I started Spark People 16 weeks ago. The first time I walked on the treadmill I walked for 10 minutes at 2 mph. I slowly progressed and even added strength training. This Sunday, September 9 I walked for 45 minutes, 5 of those minutes I walked 3.75 mph, the rest of the walk was at 3.3 mph, plus warm up and cool down. First time I was able to walk 3.75 mph. And when I started I didn't know if I would be able to walk at all!