I agree completely, goldfinch. Diet has a stronger influence. My issue is that when I train hard, it's like I lose all sense of how much to eat and when. For that reason I am going to see a nutritionist to find out how much I should really be eating on days when I am riding 25 miles plus. There is almost too much conventional wisdom out there to make sense of it all. I have a hard time listening to my body too-- it sends me mixed messages!