Why am i faster while running at night?

Hi All,

First time here, so go easy on me.

I have been an average runner for the last 10 years or so. I play rugby and weight train 3 times a week, so I like to think I am fairly healthy. Unfortunately the old metabolism is needing a bit more of a hand nowadays so about 6 months ago started to up the amount of cardio.

I generally do 2 evening runs of 5 miles and a weekend one of 10.

My times are fairly average, but I have noticed something that I can't understand. In the evenings I find the running so much easier. As in last week, I went out at about 22:30 and did 10 miles in almost 10 minutes quicker than my normal time, and could of done another couple of miles I am sure.

I have tested this theory a bit and need some expert advice to try and figure out why. Any ideas?

Basically, when I run at night, I am faster and find it easier than when I run during the day/early evening.

Thanks in advance, it would be so good to shave that time off permantently!

Rich