Why yoga?
Flexibility, balance, strength, breathing, mental strength and stress relief.
Yoga improves the range of motion for your legs as well as everything else. When I began, I couldn't even sit cross-legged. The improved flexibility has allowed my strides to lengthen and my speed to quicken. Shoulders and chest flexibility assist with efficient strides and allow the chest cavity to expand for breath.
The balance and strength keep things like IT band, ankles, core, feet, knees and everything else aligned; it helps prevent injury from weak supporting muscles.
With all physical activities, breathing is key. We take it for granted in so many things we do, and in yoga you are allowed and encouraged to focus on the breath. The improved awareness of breath and deepness of breathing acquired through yoga aid in running, sports, and life.
Yoga provides a very different challenge from running and the practice of holding poses prepares your mind for the steely mental toughness required to hold onto your pace through the end of a race.
Lastly, which may not help running but is valuable all the same, yoga provides an amazing form of stress relief from the rigors of the rest of the day.
Yoga and running, you can definitely swing both ways.
