How much weight do you lose on a ride?

kleinstroker

I would like to know why everyone thinks they are right and all the computers are wrong! It's a pretty simple calculation all told so why would it be so wrong?

mikeouk

i think people get too hung up on calorie intake and calories burned. Every person is different, two people with the same starting weight could eat exactly the same for a month and exercise the same for a month, they wouldn't both loose exactly the same amount of weight.
Its very simple , burn more calories than you eat, the body will start burning fat. want to loose more weight faster then reduce calorie intake, want to loose more even faster then ride more aswell.

SPOC

kleinstroker wrote:

I would like to know why everyone thinks they are right and all the computers are wrong! It's a pretty simple calculation all told so why would it be so wrong?

When I ride my bike at 18mph for an hour at heart-rate for 140bpm and it tells me I burn off 900 calories, it doesn't take much to work out the Garmin is wrong.

Being a runner before I was a cyclist, I would say run at an 8mph pace for an hour, and even then only have burned off about 850 calories.

There is no way on earth that from those two examples (both of which the Garmin provides, I have seen these figures myself so they aren't hypothetical, this is also on the same Garmin device) that the cycle burned off more calories than the run. They wouldn't even be very close, my run would have burned off far more calories at those two pace examples.

It's clearly not something that is such a simple calculation, as they can get it so wrong.

dw300

I did 85miles yesterday, 7 hours cycling.

Garmin Edge (HR) estimate : 2,676 cals
Strava (Virtual Power) estimate : 2,720 cals

That's a difference of 1.6%.

According to that, that's about 385 cals/hr for a ride of approx. 60%FTP. At 100%FTP I'm just over 700 cals/hr, based on TrainerRoad virtual power. I weigh 151lbs, have an approximate FTP of 210 - 220W. Take what you want from that.

I once wore a Polar HR monitor for 24 hours and burned an average of 85 cal/hr (no training) just walking, sitting and sleeping. That comes to 2,040 cals/day, so I don't reckon they're worth writing off entirely, just get your stats entered correctly .. I'd say a lot of people don't even realise they're ment to put their stats into a cycle computer.

To answer the OP .. it doesn't matter how much you loose in one ride, and it's impossible to measure, as you'll regain some of the weight in the hours and days afterwards.

neeb

Calories are basically just the energy contained in food or in your body mass (fat, muscle etc). If you completely burn (and I mean literally set fire to) a bit of food or body fat it will produce a certain amount of energy in the form of heat and light and that energy is pretty much the calories it contains. Of course the way you burn stuff in your body is a little more subtle and complicated. The units are confusing, because you have "cal" for a calorie, but generally what is used is Kcal (thousands of calories), which is also written as "Cal" (big C). Usually when people talk about calories they mean Kcal (i.e. Cal.)

If you have a power meter, that will tell you exactly how much energy you have put through the pedals on a ride, and you can convert that directly into Calories. However, you will actually have expended about three or four times more energy than that, as your body is not very efficient at converting food energy directly into mechanical energy and it produces a lot more heat than it does mechanical power. If you are using a power meter, your Garmin or whatever will multiply the amount of energy put through the meter by something like 3 or 4 to produce the displayed Calories burned, and that will be fairly accurate (depending on how good an estimate the 3 or 4x calculation is of your particular metabolic/mechanical efficiency). The point is, if it is out it will only be out by 10 or 15% or something, it will not be way off.

However, if you do not have a power meter your cycle computer tries to estimate Calories from your heart rate, taking into account your height and weight, resting heart rate etc (assuming these have all been entered properly). This is a lot more hit-and-miss, as heart rate varies a lot in individuals and also varies a lot in a single individual from one day to the next, even when they are expending the same amount of energy... So it's probably not going to be very accurate.

t.m.h.n.e.t

neeb wrote:

Calories are basically just the energy contained in food or in your body mass (fat, muscle etc). If you completely burn (and I mean literally set fire to) a bit of food or body fat it will produce a certain amount of energy in the form of heat and light and that energy is pretty much the calories it contains. Of course the way you burn stuff in your body is a little more subtle and complicated. The units are confusing, because you have "cal" for a calorie, but generally what is used is Kcal (thousands of calories), which is also written as "Cal" (big C). Usually when people talk about calories they mean Kcal (i.e. Cal.)

If you have a power meter, that will tell you exactly how much energy you have put through the pedals on a ride, and you can convert that directly into Calories. However, you will actually have expended about three or four times more energy than that, as your body is not very efficient at converting food energy directly into mechanical energy and it produces a lot more heat than it does mechanical power. If you are using a power meter, your Garmin or whatever will multiply the amount of energy put through the meter by something like 3 or 4 to produce the displayed Calories burned, and that will be fairly accurate (depending on how good an estimate the 3 or 4x calculation is of your particular metabolic/mechanical efficiency). The point is, if it is out it will only be out by 10 or 15% or something, it will not be way off.

However, if you do not have a power meter your cycle computer tries to estimate Calories from your heart rate, taking into account your height and weight, resting heart rate etc (assuming these have all been entered properly). This is a lot more hit-and-miss, as heart rate varies a lot in individuals and also varies a lot in a single individual from one day to the next, even when they are expending the same amount of energy... So it's probably not going to be very accurate.

Just so you're aware. Garmin units have a preference thing going on. It goes in this order

1 Newleaf profile
2 Heart rate
3 Third-party ANT+ enabled power meter (converts wattage (kj) to calories)
4 Speed, Distance, and User Profile - calculated using speed, distance, and user profile data

If 1 isn't available 2 is used and so on. If none of these are available then local settings on the unit profile are used.

But we all know 3 is by far the most accurate.

neeb

T.M.H.N.E.T wrote:

Just so you're aware. Garmin units have a preference thing going on. It goes in this order

1 Newleaf profile
2 Heart rate
3 Third-party ANT+ enabled power meter (converts wattage (kj) to calories)
4 Speed, Distance, and User Profile - calculated using speed, distance, and user profile data

If 1 isn't available 2 is used and so on. If none of these are available then local settings on the unit profile are used.

But we all know 3 is by far the most accurate.

Hold on... you are saying that if you have a HR monitor strap on AND a power meter, the Garmin will use HR in preference to power for calculating calories...? That would be completely daft surely??

t.m.h.n.e.t

neeb wrote:

T.M.H.N.E.T wrote:

Just so you're aware. Garmin units have a preference thing going on. It goes in this order

1 Newleaf profile
2 Heart rate
3 Third-party ANT+ enabled power meter (converts wattage (kj) to calories)
4 Speed, Distance, and User Profile - calculated using speed, distance, and user profile data

If 1 isn't available 2 is used and so on. If none of these are available then local settings on the unit profile are used.

But we all know 3 is by far the most accurate.

Hold on... you are saying that if you have a HR monitor strap on AND a power meter, the Garmin will use HR in preference to power for calculating calories...? That would be completely daft surely??

That came from Garmins FAQ section

kleinstroker

SPOC wrote:

kleinstroker wrote:

I would like to know why everyone thinks they are right and all the computers are wrong! It's a pretty simple calculation all told so why would it be so wrong?

When I ride my bike at 18mph for an hour at heart-rate for 140bpm and it tells me I burn off 900 calories, it doesn't take much to work out the Garmin is wrong.

Being a runner before I was a cyclist, I would say run at an 8mph pace for an hour, and even then only have burned off about 850 calories.

There is no way on earth that from those two examples (both of which the Garmin provides, I have seen these figures myself so they aren't hypothetical, this is also on the same Garmin device) that the cycle burned off more calories than the run. They wouldn't even be very close, my run would have burned off far more calories at those two pace examples.

It's clearly not something that is such a simple calculation, as they can get it so wrong.

Calorie consumption for running is the same no matter what speed you run at. The same is not true for cycling.

edit: I didn't see the Garmin HRM thing. I'm surprised as the Polar HRM calcs have been proven to be out by as much as 25%.

MattC59

SPOC wrote:

kleinstroker wrote:

I would like to know why everyone thinks they are right and all the computers are wrong! It's a pretty simple calculation all told so why would it be so wrong?

When I ride my bike at 18mph for an hour at heart-rate for 140bpm and it tells me I burn off 900 calories, it doesn't take much to work out the Garmin is wrong.

Being a runner before I was a cyclist, I would say run at an 8mph pace for an hour, and even then only have burned off about 850 calories.

There is no way on earth that from those two examples (both of which the Garmin provides, I have seen these figures myself so they aren't hypothetical, this is also on the same Garmin device) that the cycle burned off more calories than the run. They wouldn't even be very close, my run would have burned off far more calories at those two pace examples.

It's clearly not something that is such a simple calculation, as they can get it so wrong.

Why? Based on what ? If you're going to make such statements, at least back them up with something.

SPOC

MattC59 wrote:

SPOC wrote:

kleinstroker wrote:

I would like to know why everyone thinks they are right and all the computers are wrong! It's a pretty simple calculation all told so why would it be so wrong?

When I ride my bike at 18mph for an hour at heart-rate for 140bpm and it tells me I burn off 900 calories, it doesn't take much to work out the Garmin is wrong.

Being a runner before I was a cyclist, I would say run at an 8mph pace for an hour, and even then only have burned off about 850 calories.

There is no way on earth that from those two examples (both of which the Garmin provides, I have seen these figures myself so they aren't hypothetical, this is also on the same Garmin device) that the cycle burned off more calories than the run. They wouldn't even be very close, my run would have burned off far more calories at those two pace examples.

It's clearly not something that is such a simple calculation, as they can get it so wrong.

Why? Based on what ? If you're going to make such statements, at least back them up with something.

Based on the fact the power I would have to put out to burn off 900 calories an hour cycling is way beyond anything I am capable of, let alone at a heart rate of 140bpm.

The Garmin heart rate algorithm clearly overestimates cycling's production as a calorie burning exercise. It's only a problem if you are trying to lose weight and struggling daily for a net total to be as accurate as possible. I would guess the vast majority of Garmin users aren't calorie counters to the smallest detail.

It's laughable that an hours riding at 18mph on a road bike could burn off more calories than me running an hour at 8mph, but if I simply went on Garmin's heart rate based calculation, that would 'happen'.

kleinstroker

SPOC wrote:

Based on the fact the power I would have to put out to burn off 900 calories an hour cycling is way beyond anything I am capable of, let alone at a heart rate of 140bpm.

The Garmin heart rate algorithm clearly overestimates cycling's production as a calorie burning exercise. It's only a problem if you are trying to lose weight and struggling daily for a net total to be as accurate as possible. I would guess the vast majority of Garmin users aren't calorie counters to the smallest detail.

It's laughable that an hours riding at 18mph on a road bike could burn off more calories than me running an hour at 8mph, but if I simply went on Garmin's heart rate based calculation, that would 'happen'.

I think you're both right and wrong...

At 18mph you would expend about 680 calories per hour if the road was flat and you weighed about 155lbs. To use as many calories running, you would have to run 6 miles. So 1 hour at 6mph running is equivalent to 18mph cycling. But if you weigh more than 155lbs or climb any elevation, then the rate at which you burn calories cycling will increase, so I think it would be very easy for someone to reach 900 calories per hour.

BowtomePhil

I think everybody should agree to disagree.

On my rides with Endomondo, it says I burn xxxx calories, I use that as a guide nothing else. I eat less than my 2500 calories a day, burn xx with cycling and lose weight, lost 1 stone 1 pound now. Have I any idea if garmin, Iphone apps, google apps etc are correct? No idea. I just know I am doing the right thing.

davidof

A 1 hour hard ride is largely going to be burning sugar in your blood supply and muscles not turning fat into energy. You may subsequently turn fat into sugar if you don't hit the coke etc after the ride.

Most of the advice I see is to loose weight by diet change, not hope that exercise in the form of cycling will do it all for you. I've been cycling more recently due to work changes, or rather I've had more time for longer rides rather than just short commutes but I've also had to cut down on alcohol and chocolate to reduce weight (and then I've only lost maybe a couple of kgs over the summer).