You know, Muirenn, I'm not sure...I've never worried about my hydration in my adult life (I ran xc when I was a teen, and then have spent the majority of my adult life being a general slug after having children), so I may well not be well hydrated all the time. I'll pay closer attention to that and see if that helps. I generally eat pretty healthily, but do admit to being a coffee and diet soda drinker, which probably doesn't do wonders for my hydration levels. Will do a little more experimenting today...