I've been running with a friend for a few months. I feel like I've made quite a lot of progress ( can run 3 miles without stopping, if slowly!) but recently my friend seems to be suffering badly. She keeps wanting to stop ( even more so than when we both started and could barely get around the park without stopping). In the last few weeks I've done a few sessions without her as I feel rather restricted running with so many stops in every session. She is very very slim ( I am not!) and I'm wondering if fuel is the problem (and/or motivation). Whilst she eats a hour or so before we run is the problem due to lack of "long term reserves"? Also why do some days seem soooo hard compared to other days?? Any advice is appreciated!