It's hard to imagine an unlikelier champion for what I'm about to promote.
I'm the PE class shirker, the team sport dodger and the gym junkie scoffer.
I would rather lie in a hammock and read than do almost anything else in the world.
But if there's one thing I have learnt in my adult life about physical and mental health, it's this: we have to move more.
Probably most other humans had this figured this all out long before me, but the fact is, sedentary jobs are unnatural and chairs are our enemies.
I speak as someone currently sitting in a chair doing a job that demands stillness. And I'm paying the price, just as almost everyone else in my position does at some stage or other.
You know the adage about diet that was popularised by food writer Michael Pollan? "Eat food, not too much, mostly plants."
Well, these could be our exercise rules: "Move more, through the full range of motion, and sit less."
Now, there's no need to crack out the Lorna Jane and go to a special place to do this (unless you want to of course). Many of us just need to incorporate a walk, a stretch or even a brisk bit of housework into our day.
Because the fact is, we can go from our bed to our car to our desk, and then all in reverse, and bring no movement into our days at all. There's no need to run for the train if you never catch public transport, no need to vacuum if you pay a cleaner, and no need to move around if you're required to sit at a computer or stand at a counter all day.
What's worse, a lot of young children are growing up thinking this is normal life.
I heard recently that a man I know doesn't allow his children to do school sport because he'd rather they were in the library improving their minds.
Maybe he hasn't got the memo. Kids who don't spend lots of time moving around are clumsier, have difficulty paying attention, trouble controlling their emotions, use poor problem-solving methods, and demonstrate difficulties with social interactions.
Mind and body are connected, which is not really a surprise. Movement is key for both.