Help with grandpa

Hello my fellow Glow users! I am currently looking for ways to get my grandpa more active and engaged in physical activities. We have been dealing with his diagnosed cancer for the past year. He seems so defeated. His cancer is currently being treated but he seems so disconnected to everyone. I know as humans we have bad days and more peopled dealing with sickness. But I am asking for help with ideas of things I can do with him to get his mood to brighten. I visit my grandparents every morning with my 1 year old. Please leave any ideas you think maybe helpful.