I know that most running shoes have a life of 300-500 miles. However, this is a very broad range and I'm not sure when I should retire my Mizuno wave riders. I obviously know when to retire them once I start feeling pain because of them, but I would prefer to stop wearing them before i experience pain. If anyone can give me a window of miles in which I should retire these shoes (a little more specific than 300-500 miles), that would be awesome. My foot strike is between heel and midfoot. I weigh about 130 pounds and I am about 5'8. I am a neutral runner with little to no pronation. I run on the road about 4 times a week and dirt trails about 2 or 3 times a week. I hope this is enough information...thanks