As we all learned in elementary school from that bone song, the body is all connected. And running may be a sport that mostly uses certain leg muscles, but if the rest of your body is weak, those muscles will take the brunt of your running impact. That’s an easy way to get injured. 

Instead of running five days a week, sprinkle in a few cross-training days to strengthen the rest of your body. Yoga, rowing, swimming, lifting weights, and pilates are all effective forms of cross-training that will strengthen your legs and your core, glutes, chest, and back. This will leave you stronger, less injury-prone, and ultimately a better runner. 

Source: https://www.buzzfeed.com/matthewhuff/beginners-running-tips