This is for a 69kg person, based on the
additional calorie consimption over and above sedentary behaviour, and a food cost of £1.20/1000kcals, which is the
average for my diet as of April 2022. (My food expenditure appears to be well below the figures I've seen bandied around at various times.)
Some - yes;
all - no!
Nearly all of my utility journeys are done by bike or on foot. .... I don't eat extra to fuel any of them.
Care to produce some evidence for that?
Suppose I drive my car 100 miles without stopping to fill the tank, does that prove it hasn't used any petrol? No, of course it doesn't.
Suppose I drive 10 miles on alternate days, and 90 miles on each day in between. If I stop and buy 50 miles-worth of petrol every day, does that prove the car will go 90 miles on the same amount of fuel it takes to travel 10 miles? No, of course it doesn't.
But that's exactly the same logic that you're applying to the bike. The point is if you stop driving 90 miles on alternate days, and drive 10 miles every day instead, your average daily mileage will have gone from 50m/day to 10m/day, and the amount of fuel you have to put in the tank will also have gone down accordingly.
Unless you're getting markedly lighter with each trip to the shops you must be fuelling yourself somehow, though
Exactly.
And
even if you are getting lighter, the journey is still being fuelled by fat that originally came from food, just like the car that's getting lighter if you don't stop for petrol.
Your assumption is that those who cycle instead of drive eat more than those who drive. But I don’t think that is proven.
I've given you the proof, you just choose to ignore it. The
ACSM compendium is a peer reviewed data source that has been compiled from
actual measurements of metabolic rate for over 800 everyday activities, specifically for the purpose of calculating the energy used. It's a standard reference that's been in use worldwide for nearly 30 years.
I AM getting lighter, but wouldn't notice it after a single trip to the local Lidl or Aldi...
You've just admitted that you ARE using energy to get to Aldi, there.
The lighter you are the lower your basal metabolic rate.
Yes, you're absolutely right, and if you'd taken the trouble to calculate by how much, you'd see that it's trivial compared to the energy used by cycling. A 70 kg rider cycling 220 miles at 12mph (~6METs) will burn off about 1kg of fat (7800kcals), and in so doing will knock 14 kcals of his BMR. That 14 kcals is enough to take him 0.4 miles.
Unless I have missed something no one has factored in the cost of the bike in the calculation
The cost of the bike/car/insurance/mot etc are only relevant if you're proposing to give one of them up altogether. Most people will want to own both and just be deciding which one to use, and which one to leave at home.
on average, cyclists increase their calorie consumption by a fraction of the energy we expend cycling. How big a fraction I could only speculate on.
Either the fraction is 100%, or the cyclist will lose weight over the long term.
I also ignore the cost of taking a hot shower and the carbon footprint impact of farts.
It's the emissions from agriculture you need to be looking at, they account for 26% of all greenhouse gases.
I absolutely do eat more as a result of cycling. My typical daily energy consumption is in the region of a couple of thousand kcalories when doing nothing very energetic. For the 24 hours after a 100+km ride that will be more in the four to five thousand kcalorie range, or even more for particularly long rides. That's a reliable effect which I measured/recorded a few years ago, just out of interest. My mass is stable and generally at, or a little below where I'd like it to be. If I didn't eat a good bit more after cycling I'd shrink, and I don't wish to shrink. It's a really clear, measurable effect for 'long' rides; clearly less obvious for shorter, 'utility' rides, but the energy still has to come from somewhere.
This. It's bleedin' obvious, innit.
Since my health put paid to exercise I'm eating less than 2000kcals/day, but when I was riding regularly it was about 3300, and on a 50m/day cycle tour 4500-5000. I've seen off as much as 7000 kcals in big day's ride.
On a similar note I read an interesting article a few years back which was suggesting ebikes were better for the environment than bicycles because the energy required to grow/farm/process/transport food was higher than that required to make a battery and keep it charged. Obviously I've paraphrased and didn't check the accuracy of their arguments but it does make you think.
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You can multiply that cycling figure by several times over.
I vaguely recall a tabloid article claiming driving was better than cycling a few years back.
It can be, it depends what you're comparing with what:
Turned out they assumed the car driver was in the most efficient car on the market, shared with 4 other people, and the cyclist was consuming Wagyu fillet steak for their calories...
If you go for a ride then fill up with a Big Mac on the way home, then your ride was powered by (mostly) beef, and your ride will have produced about the same emissions as a big 4x4.
