Comfortable and doesn't bounce around too much. I'm 6'2" and around 185 lbs. Not sure how different the fit is on someone smaller. I haven't had a ton of opportunities to use it yet, but I like it so far. I bought it for long runs in the backcountry along with a water bottle purifier to refill from streams I come across in the middle of nowhere. I previously used a Camelbak lumbar pack, but have gotten caught 8 miles from home with no water when I underestimated how far I could get on the size of the bladder. This system should solve that. I have noticed that it's a bit harder to get the bottles back in if I have an extra layer bungeed to the back. Side pockets are a nice size for key, couple of bars, Timex GPS pod or even a small camera.

Just picked this up last week and put in a total of 40 miles over two days with the Hydrospeed, as I'm transitioning away from handheld bottles. Overall, the pack worked well, but there are a few things that could be improved. Side pockets are placed in an appropriate location, but the zippers don't open or close all that easily. Also, I experienced some severe chaffing on my lower back from the product. I expected this as it was hot and very humid. Golite could minimize this by modifying their seems. there is actually a seem overlap directly behind one of the bottle holders that left me with some damage. All this said, I like the product and will continue to use it, but it could be better and I'm sure Golite is working on another model as I type this. Happy running.

I had seen other runners wear these things you call the lumbar pack but I never thought you could run comfortably with one due to giggling and bouncing and what have you. But I'm a big boy runner now so I need to carry my own supplies. I just busted this beaut out of the box yesterday and hit the road with it today. I did a 14er and no bounce and since I was carrying my own fuel--no bonk. The pack did kinda want to rotate a bit but a gentle elbow and it'll slide back into position. Each hip pocket will hold some Clif bars, gels, sammy bags pack with nuts, etc. I haven't figured out what all the bungee cords do but I have a week off so I'll figure them out later. Bottles give good suckage and oddly enough, they feel nice in the hands. I haven't mastered the reinsertion aspect of the lumbar pack yet so I have to use to hands and some swear words.

Buy this, you'll be happy and look cool when inexperienced runners see you.

It held enough for a 15-20 miler but I run like an animal and it bounced and bounced and bouced, irritating

I frequently run 17 to 25 milers on trials and the GoLite Hydrospeed Lumbar Pack exceeded my expectations. It simply has No Bounce. I've honestly forgot it was back there while running with my I-pod on. Would recommend to anyone wanting a secure and comfortable and light way to pack two bottles plus gels or keys.

Awesome pack - I've owned others from TNF and Nathan - this one is the best. Well thought out design - very secure, didn't budge while heading down the trail. One bottle for water, one for an electrolyte drink. Pockets offer plenty of space for your cell, Clifshot, a dry hat, i-pod, etc. The bungee cord on the back is ideal for stashing your jacket and/or gloves when you get warmed up. I've only used it for running, but it would also be great for roller skiing and mt. biking!