It's not all Calories in vs Calories out (my theory, read first)

Jon Orange wrote:

At the speed you are running, there are slight differences.

Heat production comes from the Lactate dehydrogenase reaction of which there is much more in a race than an easy run.

Slight is the key word. Go ahead and calculate the % change in energy requirements for easy (8.6 mph) vs fast running (10.9 mph) due to wind resistance. For practical purposes it is negligible.

You also made a non-sensical argument about heat production. Let me phrase it for you so that you can clarify for all of us: "You burn more calories running faster because of heat production." Please explain yourself.

You can try to confuse the issue with as many physiological ineffeciencies that you want, but you are not addressing the issue, and your inefficiencies are negligible in a practical sense.

The issue is that it is a common misconception that feeling like you are working harder means that you have done more work. If someone lifts 100 lbs from the floor onto a table, they feel like they have done more work than if they use a pulley to accomplish the same task. The pulley makes it easier, but the work done is the same.

It is the same issue here. People feel like they are burning more calories by running faster, but in reality the caloric requirements to move from point A to B are, practically speaking, the same whether you run easy pace or fast pace. That is the point. You are trying to confuse a very simple principle with negligible real world inefficiencies.

If you feel the inefficiencies are not negligible, then it is now up to you to show it. Please present the final answer in as a % change from ideal.

One factor ignored so far in this thread is insulin resistance. There may be some credence to the theory that fast, sustained running reduces insulin resistance. As a result, leptin resistance is reduced, which turbocharges the hypothalamus and increases metabolism.

Look at the research of Dr. Jason Fung. He shows evidence that, for most people, calories in versus calories out doesn't work, because our bodies will always adapt our metabolic rate to match input to output. He also theorizes that insulin resistance is the sole factor explaining obesity, and that obesity can only be reversed by reducing insulin (either through a low-carb diet or, ideally in his mind, through fasting). Using this approach, he has cured type II diabetics through intermittent fasting programs.

Everything essentially boils down to calories in versus calories out. It's just how the body functions in purely simplistic view. People drastically overestimate the calories burned during a running workout because running burns approximately 100 calories per mile but it doesn't increase very much with higher intensities. Literally ANYONE can lose some weight by diligently counting their calories and burning more than they take it in.

Psycho-logist wrote:

One factor ignored so far in this thread is insulin resistance. There may be some credence to the theory that fast, sustained running reduces insulin resistance. As a result, leptin resistance is reduced, which turbocharges the hypothalamus and increases metabolism.

Look at the research of Dr. Jason Fung. He shows evidence that, for most people, calories in versus calories out doesn't work, because our bodies will always adapt our metabolic rate to match input to output. He also theorizes that insulin resistance is the sole factor explaining obesity, and that obesity can only be reversed by reducing insulin (either through a low-carb diet or, ideally in his mind, through fasting). Using this approach, he has cured type II diabetics through intermittent fasting programs.

The "it's all about insulin" theory has been proven false:

Try to keep up.

In fact, there's a load of evidence that the theory, which kinda makes sense if you just look at nutrition theory, does not actually work when tested:

Carter Rods wrote:What I'm saying is from speculation it appears your body will adapt to what you put it through. Hence why swimmers look like swimmers, cyclists look like cyclists, and runners look like runners

And playing basketball makes you tall.

test2 wrote:

I'm not in the habit of siding with Jon Orange, but he's right that this problem isn't this simple. What's the force, F, here? How do you know it itself is independent of v or t?

You bring up a valid point. To be dead-on accurate, you would have to balance frictional, gravitational, and muscular forces at many points of time in order to integrate Fvdt properly.

The rearrangement I performed on W=Fd is simply to prove that W is the same for moving a set mass over a set distance.

Orange has pointed out that there are real-world ineffeciencies/frictions not accounted for in this equation, but my assertion is that these are negligible and miss the point of the argument.

Jon Orange wrote:

Ozzie Strawman wrote:

Chupacabra is right. It's a simple Physics 101 problem.

It's not simple.

Can you guys hurry up and figure this out? I need to lost 5 pounds before my half early Sept.

Bring back Chad wrote:

Can you guys hurry up and figure this out? I need to lost 5 pounds before my half early Sept.

Have you tried methamphetamine.

I am replying to the OP. You are talking about cause and effect here. You are saying that BECAUSE a runner is fast...they get thin. How about the simple argument that maybe being that thin...puts them at an advantage and they run faster.

Many things effect body weight from diet, exercise, to genetics.

My guess would be that 20 plus min 5kers are running much much less than the 15 min 5kers are ...and thus BURNING LESS CALORIES too.

So maybe running more = thinner (more calorie burn) = faster (less weight to carry and more efficient)

If runner A and B eat the same junk food diet...but runner A runs 70 miles/week and B only 20...then runner A will be leaner and faster...

But I also think genetics is huge factor as well. Some are built like runners and some like linebackers.

Are you guys serious?

You guys are over complicating this.

If you are lighter you can run faster.

CICO > hippy theories.

Also I NEVER believe someone's anecdotal evidence of "oh i saw some fast guy eat like a pig!".

Are you with this guy 24/7 and track his food intake? No? Then don't use this claim.

Faster guys probably put in more high intensity miles which leads to greater caloric burn. Being lighter and training harder makes you faster.

chupacabra wrote:

test2 wrote:

I'm not in the habit of siding with Jon Orange, but he's right that this problem isn't this simple. What's the force, F, here? How do you know it itself is independent of v or t?

You bring up a valid point. To be dead-on accurate, you would have to balance frictional, gravitational, and muscular forces at many points of time in order to integrate Fvdt properly.

The rearrangement I performed on W=Fd is simply to prove that W is the same for moving a set mass over a set distance.

Orange has pointed out that there are real-world ineffeciencies/frictions not accounted for in this equation, but my assertion is that these are negligible and miss the point of the argument.

My issue is that it isn't clear what force you are talking about. Moving on the flat gravity does nothing (it's perpendicular to the direction of motion). If you are going slow, wind resistance is pretty negligible. You shouldn't be scraping your feet against the road so there really isn't any frictional loss. There really isn't any simple force opposing your motion in a way that would be appropriate for that equation.

Mechanically what requires energy are the things that aren't clearly written down in a W = F dot X formula such as bouncing up and down, swinging your legs and arms forward and backward. Obviously these require internal forces but the directions of those forces are complex and there are mechanical losses due to the imperfect elasticity of muscle, tendon etc. There are also presumably biochemical inefficiencies.

This is true and I started to type this but went back to check something and found this post.

If it were force (weight) x horizontal distance, then biking or ice-skating would take the same work and calories as running.

With a frictionless bike and no wind resistance, you could push off and roll forever on a flat surface without exerting any energy.

Which proves that the earth is flat.

(not really, please don't resurrect that thread).

Are you really that stupid? wrote:

Running fast doesnt make people thin. Being thin enables people to run fast. Your whole post is idiotic from the get go.

Finally someone making some sense.

I like the skating example.

It's a little bit of a miracle that humans burn about the same number of calories per mile regardless of running pace. This isn't true of all animals. Horses use different gaits at different speeds and each gait has it's own efficiency. Kangaroos are really weird because their energy expenditure depends very little on speed: they burn essentially as much energy bouncing in place as they do running fast.

OP you don't have a clue what your talking about.

Energy expenditure is just one point, a good diet really matters. not only because of needed energy but also the increased need for building blocks and electrolytes and such.

As training is metabolism training it means the fitter you get the more efficient.

Lighter with the same speed is more efficient, that also counts for sprinters.

That is why some uk athletes are in the top cause they juice something that make you super lean while maintaining good immunity and strength.

Low Weight apptitude is way more about genetics than training. The majority of people simply can't do 18 BMI and even less than ideal body fat percentages can get extremely stubborn, at the risk of health to overcome them, no matter what diet. Sustainable health for most people is just at a place prohibitively above elite marathon skinny.

If there is some nuance in metabolism rates by exercise type, they are trivial in this picture for the average person. What really matters is that someone can be thin without the requirement to catobolize too much of the meat that his or her genetics want on his or her bones. Try to ignore nature and there will be no recovery from even basic exercise and likely serious immune problems.

Exercise intensity does possibly effect that elite runners weight in important ways but that's from an already nearly ideal body size and composition for the sport.

dukeboss wrote:

That is why some uk athletes are in the top cause they juice something that make you super lean while maintaining good immunity and strength.

Why stop at UK athletes? This is the whole story behind the TUE!

test2 wrote:

My issue is that it isn't clear what force you are talking about. Moving on the flat gravity does nothing (it's perpendicular to the direction of motion). If you are going slow, wind resistance is pretty negligible. You shouldn't be scraping your feet against the road so there really isn't any frictional loss. There really isn't any simple force opposing your motion in a way that would be appropriate for that equation.

Mechanically what requires energy are the things that aren't clearly written down in a W = F dot X formula such as bouncing up and down, swinging your legs and arms forward and backward. Obviously these require internal forces but the directions of those forces are complex and there are mechanical losses due to the imperfect elasticity of muscle, tendon etc. There are also presumably biochemical inefficiencies.

Good points. I'll address the 2nd paragraph first.

When you are talking about the same runner, all of the points you bring up are roughly constant between easy pace and fast pace. If we're talking about a 15:00 5ker, you can simplify the problem by assuming all ineffeciencies are roughly the same between 7:00/mile and 5:30/mile. This is reasonable. If you take it to greater extremes, there will be large variation in efficiency between 4:00 pace and walking. But that's not what we're talking about. Most people's mechanics don't change drastically between 7:00 and 5:30 pace.

To your first paragraph, look at F as an average over a period of time. This is easily measurable. Instantaneous forces are difficult do deal with. There is certainly gravitational force (running involves up & down motion) and frictional losses (your shoes allow you to push off the pavement for a reason). But say we're talking 8 miles worth of work? Average force is better.

But we don't need to calculate F to prove that calories/mile is the same. That's the beauty of physics and math. You'll certainly agree that average F is greater at 5:30 pace than 7:00. What W=Fd proves is that if you multiply your average F by 8 miles, W will be the same in both cases.

The problem with these studies are that they ignore the effects of fasting and calorie reduction on the overall metabolism. If you look at the biggest loser participant studies, their metabolic rates plummeted and never recovered. I will not provide links, because the studies are easy to find, but it has been shown that you get a more positive metabolic effect from skipping a meal than you do from eating a small meal at a caloric deficit. If you eat 300 calories per meal (even on keto), you will wreck your metabolism. But, if you eat one meal a day of 2,000 calories, you will gain the positive metabolic effects of skipping the other two meals.

Keto and fasting work, but only if you do not operate with a significant caloric deficit when you do actually eat.