Description of Patagonia Nine Trails Jacket - Men's:
The Patagonia Men's Nine Trails Jacket uses a DWR-coated nylon shell with stretch-polyester panels to provide weather protection with excellent freedom of movement. The Nine Trails Jacket's stretch panels also increase breathability, so you don't overheat on your trail run or backpacking trip. This ultra-packable jacket fits into the smallest cranny of your pack. You always have room for this Patagonia jacket.
Bottom Line: Going on a trail run? Pack the Patagonia Nine Trails Jacket.
This jacket is perfect when you are out all day and want a little something in reserve in case the weather changes. It's very lightweight but does an excellent job keeping you warm enough if the wind starts blowing. I use it for trail running and the stretch panels do indeed provide adequate breathability.
I keep this jacket in my back back on long trail runs for when the weather changes (packs up nice and small, see my picture above). It's light as a feather, sheds water pretty well, yet still breathes if I just need to stay warm. I like the stretch panels under arms and back. It also comes down a little lower in the tail which helps with water mud splashing up on my back, but not down my shorts.
Patagonia makes excellent gear and they nailed it with this jacket. A moderately athletic cut allows for good movement when running, the back fabric is a nice touch and enables moisture to move freely and sweat to evaporate quickly, preventing the clammy feeling that happens with so many other shells. I've worn this jacket as a standalone piece with no baselayer underneath on brisk mornings with no problems, it feels great next to skin as the shell material is soft handed. Perfect for those chilly start runs in the morning around 40-50F then shed it after you warm up. I wouldn't use this on the windiest of days, as it does breathe quite a bit, so not the best at cutting really brisk wind. I hope Patagonia brings this jacket back with one update, thumbholes!