I'm 6'1 about 200lbs and far from being "Fat." The tape test is a very inaccurate way of measuring body fat, but it's quick and easy and that's why the military does it. If you work out regularly, you shouldn't have that problem, but some guys do have slower metabolism a which can make it harder, but that doesn't exactly mean their physical endurance is worse than someone that's 5'11 165. I know this from experience.