A new Radio 4 documentary tracked the stress levels of musicians as they took to the stage. Presenter Chris Hawkins explains why they found the experience can be addictive... and dangerous.
Lots of singers have a ritual before heading on stage.
As a DJ, I've seen the group huddles, the performers who go quiet and the ones who get nervous - but I've never appreciated the sheer toll live performance can take on the body.
As part of Radio 4's new Art of Now series, Playing Well, I've been talking to musicians about mental health - and when we were given the chance to measure the stress involved in playing a gig, we got some surprising results.
By carefully measuring the responses of singer Marcus Lesycsyznski-Hall, scientists from the University of Westminster found stress levels which were comparable to a sky dive.
Mark Wetherell, professor of Psychobiology of Northumbria University, designed the experiment and has carried out extensive studies into stress.
He told me: "If you're anticipating any kind of challenging or stressful event your body mounts a response to help you deal with it.
"You release adrenaline, and people associate that with fight or flight response. Slightly longer-term, you also release a stress hormone called cortisol.
"That makes it sound very negative but these responses help us prepare for the demand that we think is going to happen."
Our guinea pig Marcus, from the band Pagans SOH, had to agree to a testing regime that involved giving 12 saliva samples on the day before, the day of the gig, and the day after.
"Interestingly, the day before the gig was very normal, which is a great sign for Marcus it means he's healthy," said Professor Catherine Loveday, who led the study. "He woke up and his cortisol went up just as it should do.
"The day of the gig, already in the morning it was quite disrupted [and] after the gig it shot right up by about seven nanomoles. That's really quite a large leap."
The cortisol level was not back to normal before Marcus went back to bed at 3.45am - but this was influenced by the fact that Marcus went on to a second gig of the night in Liverpool.
The professor explained that the next day's cortisol was "flat", with less of the typical morning spike, but it was back to normal by bedtime.
The comparison between playing a concert and jumping from a plane was possible, by the way, because Professor Wetherell has carried out similar tests on skydivers.
Marcus couldn't help but offer a "wow!" when I rang him with the results. He did, however, say he should probably reconsider playing two gigs in a night.
What the experiment showed us is that our bodies are often well-suited to the sudden, stressful demands of performance.
But what about the long term?
In an industry which has placed an increased emphasis on live work, musicians may run into difficulty when a punishing schedule offers their cortisol levels little chance to settle down.
Professor Loveday included "recovery time" as one of her five tips for looking after your mental health in the music business - all of which are included in the documentary.
Interestingly, one of the others was "hang on to your friends outside of music" - as being grounded is a crucial way to stop the intensity of the business affecting you negatively.
In the second episode of the series, we speak to musicians on the road, including Idles, Wolf Alice, Bill Ryder-Jones, John Grant and She Drew The Gun about how they manage the intensity of touring.
But in the first, we consider a recent tragedy - the death of Frightened Rabbit's lead singer Scott Hutchison.
A life in music is obviously a dream for many, and we tend to take protestations of suffering from rock stars with a pinch of salt.
But as politicians and sports stars increasingly discuss their mental health, I hope lots of performers hear the frank discussions about well-being in the series - and perhaps reflect on the idea that lyric-writing is not the only way to display your emotions.
The Art of Now Playing Well series starts on Tuesday November 5 at 1130 with "Frightened Rabbit".