1 Mile Benchmark Run?!?

On a whim I decided to run a mile all out tonight. I ran a warm up mile to get my HR up to around 160. Once warm, I restarted my HR monitor timer and took off like a shot. I went too hard and had to back off a bit after the first 200 yards. As I rounded the halfway point I felt like I might loose my dinner briefly, then recovered. I felt myself slow a few times, but forced myself to kick up the pace over and over again. I was really hurting at the finish and was just hoping to see around 6:15 for my time. As I crossed the 1 mile mark, I pulled my monitor band off to stop the time and tried to catch my breath. I ran this mile like I was running for my life, each stride was accompanied with a grimaced out of control breath.

When I recovered a bit, I walked over to a street light and was stunned to see my time.... 4:25!?!?!

Of course, I have to go to a track to confirm this... but if it's legit I need to think about trying to train up to win the local 5k races. I'm stunned.

Update: I double checked my HR monitor, it seems to be correct and the time looks good. I double checked my distance, it is correct according to mapmyrun.

I'm still skeptical, because that's pretty quick for someone who bikes a good bit and runs a little on the side. I knew I held back with my 5k in May and I've done a good bit more training since that race. A 4:25 mile run on natural ability and limited training means I could get serious and get dangerously close to that magical number 4. Maybe this is why people run :)