I was talking to an old friend - a former cricketer and renowned cricket coach - about the alarming extent to which our Test Match teams seem to be determined less by the selectors' preferences than by the mundane matter of who is or isn't in a fit state to stagger onto the pitch at Headingley or Trent Bridge, Lord's or the Oval. Why, I asked him, do so many players get injured these days? 'Too much training,' he said. 'They were much fitter when they trained on beer and cigarettes.' If he wasn't being entirely serious, he wasn't wholly joking either. For you can overdo the training: the highly-wrought will often become fragile. A string tuned to concert pitch is more likely to snap than a slack one; a piece of hand-blown crystal will shatter more readily than a machine-pressed pub glass. It is, as they say, the same with most things.

Except, perhaps, poetry. Here, you might think, perfection of the art is so unequivocal a goal that no amount of training could ever be excessive. And that's true enough, although there may be room for lively disagreement about what a poet's training should entail. Philip Larkin recalled how as a young writer he'd 'limber up by turning the pages' of Yeats's 1933 Collected Poems 'before opening my large dark green manuscript book': early to mid-period Yeats, as he acknowledged, wasn't an unmitigatedly benign influence, but 'limber up' is exactly right. I ...