3 ms·

0.15 per gram would be 150 per kg, not 15. And presumably they mean cal, not kcal.

kelnos 2y ago
So a 75kg person can ride a kilometer only expending 11.25kcal? That doesn't sound right either. 75kg * 1000g/kg * 0.15cal/g * 0.001cal/kcal = 11.25kcal Right? I would expect an order of magnitude higher. But if that is correct... damn. Bicycles are incredible.
- Jtsummers 2y ago
  Let's say it is an order of magnitude more (~100kcal/km), I ride about 30km per day average right now that'd mean I burn 3kcal/day extra just from this training. I am eating nowhere near 5kcal/day (assuming ~2kcal maintenance just for living plus other movement during the day) so I'd be losing weight very quickly if that estimate were correct. The .15cal/g is much closer to what I'm probably burning. According to my Garmin it was 540 calories which is 18kcal/km, and I weigh ~86kg which puts me at about .20cal/g, not much higher than Walton's number. And I was definitely not taking a casual pace, there was no coasting on that ride.
  - kelnos 2y ago
    Wow, okay. Bicycles are just incredible machines after all. An interesting result of this is that if you're trying to lose weight, cycling isn't the most time-efficient way to burn calories!
    - jseutter 2y ago
      Yes, this is very true. In my case, I think my weight loss from mountain biking comes from riding hills I wouldn't normally (and often pushing up hills), eating better (I'm not sitting at my desk and therefore spend less time snacking), and building leg muscle. Running is a much quicker way to burn calories. I hate running. :)
    - pastage 2y ago
      Commuting by bicycle is time efficient though, since you will do exercise instead. It also makes other training more efficient since your base fitness goes up.
    - elric 2y ago
      You can't outrun a bad diet, and you certainly can't outcycle it. But it keeps you fit, keeps your legs toned, and (depending on where you are) gets you from A to B for nearly free.
      - watwut 2y ago
        I hate this meme. Adding mild sport to the lifestyle consistently improves peoples health results. It improves how they feel on emotional level too. And in my experience, hunger/satiety regulation works better when I do mild sport. So, if the loosing weight thing is about more then just an aesthetics, if there is a hint of "I actually care about health too" motivation, then cycling or running or whatever sport one likes adds a lot of benefit. Certainly going to work by bike is better for weight itself then going by car.
        elric 2y ago
        > Certainly going to work by bike is better for weight itself then going by car. "Certainly"? Not really. Depends entirely on your habits. If you get to work after your bike ride and eat a Snickers because it made you peckish, and you didn't do that when going by car, you've effectively done nothing for your weight. It's true that exercise is good for you regardless. But it is orders of magnitude easier to ingest calories through food than it is to burn them through exercises.
        watwut 2y ago
        If it made you hungry more, it is because your body needs some more nutrition as the trip was something body still needs to accustom itself to. There is nothing damaging with that. It likely means you had too small breakfast which can be composed of slow metabolizing food. If you go to work on bike regularly, your body don't even register it as something to triger you needing more food. If you are extra hungry after 30 min transport trip on bike, you are likely in very bad physical shape. 98% of diets end up failure in the long term, precisely because just skipping food does nit work in the long term. You end up miserable, tired, passive, anemic, underperfoming on the job.
      - 2y ago
  - LRVNHQ 2y ago
    We still understand what you mean, but FYI most of your numbers are off by a factor 1000. A single calorie is a completely irrelevant amount of energy at the scale of a human body, hence the use of kcal as the basic unit when talking about nutrition. In the first paragraph you mean 3000kcal, 5000kcal, etc. Not 3kcal, 5kcal, etc. The reference daily caloric intake is 2000kcal, not 2000 calories. This is all made more confusing by the fact that in most of the world "kcal" is just pronounced "calories" (ignoring the 'k' which is implied in this context), while in the US "Calories" (with a capital 'C') stands for kilo calories. But back to your point, 0.15cal/g/km = 0.15kcal/kg/km indeed passes the intuition test. For a 100kg bike+rider package that would be 15kcal/km => 1500kcal for a 100km, which seems to be the correct order of magnitude. Of course this is an obvious oversimplification, but it gets the point its trying to make across.

So a 75kg person can ride a kilometer only expending 11.25kcal? That doesn't sound right either. 75kg * 1000g/kg * 0.15cal/g * 0.001cal/kcal = 11.25kcal Right? I would expect an order of magnitude higher. But if that is correct... damn. Bicycles are incredible.

Jtsummers 2y ago
Let's say it is an order of magnitude more (~100kcal/km), I ride about 30km per day average right now that'd mean I burn 3kcal/day extra just from this training. I am eating nowhere near 5kcal/day (assuming ~2kcal maintenance just for living plus other movement during the day) so I'd be losing weight very quickly if that estimate were correct. The .15cal/g is much closer to what I'm probably burning. According to my Garmin it was 540 calories which is 18kcal/km, and I weigh ~86kg which puts me at about .20cal/g, not much higher than Walton's number. And I was definitely not taking a casual pace, there was no coasting on that ride.
- kelnos 2y ago
  Wow, okay. Bicycles are just incredible machines after all. An interesting result of this is that if you're trying to lose weight, cycling isn't the most time-efficient way to burn calories!
  - jseutter 2y ago
    Yes, this is very true. In my case, I think my weight loss from mountain biking comes from riding hills I wouldn't normally (and often pushing up hills), eating better (I'm not sitting at my desk and therefore spend less time snacking), and building leg muscle. Running is a much quicker way to burn calories. I hate running. :)
  - pastage 2y ago
    Commuting by bicycle is time efficient though, since you will do exercise instead. It also makes other training more efficient since your base fitness goes up.
  - elric 2y ago
    You can't outrun a bad diet, and you certainly can't outcycle it. But it keeps you fit, keeps your legs toned, and (depending on where you are) gets you from A to B for nearly free.
    - watwut 2y ago
      I hate this meme. Adding mild sport to the lifestyle consistently improves peoples health results. It improves how they feel on emotional level too. And in my experience, hunger/satiety regulation works better when I do mild sport. So, if the loosing weight thing is about more then just an aesthetics, if there is a hint of "I actually care about health too" motivation, then cycling or running or whatever sport one likes adds a lot of benefit. Certainly going to work by bike is better for weight itself then going by car.
      - elric 2y ago
        > Certainly going to work by bike is better for weight itself then going by car. "Certainly"? Not really. Depends entirely on your habits. If you get to work after your bike ride and eat a Snickers because it made you peckish, and you didn't do that when going by car, you've effectively done nothing for your weight. It's true that exercise is good for you regardless. But it is orders of magnitude easier to ingest calories through food than it is to burn them through exercises.
        watwut 2y ago
        If it made you hungry more, it is because your body needs some more nutrition as the trip was something body still needs to accustom itself to. There is nothing damaging with that. It likely means you had too small breakfast which can be composed of slow metabolizing food. If you go to work on bike regularly, your body don't even register it as something to triger you needing more food. If you are extra hungry after 30 min transport trip on bike, you are likely in very bad physical shape. 98% of diets end up failure in the long term, precisely because just skipping food does nit work in the long term. You end up miserable, tired, passive, anemic, underperfoming on the job.
    - 2y ago
- LRVNHQ 2y ago
  We still understand what you mean, but FYI most of your numbers are off by a factor 1000. A single calorie is a completely irrelevant amount of energy at the scale of a human body, hence the use of kcal as the basic unit when talking about nutrition. In the first paragraph you mean 3000kcal, 5000kcal, etc. Not 3kcal, 5kcal, etc. The reference daily caloric intake is 2000kcal, not 2000 calories. This is all made more confusing by the fact that in most of the world "kcal" is just pronounced "calories" (ignoring the 'k' which is implied in this context), while in the US "Calories" (with a capital 'C') stands for kilo calories. But back to your point, 0.15cal/g/km = 0.15kcal/kg/km indeed passes the intuition test. For a 100kg bike+rider package that would be 15kcal/km => 1500kcal for a 100km, which seems to be the correct order of magnitude. Of course this is an obvious oversimplification, but it gets the point its trying to make across.