Compound exercises that work a variety of muscles are great, especially for runners as we need a strong core and strong legs. The single leg deadlift works your core as it forces you to balance, but it also works your legs and your glutes with the weight that you are lifting. Check out the video below for how to do this exercise.
Try this with light weights first and progress. As you do this exercise, lift your leg slowly. A lot of people make the mistake of speeding through, which may not put as much emphasis on the muscle they want to attack. So go slow. It hurts a little more, but you can do it :)
Cheers Eights & Weights!