With this longer runs, I moved from carrying my hand held water bottles to a hydration pack. Even after doing some research in selecting my first one, I still felt like I didn't know what I really needed.
After using it during several races and training runs, I begin making a mental check list of of things that I liked and disliked about it.
Some of the things that I liked were the fit and the extra food that I could stuff in the pack. I liked the way that I could disconnect the hose from the bladder for cleaning.
Things, I didn't like were the way it rubbed in the middle of my back and the difficulty in refilling while out running. Literally, I had to unstrap, and remove the entire bladder just to refill which was a major drawback for me. I mean the other things, I could live with them being a pain but just the amount of time that it took to remove it and then put it back was a huge frustration point.
This led me to buying the Camelbak Hydration Pack. The bladder is a bit bigger - closer to 3 liters if I fill it completely full. The storage space is a bit smaller. The bladder is a bit more difficult to clean and the hose doesn't disconnect in the same way as my first one.
The major perk and the reason that I purchased this one is the ability to uncover the opening to the bladder and refill it without removing it from the pack.
My first run using it was my 35 miler past weekend. I probably over filled it because I had plenty of water for the entire first lap. I had prefitted it prior to wearing it, but then promptly forgot to use any body glide prior to my run. I expected to have a few rubs but nothing appeared. None of the rubs that my other pack gives me happened which I was greatly appreciative. The ability to refill it easily was awesome. I just uncovered the lid, poured in the water, and refastened it. It was both easy and quick.
I'll still use my older one from time to time and for runs where I do not need to fill it, but for racing and longer runs where refilling is a requirement, I will definitely be using the Camelbak.
If you are looking for something light weight and easily to refill plus has some storage space check out this pack.
The Cool Down Runner