Let's say that there are 2 identical people with the same fitness level. They both weigh 150 pounds, but 1 is at 9% bodyfat and the other is at 14% bodyfat. They are identical in every way except for the fat factor I just mentioned. Whose heart is working harder?
I'm thinking the person at 9% bodyfat because the extra muscle he's carrying needs that extra blood.
What do you think?