Has anyone got a hydration system that works for running? I have a platypus 2l pouch and tube, which would be invaluable for long runs in summer but the rucksack i have to go with them isn't really stable enough for running. I did one run with it but couldn't adjust it so it didn't move around and it was more annoying than it was worth!!
Anyone run with such systems? any advice on which to go for with a 90-120min long run in mind?