better to rest longer and keep a good stroke than get tired and flail around like a windmill.
I could be the coach 😉
The thing with swim training, getting decent technique is a lot more important than just working on fitness. In general, reducing the number of strokes per length is a good way of improving efficiency. Though you can overdo it (it sounds possible that iDave is – I do more strokes per length, yet go faster), which means you’re gliding too much (bad, as when you’re gliding you’re slowing down, your body is dropping creating more drag, when you should be keeping constant power on) or that you’re over-reaching (bad, as it results in you doing a snake wiggle). What could be worth trying is doing a slightly faster stroke rate by dropping the exaggerated lengthening of the stroke and relaxing a bit more – rather than consciously upping the rate, which is when you start flailing and getting inefficient. You’re after efficiency rather than the ultimate longest stroke.
TSY – got a 910XT, or is there some other watch which does that?