I am a backslider.
I have had an on-off relationship with sports and physical activity. I ran around a lot as as child, but never got the hang of ball games at school, particularly those that involve charging at larger people or rolling around in the mud. Being one of those who it really wasn't worth putting into a rugby team on a Wednesday afternoon, I was regularly consigned to the group that ran vaguely around under the even vaguer direction of the school chaplain - in the unenlightened early 60s, we were charmingly listed on the noticeboards as "Remnants" (but I'm not bitter, honestly).
Eventually, I discovered rowing which - joy of joys - one can do sitting down. And I actually did quite well at it, with a few battered pewter pots sitting on a shelf.
Since then, I've tried. Fresh fruit genuinely is my snack of choice, I don't keep biscuits in the house, and I have only a nodding acquaintance with strong drink and cream cakes. I don't keep a car, and, unlike many of my neighbours, I find it quite normal to walk. I've had periods of going to gyms - indeed a large chunk of the service charge on my flat goes to maintaining one here. So when a few months ago a routine check showed some of the vital measurements on or over the "Do something about it, NOW" level, I started again; and the belt came in a few more notches, I was running for the bus without turning purple, and generally feeling all the better for it. What's more, I work at the kind of place that goes in for claiming to support healthy activity, and we had a challenge to log our activity as a group "marathon" (20 minutes = 1 mile).
And somehow I fell off the wagon. Too much staring at the screen at work tiring me out, the odd minor injury - who knows why these should give me an excuse now when they didn't a month or two ago? I have back-slid: and there is no health in me.
That, I suspect, is the root of the odd relationship many people have with both intake (food and dieting) and output (activity). We talk about it in the language of sin, fault, virtue and reward, and put too much emotional strain on ourselves as a result.
After all, I am still walking up the escalator on the underground. But only when they're going up.