Body Fat Percentage
 

I recently bought a scale that calculates weight, Body Fat, and Hydration Levels, among other things. I did my first weigh in and it said that I only have about 3.9% body fate and weigh about 136 lbs. Now, before you go saying that the scale is inaccurate, I intentionally bought a scale that was a little more expensive and is designed for lean athletes.

My questions is, is my super low body fat actually hurting my cycling? I will say that my FTP and endurance is definitely on the low side, but I'm not sure if that's from my lack of training, only starting training seriously a couple of weeks ago, or something else.

Thanks
James

BTW I'm only in my second season of cycling and I'm 5'11, in case that matters.

It's inaccurate.

It is.

Doesn't matter if it was $12,000. The Bioelectrical Impedance Analysis scales are inaccurate when it comes to body fat. They are good for seeing a change over time or other changes but the actual value is not accurate. If you want a valid number get a skin fold test.

We bought a Tanita scale for about forty bucks a few years ago. My partner finally got around to one of those expensive water-immersion tests, and it showed him having a body fat percentage of 14.9%, compared to the Tanita reading of 14%. Seems pretty accurate to me!

Dunno bout the scale but if you're 5'11" and 136, you are one skinny dude. Have a frickin sammich, huh?

I'm 6' and around 165 lbs. In the "athlete" mode, my Tanita ranges from 4.9% to 7.3%. In the non-athlete mode, it ranges between 10-14%. I'm guessing I'm probably about 10%, but I haven't been immersed. I'm going to get calipered soon and see what that looks like. It is rather unsettling to see the numbers come up as 166.6 lbs and 6.6% body fat.:eek:

I just weighed myself again, this time in the morning, and this time it showed me at 133 and the same body fat.

Well, I strongly suspect any body fat reading lower than 5%. That is about as low as human beings can get without expiring. I have heard people claim 0% which means just really lean. They are blowing smoke. Physiologically, it is impossible. Your cell membranes are made of fat (phospholipids). If you had a 0% body fat, you would just fall apart because you would have no cell membranes.

None of the scales is very accurate. The skin fold is OK for comparative purposes but not absolute.

I suspect the only truly accurate way is to grind up the person in a blender and render off the fat. But that is a tad bit hard on people so most people decline doing things the truly accurate way. Where has dedication gone anyway?

Your reading of 3.9% is freakishly lean. Body builders hit low body fat levels but just briefly and they say it is like being almost dead. I suppose it is possible but it is not likely.

Speaking of scales, I just came in here to look around a bit and search the topic.

I want to get one. How much does a guy have to spend before you're wasting money on functions you don't need?

Is a $50 scale as accurate on the body fat readings as a $150 one for instance?

And what about readings like body water %. Sketchy accuracy on that too?

Caliper test are hugely dependent on the skill of the person taking the measurements...I doubt most are any more accurate than your scale.

The average cyclist would kill to be that low as cycling is all about power to weight (and knowing how to race, i.e., tactics). That said from what I've read you could potentially compromise your immune system with a body fat % that low as you add training load over time.

When you say you have endo issues what do you mean? What's happening on your rides? Are you running out of fuel when riding moderate to lower intensities for long distances? How often do you refuel on longer rides?

Last, what's your athletic background pre-cycling? Were you a distance runner? With a body fat % that low you obviously have genetics working in your favor but I'm sure you weren't sitting on the couch pre-cycling.