Today I went out for another week 8 day 1! I've done it successfully 2/3 times now and completed week 7 day 3 successfully a few times also!
Problem today was, I got 8 minutes in and my chest was sore, almost under my lungs! I couldn't carry on and had to walk the rest. My route was no different than a previous successful attempt! Any clues as to what went wrong? I had a good sleep, had eaten my usual pre run breakfast beforehand!