Hii i jog for nearly 6miles and walk for 6miles everday does this effect my health or body parts?

I am following this routine from last 15 days .Earlier when i statred there were pains in my legs as i used to regularly the pains disappeared ,but from lat 2 days when i get up for joging my legs pain and feels like i cant jog but when i start run after some time everthing will be ok.Is that walking or joging for such long distance is bad for health.Please provide me some food that i have to take at night before joging or after joging so that i can stay healthy.Thank for answering