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“If you want to find the secrets of the universe, think in terms of energy, frequency and vibration.” - Nikola Tesla

Calorific

quads, sumoman
My massive quads

Preamble

I've met quite a number of fat people who say they are quite happy being fat, yet in the same sentence they will say that they are on a diet...

This is because fat people are not happy. In fact regular people are not happy about their appearance because pretty much everyone wants to be beautiful, its just that regular people are less unhappy about their appearance compared to the flatulently obese.

Even if happiness wasn't the case the economic cost of fat people is very expensive, globally a figure of $2,000,000,000 has been mentioned. Whatever the figure, the solution is simple... stop piling on the calories with fast food.

The Solution

Losing fat is quite simple which is why the trillion dollar fat loss industry is based upon making fat loss as complicated as possible.

All that is actually required to lose fat is to increase the energy output to energy input ratio, to above one... so expend more energy than consumed.

This can be achieved by either decreasing the amount eaten or increasing the amount expended... or some combination of the two.

There are other things to consider such as what the diet is composed of, or is the hormonal profile geared towards muscle or fat... but here I talk just about calories.

'Til You Die

The process of losing weight is easier than that of gaining weight. This does not mean that starvation is more pleasant than gluttony, however the process and effort is less with losing weight because the plan is to eat less and doing less is easier than doing more.

Exercise-wise the fatty can expend more calories with aerobics. The fatty should also take up weight training to maintain their muscle and perhaps gain some muscle; muscle burns energy.

Is Aerobics Worth It?

On a discussion board Robert asked whether there was actually much point in doing aerobics. His premise was that Superslow©®™ and Mike Mentzer©®™ had argued that the amount of aerobics to lose a pound of fat was on the order of 10 hours and that such a time would not be worth the effort. That's sort of true but fat loss has to be looked at as part of the whole process; accumulating a greater ratio of burnt calories to consumed calories. Its the total accumulation of the extra calories burned that makes the difference, just as the total accumulation of the calories gained in the first place lead to all that fat.

Thus

  1. During an aerobic session you might average say 3 l.min-1 of oxygen. Each litre of oxygen consumed equals about 20.3 kJ of energy.

  2. 3 l.min-1 × 20.3 kJ = 60.9 kJ.min-1 = 1015 W (a Watt being a J.s-1).

  3. However if Robert weighs 90 kg and is moderately active then he will consume 12.5 MJ.day-1 which is 144.4 W. At this wattage he is maintaining his weight, so 870.6 W (1015 - 144.4) will actually go into burning excess fat.

  4. At 25% mechanical efficiency 870.6 W equals 217.6 W.

  5. A kilo of pure fat contains 39 MJ. Bodyfat is about 87% fat so that would be 33.9 MJ.kg-1. So it would take 33.9 MJ / 870.6 J.s-1 = 38965.5 seconds (10.8 hours) to burn a kilo of bodyfat.

  6. Robert wanted to lose 28 lbs (12.7 kg) of fat. So it would take 12.7 kg × 10.8 h = 137.5 hours of exercise. Over a year this would equal 137.5 h / 52 weeks = 2.6 h per week of exercise at 217.6 W.

  7. 28 lbs of bodyfat contains 12.7 kg × 33.9 MJ.kg-1 = 430.5 MJ. So a calorie reduction of 430.5 MJ / 365.2 days = 1178.8 kJ.d-1 (280.7 kcal.d-1), in addition to the exercise, would double the fat loss rate in a year.

Thus Robert could lose 28 lbs of fat in 12 months with 2 hours 36 minutes per week of exercise at 217.6 Watts, but if he also included a calorie reduction of 280.7 kcal.d-1 he would lose it in 6 months.

At rest a person consumes about 0.3 l.min-1 of oxygen so in the above example the person is expending 10 times the energy during exercise as compared to that at rest.

From my exercise physiology book a 74 kg runner generates about 1078 W at 12.1 kph (7.5 mph = 8 min per mile pace).

Metabollix

Fatties who claim that they eat like a bird and exercise as much as tri-athletes are kidding themselves to the multitude of scientific studies that show that, in fact, they eat enough to feed France and are as active as a sofa.

Then there are those who claim they have a slow metabolism. As one physiologist stated somewhat bemusedly; "I've tested thousands of fat people. I'm sure there are medical curiosities.... but all the fat ones I tested had higher metabolisms due to them being bigger."

Oxygen

I have a friend called Alun, he is 6' 5". When I first met him he weighed just under 16 stone. He kept adding muscle. One Xmas he went up to 17½ st, he continued to add mass onto 18½ st and then 19 st. Each time I ask him how he keeps getting bigger and he laughs and says, "I don't know!!"

The local fitness suite had two fitness competitions involving rowing, running and biking. Alun won both of them. In the last competition the competitors had to cycle on a recumbent electronic device for 20 minutes, the winner being the person who went the furthest. Alun got 12.8 km and the 2nd person (a National level triathlete) got 11.8 km. As before everyone was flabbergasted, as they thought Alun was fit despite his huge muscles rather than because of them.

Some Numbers

Consider an average man of 70 kg, he has the following oxygen capacities;

1 55% non-muscle
ml.min-1 (ml.kg-1.min-1)		 45% muscle
ml.min-1 (ml.kg-1.min-1)		 100% bodymass
ml.min-1 (ml.kg-1.min-1)
at rest 137.5 (3.6) 112.5 (3.6) 250 (3.6)
maximal work 137.5 (3.6) 3362.5 (106.7) 3500 (50)
Note that whilst his aerobic metabolism goes up by 14 times (from rest) it is the 45% muscle mass that accounts for this - its metabolism goes up by 29.9 times.

Now consider that this man adds 30 kg of muscle, he now weighs 100 kg and has the following capacities;

2 38.5% non-muscle
ml.min-1 (ml.kg-1.min-1)
 61.5% muscle
ml.min-1 (ml.kg-1.min-1)		 100% bodymass
ml.min-1 (ml.kg-1.min-1)
at rest 137.5 (3.6) 219.6 (3.6) 357.1 (3.6)
maximal work 137.5 (3.6) 6564.9 (106.7) 6702.4 (67.0)
From rest his total aerobic metabolism goes up by 18.8 times but the muscles again goes up by 29.9 times. His total aerobic capacity has gone up by 1.9 times that of when he weighed 70 kg. Again note that it is the muscle mass which is using the extra oxygen - the rest of the body ticks over at its usual rate.

Now consider that this same 100 kg man instead maintains his original aerobic capacity of 50 ml.kg-1.min-1. He now has the following capacities;

3 38.5% non-muscle
ml.min-1 (ml.kg-1.min-1)		 61.5% muscle
ml.min-1 (ml.kg-1.min-1)		 100% bodymass
ml.min-1 (ml.kg-1.min-1)
at rest 137.5 (3.6) 219.6 (3.6) 357.1 (3.6)
maximal work 137.5 (3.6) 4862.5 (79.1) 5000 (50)
From rest his aerobic metabolism goes up by 14 times (as when he weighed 70 kg) but the muscles go up by only 21.1 times instead of 29.9 times. His total aerobic capacity has gone up by 1.4 times that of when he weighed 70 kg.

But what if the 100 kg man's total aerobic capacity remains at 3500 ml.min-1? His capacities are now;

4 38.5% non-muscle
ml.min-1 (ml.kg-1.min-1)		 61.5% muscle
ml.min-1 (ml.kg-1.min-1)		 100% bodymass
ml.min-1 (ml.kg-1.min-1)
at rest 137.5 (3.6) 219.6 (3.6) 357.1 (3.6)
maximal work 137.5 (3.6) 3362.5 (54.7) 3500 (35)
From rest his total aerobic metabolism goes up by 9.8 times and his muscles go up by only 15.3.

Discussion

The figures are illustrative rather than meant to represent the results of some experiment, however they can be derived from any standard University text on exercise physiology. Tables 2, 3 and 4 are derived from table 1, you can check the figures with a calculator to verify if they are correct. Note that at rest and at max the oxygen uptake of the non-muscle tissues remain the same, this is pretty close to what actually happens in reality. There are variations for example, the digestion shuts down during exercise and the skin increases it blood flow to aid cooling but as a whole non-muscle tissues remain similar in their oxygen usage.

Note that in discussions of aerobic capacity people usually only consider the last column of the 4 tables. I consider it more illuminating to look at the 3rd column of each table. Although I've set out 4 tables more could be added to illustrate the various permutations.

You can see from these tables that it is the muscles which are determining the aerobic work capacity. At rest they output 3.6 ml.kg-1.min-1 whilst with exercise they go up in table 1 by 29.9 times in metabolic rate to 106.7 ml.kg-1.min-1, however the total output is 14 times because the non-muscle mass doesn't change in metabolic rate.

Summary

Fat loss is like fat gain in that gaining fat happens over time rather than in one sitting. The fatty gets fat by consistently overeating and under exercising. Losing that fat requires a consistency of 'under' eating and 'over' exercising.

From an exercise point of view the 'extra' calories burned come from doing more mechanical work and the creation of more muscle not only requires energy to create that muscle but maintaining it requires energy and that extra muscle allows more mechanical work to be performed.

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23rd September 2023