Whether you’re training for a 5K or an ultramarathon, you’ll need a trusty pair of running shoes that will take you to the finish. Part of a successful training cycle and pain-free race day is making sure your running shoes aren’t too worn out. Studies show that worn-down shoes cause runners to change their posture and gait (their manner of running), which can lead to injuries down the line. This is largely due to a decline in the shoes’ shock-absorption…