Theo Chisholm needed an outlet to cope with stress brought on by the death of her beloved sister, Bettye, 13 years ago. She found it in running. Nine marathons later, the Stamford woman says it's still the best way to clear her head.

"It helped me with the healing,'' says Theo, who will run her third Boston Marathon on April 18. "I had never been serious about running before that. My husband (Sam) says I'm still not serious about it."

Chisholm runs for the same reasons as when she started. She's semi-retired after a long career at IBM, where running helped her handle job-related stresses. "When you're working, running is a great stress reliever,'' Theo said. "You're at the top of your game when you're training."

Her first marathon was in 1999 at age 50 in Chicago. She has run nearly one a year since, including Jacksonville, Marine Corps and Hartford. She competed in Boston in 2003 and 2007, and qualified again by running the Hartford Marathon in 4:25:12. She took an injury deferment last year. She also ran the Amica Insurance Marathon last fall in Newport, R.I. Her best marathon time is the 3:58:13 at Chicago. She ran 4:13:09 at Boston in 2003.

"When I qualified for Boston the first time, I really didn't know about it,'' Chisholm said. "But when you go to Boston, it's special. Once you've done it, you want to go back."

Runners all over New England struggled to train this winter. The heavy snowfall and road conditions made running treacherous. Chisholm worked on treadmills during the week. She did her long training runs on roads on Saturday mornings. "I was out there in the snow,'' Chisholm said. "Because of the weather, this was the hardest it has ever been to train. I had a couple of falls because it was icy. I'm fortunate I didn't get hurt."

Chisholm completed every race in the Club Connecticut Boston Buildup Series and ran the Boston Blowout on March 27 as one of her final long runs. She's registered for the lottery for the ING New York City Marathon. If she isn't selected for New York, Boston will her 10th and perhaps final marathon. "I think I'm ready,'' she said. "Oh, I'm sore. I have a regiment of Advil and Aleve."

As she puts in her final weeks of training before Boston, Chisholm remembers the reason she picked up running in the first place. "I did it for my sister at first,'' Chisholm said. "I felt that if I ran, I'd outrun a disease like cancer or heart disease. I thought if I run, I'll outrun all those things."

Have you run the Boston Marathon? What was your experience? Start the discussion below!