Body Energy Usage

I ponder macro-nutrition needs a whole bunch. Here’s what I have handy, though my technical references are scattered and omitted.

There’s always a need for roughage, vitamins, and minerals, which come from foods with very low calories/kilojoules. Aside from that, the three main macros have specific needs.

A body needs 125 grams of carbs for your brain/nerves; just under 1 gram of protein per kilo of lean body mass to maintain tissues/muscles; and around 30g of fat for cellular and neurological structures. This is usually around 1200 kcal per day, but varies by person 10-20 percent.

Anything else you eat is either poop, or gets converted to sugar. Sugar is burned if it’s needed immediately for exercise (growing, standing, walking, cardio, whatever, anything other than sleeping). Any sugar that is not immediately needed is stored in muscles as glycogen, up to around 4% of your muscle mass. All sugar past that is turned into fat and stored in our fat cells.

This is where “whole grains” comes into play. If it’s not ground up, it takes longer to break it down. However, if you take grains, and mill them into a powder, IT IS NOT WHOLE GRAINS. Just because there is fiber in the food does not mean it’s slow to absorb. The less processed the food, the longer time period over which it trickles energy into your body. If it’s super processed, it all absorbs very quickly, and your body may have trouble figuring out what to do with it unless you’re depleted already.

This is also where some insulin resistance comes from, and why diabetics have normal sugar metabolism in their muscles during exercise, even if they are short on insulin, or are resistant to it. Resistance is GLUT4 which causes glucose receptors to move to the cell membrane, but exercise does the same thing – muscle is hungry, it asks for more. Muscle is not hungry, it asks for less, even if you try to overfeed it. Where would it put this excess sugar? It can only store so much.

During exercise, your fat cells can liberate about 90% of your weight in pounds as usable calories per hour. For me, it’s about 260 calories. The gap is made up from glycogen in the muscles, which is good for just about 90 minutes. If you exercise hard, and stop at 60, and rest for 30, those 30 mins still use up that glycogen for delayed processes, cleanup, etc.

Eating carbs cannot provide as much energy as glycogen, but it’s the next best thing. Also, if you’re fasting, your glycogen reserves get burned up pretty quickly. Glycogen is 3:1 water to sugar, so this is why the first week of dieting is so awesome. No, that’s not fat. It’s muscle energy.

Any energy deficiency not covered by food will be covered by muscle damage. About the same number of calories can be broken down out of injured muscle cells. For me, this is a total of muscle and fat sourced calories of about 520 calories per hour. If I exercise for 3 hours with no food, then my power output drops to 130 watts, which is about 520 calories per hour.

The best option to limit muscle damage, limit recovery time, and optimize exercise benefits when going for more than your glycoge, is to eat as much every hour as you burn, minus the calories that can come from fat. Staying carb focussed can give more energy, and can be easier to absorb, though for some people, this slows the breakdown of body fat.

Staying fat focussed keeps the fat burn mechanisms running, but it takes twice as much oxygen, which means you’re hear-rate limited. It’s less about muscle conditioning then, and more about cardiovascular improvement.

Staying protein focussed is tougher on the kidneys. The aminos have to be converted for use as fuel, and that’s a lot of extra ammonia to pee out. That can be an issue when dehydration might already be at play.

Cycling Fuel

Max bodyfat you can burn in an hour is roughly 1 gram per 10 pounds, or in calories, 9 times your weight in pounds.

Anything else is food, muscle glycogen, or actual muscle tissue. Glycogen max is about 4% lean muscle mass, which usually is enough for 90 mins, plus or minus. Food is whatever is in your gut, though exercise slows digestion.

Bonk is when you have used up all food, and your glycogen stores, effectively exercising while fasted.

Bonk power is the max sustained energy ouput when you are fasted/bonked. This is fat burn, and muscle breakdown, combines.

Average watts is roughly 1/4 your calories per hour.

Me as an example
I’m 280 pounds, and bonk power for me is 133 watts, which is about 520 calories per hour. Doing that pretty much guarantees cramps from muscle breakdown.

Biking, I tend to burn 750-850 calories per hour, but I can peak at over 1000 in some instances (beginning, well fed, well rested, very driven).

That’s a big gap, because being big, I get more wind drag, which is 50% of your energy above 15mph. I also take more energy to climb a hill.

Downhill is faster, so less benefit (less time spent going downhill), and often waste the energy by riding brakes so as to not plow through others.

I do best consuming 600 calories per hour while riding more than 90 mins.

So, I have to eat the equivalent of a meal every hour to keep up, and reduce cramp risks. Most of that needs to be carbs that break down in less than an hour. Also, I don’t want to have a bathroom break every hour.

Ride Fuel
Sugary colas have phosphate, glucose, and fructose – all good for refueling. Cookies, sandwiches, etc usually are low roughage, good energy density, and include salt. M&Ms were actually designed to be endurance fuel for the army, and they hold up pretty well in a plastic bag.

Basically, all the things that are bad for you normally make great endurance fuel.

As to proper “race fuel”, honestly, it’s too low calorie for someone my size. Some people only need 200 calories an hour to stay fueled, so half banana, a 2″ square of granola, and a swig of gatorade is fine. For me, that would be a whole bunch bananas, and two quarts of gatorade. Just too much bulk.

Add to all that the need for oxygen to build ATP (actual muscle energy chemical). It takes 35% more oxygen to burn blood glucose than intra-muscular glycogen. Fat takes twice as much oxygen as glucose. High heat, humidity, low pressure, altitude, carbonation, and alcohol all reduce oxygen availability. Transport of glucose into the cell takes ATP. Digestion of food takes ATP.

Diabetes, Insulin Resistance, and Metabolic Syndrome
The key there is to not eat much carbohydrate outside of the exercise times. When glycogen reserves are full (muscles recovered), and adipose cells are replete, then why would you need more fuel? That’s the practical wording of the physiology here, despite the perception of a faulty hunger mechanism for the obese, or lack of islets for type I, or the defective signalling in Type II without obesity triggers.

Exercise induced glucose uptake is normal in diabetic muscle cells:

Exercise may increase glucose sensitivity:

While glycogen is being replenished, glucose uptake by muscles in normal. GLUT4 is transported to the membrane during exercise, even in absence of insulin.

Zero Momentum

If time slows to a near stop for objects travelling close to the speed of light, what happens to time when all momentum is at a dead stop?

The short answer is, with true zero momentum, you would cease to exist. If you had very small momentum, then time would pass very very fast for you. This is because relativistic momentum is much more complicated than just a car on a highway.

Can you be relative to nothing?

Every mass affects every other mass in the universe via gravity. There is no point of zero *inside* the universe. That would be past the margins of the expanding universe, which doesn’t have spacetime, so we can’t exist there. *There* doesn’t even exist.

At what point is a body its own body, and not part of the big thing with gravity it’s sitting on top of?

When/where do you want it to be? This is not a binary transition. It’s gradual, from the center of a black hole, out to two photons spiraling across the universe in opposite directions.


Everything is energy.
* Mass is a 4-vector, and relates directly to energy.
* Energy is a 4-vector, and relates directly to momentum.

Because of this, time is affected by both:
* More velocity = slower time, shorter length in the direction of travel
* More mass = slower time, shorter length radial to the mass.

Spacetime is a foam.
* The speed of time, like the size of space, is the size of the bubbles.
* The stretch of the foam is gravity.
* The more energy/mass on the skin of a bubble, the smaller it gets (and the more it pulls on its neighbors).
* Less energy (and mass) means bigger bubbles (ie, more time and space).

Bosons are energy carriers, and they live on a bubble.
* To move a boson, you have to input energy.
* When they have enough energy to move, they move at the speed of light.
* Photons are the most familiar bosons.

Speed of light is actually “speed of light in a perfect vacuum”.
* Put light into a ceramic crystal, and it’s slower.
* Spacetime foam is more dense, so more bubbles to transit.

To travel faster, you have to input more energy.
* More energy means you compress the foam.
* That means more bubbles to transit, which means more energy.
* As a baryonic mass approaches the speed of light, the energy inputs approach infinity.
* Infinite energy (and mass and spacetime) do not exist, so we are constrained.

Bosons and some small particles can seem to violate this on very small scales (tunnelling).
* This is because they can slide through the skin of the bubble rather than having to compress the bubble.
* You cannot do that as baryonic mass, but maybe if your pattern was translated into bosons.
* That high of an energy density would probably condense AND dispese, so you’d lose the pattern along the way.

Special relativity covers “objects at rest”:
* energy-momentum relation: E^2 = (pc)^2 + (m0c^2)^2
* energy-mass relation: E = mc^2 (p is zero, so you have E^2 = (mc^2)^2) which becomes E=mc^2

So, if you were to come to a complete rest relative to the fabric of spacetime,
* the passage of time is still affected by your own mass/energy.
* You could decreate your energy, reduce your mass, dispurse your mass, and you would expand the bubbles.
* This would cause time to pass more quickly for you, if “you” could exist that way.

At zero energy, the bubbles would be infinitely large.
* How do you pump energy out of the bubbles (vacuum fluctuations).
* Time would pass at infinite speed (same issue as photons at infinite velocity).
* Just as there is not infinite energy, there is also not infinite time velocity.

Imaginary mass/energy is described by tachyons.
* They do not travel faster than light,
* nor do they travel backwards in time.

To travel backwards in time:
* You need negative energy.
* This is also the principle behind the Alcubierre Warp Drive.
* This would cause spacetime to move around an object, instead of the object through spacetime.
* There is no known way to form negative mass/energy:

This is not the same as antimatter, which is just opposite quarks.
* Basically, you’d have to pump energy out of the bubbles.
* The excess energy generated would accumulate at the margins of the bubble, trying to get back in.
* When the bubble is allowed to collapse, it would be a giant explosion of radiation.
* If you had a way to direct this to one side, perhaps travel would be possible, leaving a radiation wake.
* Perhaps it would lead to a spike of radiation that pierced the ship, or whatever was in front of it.

That’s a theoretical exercise, which I don’t believe is likely to happen.
* We’re more likely to find a way to connect the quantum foam in different places (wormholes).
* Would a wormhole unravel spacetime, or collapse instantly?

Other thoughts:
* The margins of the universe are probably expanding at the speed of light.
* The volume grows more rapidly as time passes, even though the mass/energy is constant.
* Eventually, the universe will be so dispersed as to be useless (heat death = cold death).
* Even solid matter will disperse given enough time. Bosons trickle away, and atomic forces will decay.

Bicycle Energy Calculator

This is how a SWAG average power on a bike ride:

My assumptions, recently updated, are:

  • 86F, 600′ elevation, 30% humidity, and 1 atmosphere of pressure
  • 25% human efficiency (racers might be a little more, newbies a little less)
  • 95% bike efficiency (Rusty bearings and flat tires would be less, race-bike better)
  • 0.004 Coefficient of Rolling Resistance (Recently adjusted – on the low side for road, just to be fair).
  • 0.6 Coefficient of Wind Resistance (on the drops, relatively upright, larger mass)
  • 1.1 m^2 frontal surface area (I’m a big guy)
  • One stop every mile (Roughly what I do in Irving).

There are such huge variances in some of these based on intarwebs scientific abstracts that I’m not even sure if this is valid. Whenever I get a power meter, I’ll tweak this to be more accurate. I may get a couple different sized people to ride my bike for comparison. That won’t show any of the Coefficients of Friction directly, nor human or bike efficiencies, or any of these numbers.

There are plenty of other tools out there, such as: