When to Replace Your Running Shoes
July is the peak of training and racing for all amateur athletes. Chances are, if you're training for a marathon, triathlon, adventure race, or any other competition, you're wearing shoes that are a few weeks or months old.
Finding the right pair of running shoes is an extremely important task; and one that multi-Ironman Champion Paula Newby Fraser has blogged about here. But, timely replacing those shoes is just as important for staying on track with your training and remaining injury-free. Running in overly-worn shoes can cause blisters, plantar fascitis-and worse yet-knee pain.
When should you replace the kickers? Like the bird that gets the worm, better to be early than late on that decision. Some experts recommend replacing shoes in a manner similar to changing automobile tires; after a certain number of miles. However, I believe time spent in the shoes is a more reliable and logical replacement criterion versus distance. Why? Consider this example:
Two runners jog 50 miles every week. Runner #1 averages a 7-minute/mile pace during the week. Therefore, she wears her shoes 350 minutes each week-almost 6 hours. Runner #2 maintains a slower pace during his weekly workouts and averages a 10-minute/mile pace. He spends 500 minutes (more than 8 hours) in his shoes each week; almost 50% more time than Runner #1. If both runners used distance as a basis for their shoe replacement (some experts advocate replacing at 500 miles), R#1 and R#2 would both purchase a new pair of shoes after 10 weeks of running. However, the slower runner's shoes would have endured 1500 more minutes (25 hours) of wear and tear than the faster runner's shoes; a significant disparity.
My "magic" number has always been 50 hours in the shoes. It's certainly not a strict number, and can be increased if a lot of your training is done on a treadmill (the rubber track is more forgiving on shoes than pavement or concrete). But 50 is a good ballpark figure to keep in mind. Also consider rotating a new pair of shoes (on shorter jogs) into your running routine as you approach 50 hours.
Replacing your shoes more frequently will certainly increase your expenses, but the additional $100-$200/year will help prevent a much higher doctor or hospital bill from arriving in the mail.