Hi, I'm new to the forum but I'm on Week 4 of C25K.
This forum is a life saver, I've been really struggling on the week 3 runs and was dreading this week, but after reading a lot of posts, my salvation was revealed.
I was going too fast!!
It sounds stupid, but I'd start running at what I thought was a comfortable run and wouldn't be able to run for very long. I just didn't think I could run. I've no idea why slowing down didn't occur to me before.
So, dreading the 3min / 5min runs of week 4, I tried a different approach. When I got on the Treadmill yesterday, I used a heart rate monitor. I set my speed to the usual 10.5 kph and watched my heart rate fly through the roof. Basically when running at that speed I was approaching my maximum heart rate (MHR) which isn't usually a good idea. I slowly dropped my speed until my heart rate was in the 60-80% training zone and I was running at a steady 8kph.
At this speed I managed the full run (could have probably done a bit longer to be honest) and it felt great. So this is my new starting speed from which I will adjust as my fitness improves.
Again, I'd just like to thank everyone on here for their helpful posts and just to reiterate that if you think you are running too fast, you probably are. If you think you are running too slow, it doesn't matter. The aim is to get you running for 30 minutes, the speed and distance is irrelevant. Once you've managed this, do the C25K again but faster!