PRODUCT REVIEW: Nathan's Vapor Air 4.0 8L Hydration Vest

For such a little, light weight vest there's an outsized amount of storage space here. Let's start with the 2L capacity bladder conveniently accessed by the straw. No problems in the water flow during testing even with the bladder only half full. The nest itself is comfortable and breathable. The sizing is unisex and each vest size adjusts to comfortably fit two body sizes (S–M, L–XL, XXL). I've had problems with hydration vests previously with skinny cord straps at front causing discomfort but didn't experience any of the system this pack uses. Aside the hydration bladder compartment at the back there are four expandable front mesh pockets and two large side pockets (for gels flasks, bars etc.) and an interior zip pocket secure essentials like keys, phones or ID cards.

I don't recommend hydration packs in general for triathlon racing, even Ironman, and honestly there's probably too much storage, hydration space here for just your average long training run. This vest would be best suited to long, self-supported ultra and trail running and even all-day hiking and running. If you wanted to carry even more fluids than what's available in the bladder you could add soft flasks to the four front pockets which comes with elastic cords to hold them. Perfect hot weather vest with maximum storage capacity in a breathable, light weight vest.

The Nathan VaporAir 4.0 8 Liter Unisex Hydration Pack Retails at $160.