I ran for 30 minutes today after a month due to my dodgy knees, and it was wonderful! The only run I've done in the last month was a quick 15 mins 10 days ago (I count it as a warm up for weights, not an actual run) and I was really scared I'd have lost a lot of fitness. In fact, at the 5 min mark I was trying to decide which week to redo the programme from - 5 or 6. But I plodded on, resisting all temptation to pick up the pace. Slowed down to a walk at 15 mins to drink some water, but in less than a minute I was recovered so just started running again and ran all the way to 30! (I'm very pleased to be a graduate so I can run/walk as I like and have this count as a proper run). I was more interested in doing the time rather than reaching a certain distance, so I kept a steady pace all through and sped up just for the last 2 mins.
Hopefully the knees hold up and I can do more 30 min runs before aiming for longer distances. Good start to the week