Little things, like what is on the telly, keep them perfectly happy and medically sound.
I also have friends who pound roads and cycle up mountains.
These friends are all crippled with Achilles tendon injuries and anterior cruciate ligament damage.
I have always leaned towards the former, although I do exercise regularly.
But I walk.
Quietly.
If I wanted to stride out on pavements in front of people while wearing outrageous clothing, I would model at the Dunedin Fashion Show.
Recently, I have been doing a lot of recuperative walking around the Ross Creek Reservoir, surely one of Dunedin's most breathtaking spots.
It is popular with runners, albeit usually the more recreational kind, the ones who have decided to try to get fit this year, or are merely running off the tawdry excesses of the night before.
Rarely do I see the supremely fit.
For every taut, upright body, there are five toppling over like dogs in a bag.
Interestingly, men often run in threes, women almost always only in twos.
Behavioural psychologists could explain this, so I won't try.
I strain to catch snatches of conversation, but this is not a restaurant, where you can cock an ear and pick up a full daytime soap opera episode - these are just stray sentences.
Men cover business, money and other men.
Women lower their voices when they approach and raise them when out of earshot, probably discussing Barbara Kingsolver's La Lacuna.
Most people run anti-clockwise, like the Olympics, but I go around clockwise, like the Auckland Trotting Cup, which means I am constantly directly meeting people.
I learned very early on there is a conversational protocol.
My cheery hail to single women was always met face-down in stony silence, so I went face-down as well.
Speak only when spoken to.
Some days my face was so far down it was poking through my legs looking backwards.
I remain incredulous that the penetrating newshounds at Close Up have yet to run a story on The Headless Man Of Ross Creek.
My reward near the end of a circuit is the bench overlooking the smaller stretch of reservoir where I gaze at the water and trees and think deep philosophical thoughts.
Often I fall asleep.
Sometimes when I am walking I think deep philosophical thoughts, too.
Once, on a dark section of the track, my failing eyesight determined I was approaching the tallest person I had ever seen.
And I once stood beside NBA center George Muresan, 7ft 6in, under the Chicago Stadium.
Applying deep philosophical thought, I could only conclude this person lived in the trees, surviving on power bars and Mizone stolen from runners' cars.
Boy, the Nuggets could use this one, I mused philosophically.
When the tallest person I had ever seen reached me and my fading eye, I saw it was a woman on a horse.
My wife runs like the wind while I walk.
Normally I would be affronted by this transparent show of superiority, but I take comfort in the fact that she takes nine minutes for a circuit and I take 14, which means my sedate thoughtful stroll takes place at 64% the speed of her lung-busting, eyes-bulging run.
I could probably lap her if push came to shove.
But running and walking around Ross Creek is not competitive.
Families, old people and doggy pooper scoopers do it.
A man pushing a baby in a stroller at high speed does it.
What deep and philosophical thoughts is that baby having as the wheels whirr over the loose gravel and his tiny teeth chatter like marbles in a glass jar? "Is this what life is? How long before I can get a car? And then what, the Demolition Derby at Waldronville, or, gasp, Formula One?"I tell you, Ross Creek really makes a man think.
