And a Word About Pain

I am sitting on Amtrak train 600 in the middle of my 2-hour-each-way commute to Philadelphia. Yesterday someone asked me about pain. I thought it was obvious that a guy my age exercising an average of two hours each day would be sore somewhere most of the time. This person was surprised to find my exercise program is designed around training that will get me stronger without pushing to the point of injury. I try to run one day and ride the next so I won't run on consecutive days and hurt myself. It doesn't always work. I ran a 5k race and Monday morning and did a fast 4-mile run on Tuesday. My left knee started hurting on Wednesday. I ran three miles slow last night and this morning I am moving my feet every couple of minutes to keep my knee from hurting.
The change in my push ups bothers my right shoulder, so I added a couple of exercises every other day to strengthen my shoulders. On some days I skip the sit ups because my lower back hurts. On some running days I ride and walk because my ankles hurt.
I am not complaining. I know that various pains are part of any serious training. My main goal is not to get an overuse injury that will have me otherwise healthy and sitting on my butt. Worse still, I do not want an Army profile--a paper that excuses a soldier from duty. When we are assigned training, I do not want to be sitting on a log with a profile.