A new book, Felon Fitness, has collated all the workouts that prisoners use to stay in shape. How did they work for our reporter?

It is not the point of it, exactly, but there is no doubt that prison is an excellent place to get fit. Whenever lawyer William Kroger went to visit his clients inside, he noticed what great shape they were in. Eventually he set about collecting exercises and routines from all over the California state prison system. The result is Felon Fitness, the complete guide to getting a body just like a convict serving 20 years to life.

I committed myself to attempting a selection of the exercises in the book, even though I haven't done anything wrong. Frankly most of them are pretty ordinary ? I'd done a number of them at the gym that very morning ? except in the book they are demonstrated by men with lots of tattoos using "prison dumbbells" fashioned from bed sheets and old magazines. A few, however, looked criminally difficult.

First on my list was the handstand press-up: you do a handstand, resting your feet on an adjacent wall for balance, and then raise and lower yourself on your arms. Prisoner Manuel Meza does 10 of these every Wednesday, as part of a gruelling five-day workout routine. I managed precisely zero.

Likewise, I failed to achieve a single "celly" press-up, where your cellmate lies on your back, a personal humiliation that left me trapped face down on the floor until such time as my wife decided she had other matters to attend to.

Some inspirational words from the prisoners ("Because I am in shape and by the grace of God," writes one, "I was able to fight off two inmates wielding homemade knives, with minor injuries.") spurred me on, and I breezed through 20 Romanian squats, a type of one-legged knee-bend with your back leg resting on a chair. After that I called it a day because, as I said, I'd already been to the gym that morning and I needed to save enough strength to untie my shoes later on. But one day soon I will manage a handstand press-up, then five, then 10. And then everyone around here will stop messing with me.