Will an athlete who runs for an hour at moderate pace and is not tired at the end burn more calories than an out of shape person who runs for an hour a way shorter distance but is exhausted at the end?
Assuming both have the same weight and such
What I want to know basically is if your body gets stronger will it need less energy to perform the same amount of work?
In: 1708
>if your body gets stronger will it need less energy to perform the same amount of work?
Yes it will. See *Burn* by Herman Pontzer of Duke University. Pontzer measured the metabolisms of Hadza hunter-gatherers in Tanzania who engage in massive amounts of physical activity every single day. He found that their energy output was the same (corrected for body size and composition) as sedentary Westerners, despite their activity level. Over time, the body adjusts its energy output as exercise increases to maintain it within a narrow window. Pontzer calls this “constrained daily energy expenditure”. He writes, *”The bottom line is that your daily activity level has almost no bearing on the number of calories you burn each day.”* (p. 103)
He also measured the metabolism of extreme athletes, like those running across the United States–effectively a marathon per day. He found that their energy expenditure decreased over time:
>But by the end of the race, 140 days later, their bodies had changed. Even with the same crazy marathon-a-day workload, runners were burning 4,900 kcal per day–still impressive, but a 20 percent decrease from the first week of the race. Some of that decrease could be attributed to the smaller hills out east and having lost a bit of weight over the course of the event, but at least 600 kcal per day seemed to have just vanished from their daily energy budget. This was energy compensation, their constrained metabolism at work: faced with an enormous exercise workload, the runners’ bodies were reducing expenditure on other tasks to try to keep daily energy expenditures in check. The enormous cost of a daily marathon was more than the energy compensation could fully absorb–their daily expenditures during the final weeks of the race were still well above their prerace values–but their bodies were trying. (p. 271)
yes and yes
To move a given mass a given distance takes a given amount of energy regardless, so going further faster burns more calories. Athletes can go further faster because their body is trained to store more energy in the form of glycogen (instead of fat) and so has more readily available energy for continuous exertion. Also their heart and lungs are stronger allowing them to take in oxygen and exhale more CO2 at a greater rate, thus reducing lactic acid build up which is typically what makes you feel “tired”.
Training helps athletes be slightly more efficient because they have better technique. Also, because their heart and lungs are more efficient, they burn most of their energy aerobically, which is much more efficient than the anaerobic energy production an out of shape person falls into when their heart and lungs can’t keep up.
This is part of the challenge with trying to lose weight solely through moderate exercise. With moderate exertion your body will actually get more efficient and so you need to counter this by upping your intensity. You basically need to exercise until you feel tired because breaking down that lactic acid also burns a lot of calories too.
To your latter question, not _significantly_.
By and large, it takes the same amount of energy to do the same thing, regardless of fitness. But the _same thing_ is important. If the weight is different, height, weather… that’s not the same thing. Ultimately what you are doing is moving your body against the forces of gravity, air pressure, friction, and so on. As long as all those are the same, the fitness component is small.
There are _some_ efficiency gains from training — that is, your body wastes less energy when it converts it to useful work — but they are not substantial, just a few percentage points (most of the wasted energy is converted to heat).
So the reason a trained athlete is faster or stronger or whatever is because they are able to use more energy than the beginner.
It’s not really a 1-to-1. Both are factors. If you hold a 90 pound weight over your head for an hour you’ll burn a bunch of calories, but you haven’t technically done any actual “work.”
It’s a wee bit of both. Think of the body like a truck and exercising as towing a trailer. When towing you are burning fuel (calories) in order to get the truck and trailer from point A to point B.
Now if you have a brand new 2021 Dodge Ram 3500 with a diesel (athlete) and compare it to the same truck but from 1994 (out of shape person), it starts to click. Yes there is a certain level of fuel/calories/energy it takes to move both set ups from point A to B.
You also have to look at efficiency though. The 94 isn’t going to get near the miles per gallon of the 21. It’s going to have to burn more calories to get the same amount of work done because of its lack of efficiency.
Simply put yes you burn less calories the more in shape you are. As you get into shape you need to continue to push yourself rather than stick with the old routine or you will just plateau.
Effort matters. But I have to say, exercise would be a lot more appealing if rather than focus on calories burned (assuming your exercising for weight loss), set your goals differently.
Set them towards *performance*, just a suggestion. Something you can measure that has nothing to do with the number on the scale.
Pick something that matters to you. Focus on that.
And if your goal IS weight loss, also focus more on putting the fork down. If exercise is boring you to the point where you’re going through the motions rather than mentally focused training, cutting calories takes less effort.
I’ve wondered this about running vs. walking. If I walk a mile, I feel nothing. No effort. Doesn’t feel like exercise at all. If I run that same mile at a 12min/mile pace because I’m slow and out of shape, I feel like I’m dying. Drenched in sweat. Face bright red. Need to lay on the floor for 20 minutes recovering. Surely I burn more calories running the same distance than walking?
Also, does intensity matter?
i.e. X amount of kilometres in Y minutes versus X amount of kilometres in Y/2 minutes.
Trained person can do more work by spending more energy. But it’s about the same amount of work per energy spent. It’s rather physics, than biology.
Human muscle tissue consumes about the same amount of energy per amount of work. So, feeling of exhaustion is related to amount of work per amount of muscle.
If two people have different amount of muscles, they will burn the same amount of calories for the same work. But weaker person would be more tired.
Interestingly, the amount of calories spent can be estimated by the amount of breathing. If you breathe heavily, you’re spending a lot of calories.
Sometimes anaerobic energy consumption kicks in in muscles, which doesn’t require oxygen instantly to be consumed, but it will require the molecules to be replenished later.
But anaerobic breathing also sends chemical signals to increase the amount of mitochondria in cells. Also it improves the capillary network. That’s why HIIT is beneficial, it causes muscle cells to utilize anaerobic breathing causing the improvements I mentioned.
Grand scheme of things excercise actually burns fuck all calories, the people that can burn more per session are usually those that don’t need to. I.E not trying to lose fat.
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