I used this while training for a half marathon in Jamaica. It made my 10+ mile runs much more bearable, as exercising in a humid tropical environment is a totally different
beast with the amount of sweat that you produce. I had never run with a hydration pack before, so the loudness of the water sloshing around in there with each step was rather surprising at first. But after I figured out that hooking the hydration tube between the shoulder straps across my chest held the pack tightly to me, this thing was great. I wish there was an actual strap there for this use, as unhooking the tube for a drink was rather annoying, but it was that or the pack bouncing all over the place. This thing saved me from horrible dehydration alongside a highway in Jamaica, so it did what it is designed to do.