I'm on my way to completing my 3rd week of 80 miles during a base building phase and I can definitely tell that my legs feel heavier than when I was still running in the high 50s.
Running this many miles is doable but the overall pace is about 30 sec/mile slower than usual.
How long will it take for me to get used to this mileage and is it a cold hard fact that many people who run every day need to taper or rest periodically in order to do their work justice?
For example, if someone were to ask me to crank out a 5k at this point in time I'm pretty sure i'd run it at least a minute slower than if I was still running about 50mpw