Training Phase 2, Day 38

I'm a little confused. This morning I prepared and ran in much the same way as yesterday, however I managed to go quite a bit faster. I did start with a downhill bit, but even that shouldn't make this much of a difference. The only thing I can think of is that I was wearing shorts rather than sweat pants. Should that really make this much of a difference?

10.6 km in 1 hour 1 minutes. That's 6.5 mph.