Someone with a shaven head in combat fatigues screaming at you as you agonisingly push your body to its limits.

If this is what comes to mind when you hear the words ‘boot camp’, think again: at PhysioExtra’s new Saturday morning boot camp on Ham Common the trainer, Austin, doesn’t wear any military clothing.

And he is actually a nice lad who certainly knows his stuff when it comes to varying exercises and stretches.

Quite a lot of the hour consists of warming up then stretching down.

Frankly I was knackered after the warm up. The press-ups and squat thrusts on the circuit demonstrated what I already knew: I am unfit. This felt harder work than pushing my ageing body around the park for a gentle jog once a week.

One of the positives about training in a group is that there is usually someone suffering more than you – or someone who makes it look easier, shaming you to not collapse in a sobbing heap. In other words: it caters for a mixed range of abilities from the super keen to the reluctantly resigned.

And despite the macho name, it’s more about encouragement than pressure. You do the exercises to your own level and can do simpler variations if you have any injuries (or are just decrepit like me).

If you haven’t done it before, it’s basically circuit training outdoors – which is marginally preferable to being in a gym. Especially if you have an aversion to Kiss FM.

Ham Common is beautiful. And being a nice area, there isn’t any dog poo.

The session costs £10 and the first one is free (plus a complementary beverage at the nearby café). It starts at 10 a.m.

You certainly feel like you’ve earned a weekend of sloth and indulgence afterwards.