As the body becomes more efficient at utilizing energy stores through the process of training does the number of calories needed to maintain the body (without working out) decrease as we get fitter?
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Your probably can’t measure your weight and intake accurately enough for any of those changes to matter much.
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Sure you can…there are devices that can accurately measure your RMR based on analyzing your exhalation gases.
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I don’t think the body becomes more efficient at utilising the energy stores, it’s more a case of your muscles working more efficiently when you get more trained. By that I mean you stop doing unneccessary movements, for example a beginner might grip the bars very tightly, which needs energy for his arm muscles, while later on you can stay more relaxed. Also I’d think on a smalller scale muscle bundles develop a more synchronised firing pattern that fits the movement better, etc. However none of that affects your energy needs for other functions, eg to keep warm, supply the brain, or other organs. There might be a slight increase in efficiency of the heart and lungs, eg lower HR at rest, but I can’t see that making a big difference in resting matabolism.
If anything, if you have increased muscle mass and less fat to keep you warm, you’ll likely burn more calories, even at rest.
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Isn’t this what efficiency is?
Sure, but he’s talking about efficiency of movement during exercise. And he’s hypothesizing that those efficiency gains don’t transfer to your BMR. E.g. the efficiency of your leg muscles when pedaling doesn’t translate to the efficiency of your stomach for digestion or even necessarily your leg muscles while sitting on the couch.
Most of the efficiency gains you see as you get fitter (i.e. those that lead to lower HR for the same power) are mostly about oxygen efficiency and not energy efficiency (might be different fat/glucose usage but total calories would be similar). So assuming you aren’t wildly flailing on the bike then you will burn roughly the same amount of calories pedaling 300W as a newbie as you will 5 years later and fitter but you will likely require less O2 and a lower HR.
If anything, you will probably have increased your lean muscle mass and your body will require more calories at rest. (assuming your fit and unfit self are similar weights) Also, recovery requires calories. This is partially why bodybuilders require so many calories. Not only are they huge with tons of muscles the burns calories but they also inflict major damage to their muscles that require energy to repair.
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Ah, I see, so the efficiency boost in the body’s aerobic system through training has nothing to do with our body’s increased ability to utilize energy stores such as fats and carbohydrates, but rather the heart and lungs ability to transfer oxygen to larger and more efficient muscles.
So it’s like we’ve got the same size oven (aerobic capacity) but with training, we can blow more air onto the wood (fat, carbohydrate) but we still need a certain number of logs for a certain temperature (calories) even though we can heat things up faster and reach higher temperatures now, but it’s not like we burn any less wood for certain temperatures (output, watts)
I guess my question now (if you’re willing) is, how come certain cyclists at altitude who experience less oxygen uptake than they are used to can acclimatize? What process allows them to utilize less oxygen for the same output (watts)?
Just curious,
Cheers
Yeah if my understanding is correct then I think that analogy is pretty good. But depending on what you mean by aerobic capacity then that also grows as you get more fit. But the rest is pretty close.
As for the altitude part of it, most of the short term acclimation is blood volume and then when your body is exposed to the lower partial pressure of oxygen you start to create more red blood cells.
But when you go to altitude it’s almost like you revert back to a less trained version of yourself but now the oxygen pinch point is in a different place. Instead of your heart/blood not being able to deliver it to your muscles it’s now that your lungs/blood can’t exchange it out of the air as quickly and efficiently.
So they are using less oxygen to make the same watts because they use a different energy system. Essentially how 285W for someone with a 300W FTP is high SS and sustainable for maybe 1.5-2hrs but that same 285W for someone with a 275W FTP is a 20 min all out effort. They are creating that power using a greater percentage of anaerobic energy systems that don’t require oxygen. So that’s why it’s simplest to think of going to altitude as a reduction of your FTP. If 6000’ results in a 10% drop in FTP then that 300W athlete at altitude becomes almost the same as that 270W athlete at sea level. (For argument sake. there are other difference but close enough)