Well, I guess I can share some thoughts here, although I am not a racer. I used to run half-marathons well enough to be among the top ten in my age group in local races, and my times were still improving. Then I discovered I had a very aggressive breast cancer. After a mastectomy and chemo, I had a bone marrow transplant, followed by radiation. By the end of a year of this, I was pretty depleted and getting epogen shots three times a week because I was so anemic. However, other than about two weeks of hospitalization during the bmt, I was out running nearly every day, albeit slow and shorter distances. After all the treatment, I never was able to get my times down. I still kept trying for several years, usually in the back of the pack, and in one 5K, I was actually the very last runner in! Gradually running was less fun, since I could no longer achieve the success I wanted. So I took up mountain biking, where my goal could be to ride without falling or dabbing, or just to enjoy the trail, rather than worrying about pace. During the first year, my friends always had to stop and wait for me at the top of every climb. My cycling improved, and my friends don't have to wait for me any more, but I know I could not be competitive. This summer I bought a road bike, and once again am hooked into the old going faster game. But, I am competing with myself, not others. In the fall, I plan to "compete" in a duathlon (sprint length), and I will probably come in last. But I plan to have fun, and if I decide to do more duathlons, I will just seek to improve over time. So that is my little story.
Did I worry that training might cause me to relapse? Well, that was a consideration. Especially when sometimes my worried husband would tell me that maybe the reason my bone marrow wasn't recovering was because I was working out too hard. However, I feel better, physically and mentally, when I exercise. I think the reason I got through my cancer treatment as well as I did was because I was fit. And I think maybe the reason I am still here, now seven years post-transplant this month, is because I am fit. This is my life, and I am lucky to be here, lucky to be healthy, and I am going to pursue every dream I have. If I become ill and am forced to quit, I'll deal with that when the time comes. But changing my lifestyle out of fear is not an option for me. Yes, even now there are still little fears that creep in. I push them away, don't give in to them, because my quality of life comes from enjoying the training.
So, I say to you, Lisa, GO FOR IT! Do what you want to do. Have fun, enjoy your life. If you maintain balance, you will stay healthy. Just listen to your body.
Good Luck!