Gday Trickymac because say you are 80kg and want to drop 10kg of fat ( but you don't want to lose muscle mass). Scales and the mirror are not really accurate. It's only $80 a go. You look at how much money, out of shape people spend, on the lightest, & greatest bike's. They would of been heaps better off. Keeping 95% of their money, and just get fitter. Obviously if you are already fit say around 11% body fat, & you just wanted to tighten up a bit. A dexa scan is not necessary. This more for the sort of people that don't have any muscle definition yet because their body fat % is to high. Or a road cyclists that have a low muscle mass, & they want to increase it without putting to much fat on. Because they have finally realized that MTBing is heaps more fun, than road riding