One for the Mathematicians

[falmouthtony]

How many calories have I burnt!!!

So ... this year so far My Garmin Edge GPS tells me I have:
Cycled 2300 miles
In 200 hours
Gained 179,000 feet in elevation
And burnt 172,000 calories!!!

Of course I haven't burnt anything like that on my electric bikes .. but I'd like an idea of how many I have burnt.

My guestimate is:
1000 miles level or downhill with no assistance
1300 miles level with assistance or uphill with an average assistance for both of +150%.

Answers on a postcard .............. or better still on here.

 

[Alan Quay]

Pedant alert!

172,000 cal = 172 Cal (aka Kcal) = fun sized Mars Bar.

The food industry have somehow gotten away with calling 1000 calories a Calorie. (Note the capital letter).

Cheeky F#ck3rs.

 

[jackhandy]

You really need a fair idea as to what your heartrate was during those rides to get some notion of calories burnt, mate.
Next purchase - chestband

Did you decide against riding the Beast?

 

[Geebee]

Even with heart rate, weight, elevation gain and loss, bike type, tyres, battery watt meter readings etc. it would still be a totally inaccurate guesstimate.
Best way to look at it is the harder you work over the same time the more calories you burn.
If you are looking at weight loss, that is 90% in the kitchen and exercise is a bonus that can accelerate it and make you healthier and setup a better life style.

 

[VictoryV]

How many calories have I burnt!!!

So ... this year so far My Garmin Edge GPS tells me I have:
Cycled 2300 miles
In 200 hours
Gained 179,000 feet in elevation
And burnt 172,000 calories!!!

Of course I haven't burnt anything like that on my electric bikes .. but I'd like an idea of how many I have burnt.

My guestimate is:
1000 miles level or downhill with no assistance
1300 miles level with assistance or uphill with an average assistance for both of +150%.

Answers on a postcard .............. or better still on here.

On my exercise bike I cruise at 100 watts, that equates to 90 Kcal per hour,
The average being can generate 100 to 200 watts - TDF folk a lot lot more! I'm sure Mr Flecc has raised an ancient posting on just how much power the competetive cyclist can produce - sustained and peak.

This means that in 200 hours you are likely to have burned something between:

At 100 watts: 200 x 90 KCal = 18,000 Kcal
At 200 watts: 200 x 180KCal = 36,000Kcal

Your Garmin is giving an average calorie burn of 860KCal per hour (172000/200) which is very close to 900KCal or 1000 watts per hour, so the bike must be making up the difference of 760 watts or so

Incidentally 1hp is equivalent to 745 watts

 

[Gubbins]

I read recently that a 4 mile run will burn off a can of coke! If I ran 4 miles I would burn off the entire nation debt, whereas an athlete wouldn't even break a sweat...
I reckon that if you don't feel tired and you can still run upstairs then you haven't done enough.

 

[jackhandy]

Just as a hexample:
I've just got back from a fairly leisurely ride to Newquay;
33 miles, 2250' climbed, 1540 kcal burnt.

My calorie burn rate has steadily decreased as my fitness has improved over the 2 years+ that I've been riding a knee-bike.

 

[falmouthtony]

You really need a fair idea as to what your heartrate was during those rides to get some notion of calories burnt, mate.
Next purchase - chestband

Did you decide against riding the Beast?

No JH. Done it a couple of times - in fact was over to Lanhydrock playing (without horse flies) today.
Had a few probs of late that have taken me up country.
Busy week this week but good to meet up on a good day in November.
Yours or ours?

 

[trex]

How many calories have I burnt!!!

So ... this year so far My Garmin Edge GPS tells me I have:
Cycled 2300 miles
In 200 hours
Gained 179,000 feet in elevation
And burnt 172,000 calories!!!

Of course I haven't burnt anything like that on my electric bikes .. but I'd like an idea of how many I have burnt.

My guestimate is:
1000 miles level or downhill with no assistance
1300 miles level with assistance or uphill with an average assistance for both of +150%.

Answers on a postcard .............. or better still on here.

I guess your body contributes about 5AH per mile.
2300 miles = 11,5000 AH = 9894 kcal = 12.8kgs of body fat.

You burned on average 35g of body fat a day.

 

[falmouthtony]

I guess your body contributes about 5AH per mile.
2300 miles = 11,5000 AH = 9894 kcal = 12.8kgs of body fat.

You burned on average 35g of body fat a day.

THAT is what I wanted to hear............thanks Trex. Thread closed

 

[peb1968]

I used the following method to calculate calorie burn while commuting on my e-bike.

I do 1.25 hours each way, so 2.5 hour round trip.
My battery will deliver 500W for one hour
At the level I have the bike set to, I can get three hours out of it, so it is delivering 166W per hour
Converting to calories, that is 166 x 2.5 (hours) x 3.6 (conversion factor) = 1,494
I generally average around 16 mph

According to common wisdom, websites, etc, the energy required to cycle without assistance at that speed (with my weight, which is not insubstantial) is 800 calories per hour. Given my e-bike weighs 25kg, it may be more, but I use that conservatively).

So, total energy required for my round trip commute is 800 x 2.5 (hours) = 2,000 calories. The battery is delivering 1,494 so my net calorie consumption is 500. Not massive, but not bad.

I've seen a lot of stuff on other forums from people (usually cycling purists) who say e-bikes are no good for exercise/require no effort. They are wrong.

 

[Woosh]

assuming you ride at max assist speed (15.5mph) for 32 miles:
load: 200WH * 2 = 400WH
Assuming you ride on speed turbo mode, you only put in 100WH of pedaling power.
You lose a lot more in body heat being exposed to our weather for two hours. That's where the 'exercise' comes from.
Cyclist commuters lose 400WH on the same commute.

 

[peb1968]

assuming you ride at max assist speed (15.5mph) for 32 miles:
load: 200WH * 2 = 400WH
Assuming you ride on speed turbo mode, you only put in 100WH of pedaling power.
You lose a lot more in body heat being exposed to our weather for two hours. That's where the 'exercise' comes from.
Cyclist commuters lose 400WH on the same commute.

I do more than max assist speed (most of my commute is off road). I do 38 miles in total. I don't use Turbo - only Tour.

 

[peb1968]

Also, I don't think I've lost too much body heat these past few days ... 30+ degrees!

 

[Woosh]

Also, I don't think I've lost too much body heat these past few days ... 30+ degrees!

you still lose calories through sweating.

 

[vfr400]

When you consider how many calories you burn, you have to consider human efficiency in converting food to energy, which is somewhere around 25%.

You can do an easy approximate calculation. When riding a bike, an average person puts around 100w through the pedals. You can decide how much you match an average person's effort and adjust accordingly, i.e. if you're reasonably fit and pedal purposely all the time, you can increase that to 150w, and if you're weak or lazy, down to 60w. Let's stick with 100w.

100w worth of output power requires 400w of input power. 1 calorie per hour = 0.00116222222 W, so 400W = 344 Calories per hour (note the big C). That's the approximate rate at which you'll burn fat due to pedalling. The Garmin and Fitbit algorithms will always show more because they include the energy you're burning without pedalling, which is about 83 Calories per hour, so about 430 Calories per hour total.

Whether you go uphill or downhill makes no difference because it's your level of fitness and motivation that decides how much power you output, and that is probably constant, and even if it isn't, it'll average out over time. What's important is the time you spend on your bike.

344 Calories is about one and a bit mars bars or one low calorie ready-meal. There are about 3000 Calories in a large cheese Pizza, so you'd have to pedal all day (9 hours) to compensate for one of those. That should make you think twice about eating one now you know the facts.

If you want to lose weight, the only logical option is to to stop eating so many calories because it's a lot easier than doing it by pedalling. All you have to do is use will-power or, better still, won't-power.