I am recovering very well after a diagnosed tibial stress fracture on Feb. 12. I have resumed full running status with no problems. ( the only difference is I train smarter and more patient now) All of my training has been on completely flat rail -to - trail trails. I would like to incorperate some gradually hilly trail runs. Are there any suggestions as to a time frame to slowly mix some hills in? I have been back to all-running every other day for the last two and a half weeks. Thank you for any responses.