Endorphins & Exercise

Endorphin is a combination of the words "endogenou" (produced within the body) and "morphine"

How many of you have taken out your bad day in the office on the spin bike or lifting weights… I know I have, working up a sweat can easily turn your day around.

And by now you've probably heard that endorphins are the magic bullet behind that post workout bliss. People love the feeling so much that "endorphin junkie" has even become synonymous with someone who's constantly chasing that exercise high. But while endorphins may get all the credit for your post-run buzz, there's actually a lot more going on behind the scenes. Here's what you need to know about endorphins — and why you might not be an endorphin junkie after all

What Are Endorphins?

When your body comes under stress or experiences pain (hello, burpees), neurochemicals called endorphins are produced in the brain's hypothalamus and pituitary gland,. Endorphins, which are structurally similar to the drug morphine, are considered natural painkillers because they activate opioid receptors in the brain that help minimize discomfort. They can also help bring about feelings of euphoria and general well-being. Endorphins are also involved in natural reward circuits related to some other daily  activities.

The Blood-Brain Disconnect

Yes, blood plasma endorphin levels do increase in response to stressors and pain, research shows. For example, a 2003 study found that the more severe pain someone experience post-surgery, the higher their blood plasma endorphin levels. And research shows that exercise can have a similar effect, but research also suggests that endorphin levels might not increase at all until an hour after you've started working out. (Which doesn't explain why those 30-minute HIIT sessions still leave you feeling awesome.)

So what gives? The problem with jumping to the conclusion that endorphins cause your "exercise high" is that in large-scale studies, scientists measure endorphins present in the blood — not the brain. Then, they make the assumption that if endorphin levels rise in the blood, then it must be because of an increase of endorphins in the brain, . But their findings don't necessarily prove that. And it's the endorphins in your brain that would be causing that "high."

In fact, a recent study found that, while endorphin levels are higher after a run, endorphins can't pass through the blood-brain barrier, which means they probably don't have much to do with experiencing an exercise high. What does affect the brain,, was a neurotransmitter called anandamide, which is elevated after exercise and can travel from the blood to the brain.

What's Really Going On?

So if you aren't an endorphin junkie, then what are you? Well, you might be a serotonin or norepinephrine junkie,. When you exercise, your brain increases production of these neurotransmitters, which send messages throughout your nervous system.

Studies have linked low levels of serotonin and norepinephrine to depression, which is a much more solid link to feelings of post-workout euphoria than the evidence for endorphins,. And it's not just that exercise leads to an increase in serotonin and norepinephrine which may, in turn, reduce depression and stress. Exercise may actually help ward off depression and anxiety by enhancing the body's ability to respond to stressors, 

What appears to be happening is that exercise affords the body an opportunity to practice responding to stress, streamlining the communication between the systems involved in the stress response,. The less active we become, the more challenged we are in dealing with stress.

While the science about why you feel a rush after exercise may be complicated, that doesn't mean the runner's high isn't a very real feeling.