VJ,
Excellent, insightful article. Thanks for sharing.
I liked a lot of things about the article, but especially the overall attitude that you can break through barriers if you use a flexible, persistent approach.
As I've said before, I am extremely fragile, which gets in the way of a lot of things because I love to be physically active.
I have been a soldier in the reserves for about 20 years and at one time did 200 pushups a day. In recent years, especially as I age (I will be 54 tomorrow) I have found that I have to stay in shape at all times, because if I get out of shape--due to slacking off for a few months--I can't do any kind of normal workout without hurting myself. This past winter, after letting myself go (again), mainly due to a horrendous job commute, I found that I couldn't do even 10 pushups
without pain. Well, as a soldier, I can't live with that kind of physical weakness, so I developed a program. I did 10 pushups (even though it hurt) every other day for a month. I pushed through the soreness and a general feeling of weakness and instability in my shoulders and that routine strengthened me. Then I did 20 pushups every other day for a month. Eventually I found I could add pushups quicker, and I could get back up to 100 pushups every other day (not 100 pushups all at once, but in sets of 10-20). I think 100 pushups every other day is probably a good, safe place for me to be right now.
Similarly, I have been struggling to run even 2 miles lately, with multiple leg and back pains. It was getting to seem like it was ridiculous for me to try to run at all, I felt so limited. Partly inspired by Rich's high mileage, yesterday I went to the park and ran extremely slowly--crept, really--at around 10:00 mile pace, and found I could do 6 miles. I have never run that slow before in my life. But right now, running very slowly helped me to do the mileage. Today of course I am sore as a b*st*rd, but I don't feel injured--there's a big difference. 
Dark Horse
I'm a dark horse, running on a dark race course.