Twerk n Grind fitness class review: 'It's so much more than just shaking your bum'

"And pop! Pop! Pop! Pop! And roll to the back. And roll to the side-" and my thighs are killing me.

The teacher is trying to tell us which direction to twerk in and I can only concentrate on trying to stay standing. This Twerk and Grind class is surprisingly hard physical work. I'd probably sit the rest out if I wasn't enjoying it so much.

The source of my pain is coming from having to squat as wide and low down as I can manage with my hands on my knees, while trying to keep my shoulders still, and at the same time push my bum upwards and backwards in sync with the music.

“Pop! Pop!” our teacher Kelechi shouts over the afrobeats track she's chosen, marking out with her voice the points at which our pelvises should be tilted forwards and our bums should be in the air.

People think twerking is just shaking, Kelechi tells me, but it's a skill - and she is not wrong. She describes this basic movement we're honing as like having a fishhook attached to your lumber vertebrae, which is being repeatedly pulled backwards and forwards.

At first I definitely feel silly – partly because I have an embarrassing affliction that means whenever I do more than five minutes of exercise my face goes beetroot red and this room is lined with mirrors, and partly because I'm completely out of time, not sure if I'm twerking right and pretty out of breath.

I complain about how much my thighs hurt to the woman behind me. “My thighs are fine, it's my back that hurts!” she responds. We both giggle and carry on.

But once I get the hang of how to use my stomach and lower back muscles properly to get my bum in the air in time with the music, I start putting my weight in the right place, moving my feet on the beat and really enjoying the routine we're learning. If you love afrobeats, hip hop, dancehall, or dancing in the crowd at any carnival then this is a class you will want to try.

Then Kelechi puts her hands on the floor, jumps her feet up onto the wall and starts twerking upside down. The woman with the aching back and I exchange troubled looks.

The next thing I know, my hands are on the floor and it suddenly strikes me that I have no upper body strength before I obediently jump my feet up onto the wall. Twerking upside down? Definitely not something I thought I'd learn how to do in my lifetime, but as long as you use the wall properly for support, it’s doable, even for a novice.

By the end of the class I am sweaty, out of breath and red in the face. My legs are like jelly, but I don't feel silly. I genuinely feel great. Kelechi says she wants her class to be about feeling good and being body confident. Judging by the smiles and laughter coming from everyone, her methods worked.

Incidentally, I still feel great the next day, though I spend it aching from hip to toe and struggling to make it up various sets of stairs. But would I put myself through it again in the name of fitness and fun? Absolutely.

Twerk n Grind is held at London Dance Academy on Old Street, East London every Sunday at 1pm and Thurs at 7.15pm. Classes can be booked on the lifestyle subscription service Wonderush. New subscribers can get their first month for £5 using the code HIGHFIVE.