It's common for runners to have tight hamstrings or calves, as these are the muscles they primarily use during a run. Yoga instructors can help runners keep the muscles long and lean by focusing on lower body stretches. This will allow the muscles to maintain flexibility, which will help prevent future injuries or strains. Continue by providing an overall body stretch to help keep the body balanced. Some runners carry stress in the neck, shoulders or back, too, so it's important to let all the muscles stretch and release.