Just got a Dexa scan and I’m sitting at 10% body fat. (46 yo male - non competitive but train 10-15 hours a week on the bike…plus weight lifting)
I am wondering how to guage what is too low?
My understanding is “too low” varies person to person, But endurance athletes are much lower than other athletes.
Not trying to hit a certain number. Just want to be healthy overall.
Would like to hear others opinions as I’m fairly new to endurance sports (been at it under a year).
Tyty
As an almost 50 year old non competitive rider not sure I would go below 10%. Seems like a level that looks good is healthy… someone I am sure will have a more medical based opinion 
Regardless of opinions that might be shared here, I think a proper visit with a personal physician is the best direction for finding relevant info.
If you believe the app for my scales below 12% is too low and 12-18% is healthy 
I don’t think a doctor is needed… plenty of studies out there. Everything I have read puts it at 10-12% is healthy. And looks good… 
I do not have current studies to reference which is what I am was expecting someone more up to date to chime in with…
Watched this video linked below and he says 5% for men is getting to be too low. He said under 10% is fine but hard (and potentially unhealthy) to sustain - like being hypocaloric too long, not getting enough nutrients in food, etc.
He did mention endurance athletes can be healthily below 10% but didn’t specifically say what to look out for.
Just curious to hear opinions from those with experience (or any of the coaches, docs, dieticians, etc).
I think the simple answer is to gauge how you feel when and how well you handle stress. Signs you might be too low is if your libido is low, get sick often, are slow to heal, etc. There are probably more concrete hormone levels but knowing what those are may be hard to know in a regular basis.
Dexa scans are a lot more accurate than older methods (ie body fat calipers). The extreme lows/“essential body fat” levels for men when I was in school ('90s) was 4% - that’s the amount you HAVE to have for bodily functions; however, that’s probably more like 6-7% on a Dexa. So 10% on a Dexa is pretty lean. Stevie_Dee makes a good point; I wouldn’t intentionally try to go much lower
DXA is precise, but the accuracy depends on the algorithm used by the manufacturer to do the calculations. You can therefore get markedly different results in different brands, or even on the exact same scanner after a software “upgrade”.
Yup. Skinfolds are pretty darn good.
Here’s the most recent opinion on body composition in sport, including an evaluation of assessment techniques: Best practice recommendations for body composition considerations in sport to reduce health and performance risks: a critical review, original survey and expert opinion by a subgroup of the IOC consensus on Relative Energy Deficiency in Sport (REDs) - PubMed