It’s pretty common for runners to have weak abductor muscles and limited glute activation during running, particularly of the gluteus medius. The challenge is that trail runners need to be able to move quickly in all directions, and by targeting the abductors, you prepare yourself for these lateral movements. For that, Wilcock picks band walks. Loop a small resistance band around the balls of your feet, and after lowering into a half squat with your glutes and core engaged, take 10 steps to your left, then reverse the movement and take 10 steps back to your right. Perform three sets.