Recently, I've stopped drinking still water and drink unsweetened, unflavored seltzer with no sodium almost exclusively. I started wondering if there was a difference in hydration between fizzy and still water. It seems that there is (thankfully!) no difference at all. The Times reports that there's no health difference between the two. It does appear that the general advice for high performance athletes is to avoid carbonated water, but that is because they tend to drink less of it (on average) than non-carbonated drinks -- it seems that it may quench thirst more quickly than still water, and so athletes may stop drinking it sooner.

But since I'm not a high performance athlete, I'm going to keep guzzling my fizzy water because it makes me happy.