kuan

WHen you lose muscle, are you losing that hard earned mitochondria you've been striving to build all season? When you build muscle during the "off season" do you have to start allover again?

Enthalpic

Here is a start. This study had people losing a significant amount of weight while monitoring mitochondial function. We know that with significant weight loss, even with exercise, some muscle mass will be lost along with the fat. Their study showed that mitochondria function actually increased, for me suggesting that most of the muscle proteins lost were contractile.

https://www.ncbi.nlm.nih.gov/entrez/q...=pubmed_DocSum

However, the subjects were exercising and this may not mimic changes occurring during inactive wasting.

Yo-

What do you mean by contractile? Are you saying their strength did not decrease?

Enthalpic

By contractile I mean not mitochondrial. Did their strength increase? Probably but that can occur simultaneously with loss of contractile proteins due to increased neuromuscular recruitment.

NoRacer

wolfgang

Coming over from the rock climbing world, I know the importance of motor unit recruitment. Are there techniques to train for maximum recruitment in cycling? In climbing, it was all about overloading the muscle briefly while the muscle stretched (eccentric?). How do you do it in cycling?

wolfgang

By stretched I mean elongated (while trying to contract.)

Richard Cranium

If I was going to make wise cracks about where and how muscle-mass is gained or lost - I'd point to the nature of blood vessels surrounding the fibers and the tremendous changes in volume that blood and glycogen produce. Too bad no pictures can depict this "swelling" and shrinking of a muscle produced by these factors, I'm sure they count for something. In this pic, glycogen doesn't look like it is taking up much space........

https://dayton.fsci.umn.edu/~bill/fig%203.jpg

Enthalpic

I agree that swelling due to any factor be it water, glycogen, fat droplets etc may effect measured mitochondrial function in that the distance fuel and waste must diffuse will be increased with swelling. We know that the degree of capillarization is one of the most important factors determining exercise performance and fatigue resistance. So losing a small amount of contractile protein may increase mitochondrial function just by the fact that the mitochondria and capillaries are closer together.

Fortunately, that study not only measured total mitochondrial function but also mitochondrial gene expression/concentration. They concluded that the mitochondrial mtDNA did not change significantly (up or down); suggesting that the mitochondria were basically “ignorant” to any whole muscle changes occurring and that functional improvement was likely due to what I mentioned above.

“Also, muscle mtDNA content did not change significantly [1665 (213) vs. 1874 (214) mtDNA/nuclear DNA], denoting functional improvement rather than proliferation of mitochondria as the principal mechanism of enhanced ETC activity.”

I am by no means saying I have all the answers and would love to hear others opinions on this very interesting subject. Could muscle mass “cycling” be a way to increase mitochondrial density? For example if I gain a large amount of muscle mass, followed by endurance training and hypocaloric wasting will that lead to a greater MT density than just endurance training a “small” muscle? Assume that in the final state both the “cycled muscle” and the “always small” muscle are the same size. Discuss.

ratebeer

I sure hope so. If anyone's doing a study, sign me up. I plan on dropping two pounds a month for the next year or so.

cmh

Hi wolfgang, I spent some time in the rock climbing world as well.

Cycling is mostly an endurance sport, so you usually don't wan't to maximum recruitment. Sprinting is the exception. I believe track sprinters do a lot of weight lifting, and plyometrics (on top of riding a bike as fast as they can, of course). I won't go into the details of plyometrics, but they provide the same type of eccentric contraction that is so effective at training for the short explosive bursts of power you need for rock climbing.