Disappointingly but I suppose inevitably, The Critic has a disproportionate number of critics among its readers. They have been quick to point out that they might have obeyed every instruction in Part One of the Nick Cohen Health and Beauty Workout ™ — “from Drunk to Hunk” — and never have moved a muscle, except perhaps to walk to the bar to get another round in.

That’s because, I cried, while trying to restrain myself from grabbing the dolts by their lapels and lifting them off their feet — those, that is, who weren’t so obese it would take a crane to lift them — “I was trying to prepare you mentally for the work ahead. I was trying to explain that cognitive biases create psychological as well as physical obstacles to exercise.” 

It’s not just that you do not have the muscle, bone and joint strength — you are mentally conditioned to dismiss all warnings against idleness, gluttony, drunkenness, drug addiction or whatever other pleasures you enjoy as health fascism. Since I have taken up running I have lost count of the number of men my age who have looked at me pitifully and said, “Ah but you will wreck your knees.” 

I refer them to the Stanford University study which found that not only was there no risk of running producing arthritic knees but continuous exercise actually protected the knee joints of runners who were at risk from arthritis. All in vain. Before I had finished, they had nipped off for a burger.

If I can get them walking the editors and staff of The Critic will be demonstrating with Extinction Rebellion in six months

A good friend, who introduced me to running, encapsulated the cognitive bias brilliantly. He invited me to take a test I’d like all readers to copy. Announce on your Facebook page that you are going for the mother of all lunches. You are going to drink the wine cellar dry and not return home until the waiters call the police.

I guarantee that your friends will not say, “Think of your heart, you fool.” Or insist that a man/woman of your age “ought to worry about strokes and type-2 diabetes”. They will say, “Can I come too?”

Announce, however, that you are taking up running and all the cavaliers in your circle will turn into round-heads in an instant and cry, “Are you insane? For God’s sake man, think of your knees.”

I am thinking of your knees right now, and, frankly, I’ve seen better. The time for behavioural psychology has passed. No more pussyfooting about getting you in the right mental state. You are now going to do something, and the thing I want you to do is walk.

The “take 10,000 steps a day” instruction is now buried deep into the global psyche. There’s no logic behind it — the arbitrary target came from a marketing campaign for the 1964 Tokyo Olympic Games and somehow stuck. Recent research from the Harvard Medical School suggests that 7,500 steps are enough to produce noticeable health benefits. Both, however, require you to walk about 2.5 to 4 miles every day beyond the normal pottering about.

When I started walking, I found the best way of meeting the distance was not to go to a gym and tramp on a treadmill but to incorporate walking into every part of my life. Instead of driving to the supermarket for a weekly shop, I would walk and buy food as we needed it. Instead of catching a bus or Tube to work, I would walk and so on. I got to the stage where walking felt natural: as much a part of my life as eating or sleeping.

I lost four stone just by walking and watching my diet. It is by far the simplest way of changing your life. If millions of people in Britain just walked (or cycled) the national health would improve exponentially and so would British politics. 

Walking makes you aware of how this country has been redesigned in under a century to suit motorists; of how hard it is to move around under your own muscle power, not just on council estates cut off by urban motorways but in villages where the pavement ends as soon as the streetlights disappear. 

Trust me, if I can get them walking the editors and staff of The Critic will be demonstrating with Extinction Rebellion in six months.

But this column has higher ambitions for you than raising your environmental consciousness. It will make you a runner or die in the attempt. So, as your strength builds, try 30-second bursts of walking at a brisker pace, then one and two minutes of fast walking. Seek out hills and try to incorporate them into your routes. 

When you can manage three to five miles over hilly terrain without needing to call for an air ambulance, Part Three of this wellbeing guide will be waiting for you. For, to the surprise of everyone who knows you, and I warrant to your own surprise as well, you will be ready to run.