I have to agree with Susan. At a certain point, you have to look at what is too much for you. I can ride 100+ miles a week, but not do that and do boot camp. And I can't ride and run much, either. No matter how much I space it out, if I run, my legs hurt and then it affects my cycling speed and my general fatigue level. If I ever wanted to really work on being a better runner, I'd have to limit cycling to 1X a week and I made the decision not to do that. Running makes me drop pounds more quickly, but it's not worth the wear and tear on my body. In fact, boot camp is pretty stressful to me in a general way, but I need the muscle and bone building. I have to take 2 rest days now, although one of them is sometimes an easy ride or yoga. Granted, I am almost 60, but over training has always been an issue for me. I used to teach 7 aerobics classes a week when I was in my early 30s and I weighed 10-15 pounds less than I do now, had 2 little kids, a full time job, and lots of volunteer activities. I was sick ALL of the time, had a stress fracture and plantar fascitis all during this time, as well as asthma. People who didn't know me well always thought I was anorexic.
I learned my lesson.