Endorphins, the body’s own opiate-like chemicals, have long been held responsible for the so-called exercise “high”, and experts once thought that we needed to tough it out at a certain intensity, for a given length of time, in order to “flick the switch” and get an endorphin boost.
For example, a report in the journal Physician and Sports Medicine concluded that to get an exercise “high”, you have to work at 76 per cent of your maximum heart rate, and may need to keep going for two hours or more.
But with some exercise fanatics blissing out by doing much less work, and others putting in even greater amounts of effort to no avail, researchers began to realise that the formula wasn’t so simple.
The endorphin fitness myth
Although it’s been proven that endorphin levels in the blood increase in response to exercise, those endorphins can’t cross the “blood-brain barrier”, so wouldn’t necessarily have much of an effect on mood.
So what is putting that smile on your face when you work out? Researchers now believe that there are a multitude of factors at work – both physiological and psychological.
Simplest of all is the idea that the sense of accomplishment or mastery we get from undertaking a challenging workout leaves us aglow. It boosts feelings of self-esteem by demonstrating that we can achieve our goals. But of course, challenge is a personal thing – and it’s important that the level of intensity is pitched just right.
If exercise is too easy then we won’t feel we’ve achieved much – whereas if the exercise is too hard we may become stressed and uncomfortable.
In one study, from Kyushu University in Japan, runners who completed 10 to 15 minute runs at a self-selected pace – rather than sprinting all-out – successfully enhanced their mood.
And backing up the idea that you don’t need to put yourself through a near-death experience to get a high, Indiana University found that even low-intensity aerobic activity (40 per cent of maximum capacity) could assist anxiety reduction and promote a more positive mood.
Another potential explanation for the workout buzz is the warmth it created in the body, which – like a hot bath – helps muscles to relax and tension to dissipate.
But we can’t rule out chemicals entirely. Nor are endorphins the only substances that respond to exercise. For example, exercise can prevent serotonin being taken back up by brain tissue, just like some anti-depressant drugs. It also has an effect on levels of adrenaline and dopamine.
www.realbuzz.com in partnership with Saturday Monitor