I started running a couple of months ago, mainly for cardio and some fat loss. At the moment, I'm running 2 miles in about 15-18 minutes. My questions are: 1. I normally run at night. Is there a difference running when the sun is out and it's warmer? I know I'd probably sweat more, but is there much of a workout difference? 2. Should I try to run my 2 miles faster or go for 3 miles @ the current speed I run? Any other running tips would help. Thanks alot!