Fat burning zones, a question
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Alex_Simmons/RST wrote:If you are referring to Respiratory Quotient, then I would take RQ1 to be ratio of CO2 volume produced to volume O2 utilised being 1:1.
That being the case then yes, that is when use of FFA as an energy source diminishes substantially and is at or close to 0% and we are fueled primarily by glycogen. It also corresponds to our VO2 being at or near our VO2 Max levels.
sorry missed your post, thanks for that. So does this not prove that to burn fat you need excercise below this point.0 -
Here, let's see if this helps. from The Textbook of Work Physiology by Astrand & Rodahl.
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That's right, so we don't go out there and do VO2 Max work (maximal efforts for 3-8 minutes) to burn fat on that ride. I challenge anyone to ride at VO2 Max inducing levels for longer (hint - it isn't possible). Hence any endurance ride we go out there to do will always utilise FFA as a fuel source.method wrote:Alex_Simmons/RST wrote:If you are referring to Respiratory Quotient, then I would take RQ1 to be ratio of CO2 volume produced to volume O2 utilised being 1:1.
That being the case then yes, that is when use of FFA as an energy source diminishes substantially and is at or close to 0% and we are fueled primarily by glycogen. It also corresponds to our VO2 being at or near our VO2 Max levels.
sorry missed your post, thanks for that. So does this not prove that to burn fat you need excercise below this point.
But we do do VO2 Max intervals as one way to help us become aerobically fitter, which in the long run helps us to burn more fat at higher overall intensities on other rides.0 -
Or to put it another way, it matters not one iota what the fuel source is, so long as more energy is expended than consumed (if you wish to lose fat mass).Professional cycle coaching for cyclists of all levels
www.cyclecoach.com0 -
I'd agree with that. Just I'd add that it seems some can be more efficient at burning (converting) fat and being more able to tap these reserves, therefore they can ride a for longer and thus burn more calories. Sort of a virtuous circle.0
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Hi all.
Great, we're right back to where we were on page 1. Eat less, ride more, that's it.
Imho, the 'fat burning' settings I've seen on gym cardio equipment is purely there so that the less fit can get an 'easier' workout done, but still feel good about themselves. Which is what I meant by marketing. In reality, the more pain, the more gain!
Cheers, Andy0 -
Andy, I understand your point, but the fat burning zone isn't necessarily easy. As one becomes a better fat burner, you'll be able to do it at a higher intensity. Here's some data that illustrates the fat burning zone. First column is heart rate, second column is fat burnt in kcal/min
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In which case, age ( and base metabolic rate) must have a big influence onm ability to lose body fat through exercise. I generally ride as hard as I can for almost every ride I do (between 5 and 9 hours week). This is a lot mnore than I did when in my 20's, yet I am now 15 - 15.5 stone and cant go lower. In my 20's I was 13.5 stone. During the off season this would go up to 14.5 st but I'd lose most of the weight between March and May. I know I eat no more, probably less, and much more healthily, and my beer consumption is much lower so what the hell is going on!! Time for a food diary methinks...
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Tooooo many variables Steve.
Age and metabolic rate changes, diet changes, tolerance to certain foods, crap food with addatives, stronger beer
As the chart shows above, endurance training is good generally for fat burning if its your main goal.
I would certainly not ride as hard as I can every ride, I vary my rides.
My diet is not the best, hence a podgy belly but I say its my reserve for the Marmotte 0 -
method wrote:Andy, I understand your point, but the fat burning zone isn't necessarily easy. As one becomes a better fat burner, you'll be able to do it at a higher intensity. Here's some data that illustrates the fat burning zone. First column is heart rate, second column is fat burnt in kcal/min
129 0.3
etc.
Hi there.
If I understand you right, your figures are the same info that Alex conveyed in his graph above? I'm not disagreeing with the pysiology at work. All I'm trying to say is that you burn more calories if you work harder. If you have a net calorie defecit you'll lose weight, that's the bigger picture. Calories from fat, from muscle glycogen etc is just the minor details.
The only way I could see the fat burning argument working is if you were somehow able to burn calories _exclusively_ from fat during your training ride, leaving your glycogen levels completely untouched. Perhaps you've got some data on how this could happen?
Cheers, Andy0 -
Riding at lower heart rates burn off fat at a higher ratio of fat/carbo than higher heart rates where the ratio of fat burnt reduces so while you will burn off more "calories" at high intensity, it is less efficient . Loosing weight and reducing body fat are not the same thing. By your definition, if you stop eating and sat in a chair for days you will loose weight which is absolutely true, but you may not reduce your percentage body fat as quick as you imagine.
How many skinny people have you seen with high percentage body fat? Loads.
Strange how most endurance athletes have low body fat percentages.
How come some footballers have higher percentage body fat. What about rubgy props?
Their exercise is intense so how come they do not look like Paula Radcliffe?
I never saw a fat TDF rider and they don't do all high intensity training, in fact most of it is endurance.0 -
It doesn't exist because it doesn't happen.andrewgturnbull wrote:The only way I could see the fat burning argument working is if you were somehow able to burn calories _exclusively_ from fat during your training ride, leaving your glycogen levels completely untouched. Perhaps you've got some data on how this could happen?0 -
andrewgturnbull wrote:method wrote:Andy, I understand your point, but the fat burning zone isn't necessarily easy. As one becomes a better fat burner, you'll be able to do it at a higher intensity. Here's some data that illustrates the fat burning zone. First column is heart rate, second column is fat burnt in kcal/min
129 0.3
etc.
Hi there.
If I understand you right, your figures are the same info that Alex conveyed in his graph above? I'm not disagreeing with the pysiology at work. All I'm trying to say is that you burn more calories if you work harder. If you have a net calorie defecit you'll lose weight, that's the bigger picture. Calories from fat, from muscle glycogen etc is just the minor details.
The only way I could see the fat burning argument working is if you were somehow able to burn calories _exclusively_ from fat during your training ride, leaving your glycogen levels completely untouched. Perhaps you've got some data on how this could happen?
Cheers, Andy
I thought we were talking about burning fat and not just losing weight. Perhaps I didn't read the earlier posts properly. I only posted as I think that to say a "fat burning" zone didn't exist is wrong, it clearly does. Whether or not its the best "zone" to lose wieght in I don't know. From personal experience lowering the intensity of my long rides to 130-140bpm resulted in me losing wieght much faster than I had before. But that could just be me...0 -
Method - are you arguing that by riding at a relatively low intensity you burn a greater proportion of fat and this makes you a more efficient fat burner - in other words that when you ride faster you will conserve your glycogen stores because you can get more of your energy requirements from fat ?
it's a hard life if you don't weaken.0 -
Tom Butcher wrote:Method - are you arguing that by riding at a relatively low intensity you burn a greater proportion of fat and this makes you a more efficient fat burner - in other words that when you ride faster you will conserve your glycogen stores because you can get more of your energy requirements from fat ?
yes, this is what my coach told me to do, everything I've been doing for the last year has been to improve my fat burning efficiency, as my body isn't that good at it. He said that a good endurance athlete would be up to 7kcal min from fat (something like that).0 -
ask your coach for the evidence for this approach.method wrote:Tom Butcher wrote:Method - are you arguing that by riding at a relatively low intensity you burn a greater proportion of fat and this makes you a more efficient fat burner - in other words that when you ride faster you will conserve your glycogen stores because you can get more of your energy requirements from fat ?
yes, this is what my coach told me to do, everything I've been doing for the last year has been to improve my fat burning efficiency, as my body isn't that good at it. He said that a good endurance athlete would be up to 7kcal min from fat (something like that).0 -
this is all very interesting and technical but I kind of err towards the move more eat less approach to both fat and weight loss. Eat a balanced diet. Don't eat junk food or have too much beer. Ride your bike as much as possible and enjoy. The weight will take care of itself and the body will find it's own happy limits in both its weight and the performance it give you.
I think its all too easy to get bogged down with the whole micro/macro nutrients and deep down theories on how to burn more fat. Every bodys body is different so what works for one person may not work for another. Sure the fundamentals remain but in practice is something that is personal.
The basics as I see it (unless you have a coach and are training for specific events) To lose weight burn more calories than you consume. Where this weight loss comes from ie fat, water carbs is irrelevant as your primary goal is weight loss the only danger is when you get too low and it comes from muscle. Your body will tell you the intensity to train at and will burn whatever it needs for optimum performance. If you want to lose BF do some weight training and build muscle.
Sorry for the layman lowdown in such a great technical post but thats just MHO.
Gats0 -
Is it not the case that at a steady pace, you can tell from the gaseous exchange the rate of "fat burning"?
Even if there was evidence to prove or disprove this, most sports science experiments tend to focus on small sample groupsAlex_Simmons/RST wrote:ask your coach for the evidence for this approach.0 -
all body energy generated at cell level comes from ATP which can be made from carbs proteins and fats.
Proteins contribute up to 10% for endurance events or very intense exercise
Intensity decides whether carbs or fats are used
Low intensity - greater proportion of fat, higher intensity great proportion of carbs.
max energy output can only be sustained for a short time (minutes)and uses only carbs and results in muscle 'tiredness' due to the incomplete energy generation process.
If you are a 100m sprinter you will probably only burn carbs during your sprint, but during warm up etc adn anything less than all out sprinting you will burn fats..
to answer another q blood glucose levels are maintained (when glycogen has run out) by converting from glycerol (fats) and amino acid residues (proteins). Falling levels of blood glucose can be sufficeintly stressful to make your body release cortisol which will affect the immune repsonse (you will get ill easier) and encourages the release of fatty acids (you won't get thinner!)
In other words eat slightly less , do slightly more, work as hard as you can over a longer period of time andmaintain blood sugar levels during training if you exercise very hard or for a long time....but the overall daily input should be lower than the output if you want to lose weight. As long as you don't exercise at 100m sprint levels you will lose fat too...0 -
not sure where you're going with that, anyway...Kléber wrote:Is it not the case that at a steady pace, you can tell from the gaseous exchange the rate of "fat burning"?
Even if there was evidence to prove or disprove this, most sports science experiments tend to focus on small sample groupsAlex_Simmons/RST wrote:ask your coach for the evidence for this approach.
In a normal healthy individual fat stores represent about 50 times the energy capacity of glycogen. We have about enough glycogen to ride very hard for ~ 90 to 120 minutes, about 2000 Cal. We will always use fat as an energy source for any ride of substantial length, no matter what we do. Indeed the longer we ride, the more we use our fats as an energy source, even on harder rides.
physical training which increases the maximal oxygen uptake also increases an individual's ability to use fats as fuel. we don't improve these abilities by riding at lower intensities.
Coaches who recommend lowering the overall intensity presumably do so to compensate for an overall increase in the volume of riding and to ensure such volume-intensity combinations are sustainable for that athlete.0 -
My point about gas measurement is that I think - please advise if I'm wrong - that there is a optimum level of intensity to metabolise fat, not to maximise the burn but a point where you get the right balance between effort and calorie consumption, where if you rode faster, you couldn't burn the fat faster and so would bonk, and any slower/less watts and you'd be holding something in reserve. In lay terms, a sort of "cruising speed" where you can burn fat and ride for a long time at the fastest speed thanks to this.
I'm not talking the best way to lose weight, that's more the basic realm of thermodynamics, rather trying to see if this can be applied to long-distance riding like cyclosportives, endurance and "ultra" cycling.
(Alex, on evidence, my point is that sports science journals are full of reviews where the sample size of athletes tested is very small, the epistemology is not always rigourous, compare it to a pharma 3-phase trial and even these can be wrong! Sometimes 12 can be tested and usually less than 50. Sample sizes like this are highly likely to generate "anecdata". On top of this, the other controls can be weak. So it can be easy to find articles saying one thing and then dig up another saying the contrary.)0 -
That would be the case for any individual ride. My point has been that by improving our aerobic fitness, it raises the absolute level of the rate of energy output we can sustain on such rides and, inter alia, the relative utilisation of FFA as an energy source at a given absolute intensity level increases as well.Kléber wrote:My point about gas measurement is that I think - please advise if I'm wrong - that there is a optimum level of intensity to metabolise fat, not to maximise the burn but a point where you get the right balance between effort and calorie consumption, where if you rode faster, you couldn't burn the fat faster and so would bonk, and any slower/less watts and you'd be holding something in reserve. In lay terms, a sort of "cruising speed" where you can burn fat and ride for a long time at the fastest speed thanks to this.
Fair enough.Kléber wrote:I'm not talking the best way to lose weight, that's more the basic realm of thermodynamics, rather trying to see if this can be applied to long-distance riding like cyclosportives, endurance and "ultra" cycling.
My take is this: you can only ride so hard for so long. Knowing your Mean Maximal Power - Duration curve is pretty handy. Pushing the curve up and out through training enables us to ride further faster, whether or not we choose to do so "at our intensity-duration limit" or within ourselves.
To do that one needs to improve their aerobic fitness.
The best way to improve aerobic fitness is to ride regularly at intensities near LT up to those intensities that induce VO2Max.
I'm not arguing with you there!Kléber wrote:(Alex, on evidence, my point is that sports science journals are full of reviews where the sample size of athletes tested is very small, the epistemology is not always rigourous, compare it to a pharma 3-phase trial and even these can be wrong! Sometimes 12 can be tested and usually less than 50. Sample sizes like this are highly likely to generate "anecdata". On top of this, the other controls can be weak. So it can be easy to find articles saying one thing and then dig up another saying the contrary.)
But there can be a weight of evidence from such studies and as long as the conclusions drawn are based on the evidence/data (and not misinterpretations), then I see no reason not to consider them irrespecitve of smallish sample sizes (which are the norm I'd have thought).
Nice post, this is quite enjoyable
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Yes, this is interesting. Now I know full well that aerobic fitness is key. But say a rider can ride very hard and fast in a time trial and score well on a V02 max test. In short, he is very fit and at the point where he can no longer improve his aerobic fitness. Our rider then goes to a mountainous cyclosportive, an endurance MTB race or does some long but fast touring. Clearly the intensity will be much lower than the VO2 max test.
I'm trying to suggest that once you have the fitness in place, pacing can be very important but not from an aerobic/anaerobic pace but more to find a pace where you can ride at such a level that your blood sugar remains constant, ie the calories being consumed from the effort of riding (plus being alive!) are equal to those you can extract from body fat, plus anything you might ingest whilst riding.
So in short, once you have fitness in place for long rides you need to think of an optimum pace to ensure you don't crack. I think this intensity can be derived from gas analysis but I haven't seen much on this, obviously a 6 hour lab test is mentally crushing!
I'm not saying you don't need to consider your aerobic fitness, far from it, this is still the crucial determinant. Just that in longer efforts, you have to keep an eye on the fuel tank and that perhaps this can be done approximately via HR?0 -
I just posted this on another forum:
A plot of mean maximal power verses duration for two season's data. My own ride data BTW
On each axis, the power is shown as Log10(MMP watts) and duration is shown as Log10(duration in minutes). This covers durations from 5 min out to 3.75 hrs. The relationship is apparently quite linear.
Perhaps this relationship extends out to longer durations but I'd need to assess more data to know. I'm not an endurance MTBr or Audax rider - I'm a track enduro kinda guy
Essentially there are "rules of thumb" when it comes to impact of duration on sustainable power for the purposes of predicting optimal (sustainable) pacing. Certainly the critical power model (which is great for predicting maximal intensities for durations from say 3-min to 60-min) falls down at long durations so perhaps this is an alterntaive method.
One thing you will notice from the trends shown in this chart is that in 2007 I was able to generate more power for longer than in 2006, hence the shallower gradient.0 -
Course, on this issue there's also the difference between men and women. I think its known that for women, they find it harder to shift fat stores as the body has a tendency to hang on to it for energy to use when rearing a child. Is that right? I don't fully understand that though as surely if the equation of what goes out vs what goes in is tilted correctly they should surely lose weight?0
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While women do in general have a higher proportion of body fat than men, as Kleber said, sustainably reducing weight is a matter of thermodynamics. One's sex has nothing to do with that.Heavymental wrote:Course, on this issue there's also the difference between men and women. I think its known that for women, they find it harder to shift fat stores as the body has a tendency to hang on to it for energy to use when rearing a child. Is that right? I don't fully understand that though as surely if the equation of what goes out vs what goes in is tilted correctly they should surely lose weight?0 -
Why is it that you get plateaus with weight loss then? I'm from the school of thought that says any intensity of exercise coupled with less calories and healthy diet should mean a steady weight loss but it seems that doesn't always appear to be the case, especially for women. This is just from what I've heard by the way. Being built like a racing snake myself its not really a concern for me.0
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Every human is diferent. Also, your body constantly adjusts and changes how it burns fats.
For my lifestyle (without cycling) I should eat 2350 cals a day to maintain weight. I should also eat any calories I burn off through additional exercise.
For those who don't know there are 3500 cals in 1lb of fat. I eat 1600 cals a day so that I lose about 1.5lbs a week. I have stuck to this religiously for the past coule of months. n the same time I have also an exercise deficit of 29K calories.
I should have lost 20+ pounds, but instead have lost about 2lbs. My body has decided it doesn't want to lose any more fat and is running so efficiently that it can run on 1600 calories a day while I cycle 250 miles a week.0 -
guinea wrote:Every human is diferent. Also, your body constantly adjusts and changes how it burns fats.
I should have lost 20+ pounds, but instead have lost about 2lbs. My body has decided it doesn't want to lose any more fat and is running so efficiently that it can run on 1600 calories a day while I cycle 250 miles a week.
How frustrating! So, what would you tell Guinea, or someone else who wanted to lose more than those inital 2 pounds? Just to stick at it?0 -
Attempting to lose 1.5lbs / week is a bit too much IMO unkes you're large or carrying lots of excess. That's equivalent to a deficit of ~ 875Cal/day. (I'm working on 1lb/fat = ~4200Cal although with water content of fat tissue I suppose it's Cal value per lb would be less).
Metabolism will slow with a long term large calorie deficit, and cycling performance can be degraded. You need to fuel properly in order to train properly and have enough energy to keep your metabolism up.
For relatively fit riders, eating too little is worse than eating too much.
Train well, eat well and the weight/fat usually takes care of itself.0
