This evening's long swim was just over target at 2300m. Some lengths were at a slower pace than I wished due to others in the lane, but in general my pace declined through the hour. I did start off gently but my form deteriorated noticeably and is quantified by an increase in SPL from 21 to 25.
Last week I was clearly faster than today. But I mustn't be disheartened as last year I swam a very similar distance at a pace of 2:53min/100m compared to today's of 2:36min/100m; so now I'm 10% faster.
As I'm taking the long session beyond 200m it is evident that I'm needing to drop the pace, as I do in running to a 'long slow' approach. An hour of exercise doesn't permit working at a threshold of any part of the metabolic or muscular chains.