Morning Gloryville is a sober rave that starts at 6.30am. This is a thing now. You go clubbing in trainers before work, get high on the endorphins, then go to the office. It sounds contrived, a bid to cool-ify an aerobics class. I expected fitness-freaks arriving alone, doing star jumps for an hour before heading to the office at 8 in Lycra with branded water bottles and rucksacks full of work clothes.

But I was wrong. I turn up at 6.30am to what looks just like an actual rave: a half-hour queue, bouncers checking bags on the door. There are lots of women in neon vests covered in glitter, hallooing each other with “YOU LOOK BEAUTIFUL”. Two men are drumming. It is rare to be solo, and I feel just as old and shy as if I’d turned up alone at a regular club. But it’s not an alienating crowd, unless you find everyone’s outrageous beauty off-putting.

In the Ministry of Sound’s front room I find a trance-flavoured yoga session and some protein balls for sale. The larger room at the back has a DJ and a… let’s call her a leader: charismatic, spry and bouncy, in Goa beachwear, shouting “feel it” and “wave your hands in the air”. A largeish crowd follows her movements. It’s not really aerobics, it’s more like follow-my-leader. We stomp, leap and do a speeded-up version of that hippy prayer where you start as a seed and grow into a tree. Naturally, there is some waving of hands in the air. It’s moderately cardio and very free, which is to say, when the leader starts stomping in one direction, half the crowd follows her and the other half mirrors her. I find it fun but formless: inhibited by social codes such as “don’t bump into people”, I just can’t throw myself into it. I never get out of breath, which is meant to be the point. The others seem to be having a great time; I’m amazed to see there are people trying to pull, at seven in the morning, a pursuit I wouldn’t wish on a dog.

I talk to Sam Moyo, the 31-year-old founder. She set it up four years ago primarily as a way to rave without raver consequences. “I was taking loads of drugs. And being naked. Just being a party-girl, you know?” Sort of. “I just started finding it really unsustainable.” I love millennials. They talk about themselves like rain forests.

Essentially, Morning Gloryville is more about hedonism than fitness – the “manifesto” talks about “vitality” and “harmony”, and “playfulness”, rather than calorie burn or abs. And I think it’s morally better to do exuberant jumping and dancing and sweating to loud music for its own sake, rather than as self-improvement. When I come blinking back into the day at 8am, I feel pretty buoyant and self-righteous anyway. Would I go again? Not alone, but maybe with a friend.

This week I learned

It’s much more fun to dance and sweat in the name of fun rather than fitness.