.... and another thing... How warm does the water in your pools get in the summer? I am finding that the older I get (I'm 45 now) the less tolerance I have to swimming hard sets in hot water. It is as though my muscles are lulled to sleep, and at the same time that my heart starts pounding to hard to be able to put together a quality set. I need way more rest after hard 100s/200s and my endurance or ability to hold a decent pace on 400s+ seems to vanish. I start noticing this effect at 83 degrees. By 87 degrees, i might as well do the whole workout = drills and breath control. By October things have cooled down enough to not feel like I am hard boiling my eggs any more, and by December my pool is in the low to mid 70s again...so I'm happy again.
So, how hot are the pools you are swimming in, and do you have the same issues with warm water affecting your workouts as we do???