metabolism of strong muscles vs large muscles

[lint]

Don't think I've ever seen this addressed, but what is more metabolic? Size or strength? From what I've read, much of strength comes from CNS conditioning, so training more of your muscle fibers to fire when you want them to. Does this have a pronounced effect on the resting metabolic rate of the muscle fibers themselves? If we have a theoretical situation where we have 2 individuals, same height/weight/lean mass. One person is stronger due to strength training vs hypertrophy training of the other. Who burns more calories at rest?

[lovestolift]

If we have a theoretical situation where we have 2 individuals, same height/weight/lean mass. One person is stronger due to strength training vs hypertrophy training of the other. Who burns more calories at rest?

The way you've phrased the question is specious. It's akin to asking which weighs more; a pound of feathers, or a pound of bricks?

[lint]

I think it's worded exactly the way I'm asking. More simply put, does being stronger mean you burn more calories at rest, or is metabolic rate only tied to muscle size?

[l1n3n01z]

A rephrase might be: Given x time constraints, should you train for hypertrophy or strength in order to burn the most amount of fat. I was just thinking about this as well, actually.

[lint]

^^ yep, another way to look at it. Just from my own initial research, metabolic rate is tied to mitochondria, and it seems that the only way to increase those numbers is to do low intensity cardio. Mitochondria support aerobic exercise. Strength training and hypertrophy training seem to leave the mitochondria numbers alone since both are considered anaerobic in nature, and actually decrease mitochondria density as your muscles grow larger.

Just wondering if there's any other research/studies that can elaborate on this.

[LiftingNerd]

Could that be because the only format these numbers have been evaluated under is aerobic conditioning? Where are you getting the above statements from?

[lint]

google. mitochondria, weight lifting, strength training
example
http://books.google.ca/books?id=YfXXhCd ... ng&f=false
http://home.hia.no/~stephens/str&end.htm
"Mitochondrial Dilution

When a bodybuilder trains, the goal is to make each muscle fiber as big as possible. Muscle fibers have contractile protein, mitochondrial protein, and other components. Increasing the relative proportion of one component (like more contractile protein) means that you have relatively less of everything else in the same fiber (like mitochondria). From an endurance standpoint this is not a good adaptation. We even give it a name in sports physiology circles, mitochondrial dilution. The bodybuilder's muscles may actually become more easily fatigued as they get bigger, because their mitochondrial density is not increasing at the same rate. The bodybuilder accepts that because the name of the game is size, not endurance.
It is possible for the endurance athlete to gain some muscle size and maintain mitochondrial density, but it requires that the volume of endurance training be maintained. If you are a runner and you decide to get stronger in the weight room by really doing a lot of strength training 3 days a week for an hour, you will probably drop some of your running volume to fit it in. After 6 months you have gained 5-10 pounds of muscle, you look really good, and you are running 2 minutes slower for 10k! Why? Well besides having to carry around 5-10 more pounds of muscle that you can't use when you are running, you have probably lost endurance capacity in those bigger stronger quads. So, you have a lower lactate threshold due to the detraining of your leg muscles, plus you are less efficient due to the increased bodyweight (and decreased training volume). Oh well, at least you LOOK Fast."

also cellular respiration:
http://en.wikipedia.org/wiki/Cellular_respiration

But as I said, I'm looking for more studies into this.

[muddy]

Low intensity cardio and strength training are not the only two options out there. If we're talking about muscle energy, it's probably best to view various exercises as a continuum along a work/time curve (i.e. power), with work as the y-axis and duration(time) as the x-axis. Up high on the far left of the curve (high power, short duration) you have olympic lifts. As you slope down to the right, you find things like the squat, deadlift, etc. You've also things like sled drags, sprints, and a host of other training modalities before you end up on the far right of the graph in the 10k jogging area.

In my opnion, the mechanisms for how the body decides to retain fat is too complicated to fit within a model where we hope to maximally stoke the metabolic fires with the least effort by some particular form of exercise for sustained fat burning. There is growing evidence that medium to high power output for shorter duration is more effective at fat burning than long distance cardio. (e.g. tabata protocol)

Probably most convincing to myself, if I look at people who train with high power shorter duration exercises and look at people who run a lot of 10ks, I would rather look like the high power people. This is not because they look stronger (although they do), but they look to me healthier.

[muddy]

After 6 months you have gained 5-10 pounds of muscle, you look really good, and you are running 2 minutes slower for 10k! Why? Well besides having to carry around 5-10 more pounds of muscle that you can't use when you are running, you have probably lost endurance capacity in those bigger stronger quads. So, you have a lower lactate threshold due to the detraining of your leg muscles, plus you are less efficient due to the increased bodyweight (and decreased training volume). Oh well, at least you LOOK Fast."

Sure, if your definition of fitness is running 10k races, this is true. For similar reasons, bird bones are very lightweight and so on.

It would not be my definition of fitness. I have personally seen long distance runners put in situations where they have to sustain reasonably high power outputs for 8-10 minutes. Generally, they gas badly. I personally would find this unacceptable for myself.

There is an unconscious bias to view marathoners and the like as pinnacles of human fitness. I think this is a bit insane. A better definition would be in my opinion to measure areas under the power curve I mentioned in the previous post for a given person by using many different exercise tests that require different power outputs. The more area under that power curve a person has, the fitter they are.

The exception is obviously someone who is specializing. If you want to be a marathoner- great! Yes, definitely do not pack on the muscle then. Similarly, does an olympic lifter need to be able to run a 10k? Nope.

[lint]

^^^ ummmm, thanks for the replies but they don't address the questions I'm asking. I'm not asking about what people think the definition of fitness is, or who looks better, or who's a better athlete.

[Bman1]

Lint - the original question was an interesting one, that I do not necessarily have an answer to. My guess is that, because the "strength" conditioning focuses more on myofibrillar growth (denser muscles) whereas the hypertrophy causes more sacroplasmic growth, the strength-trained muscles might burn slightly more calories at rest than the hypertrophy trained muscles. I further guess that, if this is true, the difference is so small (a few percentage points) that it is not worth worrying about.

[ada24]

This is a tough question: so many variables at work.

Going back to your example, lint -- if we had two persons of equal weight with one training for myofibrillar hypertrophy and the other training for sarcoplasmic hypertrophy, the first would be more dense as his mass would take up less volume. But proportions of lean mass vs. bodyfat are measured in weight, not density, when we calculate (albeit roughly) a person's basal metabolic rate with their proportion of lean mass to fat. Thus I would hypothesize that their metabolic rates would be fairly similar.

Do I have evidence in case studies to support this? No.

You can increase your metabolism by shifting your diet, shifting your eating schedule, and training. The question remains: do you want to train for performance, with side-effects that may include an increase in size? Or do you want to train for size, with side-effects that may include better performance? I'll take the former over the latter.

[muddy]

Sorry, I didn't mean for it to be a complete non-sequitur. What I was trying to say is I think the human body and how it will burn or retain fat is more complicated than just looking at muscle size or density. Insulin response and blood chemistry has much more to do with it than muscle size or density. The reason I went on to talk about performance was largely due to the extended quote talking about weight lifting, adding muscle and running that you cited. The two aren't totally unrelated, as you can probably more easily regulate how your body burns fat via high power output as the primary consideration, rather than muscle size/density being the primary consideration. If for you high power output sustained for a modest interval on a regular basis means you have larger or denser muscles, that's really a secondary factor.

[lint]

This is a tough question: so many variables at work.

Going back to your example, lint -- if we had two persons of equal weight with one training for myofibrillar hypertrophy and the other training for sarcoplasmic hypertrophy, the first would be more dense as his mass would take up less volume. But proportions of lean mass vs. bodyfat are measured in weight, not density, when we calculate (albeit roughly) a person's basal metabolic rate with their proportion of lean mass to fat. Thus I would hypothesize that their metabolic rates would be fairly similar.

Do I have evidence in case studies to support this? No.

Isn't myofibrillar hypertrophy a measure of efficiency more than anything else? Hence the CNS adaptation? You're able to recruit more of your muscle fibers into a muscular contraction, but does this actually mean that the muscle fibers themselves are any denser? And if density is a factor? Does a gram of muscle tissue that takes up 1cc volume actually consume more energy than a gram of muscle tissue that takes up 1.5cc volume? If so, how is this accounted for at the cellular level? From my understanding, cells themselves don't burn calories, mitochondria, the cells power-houses do. Based on this, unless strength training (myofibrillar or sarcoplasmic hypertrophy) has a pronounced effect on the number of mitochondria that a person has, the notion that more muscle = higher metabolism seems to be conjecture more than fact. I guess that's really the crux of my question.

[ada24]

Isn't myofibrillar hypertrophy a measure of efficiency more than anything else? Hence the CNS adaptation?

Sure. But you can perform more work with efficient muscle. But then we get back into volume and density again.

And if density is a factor?

No, since we estimate BMR in weight, regardless of density.

Maybe a higher mitochondrial count like you see in sarcoplasmic hypertrophy will yield a higher metabolism, with those powerhouse burning. Maybe it won't. Maybe myofibrillar hypertrophy will yield a higher metabolism, with more work capacity in the muscle. Maybe it won't.

...the notion that more muscle = higher metabolism seems to be conjecture more than fact.

It's tough to say. What we can be more certain of is that the higher the ratio of lean mass (muscle, bone, ligament, organs, etc) to body fat, the higher the metabolism of that individual. Whether you achieve this through growing more muscle and keeping the fat constant, or by burning away fat and keeping the muscle mass constant, the end result is the same.

Which is precisely why weight loss programs that work by reducing the caloric intake without training the body in some manifestation will result in weight loss, but a constant body fat/lean mass proportion. And that body fat will keep the metabolism low and slow, increasing the probability that the individual will gain the weight back. (There is a UPenn study that supports this conclusion; I'll try to dig it up.)

And interesting question; would make for a compelling Master's Thesis. Anyone? Anyone..?