Yesterday I purchased my seventh pair of running shoes so far this year. That is an all-time record!
You probably don't need seven pairs of running shoes (and I only have four at a time) but at a minimum you'll need two at a time and here's why:
I used to wear just one pair of running shoes, and run them to the ground, and then get a new pair. Now I wear 3-4 different pairs of shoes everyday at different activities. I learned from a running shoe guru friend of mine that running shoes need a rest too. Runners need at least 24 and preferably 48 hours to regain their cushioning. My shoes now last almost twice as long as they used to because I rotate them.
Two years ago I started wearing proper training shoes (as opposed to just running shoes) and I love the difference! I used to feel like my feet were spilling over the edges but trainers are so much more comfortable because they control for vertical and lateral movements. My running shoes last longer now because I wear them only for what they are built for: running. I wear Nike Free Trainers at Bod Squads, Sacony Trimphs on longer runs and with clients, and Nike Free 5 running shoes on interval runs and Bod Squad field trip days (all pictured below). Whenever possible I take my training/running shoes off and wear flip flops. When you walk around in your shoes that will also cut their lifetime down a lot.
Having proper shoes improves activity enjoyment and it helps prevent injury! It is so important that your foundation in exercise be solid. Don't skimp on the shoes, your whole body will thank you for it!
Bottom Line: The standard rule of thumb is if you're a regular (3-4x per week exerciser) you should get new shoes every 3-6 months or 500 miles. And if you're asking this question … you probably need new shoes.