My new coach wants me to wear trainers instead of flats for easy and long runs. I've been wearing flats (Adidas CS/Adios) for all my runs for over a year with no problems, but I took the coaches advice and bought a pair of trainers. After two runs in the trainers I had aches and pains I'd never had before.
Has this happened to anyone else? I'm wondering if my body just needs to adjust to the trainers, or if I should just go back to wearing flats (I don't really like trainers). I don't want to offend my coach however.
In case it figures into your thoughts, I run about 80 a week, mostly on soft surfaces except for speed workouts (twice a week on asphalt or track).