That's not what I tell Pauline, my psychotic personal trainer. "It's because we're on... (pant)I the Healthy Schools Programme... (gasp)... One in three children overweight... One in six clinically obese... Must set example."
A malicious smile flicks across her face as she increases the incline on my treadmill by another two degrees.
Pauline sets me several targets that remind me of our key stage 2 ones: we like to use the term aspirational, as it's less de-motivating than never in a million years. Also I think I'm in her booster class because an hour later I'm still at it, only now I'm pumping iron. Muscles I never knew I had scream for mercy.
Unfortunately, Pauline doesn't know the meaning of the word. And there's something else. I'm being stared at by a guy whose bling weighs more than my dumbbells. I look him straight in his perfectly defined pectorals and proceed to new levels of agony.
I think the endorphins kick in next because everything turns weird. The past year flashes before my eyes. It includes a giant Jamie Oliver using a blowtorch to slaughter a platoon of turkey Twizzlers dressed in combat boots and black bandanas. "They're killing the kids," he explains before, Whoosh! Sizzle! "Take that mother pukka!"
"Halt!" shrieks Pauline, and I collapse over a fitball. After a while, the black spots begin to fade, along with some of my dedication. Does the Government really want healthier kids? I mean, won't that get in the way of its targets on improving pupil behaviour?
In my experience, unhealthy kids are rarely a problem. It's the fit ones you have to watch out for. They're the ones with the strength and agility to climb out of the window, shin up a drainpipe, slither under razor wire, evade anti-vandal grease and mouth obscenities from the rooftop while simultaneously kicking loose ridge tiles.
"Remember me, sir?", says a voice like an industrial grinder. It's the guy with the bling. "I was in your class... climbed out the window... threw ridge tiles... month's detention..."
See what I mean?