Just read about this general formula. I’ve been getting leaner since taking up cycling. I was never fat, just lost 3-4kg. I am now the lightest I have been since high school. I am 14% fat on a DEXA scan. Pretty happy.
According to that link, my ideal weight is still 15-18KG lighter. Wtf.
Does this formula work for anyone else?
I think it’s one of those things like BMI where it’s a massive generalisition.
Based on that, i need to be 72.5kg, which is 6.5kg lighter than i am at the moment. I do think i’d be able to get down to that if i really worked on it, however i’d literally be a skeleton.
I think everyone’s ideal weight is 0kg. That way you’d go at light speed all the time for no effort.
According to this formula my optimum running weight is 67 kg. According to the DEXA scan from a week ago, my lean body mass is 65 kg. The lightest I’ve ever been was 70.5 kg and I was getting see-through already. Would love to be 67 kg though, could get above 5W/kg at peak FTP 
You should read Racing Weight by Matt Fitzgerald…its mostly focused on nutrition but its incredibly interesting. The things I learned helped my adjust my diet to fuel for workouts. The beginning chapters outline a simple way to find your racing weight. You can pick it up used on Amazon or similar for under $10 US
A review on Amazon:
I guess I don’t know what I was expecting - a silver bullet of some sort, maybe 
It has plenty of specific information across a number of endurance sports, but really boils down to two points.
I happen to be this exactly:
I am 145lbs or less, 5-6% body fat per the Tanita athlete setting. So I guess I’m “good”, but why am I still so darn slow running 
I’m 5"8 small frame and according to this should be around 60ish kg. I normally walk around at 65kg and I aim to race at around 61-62kg and at that weight I’m not super lean so it’s not a million miles away for me.
It works for me, I’m 5 ft 10.5in (don’t forget the 0.5in) Medium Frame 140lbs & Small 130 - 135. I’m between the two. Sadly I’m not at weight at the moment hope to be come spring 2019.
For me between the frames Medium and small is perfectly aligned with the recommendations in Racing Weight by Matt Fitzgerald.
At 5’8" (or just slightly under) with a small frame. it puts me at 131lbs (59.5kgs for the rest of the world!)
I don’t think I’ve weighed less than 60kgs since I was 14 or so, and I’m pretty sure the wife would start asking questions if I dropped that low.
If I’m purely marathon training I naturally drop to around 60.5, so it’s actually fairly accurate in that respect. Triathlon training seems to add bulk and weight (shoulder and leg muscle presumably?) - usually up to around 62.5kgs.
Still think the best advice is eat well, train well, and the weight will sort itself out.
Probably pretty good. At 5’9”+ I ran well under 140, but tri weight is 145-147 since I have some upper body muscle. Float around 150-155 otherwise but don’t have much issue dropping to race weight when training.
Coming from a rugby background and carrying a bit of excess weight (new baby sleep deprivation not helping diet or training) at the moment but I’d imagine my results mainly relate to the top end of the sport.
I’m 6ft with a large frame which equates to somewhere between 67-70kg. I believe that’s in line with Geraint Thomas at this years TdF and he didn’t look as skeletal as some of his rivals.
Yeah ok. It seems to work for others. Interesting. I couldn’t imagine what I’d look like if I lost 18kg 
I think I’d be on deaths door.