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Comment by throwaway09223

3 years ago

> if I go all out on a row machine for 30 minutes, I'll burn 300 calories.

A stationary bike at a steady 20mph pace is about 500 calories in 30 minutes. That's really significant. An hour will erase about a third of a normal person's diet.

When I used to do heavy training (long distance running, weight training) I would eat close to 8k calories a day and I was in fantastic shape. Eating more was necessary to survive, given how much energy I was expending.

> A stationary bike at a steady 20mph pace is about 500 calories in 30 minutes. That's really significant. An hour will erase about a third of a normal person's diet.

That assumes a “normal person” will not compensate for the effort with a snack.

A “reward” pint of ice cream will re-add more calories than the hour of cycling. A “standard serving” will nearly match your half hour.

And that’s an hour at 20mph, which really isn’t in any way the norm.

  • > That assumes a “normal person” will not compensate for the effort with a snack.

    You're also assuming the same normal person will not compensate for their healthy lunch with a snack.

Most people can't manage to burn 1000 kcal in a 60 minute workout. I am a large man in fairly good shape and have to put in a pretty hard effort to hit those numbers. People who are smaller or not well trained are going to be significantly lower.

Measuring stationary bike workouts in terms of mph is kind of meaningless. What actually matters is the measured power output based on the resistance setting.

  • I'm a 40 year old guy who's been sitting behind a desk writing software for two decades. I was in good shape in my 20s but haven't exercised significantly in a very long time.

    It took me about three months to get up to that speed, cycling every other day. I started out doing 10 miles, at 10mph.

    Three months isn't all that long for an exercise program.

    • Color me skeptical. In order to burn 1000 kcal in 60 minutes a cyclist would have to sustain a power output of about 280 W. Do you have a calibrated power meter, or are you going by the "vanity" calories displayed by most stationary bikes?

      There are certainly plenty of trained cyclists who can maintain that power output, but I've never seen anyone reach that level after only 3 months. If you really did that then you're an extreme genetic outlier with an unusually fast training response.

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    • Not that it matters, but reporting mph for a stationary bike (indoor trainer I assume) is meaningless in this context. This could mean that you're cycling anywhere between 0 and 2000 Watts.

      I cycle on and off for ~8 years (35yo) and going at 20mph in the real world for an hour or more became possible only after a few years for me.

    • same here, I'm in my late 20s and was generally unhealthy because of the pandemic, and I burn 630-700 calories per 30 minutes worked out

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>A stationary bike at a steady 20mph pace is about 500 calories in 30 minutes

It is also something at most a tiny minority of the obese population can do.

  • I just plugged a 300 pound person in to a calculator for a “moderate” walking speed, and that’d burn nearly 500 calories in an hour.

    • Most 300 pound people I know cannot walk for an hour at a moderate walking speed.

    • You are severely overestimating the physical abilities of a severely obese person.

An hour will replace a third of a healthy persons diet.

Fats are the secret to obesity, hands down. I have a remarkably small appetite and I can easily down 1000 calories of ice cream in a single sitting (a single pint of Ben and Jerry's. You can row like crazy for 30 minutes, but if you have two extra candy bars, it's meaningless.

  • Avoiding calorie dense foods is big, yeah. But exercise is exercise and at higher levels (1+ hour/day) the caloric burn is very significant compared to baseline metabolic rates.

    Yes, our bodies are built to take in more calories than we can burn (thankfully!), but if you keep your eating habits constant the exercise will make a huge difference.