I think yoga and strength training work particularly well with running.
It actually surprises me how many runners don’t do strength training. If you want to run faster and run better, you need to strengthen your muscles! Even doing body weight squats or lunges will help and make a big difference.
I love yoga for the stretching and for the flexibility I gain from it. Many runners start to lose their flexibility and will have problems with hamstrings and the IRT band. So if you love running and want to be the best runner you can be, do some yoga! Personally I’m a huge fan of Bikram yoga as I love the heat and being in a hot room for 90 mins.