of BDNF, a neuropeptide in the brain that reduces stress and lifts mood. He also mentions phenethylamine, a psychostimulant, and anandamide (a cannabinoid) that both cause feelings of euphoria. 

At Cardio High we like intense exercise because of the way it makes the body feel. A sloggy jog makes us feel just ok, slightly better than a session sitting on the couch. But breaking a sweat and hitting 80+% for even just a few minutes makes us feel way better and improves energy for hours after a session. It turns out naturally occurring “weed” may be an important contributor to these positive feelings. 

Dear Dr. S –

Some of the commenters in the NYT article pointed out “…it might just be easier to sit back and just spark up a joint to get a runner’s high…” What’s your take on this simpler approach?

Dr S. replies:

I love endocannabinoids, but THC has been demonstrated to be actively harmful to the brain. ENDOcannabinoids are made and regulated by the body. You’re never going to flood your receptors and begin to downregulate them. Also, Pure THC unbalanced by protective CBD has no chemical “brake” for paranoia, dysphoria or psychosis. If you’re inhaling THC, you are damaging your lungs. If you use edibles, you are still doing damage to your brain without all the other benefits that exercise provides. I recommend hitting the gym instead of the local weed shop.