a bit miffed...

I went for a quick 5km run this evening - I'm not a that keen on running, but feel it's an essential part of general fitness.
I headed out and immediately felt good - I'd had a horror of a run a few weeks back, so it was a relief. The pace was settled and I got into a good rhythm early on, so upped the pace. I'd been talking about improving my running with some friends who are training for a half iron man and they'd said that a good rule of thumb is that you will keep improving if you train at a reasonable level of respiratory discomfort! So, taking this on board, and with a nice long pace I was hoping to do a good time.
Anyway, the end of it is that I did it in exactly the time as the last five or so runs - 24 mins! Bloody annoying! It doesn't seem to matter if I saunter around barely puffing or push myself so that I'm hanging out, it's always 24 mins. Gaaah!
Perhaps I'll have to bite the bullet and start interval training :(