Today was a swimming day and, thanks to domestic responsibilities that need not detain us, I swam in the evening and had time to do only the prescribed exercise in the endurance training plan. It consisted of 25m warm up, then 100m of fast crawl, then a rest, then 50m of any stroke, then a 25m cool-down, 200m in all.

Here’s the rub. The 100m of fast crawl were to be swum fast, but with increasing speed. I had no idea how difficult this would be. NowI understand the endurance plan, and I beg forgiveness from its author for finding it undemanding.