Indeedy.
I have recently done a Personal Trainer course so I know the ‘measurements’ at the moment. ‘Measurements’ in quotes because all these methods are approximations. I prefer the ‘if you can see your abs and the split in your biceps then you’re under 10%’ approximation. Because that gives me an answer I like even better.
When I train for bike racing I won’t get on the scales, I closely monitor the power meter on the turbo or on the bike. And do geeky graphs etc (which probably don’t help either).
I suppose the important point is that if you think your monitoring will do some good, by placebo effect it probably will. And for that reason it may be worth doing. I’d just rather do the stuff that I think monitors the results that may be transferable to the goal (more speed = winning races).
I’ve also found I’m fastest running when thinnest, but fast cycling seems (in my case) to need a couple of extra fat kilos…