I've exercised first thing in the morning for years now. I work from home so I find going out of the house in the morning to walk/run/lift weights really helps with concentration and stress levels.

I'm new, however, to the whole paleo lifestyle and have been doing LOTS of reading including Jack Kruse blog. On his leptin reset diet post he talks about how exercise can initially be less than beneficial for those who are leptin resistant: THE LEPTIN RX……….. FAQ’s | Jack Kruse

In a reply to one of Mark's post yesterday someone else mentioned that fasted exercise can have a negative impact on mitochondria which ties in with much of what Jack Kruse talks about.

Anyway, I'm confused. I know there are a lot of variables but if anyone could point me in the direction of any more information as to whether fasted exercise is a good/bad thing, life shortener etc that would be great.