Fitness and Calorie Counts - Would like some opinions on accuracy of various outputs!

BikeMarrow

New Member
Hey guys!

I'm pretty new to the world of cycling and although I've had a hybrid road bike for a few years now, have only recently started using it outside of commuting and the odd ride into town when the suns out, and more for longer rides and fitness. I've almost certainly got the bug!

I've found myself treading the murky waters of calorie burning. While I understand this to be a difficult topic for cycling especially, what with all the variables, I wondered if you guys could shed some light on the best way to track what I'm burning and when?

I've been on Strava for a while and have recently bought a FitBit Charge 3, which is synced up and gives Strava my GPS ride, gradient and heartrate info when out on rides, which I've found fantastic! I'm logging quite large calorie-burning numbers when out on 2+ hour rides of around 30 miles, with some pretty decent climbs of 5/6% and maxes of 11%. I live in South Manchester so it's great for getting out and mixing flats with pretty decent climbs when getting towards the Peaks and Cheshire and it's on these routes that I'm logging a calorie burn of around 1200. I've read up lots on the Charge 3 and a lot of sources say it should be taken with a pinch of salt but the heart rate info it's providing Strava with seems to be helping towards a more accurate number, as Strava was initially logging pretty low.

Anyway, I've seen a real change in my fitness, weight loss and am starting to feel great about it! But this week, with the weather changing and the wind being up a bit, I've been doing GCN Youtube training sessions on an indoor exercise bike - the Reebok GB40s. Today's session was a 40 minute Sweetspot session which absolutely nailed me!

View: https://www.youtube.com/watch?v=vxrEqrdSPgw&t=2s


Pretty high resistance all the way through, constant RPM of around 80 and to 100+ when sprinting, so I was working a lot harder than I would be for the first 40 minutes of any ride out on the roads. The attached photo is the bikes stats once finished. I'm a bit annoyed I didn't snap a pic just before finishing so It could show wattage etc. but as I recall it was up around the 200 mark generally.

My Fitbit struggled with any other data but Heart Rate, as I had it set to 'Ride' and the GPS didn't track any movement, as there obviously wasn't any, so I'm sceptical about the data. Nevertheless, it's given me around 500 Calories burned. The Reebok bike, as you can see, is STUPIDLY different, at well over 1000 calories burned! Now, I know this cannot be right, but given the amount of work put into the 40-minute session and the amount of sweating and aching, I wondered if the 'true' number might be between the two somewhere?

This isn't something I'm going to be solidly monitoring, but as a beginner, I'd like some clarity and consistency as I start to train harder and hopefully get fitter. Anyone any thoughts, similarities or stats/number that they can show me that will help me here?

Sorry, this is long-winded but it's been an intense lockdown!

Cheers in advance,

Mike
 

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YukonBoy

The Monch
Location
Inside my skull
The 1321 calorie count is way off the mark. Even working really hard for 38 mins you’re unlikely to burn much above 400 calories. You say you are losing weight so best way is to monitor your food intake versus amount of exercise you are doing versus amount if weight changes that are occurring. You’ll then find an appropriate balance.
 

vickster

Legendary Member
All guesstimates at best.
my guesstimate is 30-40 a mile. I probably manage 12 miles in an hour, so 350-400 an hour would be my guess

Your weight and effort may mean more or less.

Just forget the numbers if you’re losing weight and feeling fitter :okay:
 

Knightly85

Well-Known Member
I'm pretty much in the same boat as you mate! Eating really well cycling plus other exercise waiting to see my results!
 
Location
Pontefract
All guesstimates at best.
my guesstimate is 30-40 a mile. I probably manage 12 miles in an hour, so 350-400 an hour would be my guess

Your weight and effort may mean more or less.

Just forget the numbers if you’re losing weight and feeling fitter :okay:
This is what I reckon, my garmin is currently running at about the 50cals/mile when I had the 500 it returned 40's, what it will return is usually based on HR zones, I believe, my HR is much higher than it was then possibly the difference in the numbers.
 
OP
BikeMarrow

BikeMarrow

New Member
Thanks for all the replies guys! I knew it would be a bit of a mine field and I Knew the Reebok bike would be a ridiculous amount.
for now I’m more than happy with what the FitBit is giving me. I just want to have the consistency there so I can continue tI burn the cals and get fitter on the bike!

I’ve priced up power meters but that won’t be happening any time soon, unless I take cycling to the next level!
 

SkipdiverJohn

Veteran
Location
London
Let's not overthink this stuff. You really don't need all the gadgets and the HRM to get the fitness benefits from cycling. If you do any sort of physical activity, cycling included, that puts you ahead of the majority of the population for a start. All you actually need to do is be active - and that's it! No need to over-complicate it.
All the gadgets are really boys toys and things used to brag about stats with. The only accurate way of measuring how many calories an activity burns is to perform it under strict laboratory conditions. Anything less scientific than that is going to be a pretty rough and ready estimate and likely way off the true numbers. It takes a lot of physical activity to burn the calories in a pound of body fat, and if you were to consider the amount of miles the average person would need to ride to shift a couple of stone of lard, the number would probably equate to riding the whole way round the globe and put them off it altogether!
 

HMS_Dave

Senior Member
Location
Midlands
I started at 27 stone. A very high marker for anybody don't get me wrong. I started cycling at 25 stone. I've lost a fair old bit in around 6-7 months of cycling but im very much in the camp of just jumping on the bike and getting out there. I understand many are into the science of it all, how much watts they put through the chain, calories burned, ave speed, personal best etc but don't get too bogged down with it. My weight loss hasn't been linear, ive hit periods where i haven't lost a single pound one week and the next i lose 4. Nothing i have eaten has been different. My fitness gains haven't been linear and we all have them ups and downs that no computer can really help with... Saying that however is only my opinion and we all cycle for different reasons and if number crunching is your thing then good luck with it, just don't obsess over it and let it get in the way of cycling.
 

PaulSB

Legendary Member
You don't say why you want to log your calories burned during exercise but I imagine it may be connected to weight loss. I would question the value of this information and that it could mislead you.

The smart watch and Strava will do nothing more than use the data you input, height, weight, miles etc. and calculate a typical average based on those numbers. The result will at best be an average and not specific to you.

In my opinion to use cycling as for good weight loss we need to know our fat burning zone during exercise and then exercise within those limits. It's also important to understand which foods are providing the body with the energy it requires during exercise. Simply reducing calorie intake or apparently burning more calories isn't the answer.

Regular exercise in the fat burning zone, good diet appropriate to lifestyle and cutting out uneccesary calories will help achieve weight loss. The numbers Strava and Fitbit provide won't contribute to this in a meaningful way.

Look at your body and how your clothes fit. If you're body shape is improving and waistline reducing you're losing the right sort of weight.
 
OP
BikeMarrow

BikeMarrow

New Member
Thanks guys

All very interesting and good to see it’s as big a minefield as I suspected after the research I’ve done.
Truth is I find the numbers fascinating. It’s good to know them for progression and keeps me motivated. I find the HR monitor on the Fitbit fascinating and as it logs things like sleep and day to day HR it’s great to see it’s getting a solid work out in those higher zones when I’m out pushing it on the bike. I’ll disregard the exercise bike information, but as stated in the initial post, it’s nice to be able to keep an eye on my RPM number and Wattage at different cadences - information that seems to be far more key than just weight speed and distance.

Thanks for the replies!
 
Location
Pontefract
It takes a lot of physical activity to burn the calories in a pound of body fat, and if you were to consider the amount of miles the average person would need to ride to shift a couple of stone of lard, the number would probably equate to riding the whole way round the globe and put them off it altogether!
I did sort of work this out roughly back in about 2015'ish to loss 1lb of body fat for me was about 350 miles of riding.

1) Regular exercise in the fat burning zone, good diet appropriate to lifestyle and cutting out uneccesary calories will help achieve weight loss. The numbers Strava and Fitbit provide won't contribute to this in a meaningful way.

Look at your body and how your clothes fit. If you're body shape is improving and waistline reducing you're losing the right sort of weight.
1. As you become fitter, you tend to exercise in the lower H.R. zones which tend to burn more fat than carbs, so losing fat becomes easier or simply stay the same weight require less effort, body becomes more efficient at using energy the fitter you are.

2. Many use the B.M.I. as test on here we all know it B.S. however one I came across was to measure your height and your waist and if your wasit was 50% or less of your height you should be in the right area (slightly different figures for both genders do apply), again just a guide, the important thing there many other benefits from cycling, I smoke, but I can have a better lung capacity than many that don't ride and don't smoke, for example when I was riding a lot, I could inflate a standard size balloon with almost one set of lungs full, war as many couldn't even get the balloon going, and not forgetting it gives us time to see the rubbish our species dumps in our lovely countryside.
 

SkipdiverJohn

Veteran
Location
London
Look at your body and how your clothes fit. If you're body shape is improving and waistline reducing you're losing the right sort of weight.
I only weigh myself occasionally and I don't obsess about it. I enjoy my food & beer and that is unlikely to ever change! I lost bugger all weight from last Sept through to this March, as the weather was utterly shite and I only did half as much riding as I would normally. Since the weather has improved, I've increased my activity with a vengeance to take advantage of the reduced traffic and more pleasant riding environment. However I've probably still only lost a pound or two at the most, but I have noticed my trousers are slightly looser and my legs stronger, so the activity is doing something, but it not translating entirely into reduced weight.
However, a colleague of mine who is into weight training, reckons that becoming more muscular from physical activity creates a virtuous circle with weight loss, because having less fat and more muscle for a given bodyweight requires more food just to maintain the body, even when not being active. That means even if you haven't lost much weight overall, the body will now be burning more base calories which has a small but positive downward pressure on the amount of stored fat - assuming you do not increase your food intake of course.
 

PaulSB

Legendary Member
@SkipdiverJohn I understand exactly what your colleague is saying and agree with him.

My experience is this. Since lockdown I have been riding 30/35 miles a day at least 5 days out of 7. My normal activity is to ride 3 times a week on 50/70 mile rides. So my exercise levels are similar but the type of exercise has changed.

I've lost 1kg, 70.5 down to 69.5kg, which is not significant but I can see my stomach has reduced and the muscle definition and bulk in my thighs has increased. I'm therefore happy as I'm removing fat from my waist, an unhealthy area to carry fat, and the weight is roughly stable - all I'm doing is shifting the weight from one place to another but turning it in to healthier weight.

I'm also eating more at lunchtime because I am actually hungry.

About ten years ago a seizure meant I lost my licence for 12 months. I commuted 36 miles a day by bike and got exactly the same result!

Fat burning is the important thing as fat is the threat to our health.
 

Dogtrousers

Kilometre nibbler
I can't comment on the specific figures as I generally don't look at calorie counts, so I don't really have any idea what's sensible and what isn't. But here's a general piece of advice (and this applies to things like moving average speed and elevation gain):

Don't get hung up on accuracy. That way madness lies. These figures are derived by an algorithm and will generally be consistent from one activity to another. So you will know from one ride to the next whether your calorie count was relatively high or relatively low. They will be really useful for that.

If you have two methods that disagree (gadget 1 and gadget 2) choose one and stick with it. Don't get hung up on the fact that they disagree.

But what you should never do is compare figures derived by two different methods. They just won't be comparable. Don't use calorie figures from a gadget to compare with calorie figures on foods that you purchase. That won't be much use.
 
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