Daily energy expenditure through the human life course • Hacker News Board

Re: Daily energy expenditure through the human life course

#181

Post by tomjakubowski » Sat, Oct 14, 2023, 10:36 PM UTC

alexfoo wrote: post #177

Fricken wrote: post #135

Earlier quoted context omitted.

Strava tells me I burned 3,3000 calories this morning on my (4 hour)100km bike ride. About the equivalent of drinking 2 cups of melted butter, or eating 50 pounds of lettuce. When I'm doing exercise like that regularly it's hard to eat enough.

Strava’s calorie estimation is awful. Depends on the elevation gains in your 100km ride but I think that 3,300kcal for a 100km/4h ride is generous. 800kcal/hr is hard work and keeping that up for 4h is even harder. 25kph does not sound like 800kcal/hr unless there was some reasonable elevation gains. I’d expect at least 1000m elevation gain over that 100km for those numbers to at least approach something sensible. If…

I am also very skeptical of Strava's caloric estimates but:

> I’d expect at least 1000m elevation gain over that 100km

1% average grade is pretty mild. I'd bet OP did at least 3000m to get those numbers

Re: Daily energy expenditure through the human life course

#182

Post by missedthecue » Sat, Oct 14, 2023, 10:39 PM UTC

tomjakubowski wrote: post #175

missedthecue wrote: post #155

Earlier quoted context omitted.

Humblebrag? Almost 100% of humans are incapable of doing a four hour 100km bike ride without a lot of prep and training. Nevermind doing this daily.

A lot of people could get there with like six months of not that crazy training. Cycling at 15mph on flat ground is pretty easy. If you can do that for an hour, and can progress at 10% increase in riding time week over week (pretty reasonable for someone who is still gaining fitness from "nothing"), you'll be doing four hour rides after just 16 weeks.

I would categorize 16 weeks of training as a lot of prep

Re: Daily energy expenditure through the human life course

#183

Post by tomjakubowski » Sat, Oct 14, 2023, 10:40 PM UTC

lrem wrote: post #150

Fricken wrote: post #135

Earlier quoted context omitted.

Strava tells me I burned 3,3000 calories this morning on my (4 hour)100km bike ride. About the equivalent of drinking 2 cups of melted butter, or eating 50 pounds of lettuce. When I'm doing exercise like that regularly it's hard to eat enough.

25km/h is the regulatory max speed of e-bikes around here and you averaged that. Most people would take years of training to get to the point of being able to exercise like this.

no, they wouldn't

Re: Daily energy expenditure through the human life course

#184

Post by cma » Sat, Oct 14, 2023, 10:43 PM UTC

ermir wrote: post #13

This was completely expected, at the macro level this is easily observed by measuring the outputs of metabolism and bodily function, mainly heat and physical activity. All humans have a baseline bodily temperature, meaning that the inner metabolism also is the same across all humans.

Sweating at different rates, surface blood vessel dilation including in your lungs, all change the flux. Having longer hair or wearing warmer clothing can too and can be balanced by those other things. Activity also gets balanced by those things. Eating cold food and drink vs warm etc.

That we maintain a baseline temperature doesn't tell you that metabolism alone is all that regulates it, there are other factors.

Re: Daily energy expenditure through the human life course

#185

Post by paulpauper » Sat, Oct 14, 2023, 10:44 PM UTC

XorNot wrote: post #169

paulpauper wrote: post #138

Earlier quoted context omitted.

One individual, Michael Rea, weighed (at the time of publication) 115 lbs at 6-feet and subsisted on a diet of 1900 calories a day [0], which he tracked meticulously. It's hard to convey with words how incredible this is. To put this in perspective, Ansel Key's subjects had to diet down to 1,500/day to get almost as thin. Super-fast metabolisms that cannot be explained by undereating or pathology do exist. [0] https:…

Why is Michael Rea considered exceptional here? For that height and weight, that's pretty much bang on what you'd expect as a maintenance level of calories assuming he does any physical activity at all.

trying to get that low of a weight would entail significant metabolic adaptation, which calculators do not account for. Take a 180lb 6-foot male and try to get him to 115 and you can be sure it will take way fewer than 1900.

Re: Daily energy expenditure through the human life course

#186

Post by paulpauper » Sat, Oct 14, 2023, 11:04 PM UTC

Loughla wrote: post #156

naijaboiler wrote: post #147

Earlier quoted context omitted.

No I legit ate way much much more in my 20s. I'm not misremembering. I ate more

I had to supplement with calorie shakes for workout guys in my 20's, just to maintain weight. I ate trash, and a shit load of it. And that's not considering the amazing levels of calories I would've consumed from alcohol. Same activity level now as then. But now if I think too hard about a candy bar I gain weight that never goes away.

same here. the hockey-stick or v-shaped weight rebound if I even deviate a tiny bit. amazing how fast weight comes back on.

Re: Daily energy expenditure through the human life course

#187

Post by medler » Sat, Oct 14, 2023, 11:05 PM UTC

paulpauper wrote: post #138

medler wrote: post #85

Earlier quoted context omitted.

Over my life I’ve been close to a small handful of perpetually skinny people who thought they had high metabolisms. In every case, when I watched them closely, I realized they barely ate anything. My ex-gf was one of these people and would routinely tell people about how she could eat anything and not gain weight. But when I would go on a severely calorie-restricted diet I was still eating more than she did on a norm…

One individual, Michael Rea, weighed (at the time of publication) 115 lbs at 6-feet and subsisted on a diet of 1900 calories a day [0], which he tracked meticulously. It's hard to convey with words how incredible this is. To put this in perspective, Ansel Key's subjects had to diet down to 1,500/day to get almost as thin. Super-fast metabolisms that cannot be explained by undereating or pathology do exist. [0] https:…

Was he sedentary, or did he run 10 miles a day? I see no reason to believe his metabolism was unusual without more information about his physical activities.

Re: Daily energy expenditure through the human life course

#188

Post by paulpauper » Sat, Oct 14, 2023, 11:09 PM UTC

missedthecue wrote: post #126

valec wrote: post #124

Earlier quoted context omitted.

activity levels almost certainly. uni it's not impossible you were walking over 12k steps a day. that's 3-400 calories over the average american's daily steps of 4000.

That's also completely canceled out by enjoying a single 32oz soda. Walking a lot and having a bad diet rarely even each other out. And it's so easy to cancel it out I don't think most people realize. A brisk 2km walk burns less calories than are consumed when eating two regular Oreos.

It is even worse than that. The conversion rate of activity to net calorie loss is not 1 to 1 . It can be zero or even negative, at least based on my own experience and other people. You see people on Reddit subs do 10k steps and tons of walking, hardly lose any weight. It's all about not overeating.

Re: Daily energy expenditure through the human life course

#189

Post by paulpauper » Sat, Oct 14, 2023, 11:11 PM UTC

Fricken wrote: post #135

missedthecue wrote: post #126

Earlier quoted context omitted.

That's also completely canceled out by enjoying a single 32oz soda. Walking a lot and having a bad diet rarely even each other out. And it's so easy to cancel it out I don't think most people realize. A brisk 2km walk burns less calories than are consumed when eating two regular Oreos.

Strava tells me I burned 3,3000 calories this morning on my (4 hour)100km bike ride. About the equivalent of drinking 2 cups of melted butter, or eating 50 pounds of lettuce. When I'm doing exercise like that regularly it's hard to eat enough.

Strava is probably wrong. Even if it's right, it's not like this can continue forever. At some point, the weight loss will stop despite Strava showing a deficit. So either you have to eat less or exercise even more.

Re: Daily energy expenditure through the human life course

#190

Post by tomjakubowski » Sat, Oct 14, 2023, 11:12 PM UTC

missedthecue wrote: post #182

tomjakubowski wrote: post #175

Earlier quoted context omitted.

A lot of people could get there with like six months of not that crazy training. Cycling at 15mph on flat ground is pretty easy. If you can do that for an hour, and can progress at 10% increase in riding time week over week (pretty reasonable for someone who is still gaining fitness from "nothing"), you'll be doing four hour rides after just 16 weeks.

I would categorize 16 weeks of training as a lot of prep

I wouldn't - sixteen weeks is just about 1% of the 30 years you have between ages 20 and 50.

that said, ok, 15mph is not that easy -- maybe starting more like 10mph on a road bike for an hour would be more reasonable.

I still think most able bodied people could get to OP's fitness in much less than a year.

One data point - I was horribly out of shape in my mid 20s and got to riding 4 hour/15mph about four months after I bought my bike. But I was also unemployed for about a month of that!