Do Not Agree with "Runs Small"
I'm a 5'1", 130lb, A-cup trail runner - size 4 pant. I asked for the Medium as a gift based on reviews on its sizing. Although the previous reviews say that the jacket is very light and "lacks substance", I was still surprised to receive it in its tiny stuff sack; A friend commented that it looked like a garbage bag. It is, however, perfect for my needs. A lightweight, water-resistant "shield" on misty trail runs. I will be exchanging it for a small, as I think the bagginess of the medium contributed to the "garbage bag" look.