eric, thanks for this info !!! i have always hydrated well with just water, and still gotten lactic acid build up. perhaps the protein replacement will help post workout.
also, and we have not spoken about this yet, when i began swimming for long sessions, i would cramp up and my BGs would spike post swim, you suggested that i give myself a bolus when i get out of the pool, and this has eliminated the spiking. OMG. yay 
but now that my muscles are getting stronger the longer i continue to swim, i am noticing that i no longer cramp up or feel so sore after working out. do you think that this has something to do with my body becoming more and more accustomed to the exercise? that i am not stressing my muscles out as i used to???