It takes me exactly 30 minutes to do the circuit I've devised around my home, which also takes in a series of slight inclines, and walking at a speed that makes me slightly out of breath. Sometimes I walk first thing in the morning, sometimes at lunchtime, sometimes in the evening - fitting it in to my schedule couldn't be easier.
What's more, wearing my MBT trainers - Masai Barefoot Technology - ups my exercise quota. I first wrote about these trainers in the Sunday Times' Style magazine in 2003 and have been an advocate ever since.
Independent research studies show that when you walk in these for 30 minutes, it's the equivalent of 90 minutes exercise because the instability provided by the patented sole technology is proven to increase muscle activity - one study showed activity in the thigh and buttock muscles increased by an average 37%!
And during that 30 minutes I find my mind settling and focusing. Tension reduces, my shoulders unhunch, my breathing deepens, ideas are formed, plans are made. It's a great way to, literally, think things through.
I once joined a gym. I can't remember ever going. Not a good way to exercise, then.
So like Demi Moore in her new film The Joneses I'm going to wear my MBTs, and take a walk.