[Fricken]

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.

[alexfoo]

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 it was a flatter ride than that then Strava is just lying to you.

But, yes, long distance cycling is an awesome way of burning calories. When I used to do Brevet/Audax riding I was the closest to my old teenage weight as I have been in the last ~30 years.

[Jenda_]

Yeah, 25km/h requires less than 150W [1], so it's 600Wh total, the efficiency of human metabolism is about 20% [2], so it's 3kWh of total energy input = 10.8MJ = 2600 kcal. (I have been using generous estimates, so this should be an upper bound)

[1] https://en.wikipedia.org/wiki/Bicycle_performance#Total_powe..., https://www.road-bike.co.uk/articles/cycling-power.php [2] https://www.quora.com/How-efficient-is-the-human-body-at-con...

[bennyelv]

Given that we're talking about cycling, the solution is to buy a power meter and measure rather than estimate. Unfortunately that's a rather expensive option for all but the most committed cyclists.

Being someone who has a power meter, I can say that strava's estimates over a long time period aren't that terrible, but if you're riding in a group, or there was a some wind, or a million other reasons they can be absolutely miles out.

That's hardly strava's fault, it's more about what's actually possible with an estimate.

What is completely made up and should be ignored is the calorie burn estimates you get from gym equipment.

[throwaway2037]

    Strava’s calorie estimation is awful.

Re-reading your post made me think: I bet this is intentional design -- overestimate number of calories burned. Then, people will tell their friends about this amazing device from Strava that burns an unreasonable number of calories...

[tomjakubowski]

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

[alexfoo]

It’s 2% average grade if you finish at the same elevation as you start.

[ses1984]

That’s more than an order of magnitude more calories burned than walking 12k steps.

[missedthecue]

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.

[Fricken]

A person who gets their doctor recommended 150 minutes of moderate aerobic activity each week shouldn't have much difficulty adapting their bodies to distance cycling well enough to hit comparable numbers after a handful of training rides. Elites can hold pace for those distances at 50 km/hr, which is faster than me doing an all-out sprint.

And one doesn't have to do 100km all at once. A 10km commute each way over a 5 day workweek is a much less intimidating prospect.

[0xfaded]

When I lived in Denmark I was riding 2x 5km to and from work. I then needed to start going somewhere ~80km away, and I was able to do it without special preparation. After a couple of times I was able to do it both ways in a day.

Now I live in America need a car :(

[Jenda_]

I also did a 65km and then 135km ride with similar "training" (2x7km four times a week to school), but it was way slower than 25km/h. They took 4.5 and 10 hours, respectively. I think riding 100km without training is possible, but at 25km/h very difficult.

> Now I live in America need a car :(

Why? Are there even longer distances?

[0xfaded]

No, there's just no cycling infrastructure.

I was doing it on a roadbike and could comfortably average 27km which got me there 3h. Driving was about 1.2h.

In the summer, I would start pedalling at 5am and get to a local cafe at 8. The first hour was amazing, broad daylight and you basically had the whole road network to myself.

[Jenda_]

There is almost none here (around Prague, .cz) too. I ride on the roads.

Yeah, unfortunately, for me, even after some training, it's still hard for me to average over 22 km/h (entire travel including stops; the moving average is about 25km/h, e.g. https://www.strava.com/activities/9688833121).

[throwaway2037]

Why did you leave Denmark? A job? University? That sounds like a terrible trade for quality of life, including raising a family.

[0xfaded]

Honest question, are you asking as someone who has experienced living in Denmark or a similar country? It is indeed a good place to live for the median person. But if you're a high achiever, it's a fact of life that the opportunity is in the US.

[bennyelv]

I think the numbers are more than you'd think - as a cyclist who's near the top end of "keen amateur" but still nowhere near what people are capable of at the elite level my experience is that anyone of moderate fitness can do a 4 hour 100k without too much trouble...

It could depend on how you define "almost 100%" of course. There's a big difference between 5% and 0.001%.

[jeffbee]

While true, the energy expense doesn't really scale with speed, so if a couch potato got up and decided to do 100k in, say, 8 hours, that's around the same amount of energy.

NB nobody would be able to do this without ingesting a substantial amount of food during. If you didn't start eating hourly after about 1-2 hours in, you'll "bonk" or run out of glycogen.

[nradov]

It really depends on how fat adapted your metabolism is. When untrained people exert themselves their muscles tend to produce most energy from glucose and very little from fat. By doing a lot of zone 1-2 training you can gradually shift your metabolism to rely more on fat, at least at lower effort levels where you're not limited by oxygen. This allows you to go longer than 2 hours without bonking.

[alexfoo]

It does depend on your conditioning though. When I did my first 200km ride I ate like a horse every 50km.

After a few years of regular (monthly) 200km rides I could do a 200km ride (~10h elapsed) without eating anything on the way round.

[tomjakubowski]

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.

[missedthecue]

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

[tomjakubowski]

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!

[paulpauper]

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.

[lrem]

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.

[carstenhag]

Really depends on the bike. It's way easier to achieve this on a racing bike than on a trekking/city/mtb

[tomjakubowski]

no, they wouldn't