work4bike

Not really surprising for those of us cursed by the BMI mindset


https://www.realclearscience.com/qui...y_paradox.html

mcours2006

So perhaps a better metric for measuring healthfulness might be body fat %.

These findings shouldn't surprise anyone. Exercise promotes better healthy because exercise generally helps to develop more muscles and lower body fat, generally speaking, of course. The other side of that equation is the diet.

Hondo Gravel

According to the BMI charts I’m obese. My doctor said those charts are BS now I’m stocky but not tall 5-10 with shoes on and at 190 I have little fat. I admit I could lose about 10 pounds a That is what I’m working on right now. Not recently but I lifted weights all my life in the gym or on the farm/ranch. I do a fair share of physical work. IMO don’t worry about what a chart says.

wolfchild

I don't even use BMI. I just look in the mirror and it tells me everything I need to know.

Altimis

I ditch BMI completely, its not make sense in the first place.

Height-to-waist ratio is the way to go and more accurate.

By the way, bicycling is muscle mass burner.... its quite paradox, its can make you skinny-fat if one not careful about diets.

CliffordK

BMI is probably a cheap way to get lots of subjects into a research project.

In the past, several researchers were dunking their patients... well, actually calculating the specific gravity, which is likely a better measurement.

As the price of research MRI machines comes down, one could also simply create a program to calculate muscle volume, fat volume, etc. But, it could be complex to get thousands or millions of subjects measured and recorded.

I have thought that there is a benefit of having a bit of a buffer. So, for example, having enough fat that one could go without eating for a week (or on a super-low calorie diet), and still be just fine. Or, have some buffer to endure a wasting disease (cancer/chemo).

Whereas, a person that is super thin will become extremely weak if they can't eat for one reason or another.

Certainly some muscle is good as it is much easier to pack it on in one's 20's and 30's than it is in their 60's and 70's.

One of the things I like about cycling is that I think it helps keep up leg strength, and hopefully will prevent falls as I age.

wolfchild

All forms of cardio/endurance burn muscle especially if done in excess, running is even worse than cycling due to it's higher impact. That's why every cyclist who cares about their long term health should be lifting weights or doing some form of strength training.

Seattle Forrest

That's why cyclists who put in a lot of miles have quadzillas.

northtexasbiker

BMI is a broad stroke tool to easily generalize populations health. It's not BS, it was never intended to be very useful at the individual level.


A pool of people with a BMI reading obese is going to have a lot of unhealthy individuals in it.

OBoile

Agreed. People need to understand what it is and what it isn't. The strength of it is that you only need to know your height and weight, and that it gives a number that is easy to compare against a chart that is *generally* correct. Of course, that strength is also its weakness as a single number can't possibly tell the whole story. But this is true with just about any health metric.

I'd go one step further and say that even muscular people who are significantly "overweight" have health risks associated with that extra weight.

The key word there though is "significantly". A guy who is 250 lbs of muscle (like say a pro bodybuilder) is still going to have detrimental health effects from having too much mass. This will be offset somewhat by the fact that he's exercising regularly, but it still isn't the same as a 150 lb guy who is equally fit.

Like many things in life, there a happy (or healthy) medium between extremes.

If the BMI says you're obese, you probably would be better off (from a health perspective) losing weight. There are far fewer legit exceptions than people think.

Oneder

There's too many statistical anomalies to rely too much even on an accurate body fat %, such as weight loss being a symptom in a large number of ailments that generally lead to your death. I mean you technically lose all your weight when you die, right?

But it's clear from science at this point that the most dangerous thing is simply complete inactivity. In nature people would not stay indoors much and would seldom sit down for very long, so that makes sense. And of course common sense says a fat but active and blustery personality like brian blessed is going to be a lot more healthy than a guy who just sits and eats.

CliffordK

In nature, people would tend to die around age 40.

That is if they survive infancy, childhood, and childbirth for the women.

wphamilton

Anyone here tried a DIY hydrostatic measurement of body fat percentage in the bathtub? I'm imagining measuring your volume by the level of displaced water (probably have to model the slope of the tub sides), weigh on the scales, and plug the density into some equation, should be fairly accurate.

I think Archimedes did something like this a while ago, more interested in some jewelry but the same general principle. If you've tried it, how well did it turn out?

KraneXL

The results are inconsistent and vary widely between individuals. I'd put more faith in calipers and a well trained technician. On the other hand, practically any system will work it all you want to do is show rate of change.

elcruxio

I don't think that works out quite like that, especially individually. A lot of times people who cycle a lot have pretty big legs. Then there are the people who really focus on it and manage their weight to handle hills better and they may be thinner but in general I'd say cycling increases muscle mass, not the other way around. At least it's better than doing nothing in terms of muscle mass, as is all exercise. Even running is likely a net positive on muscle mass when compared to doing nothing. And running is also high impact so it's great for muscle and bone health.

As to doing some form of strength training, it's not about whether you're a cyclist or not. It applies to everyone and it has been long overlooked by mainstream health advice.

Seattle Forrest

Why should anybody bother to do all that when they can just assume?

KraneXL

Cycling builds endurance. Only progressive resistance builds muscle. People don't cycle to increase mass, they have mass and take up cycling because they're good at it.

Seattle Forrest

People don't ride bikes to gain leg muscles because it's a sub-optimal way to do it. It's slower than squatting and DLing to build leg muscle. It still works, it's just the slow route, and people whose goal it is to build muscle want the faster routes.

bikebreak

A 150lb guy isn't "equally fit" with a 250lb pro bodybuilder. Apples and oranges.
The 150lb guy, if he rides or runs for fitness, can obviously ride or run faster and farther than the bodybuilder, who can lift and throw the skinny guy across the room. Just because the big guy is big doesn't make him less healthy, he is way more healthy than most Americans and in some ways more healthy than the cardio guy.

Neither one is more "fit" than the other, though I would guess that the skinny guy can keep doing cardio when he is an old skinny guy and stay fairly fit, while the bodybuilder may have a harder time keeping his fitness.

OBoile

From a health and life expectancy perspective, this is wrong. Extra mass, regardless of whether it is muscle or fat puts a strain on many organs within the body.

KraneXL

Still imprecise because of necessity. The one that is most necessary according to your environment, goal, etc. In modern times there is certainly no need for endurance or excessive muscle to survive.

That said, fat is not bio-active, and you can be skinny-fat and be unhealthy. Conversely, more muscle typically supplants the rate at which your body accumulates and stores fat. Only when it goes well beyond what is natural does it present a strain. Both can increase your metabolism, but from different directions.

79pmooney

This is partially offset if you ride fix gears in hill country. (At say 18 mph average, its a lot "faster" than squatting or dead lifting! And useful if you are commuting! )

Ben

KraneXL

Slow twitch vs fast twitch muscle. Yes, you will gain some muscle through cycling due to activation of the slow twitch endurance muscle fibers.

However, even under full-load climbs this is nowhere near the amount you gain from anaerobic training. Keeping them separate is safer and much more effective for each.

Seattle Forrest

It isn't running and lifting that makes some people 150 lbs and other people 250 lbs. It's how much they eat, mostly.

bruce19

I will be happy when the BMI is tossed into the junk heap of history.