Salomon Advanced Skin 12 Set Unisex Hydration Vest Backpack for Trail Running & Hiking - Lightweight Breathable Design, Large Size (Goji Berry) - Perfect for Long-Distance Runners & Outdoor Adventures

I'd recommend this vest specifically for trail running with the amazing amount of storage (both readily available and small day pack). I just finished a R2R2R at the Grand Canyon and this vest was perfect. It held everything snug to my body (including my poles until I needed them), with enough room for snacks, med supplies, and a few other odds-and-ends.Pros:Plenty of storage (luxurious for a running vest)Great fit once on your bodyCons:Takes a moment to finesse to get on (or complete lack of finesse bc its a challenge)Doesn't come with the water bladder - you will have to find it separately and purchase oneNeutral:Runs warm - not enough to keep you warm in cold weather, enough to notice when running in hot weather.