I did my 4th post-graduation run today - 30 minutes continuous running - and it was terrible. From minute 1 to minute 30 I struggled with my breathing, even when I was shuffling. I think I forgot to breathe again in the beginning and it all just went downhill from there. Did the whole 30 minutes somehow, but I haven't had a run this difficult since W1R1! Just goes to show you may be able to run for 30 minutes (and often love it) but you will still have runs that make you wonder why you even bother.