I'm pretty sure that getting this wrong has resulted in a high likelihood of me not racing Mallorca 70.3 in just over a week's time.
I've run in these pink trainers for over 600km, including a couple of Ultra marathons both on and off-road. They've been comfy, I've had no blisters or injuries and they've been great. I wore them for the Rotterdam Marathon a couple of weeks ago and got baaad blisters. I put that down to running hard, in heat and on the road. Until today.
Yesterday we ran home; 15km at a reasonable clip, and my feet got sore. The little toe joint on the left and the ball and toes on the right and a *huge* blister formed on my left arch. My right knee niggled and niggled. I decided to throw away the shoes when I got home.
This morning, my right knee was swollen, sore and I could only just bend it a bit. I'm elevating, cooling and compressing it along with taking Ibuprofen and I'm fairly sure the main contributor to this problem is the knackered state of those shoes.
So perhaps it's not quite that straight-forward, that there trainers management. And it can have some unpleasant results if you get it wrong.