Two different scans: one does bone density, the second body composition, such as lean body mass, visceral fat. I had mine done at the same time, just a minor adjustment of the device.

Oh no! I was counting on my surplus being completely converted to lean muscle!

Mia culpa if this is too much off topic 🙏🏾

Anyone have any exerience to share with 8 electrode smart scales in direct comparison with DEXA scans in term of accuracy, reliability etc... or lack there of...?

Hume Pod, Withings, Renpho, Runstar, Arboleaf others..?

DEXA is more accurate and more reproducible. In general, I see 15-60% differences in impedence results compared to a calibrated DEXA - but they are getting better.
They serve a different purpose, which is day to day measurment If you want to have fun, check out the difference between first AM and bedtime measurements on the scales that use electrical impedence to estimate water content and thereby % fat.

Thanks for the response...

That's what I've heard... hydration can really throw things off, so need to mitigate differences when measuring to get accurated or at least consistent lonitudinal change in your readings...was just wondering if anyone had good or bad experience with specific models.

The electronic components are common to many brands. At this point, I'd simply pick one out in the $150-200 range and use it to keep me honest about trends in weight and impedence.

Hard to figure out for sure... I see that the newer more expensive models have dual or multiple frequencies that are supposed to do a better job at approximating body composition... if there is no real ability to be more accurate.. maybe I just stick with my 4 electrode $30 scale 🤷🏾‍♂️

So what useful things for cycling does knowing your body fat or bone mass do? It just seems like one of the many gee-whiz numbers we like to boast.

Few people are going to have a body fat low enough to worry about materially adjusting their nutrition. And for your bones, diet and resistance exercise to keep those bones strong is needed regardless of whether they are currently losing strength or not.

So I'll do a Dexa scan when I get into my seventies and the doctor wants to determine if bone loss is happening. Till then I just do the normal things that keep them strong. I just get the body composition from my scale whenever I need a chuckle.

I'm a few weeks shy of 77, returned to 'serious' (though not competitve) road biking in 2023, love climbing the hills (I CAN climb!) around where I live now. Admitting that I'm curious about my skeletal endurance and potential for damage should I crash, I'd really like to have some idea whether my bones are more prone to being broken in minor stuff should that occur.

Inquired of my health provider what a DEXA scan would cost me out of pocket. Got quoted $600.

Good thing they don't do VO2Max, eh?

(I've had one of those four electrode scales for close to a decade. Doesn't tell me much that I can put a value on, other than weight. I have to remind myself I need to be barefoot if I want more than just weight....)

Admittedly, my case is unusual, as I'm chasing performance. A scan gave me a healthy lower limit for weight that I could shoot for. I'm kinda heavy for height...the scan basically confirmed that I actually am big boned and that dropping more than 5lbs of body fat wasn't going to be a wise choice. That being said, I didn't pay for this scan and it's not something I see myself pursuing outside of my racing goals.

Nice.
As regards the question - I first measured my bone mass as part of a research project 40 y ago (for the nerds out there - dual photon absorptiometry as it was pre-DEXA.) Since then, I've tended to always wear hip padded shorts when commuting and touring, and after flipping a track bike a couple decades ago, I have elbow protection as well.
Might not want to wait until your 8th decade of life to check how much bone mass you're starting with - a baseline can be helpful. In my case, if my first bone mass was yesterday, folks would be scrambling to get me medication. As my doctors know I haven't lost bone mass throught the decades, there's some reassurance I can continue on with my program.
Jus' a thought.

Those are good points. Though I'm imagining that both of you at the time and possibly for all your life have been very active and athletic. And always with lean body mass. Much of my thoughts for making my statement in post 33 are toward those of us that aren't so active or of lean body mass.

And perhaps just to make certain there is no real use for a Dexa scan results to materially alter our training program or nutrition. Other than perhaps, for the few that are shown to be losing too much bone mass, they need to up their resistance exercise and assess their nutrition.

I've read that 10% body fat might be reasonable for active and very athletic persons. And that currently isn't me. Though for one that is, 5 lbs of body fat lost could be a health issue.

But again, I don't feel that the average member here on BF needs to feel a need to shop around for a Dexa scan until their GP they should be seeing regularly, recommends one. Which typically is after 70 yo. It's not going to change their cycling performance or training to increase that performance to know that information.

Thanks for the suggestion. I've been on the fence about checking my bone mass, and the doctor says wait until 70. I may fit the profile of someone at risk for osteopenia (68yo, 18.5 BMI, high volume cycling over decades, limited resistance training, no regular weight-bearing activities).

I think I'll pull the trigger and shop for a DEXA scan in the area.

Same reason that I did the scan. Turning 70 in a few months and I am trying to do what I can in the next few years so that I am as healthy as possible when the inevitable happens. So for that, I wanted a baseline. My bone density is ok and visceral fat ok, and weight ok. Which means, I think, that I should have more muscle for my weight, meaning less fat. So yea, I am doing more strength training and trying to increase the weights too. Did it really change anything compared what I subconsciously knew I should do anyway? Probably not, but I wanted the numbers, the baseline.

OK, I scheduled a DEXA scan for tomorrow. Will report how it compares with numbers from my Hume scale.

terrymorse Oh, nice, taking one for the team so to speak.

OK, as promised, I did a weigh-in on my Hume Body Pod, followed within an hour by a DEXA scan. Here is the comparison:


https://cimg4.ibsrv.net/gimg/bikefor...9ce943381e.png
I was most interested in bone density, and the DEXA scan reports this:

https://cimg7.ibsrv.net/gimg/bikefor...d4432e23bc.png

It also says my overall bone density is in the 1st percentile for my age:

https://cimg4.ibsrv.net/gimg/bikefor...fef7687c24.png
If that's true, YIKES!

Edit: I gave ChatGPT my DEXA report, and it spit out this overview:

_________________________
Bottom Line

Your DEXA scan shows:

Very athletic body composition for a 68-year-old endurance cyclist.

Key highlights:

• Body fat: 12.6%
  
• Lean mass: extremely high
  
• Leg muscle mass: excellent
  
• Muscle symmetry: perfect
  
• Visceral fat: extremely low
  
• Bone density: mild osteopenia signal (common in cyclists)
  

From a performance standpoint, your morphology is well suited for climbing cycling events.
_________________________

Flattery will get you everywhere, AI Buddy!

My bone mass was exactly the same as yours, but says 14%ile. I weigh about 145lbs, if that matters. Also, your body fat was half of mine, and I am weight appropriate. You must be very thin. The "well suited for climbing events" tell all.

"Very thin" hits the nail on the head. 5'11" 133 lbs.

What's your hat (helmet) size?

Hat 7-1/4, helmet medium.

Does that mean anything?

Wow, very thin indeed. At 6', 165-170lbs is my ideal race weight. I hover around 10% body fat, but just looking at a weight rack makes me put on muscle mass. Not necessarily the best attribute for performance cycling, but I guess it's not a bad deal for general living/injury prevention.

How about this: I give you 10 lbs in weight in exchange for 2 inches of height. Then we'll be the same. I'll shortly get my 10lbs back and you'll be stuck being short.

Geesh!

I'm 5' 11" too. But definitely not 133 lbs and definitely not 12.8% body fat. Hopefully I can use this as a challenge to get fitter and less weight by the time my GP sends me off for a Dexa Scan. Probably 3 years or so from now.

I'll be extremely happy if I can get down to 151 lbs and satisfied at just 160 - 165 lbs. I doubt I could ever get anywhere near to a elite body fat 12.8%

I'd be curious to know if your doctor has given you any cautions about it being that low. Though it is a common level for the very athletic.

No, I've never had a doctor tell me I needed to bulk up. I've weighed the same since high school. Pediatrician told my mom "he's small-boned -- don't let him play contact sports".

https://cimg7.ibsrv.net/gimg/bikefor...dfde4ce38d.png