Many runners have tight hamstrings. And many of them would benefit from doing hamstring stretches!
Tight hamstrings may be related to knee pain, butt pain and perhaps even heel pain. A great way to stretch the hamstrings and also protect your back can be performed by lying on your back next to a taller object or wall. Position your self so that the leg you are stretching is supported up against the object or wall. You can modify where you feel the stretch by varying the bend in your knee. If your knee is straighter you will fill the stretch more towards your knee. If your knee is flexed you will feel it towards your butt. Adjust the tension by sliding your body forward or backward. If you have tight hamstrings spend more time with this stretch, perhaps 3 to 5 minutes.