Is there a difference in the level of effort men and women have to exert in order to achieve fitness?

Question

I have been told by a friend that women, because of their natural build, have a harder time staying toned than men, especially around the abdominals. For example, a man who does not work out but has no extra fat will still have a flat stomach but a woman usually has to work to accomplish this whether or not she is thick or thin. Does this difference really exist, and if so what are the reasons behind it?

Answer 1

Sort of. Men tend to lose weight and build muscle more easily than women. The flat stomach thing, though, that varies between individuals regardless of gender.