The runner’s high is getting some good press again as researchers have concluded that it is a very real, tangible by-product of running. Simply said, the runner’s high does exists. It is not an illusion or mythical condition.

If you’re a new runner, you’ve probably at least heard something about the runner’s high and wondered what the heck it is exactly. What the runner’s high is in general terms is an elusive, but feel good fix that some runners talk about all the time like it’s some sort of magical state of heightened awareness.

It’s not that. Nor does the runner’s high feel like some drug-induced feeling of euphoria. Instead, it’s a mild, post-run buzz that has more to do with contentment and satisfaction than anything else.

Here’s the inside dope (sorry couldn’t resist). More than 40 years ago, researchers discovered that the brain produces its own mood-elevating chemicals. Because these chemicals act in a similar way that morphine does, they were tagged with the name endogenous morphines or endogenous opioids. Today, they’re just called endorphins and are the naturally occurring drugs—if you will—that can lead to the runner’s high.

Endorphins are hormones that can have many effects on the brain, but mainly they control pain by inhibiting the transmission of pain signals and they may also produce elevated moods, even a euphoric feeling similar to what is produced by opioids. What triggers these naturally occurring drugs is stress, be it physical or emotional.

So a physical stressor like running can flood the brain with these endorphins that then block or reduce the transmission of pain messages to your consciousness.

Thus, you feel little or no pain. Not bad. It gets even better.

With the endorphins carousing through your system during or after a hard run, you may have a relaxed, comfortable feeling. Some describe it as a sensation of being able to run as long as they want without too much effort.

The condition suffers from the description of being “high”. You’re not high (in the drug sense), but the post-run feeling is usually described as unusually enjoyable, mellow and very relaxed.

Nice. Where can I get some of those endorphins?

First off, research indicates that you have a better chance of triggering the endorphin rush by running hard and fast. You can still trigger them on a long, slow run, but your chances increase with the effort since endorphins are related to the amount of stress you’re encountering. That’s why when some runners finish a long, hard run, instead of feeling extremely tired right afterward, they feel energized. (The fatigue is actually delayed by the endorphin rush.)

To quantify the effort, researchers say you need to run at least 75 percent of your maximum heart rate to stimulate the release of endorphins into your system. If you’re jogging slowly for 20-30 minutes, there usually isn’t an endorphin rush because you aren’t pushing yourself. Without stimulating max heart rate, you don’t gain any endorphins. So short, very easy runs won’t do the trick.

Interestingly, research into the distance you need to run to have an effect on the endorphins, is inconclusive. Some studies show that six miles is far enough, while another indicates that an hour isn’t long enough.

It depends on the individual runner. Some runners can trigger a major endorphin rush in only 30 minutes of running—if they are running hard enough. While others, can run for more than two hours with no discernible effect. But most runners ordinarily trigger the endorphins on relatively hard, long efforts.

Armed with this knowledge, it is entirely possible to trigger your endorphins on a regular basis. For example, if you only run two or three very easy miles at a time, and wonder what the big deal is about the runner’s high, wonder no more. Instead of very easy running for two or three miles, step up to the plate and run harder, much harder and you should be able to trigger them.

That’s the trick—harder running at 75 percent of your maximum heart rate. It can be hills, a race or a speed workout, but that 75 percent of maximum heart rate is generally the sweet spot. Again, that’s why hard workouts (or races) seem to trigger the endorphins much more than a relaxed, casual run.

This might also explain why veteran runners seem to experience endorphin rushes on a more regular basis than beginners. Veteran runners are typically running harder and longer more often than beginners and consciously or not, know how to go to the well to trigger the pleasant flood of endorphins.

But it isn’t just running that triggers endorphins. The brain doesn’t know the difference between aerobic sports. Swimming, rowing and cycling seem to work just fine, provided you can move well enough to get your heart rate up to 75 percent of its max. But, some clinical studies have shown that running elevates the levels of endorphins more than other cardiovascular sports. (Interestingly, other studies have shown that acupuncture can trigger the endorphin rush.)

Not every runner experiences the endorphin rush. Even some who run hard and long just don’t get a full release of endorphins for reasons we don’t fully understand. Older runners, for example, have fewer endorphin episodes than younger runners because endorphin production drops as you age—regardless of your speed or intensity. Fortunately though, your endorphins never just disappear completely.

So endorphins are real. So is the wonderful positive and energetic feeling you can experience after a hard, fast run or race.

Bottom line: You can get high on running.