I agree with Riya. It’s the advice I use for myself (marathoner and triathlete). And the advice I give to clients. The other thing I recommend is foam roller work/stretching. It really works to release the lactic acid build up in the muscles, release the tension build up in the tendons (especially the it band in runners) and fascia, and relax the muscles themselves. There are lots of YouTube vides showing you what to do. The great thing too, is the foam roller can be added into your next marathon training plan to help you through out the training.