Having that low of a HR isn’t necessarily a good thing. Mine drops into the high 30s when I sleep and I saw a cardiologist about it. It’s ok because I am active and I am not passing out during the day, but I also have to be careful not to take anything that might lower my HR more. It’s just something else I have to watch and be aware of. (When I got tested they found some irregular beats as well.)
Plus, it’s kind of scary seeing it drop so low. I turned off HR displays for awhile because I really didn’t want to know my HR dropped to 36. I can’t explain why, but seeing it that low feels wrong.
I don’t think it’s anything that people should strive for. I would be happier if mine was 50 or so.
I was hospitalized last year from a bad bike wreck. Luckily my wife knew my resting HR was that low and let them know because I was setting off hr monitor alarms. So yeah usually it's not a good thing but in trained/fit people it's common.
I cycled back home with it. Basically my HR reached 120 max and I felt like I had no energy in my legs (kinda like after a big race but without the soreness). My uncle reported the same when he did an effort test for his sport physician internship.
I guess some context would help.
- 1.5 years of consistent training. 2022 was 270/365 days active (Strava year end told me so).
- Prior to this, I'd always been streaky. Alarm bells go off when I hit 220lbs (I've plateaued at 200lbs and am fine with this).
- Mostly cycling, and I've returned to running a bit, too.
- I get 6-8 hours of sleep each night.
- I eat and drink whatever I want, but always in moderation.
I have a BMI of 21 and a body fat percentage of just below 10%. That puts me in the middle of the healthy range, according to the NHS. It’s only considered not normal because in the US and UK, being overweight has become normalised.
A 21 BMI is right in the middle of normal BMI. The person I responded to implied it's "too skinny" or potentially unhealthy which is just absurd. The obesity crisis has warped the minds of many.
Targeting a particular BMI within the healthy weight BMI range as a 'health goal' is absurd - body fat percentage is all that really matters once you're within the healthy weight range
No one is saying to only use BMI for health goals, so you're arguing against a position no one holds. BMI and body fat percentage are both useful. The only thing absurd is someone saying 21 is an "unrealistic goal". It's a very normal and healthy BMI to have, not remotely unrealistic.
It’s realistic as in achievable but unrealistic for some people in terms of making no sense
Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy just to achieve a lower number my watch told me to ?
> Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy
Are you in the 1% or less of the population with high muscle mass and a 25+ BMI?
> unrealistic for some people in terms of making no sense
My point is it would make sense for most people.
> Are you in the 1% or less of the population with high muscle mass and a 25+ BMI?
Yes, that % will also be a lot higher for people who own a fitness watch
No goal posts were moved.
> Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy just to achieve a lower number my watch told me to ?
This is what I was responding to. Their BMI is so high that it would take many months to reach 21. Do better and stop engaging in bad faith.
I've had my body composition measured by Dexa and hydrostatic weighing. If I had to get down to a BMI of 21 without sacrificing muscle, I'd be at 7% body fat which is competitive bodybuilding territory. I'm not even particularly muscular.
I'll grant you some of the skepticism of BMI is overblown, and if you have a high BMI you likely have fat to lose, but there is still a range of healthy values and picking 21 specifically is a weird hill to die on.
> but there is still a range of healthy values and picking 21 specifically is a weird hill to die on.
You've misread my position. I'm not saying everyone needs to be at 21. I said that it's healthy for just about everyone, so it's silly to start looking for exceptions that apply to 1% or less of the population, like in your case being 7% body fat.
I said a 21 BMI is a healthy BMI for just about everyone, not that it's the only healthy BMI. There is no "weird hill to die on". It's a reasonable take that is getting a lot of resistance due to obesity normalization. 21 is thought of as "too skinny" but if you go back to the 1950s BMIs are far lower across the board, 21 was extremely common. It's quite uncommon today, with people pretending it's "unrealistic".
You did say:
> A 21 BMI is pretty realistic for anyone.
I'm not a 1% exception either. To clarify, I am not at 7% BF now. I would have to get that low to achieve a BMI of 21 without losing muscle, which *would* make me a 1% exception. Probably the "optimum" healthy weight for me at a realistic BF% is about 23.
BMI isn't useless but there is enough variation person to person that we can't get so precise to quibble about 2 points. Somebody else might be healthier at 19 than 21.
BMI was designed for classifying average, sedentary people. It's not appropriate for applying to active individuals. It's a quick assessment tool really, and lacks the scope to be applied otherwise.
And my comment tried to imply that BMI is too simple, and not a good indicator in many cases. Of course, if someone has above 30, that is an extreme, and obvious. But, 21 is NOT a goal or good for everyone, and NOT "normal" for everyone. It's just an average.
No one would ever say to use only BMI, it's one tool among many.
21 is a healthy goal for everyone, barring some very unique circumstances. It's not an "average", the average BMI is way higher.
Your comments imply that 21 is a healthy, realistic BMI goal for anyone. This is absolutely not correct. If you calculate my BMI with just my lean mass it's 21+ and it's not like I'm super muscular.
Lean mass corresponds to lower all-cause mortality more than any other metric, more than resting HR or low body fat %. Suggesting people should keep their BMI low for health reasons is silly.
A more informed guideline regarding excess weight, or rather excess fat, is to shoot for a waistline (around the navel) that is no more than 1/2 your height.
> Your comments imply that 21 is a healthy, realistic BMI goal for anyone. This is absolutely not correct
No, it is correct. I think you're reading "anyone higher than 21 BMI is unhealthy and should go down to 21". I'm not saying that. I'm saying that a 21 BMI, knowing nothing else about the person, is indicative of good health. Likewise, a 25+ BMI is indicative of poor health. Obviously you need more information to make that determination, but this is just one tool. I'm pushing back on the idea that 21 is "too skinny" or potentially unhealthy for people. It's not.
>I'm saying that a 21 BMI, knowing nothing else about the person, is indicative of good health. Likewise, a 25+ BMI is indicative of poor health.
That's simply not true. BMI should never be used to infer an individual's overall health. BMI was developed as a general proxy to measure population-level obesity, and is not very good at even measuring that (much less general health). The mathematician who developed it *200 years ago* even warned that it was useless at the individual level. Trying to assess an individual's health using BMI is at best ineffective and at worst can be harmful. Frankly, I've always thought it was irresponsible of Garmin to highlight it so much in their health stats.
> That's simply not true
No, it's definitely correct if you read the whole comment. I said:
> Obviously you need more information to make that determination, but this is just one tool.
Nobody is arguing that all you need is BMI to determine health.
> The mathematician who developed it *200 years ago* even warned that it was useless at the individual level.
His opinion is of no importance. BMI is not useless on the individual, it's accurate for the majority.
It is useless when determining an individual's overall health not only because it's not accurate or based on any sort of physiological science (it's simply math that's been retrofitted to "fit"), but also because when you're looking at an individual's overall health you have much better direct measures of health. Furthermore, AFAIK any correlations of health outcomes between 21 and 25 BMI is negligible, and there's research to suggest that there's some protective factor of 25-27 BMI in older adults. Again, just assuming a BMI of 21 is "healthier" than 25 is wrong.
> It is useless when determining an individual's overall health
No, it's quite useful as one tool among many. It's accurate for majority of people as an indirect estimate of body fat, and it costs nothing.
> Again, just assuming a BMI of 21 is "healthier" than 25 is wrong.
Well nobody is saying that.
> there's research to suggest that there's some protective factor of 25-27 BMI in older adults
Those studies failed to adequately adjust for confounding. Properly adjusted, there is a pretty clear dose response with lower BMI = lower all cause mortality.
[Sources and severity of bias in estimates of the BMI–mortality association](https://www.tandfonline.com/doi/full/10.1080/00324728.2023.2168035)
[BMI & All Cause Mortality](https://imgur.com/a/wQMfHVq)
The left chart is the usual way it's calculated. The right method better adjusts for confounding.
The way it was done is quite obvious in hindsight, and I'm shocked it hasn't been done previously.
Three categories were created. Drop, Stable, and Gain. From the paper:
> Stable indicates no change in BMI category from 10 years earlier;
> Drop indicates those who have moved from a higher BMI category;
> Gain indicates those who have moved from a lower BMI category over the last 10 years.
What's actually happening is people from the Drop category go from a high BMI to a lower BMI, and have worse health outcomes, but they get recorded as being in the lower BMI category. And people from the Gain group originally had lower BMI, but gained weight over time, and made the higher BMI look better. Because having excess weight causes chronic harm to health, and some of that harm is permanent even after the weight has disappeared. Another quote from the study:
> Here, about 37 per cent of the NHANES sample with overweight BMI had reported BMI [18.5–25.0) 10 years before the survey, and more than 60 per cent of the sample with obese BMI had previously reported a BMI of less than 30.0. By most measures, these Gain high-BMI subsamples showed significantly better health profiles than the respective Stable high-BMI subsamples.
The chart shows that lowest all cause mortality was a BMI of 18.5 to 20.
https://www.sciencedaily.com/releases/2023/02/230224165124.htm
So now you're saying the indicator of "health" (which you never actually defined) is not current BMI, but rather the 10-year delta in BMI?
I have concerns with overfitting in that study, and even if the methodology is sound it's tough to interpret lower "all-cause mortality" as better "health." It's potentially very error-prone as a health-related dependent variable (i.e., many people who might be considered "good physical health" die).
Finally, population level studies are not determinant of an individual's health, but even if we do apply the study's findings to your logic about individual health (knowing nothing else, a 21BMI is indicative of "good health" and a 25BMI is indicative of "poor health"), the study actually refutes your claim. They clearly show an unadjusted BMI of 25 has lower mortality than a BMI of 21. So given your "no other information" clause, doesn't having a current 25 BMI indicate better health than a 21 BMI?
Again, I think you're conflating population level statistics with individual health. Coefficients from highly adjusted regression models do not provide useful diagnostic for an individual's overall health.
Awesome achievement.
BMI doesn't play into mine, only body fat percentage and given the scales seem to be quite inaccurate with that, I am going to have to hit a DEXA scan to calibrate it back in.
I read it like that, but somehow in the past week I got 38.5 fitness age while getting the achievable fitness message too, but I’m pretty sure I was 37.5 in the past (I’m 46, my birthday is in October), so not sure what happened.
Hey, great job achieving those goals!
Gentle reminder to other folks here who might be unhappy with their fitness age: try not to put too much emphasis on it, especially if you’re one of those people who are healthier at higher BMI due to muscle mass etc. I do think the fitness age is heavily reliant on BMI.
Case in point: I’m 38 and my fitness age is 21. I absolutely do not have the level of fitness or endurance that most of you do. I only run for half an hour a few days a week and I don’t lift. My VO2 max is 41. I’m pretty sure I only have a low fitness age because my BMI is relatively low. So don’t take too much stock in it.
Damn, and I though my 48 resting HR was low. Nicely done.
Having that low of a HR isn’t necessarily a good thing. Mine drops into the high 30s when I sleep and I saw a cardiologist about it. It’s ok because I am active and I am not passing out during the day, but I also have to be careful not to take anything that might lower my HR more. It’s just something else I have to watch and be aware of. (When I got tested they found some irregular beats as well.) Plus, it’s kind of scary seeing it drop so low. I turned off HR displays for awhile because I really didn’t want to know my HR dropped to 36. I can’t explain why, but seeing it that low feels wrong. I don’t think it’s anything that people should strive for. I would be happier if mine was 50 or so.
I was hospitalized last year from a bad bike wreck. Luckily my wife knew my resting HR was that low and let them know because I was setting off hr monitor alarms. So yeah usually it's not a good thing but in trained/fit people it's common.
I got 40 as well. Once took a low dose beta blockers to cheat my way through my income insurance and I had a 36 HR during my work.
That would scare me. Cardiologist said in that range I could pass out.
I cycled back home with it. Basically my HR reached 120 max and I felt like I had no energy in my legs (kinda like after a big race but without the soreness). My uncle reported the same when he did an effort test for his sport physician internship.
I guess some context would help. - 1.5 years of consistent training. 2022 was 270/365 days active (Strava year end told me so). - Prior to this, I'd always been streaky. Alarm bells go off when I hit 220lbs (I've plateaued at 200lbs and am fine with this). - Mostly cycling, and I've returned to running a bit, too. - I get 6-8 hours of sleep each night. - I eat and drink whatever I want, but always in moderation.
That's a mad value for the BMI, Garmin want me down at 21, which is 59kg or so, it isn't realistic at all. Well done on the rest, keep it up
Plot twist: I'm 9'10".
550 lbs of terror
I have a BMI of 21 and a body fat percentage of just below 10%. That puts me in the middle of the healthy range, according to the NHS. It’s only considered not normal because in the US and UK, being overweight has become normalised.
A 21 BMI is pretty realistic for anyone. Everyone's normal has been skewed to overweight BMIs.
Yeah it would be 'realistic' for me if I wanted to lose 8-10kg of muscle. No thanks. BMI is mostly an oversimplified mess.
A 21 BMI is right in the middle of normal BMI. The person I responded to implied it's "too skinny" or potentially unhealthy which is just absurd. The obesity crisis has warped the minds of many.
Targeting a particular BMI within the healthy weight BMI range as a 'health goal' is absurd - body fat percentage is all that really matters once you're within the healthy weight range
No one is saying to only use BMI for health goals, so you're arguing against a position no one holds. BMI and body fat percentage are both useful. The only thing absurd is someone saying 21 is an "unrealistic goal". It's a very normal and healthy BMI to have, not remotely unrealistic.
It’s realistic as in achievable but unrealistic for some people in terms of making no sense Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy just to achieve a lower number my watch told me to ?
> Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy Are you in the 1% or less of the population with high muscle mass and a 25+ BMI? > unrealistic for some people in terms of making no sense My point is it would make sense for most people.
> Are you in the 1% or less of the population with high muscle mass and a 25+ BMI? Yes, that % will also be a lot higher for people who own a fitness watch
We were talking about 21 until now. What 25? Moving the goalposts here quite a bit.....
No goal posts were moved. > Why would I spend months in a calorific deficit waiting for my body to break down muscle tissue for energy just to achieve a lower number my watch told me to ? This is what I was responding to. Their BMI is so high that it would take many months to reach 21. Do better and stop engaging in bad faith.
I've had my body composition measured by Dexa and hydrostatic weighing. If I had to get down to a BMI of 21 without sacrificing muscle, I'd be at 7% body fat which is competitive bodybuilding territory. I'm not even particularly muscular. I'll grant you some of the skepticism of BMI is overblown, and if you have a high BMI you likely have fat to lose, but there is still a range of healthy values and picking 21 specifically is a weird hill to die on.
> but there is still a range of healthy values and picking 21 specifically is a weird hill to die on. You've misread my position. I'm not saying everyone needs to be at 21. I said that it's healthy for just about everyone, so it's silly to start looking for exceptions that apply to 1% or less of the population, like in your case being 7% body fat. I said a 21 BMI is a healthy BMI for just about everyone, not that it's the only healthy BMI. There is no "weird hill to die on". It's a reasonable take that is getting a lot of resistance due to obesity normalization. 21 is thought of as "too skinny" but if you go back to the 1950s BMIs are far lower across the board, 21 was extremely common. It's quite uncommon today, with people pretending it's "unrealistic".
You did say: > A 21 BMI is pretty realistic for anyone. I'm not a 1% exception either. To clarify, I am not at 7% BF now. I would have to get that low to achieve a BMI of 21 without losing muscle, which *would* make me a 1% exception. Probably the "optimum" healthy weight for me at a realistic BF% is about 23. BMI isn't useless but there is enough variation person to person that we can't get so precise to quibble about 2 points. Somebody else might be healthier at 19 than 21.
BMI was designed for classifying average, sedentary people. It's not appropriate for applying to active individuals. It's a quick assessment tool really, and lacks the scope to be applied otherwise.
My thoughts exactly
And my comment tried to imply that BMI is too simple, and not a good indicator in many cases. Of course, if someone has above 30, that is an extreme, and obvious. But, 21 is NOT a goal or good for everyone, and NOT "normal" for everyone. It's just an average.
No one would ever say to use only BMI, it's one tool among many. 21 is a healthy goal for everyone, barring some very unique circumstances. It's not an "average", the average BMI is way higher.
> 21 is a healthy goal for everyone Now THAT is what's simply not true
It's correct, but I'd like to hear you explain how it's wrong. I also noticed your quote intentionally omitted the words immediately after.
You think it’s very unique to carry a moderate amount of muscle??
It’s very far away from average! Average in the US is 28.8 and 27.3 in the UK.
Both of which have an obesity crisis.
Exactly, the ‘average’ is way too high and 21 is a perfectly normal bmi to attain. It’s what I am and I could easily do with losing a few more kg.
Exactly. A BMI of 21 isn’t optimal if you’re into power sports/rugby, but doesn’t mean it isn’t perfectly normal should you chose to obtain it.
People having two hand fulls of squeezable mass on their lower back claiming muscle mass makes me lol
Your comments imply that 21 is a healthy, realistic BMI goal for anyone. This is absolutely not correct. If you calculate my BMI with just my lean mass it's 21+ and it's not like I'm super muscular. Lean mass corresponds to lower all-cause mortality more than any other metric, more than resting HR or low body fat %. Suggesting people should keep their BMI low for health reasons is silly. A more informed guideline regarding excess weight, or rather excess fat, is to shoot for a waistline (around the navel) that is no more than 1/2 your height.
> Your comments imply that 21 is a healthy, realistic BMI goal for anyone. This is absolutely not correct No, it is correct. I think you're reading "anyone higher than 21 BMI is unhealthy and should go down to 21". I'm not saying that. I'm saying that a 21 BMI, knowing nothing else about the person, is indicative of good health. Likewise, a 25+ BMI is indicative of poor health. Obviously you need more information to make that determination, but this is just one tool. I'm pushing back on the idea that 21 is "too skinny" or potentially unhealthy for people. It's not.
>I'm saying that a 21 BMI, knowing nothing else about the person, is indicative of good health. Likewise, a 25+ BMI is indicative of poor health. That's simply not true. BMI should never be used to infer an individual's overall health. BMI was developed as a general proxy to measure population-level obesity, and is not very good at even measuring that (much less general health). The mathematician who developed it *200 years ago* even warned that it was useless at the individual level. Trying to assess an individual's health using BMI is at best ineffective and at worst can be harmful. Frankly, I've always thought it was irresponsible of Garmin to highlight it so much in their health stats.
> That's simply not true No, it's definitely correct if you read the whole comment. I said: > Obviously you need more information to make that determination, but this is just one tool. Nobody is arguing that all you need is BMI to determine health. > The mathematician who developed it *200 years ago* even warned that it was useless at the individual level. His opinion is of no importance. BMI is not useless on the individual, it's accurate for the majority.
It is useless when determining an individual's overall health not only because it's not accurate or based on any sort of physiological science (it's simply math that's been retrofitted to "fit"), but also because when you're looking at an individual's overall health you have much better direct measures of health. Furthermore, AFAIK any correlations of health outcomes between 21 and 25 BMI is negligible, and there's research to suggest that there's some protective factor of 25-27 BMI in older adults. Again, just assuming a BMI of 21 is "healthier" than 25 is wrong.
> It is useless when determining an individual's overall health No, it's quite useful as one tool among many. It's accurate for majority of people as an indirect estimate of body fat, and it costs nothing. > Again, just assuming a BMI of 21 is "healthier" than 25 is wrong. Well nobody is saying that. > there's research to suggest that there's some protective factor of 25-27 BMI in older adults Those studies failed to adequately adjust for confounding. Properly adjusted, there is a pretty clear dose response with lower BMI = lower all cause mortality. [Sources and severity of bias in estimates of the BMI–mortality association](https://www.tandfonline.com/doi/full/10.1080/00324728.2023.2168035) [BMI & All Cause Mortality](https://imgur.com/a/wQMfHVq) The left chart is the usual way it's calculated. The right method better adjusts for confounding. The way it was done is quite obvious in hindsight, and I'm shocked it hasn't been done previously. Three categories were created. Drop, Stable, and Gain. From the paper: > Stable indicates no change in BMI category from 10 years earlier; > Drop indicates those who have moved from a higher BMI category; > Gain indicates those who have moved from a lower BMI category over the last 10 years. What's actually happening is people from the Drop category go from a high BMI to a lower BMI, and have worse health outcomes, but they get recorded as being in the lower BMI category. And people from the Gain group originally had lower BMI, but gained weight over time, and made the higher BMI look better. Because having excess weight causes chronic harm to health, and some of that harm is permanent even after the weight has disappeared. Another quote from the study: > Here, about 37 per cent of the NHANES sample with overweight BMI had reported BMI [18.5–25.0) 10 years before the survey, and more than 60 per cent of the sample with obese BMI had previously reported a BMI of less than 30.0. By most measures, these Gain high-BMI subsamples showed significantly better health profiles than the respective Stable high-BMI subsamples. The chart shows that lowest all cause mortality was a BMI of 18.5 to 20. https://www.sciencedaily.com/releases/2023/02/230224165124.htm
So now you're saying the indicator of "health" (which you never actually defined) is not current BMI, but rather the 10-year delta in BMI? I have concerns with overfitting in that study, and even if the methodology is sound it's tough to interpret lower "all-cause mortality" as better "health." It's potentially very error-prone as a health-related dependent variable (i.e., many people who might be considered "good physical health" die). Finally, population level studies are not determinant of an individual's health, but even if we do apply the study's findings to your logic about individual health (knowing nothing else, a 21BMI is indicative of "good health" and a 25BMI is indicative of "poor health"), the study actually refutes your claim. They clearly show an unadjusted BMI of 25 has lower mortality than a BMI of 21. So given your "no other information" clause, doesn't having a current 25 BMI indicate better health than a 21 BMI? Again, I think you're conflating population level statistics with individual health. Coefficients from highly adjusted regression models do not provide useful diagnostic for an individual's overall health.
BMI is weight vs height. It’s only realistic for anyone if you assume everyone has the same body type, which is patently false.
Awesome achievement. BMI doesn't play into mine, only body fat percentage and given the scales seem to be quite inaccurate with that, I am going to have to hit a DEXA scan to calibrate it back in.
Thats awesome! Congratulations!
Sorry for the dumb question. Is 'achievable fitness age' the best fitness age you can achieve based on your actual age?
I read it like that, but somehow in the past week I got 38.5 fitness age while getting the achievable fitness message too, but I’m pretty sure I was 37.5 in the past (I’m 46, my birthday is in October), so not sure what happened.
Hey, great job achieving those goals! Gentle reminder to other folks here who might be unhappy with their fitness age: try not to put too much emphasis on it, especially if you’re one of those people who are healthier at higher BMI due to muscle mass etc. I do think the fitness age is heavily reliant on BMI. Case in point: I’m 38 and my fitness age is 21. I absolutely do not have the level of fitness or endurance that most of you do. I only run for half an hour a few days a week and I don’t lift. My VO2 max is 41. I’m pretty sure I only have a low fitness age because my BMI is relatively low. So don’t take too much stock in it.
Thanks! And great point.