The 409's were on sale for $39.00 so I bought two pair. I was going to use one pair for everyday use and the other pair for my 40 minute walk everyday. I noticed that for doing my walks I would get a severe pain in my calf area. I tried a couple of times but could not do my two laps around the park. Today, I only got 1/4 of a mile and had to walk home gingerly worried that nothing would tear in my leg.<br />I put on my old pair of 608's and no pain in the back of my calf. I guess they will be good enough for leisure walking but not power walking.