I attend my first TRX class (at the Third Space, Soho) and gingerly test my weight on the suspension belt.
Because you're working against an unstable surface, you're automatically engaging all those core muscles without even thinking about it (there's a reason this class is just 30 minutes long).
Lucy, our instructor, talks us through shortening and lengthening the belts, after which we warm up with some squats, leg lifts and star jumps.
Then it's onto the suspension belts, where we are taken through a regime of one-legged squats (widely credited with giving Pippa Middleton her super-shapely derriere), shoulder presses, side lunges, more squats and press ups - these are tough without the solid floor to push up from.
It's hard, but not the belly-blasting intensity I was expecting.
At this point, however, we are instructed to loop our feet through the belts, so legs and core are suspended, our weightsupported through the shoulders and arms, like an elevated plank. This, my gym-loving friends, is hard, and I am soon shaking with the effort of maintaining my position.
We are there instructed to bring our knees up to our chest and piston our legs back and forth.
This is so agonising that I only manage a few reps before collapsing onto my forearms.
We are taken through this routine three more times, until our core and shoulders are screaming for mercy. I untangle myself from the suspension belts to warm down, shaking with exertion.
I feel sure that this, combined with the right cardio and diet, will trim down my waistline in super-quick time.
I'll let you know how I get on...
