Graded Exercise - How NOT to Do It

I try to get out and walk every day, even if it's not very far.  I had just started trying "graded exercise" which I've read is recommend for Fibromyalgia sufferers.  Basically, the concept is, to increase your exertion levels in very small increments over a long period of time.  The theory is, that this type of slowly increased, low-impact exercise, will not cause ME/CFS & Fibromyalgia symptoms to intensify as regular exercise usually does.

I bought an app for my iPhone that measures distances walked, average pace, altitude, where you walked and more, using GPS.  Just as a side note, I really like the app and recommend it highly.  It's called MotionX-GPS.

Anyway, the app can be set to give an auditory update every five minutes with average speed, distance traveled and time passed.  I wanted to keep track of how fast I was walking, since it's often hard for me to judge, and increase my speed slowly over time. 

I began walking, with the new app on my iPhone last week.  I was having a pretty good day, so I decided to do a 1.5 mile walk.  My average speed was 2.4 mph.  The next day I walked the same route and had a similar average speed.  The day after that I decided to try to kick my speed up a bit.  It seems I got a bit over-confident.  I pushed myself and tried to maintain 2.7 mph.  Of course, people as old as my parents were flying by me like I was standing still, but I had to really push my leg muscles to keep up that pace.  I was really proud of myself and managed to repeat my performance the next day but that was the end of that. 

I guess the two 2.7 mph days, pathetically, knocked me out.  I was extremely fatigued and weak for days after.  That was six days ago and finally, just today, I was able to go for a walk.  It was a little under a mile and my speed was more like 2.0 mph and that was as fast as I possibly could have walked.  My muscles felt weak and shaky and I kept loosing my balance.  If I'd tried to walk any faster I probably would have fallen down.  I wonder how long it'll take before I'm able to walk normally again.

The lesson here is, in graded exercise, when they say very small increments, they mean VERY small.