Doctor's note: Goal setting and your health

Dear Readers,

Last winter, my sister sent me an email asking whether I wanted to run the Chicago Marathon with her in October 2013. My initial response was, "Oh my gosh, no." I am a committed exerciser and runner, but the thought of tackling such an ambitious goal made me feel anxious and insecure. I hesitated for a long time, but after much deliberation decided that I would register for the race.

I am 53 years old and I want to keep myself as mentally and physically flexible as I can be, for as long as I can. Training for a marathon would certainly serve that purpose! I wondered whether I could set three goals for myself: train without injury, run the Chicago Marathon in under four hours, and qualify for the Boston Marathon.