Eccentric Muscle Damage impairs insulin sensitivity and glycogen resynthesis

[hailtotheking]

I found some interesting research suggesting that eccentric induced muscle damage can reduce insulin sensitivity and impair ability to resynthesis muscle glycogen in the damaged muscles.

http://www.ingentaconnect.com/conten...1?crawler=true

http://jap.physiology.org/cgi/content/abstract/69/1/46

http://www.ajcn.org/cgi/content/full/72/2/647S (look under the Exercise Induced Muscle Damage section)

This possibly suggests that with high intensity resistance training, and / or those that have an eccentric loading emphasis, extra measures maybe required in post-workout nutrition to increase insulin sensitivity and enhance muscle glycogen resynthesis. Coach's like Christian Thibaudeau suggest taking a supp like ALA or its derivatives about 10 mins before your PWO shake can help overcome this problem.

[Orinoco]

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I found some interesting research suggesting that eccentric induced muscle damage can reduce insulin sensitivity and impair ability to resynthesis muscle glycogen in the damaged muscles.

This possibly suggests that with high intensity resistance training, and / or those that have an eccentric loading emphasis, extra measures maybe required in post-workout nutrition to increase insulin sensitivity and enhance muscle glycogen resynthesis. Coach's like Christian Thibaudeau suggest taking a supp like ALA or its derivatives about 10 mins before your PWO shake can help overcome this problem.

This is a topic I read about in a magazine article quite some time ago, and up until 2002 I used to routinely take 200mg of ALA with my PWO shake. I couldn't get ALA at a reasonable price whilst living in Spain, so have gotten out of the habit of using ALA as you described. Think I'll have to look into it again.

With regards to training in a style that exaggerates the eccentric, either by increasing leverage/weight, or using slow 4-8 second eccentric contractions....I've found that older trainers respond particularly well training this way. From trial and error, I've found it's a good way to make injury free progress in those who are starting training at a later stage in life. It's less stressfull on less elastic joints, plus all that TUT will provide good circulation to tendons.

I've always thought that it's paramount to ensure that PWO protocols contain high GI carbs when training in this manner. For those who don't use carbs or use oats PWO, then it might be one of those things that over time impedes recovery and might even make you fat.

Slightly related, does anyone know the GI of WMS? A lot of people seem to use this PWO, which if using eccentric training might not be the best choice of carbs.

[allthegoodnamesaregone]

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This is a topic I read about in a magazine article quite some time ago, and up until 2002 I used to routinely take 200mg of ALA with my PWO shake. I couldn't get ALA at a reasonable price whilst living in Spain, so have gotten out of the habit of using ALA as you described. Think I'll have to look into it again.

With regards to training in a style that exaggerates the eccentric, either by increasing leverage/weight, or using slow 4-8 second eccentric contractions....I've found that older trainers respond particularly well training this way. From trial and error, I've found it's a good way to make injury free progress in those who are starting training at a later stage in life. It's less stressfull on less elastic joints, plus all that TUT will provide good circulation to tendons.

I've always thought that it's paramount to ensure that PWO protocols contain high GI carbs when training in this manner. For those who don't use carbs or use oats PWO, then it might be one of those things that over time impedes recovery and might even make you fat.

Slightly related, does anyone know the GI of WMS? A lot of people seem to use this PWO, which if using eccentric training might not be the best choice of carbs.

WMS is a high GI carb

[Orinoco]

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WMS is a high GI carb

What GI rating does it have then? My understanding was that it didn't have the pronounced effect on insulin levels that Dextrose or Maltodextrin has....and that was the benefit, along with the speed of glycogen replenishment.

[hailtotheking]

I thought WMS was meant to have a higher GI than maltodex or dextrose? Confused ...

[Orinoco]

I think it's probably me who's got it confused to be honest. I've got it in my head for some reason that WMS only had a moderate effect on insulin despite its fast absorption.

I've given some more thought to the OP though.....

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Dan Duchaine used to talk about something called the 'anabolic-drive-threshold-theory'. It basically referred to the heirarchy of what tissues were prioritised for a given amount of insulin release.
e.g. The cells we are concerned with and their hierarchy are muscle cells (which need the lowest level of insulin in the "driving range"), connective tissue (which needs a higher level), and lastly fat cells (which need a higher level still). As HTK pointed out eccentric repititions cause trauma that 'wounds' the membranes of muscle cells. This trauma causes a release of FGF (fibroblast growth factor) which is a very important hormone for muscle growth - and its release is probably why eccentrics work so well. There's obviously some plateau of FGF secretion in the cell, thereafter any further trauma would not be productive. This might explain why studies have shown that after reaching concentric failure, performing extra negatives does not cause muscle growth above and beyond just simply exaggerating the eccentric portion of the rep and terminating the set at concentric failure (although it does increase strength marginally).

Back to my point...which is this. The trauma to the cellular membrane impairs insulin sensitivity. But by how much does it impair this? Is it enough to alter the ATDT (anabolic threshold drive theory) heirarchy? If so would it mean muscle cells are more insulin resistant than connective tissue, or even fat cells? If the hierarchy is altered so that the order is connective tissue, muscle tissue then lastly fat cells, then it might explain why this style of training seems beneficial on joints (a recent t-nation article made a connection between eccentric training and a lessening of tendonitis). BUT, If muscle cells become more resistant than fat cells, then over time you might put on fat.

I don't know how you would answer this, as you have to factor in the beneficial effect of exercise on nutrient partitioning. But my instinct is that exercise offsets some of the insulin resistance in the muscle caused by eccentric exercise, so that it's just connective tissue and muscle cells that are in the "driving range", resulting in an increased uptake of nutrients in connecive tissues. But to be on the safe side it's probably best to make sure you're getting high GI carbs PWO, and to do anything you can to maximise any nutrient partitioning, such as using ALA (as HTK pointed out), taking high doses of fish oil.... or just getting lean in the first place.

[Dtlv74]

Interesting theory Orinoco. Backs up my (admittedly minimal) experience of using negatives - they seem to provoke both hypertrophy & strength gain when used instead of concentric emphasis reps, but don't seem to do a lot for me when used in addition to concentric failure reps... other than make me sore.

[Orinoco]

There's a study that would indicate that this extra soreness from eccentric training, doesn't have any negative (no pun intended) effect on the repair of the muscle or performance. This would indicate that the extra soreness doesn't impede progress.

I read it yesterday whilst perusing some old magazines....I'll type it out verbatim and post it later on.

[Dtlv74]

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There's a study that would indicate that this extra soreness from eccentric training, doesn't have any negative (no pun intended) effect on the repair of the muscle or performance. This would indicate that the extra soreness doesn't impede progress.

I read it yesterday whilst perusing some old magazines....I'll type it out verbatim and post it later on.

No, I've never felt that there's a detrimental effect caused by negatives - just that if done in addition to failure on concentric reps, they don't confer any substantial additional benefit. Might just be me though... we all train differently and it may be I've never actually done them optimally. I don't like making too conclusive a statement on such things!

If you have the time to type that article it would be appreciated

[Orinoco]

Agreed. It would seem that exaggerating the negative is sufficient, and that going closer to absolute failure (eccentric failure) adds only marginal strength. But, as you rightly pointed out, I'm sure you could find someone who's gotten big from doing this......

Going by this, you could interpret from that study, that once a certain trauma is achieved from eccentric training, no further 'wounding' of the muscle cell membrane occurs, and subsequently no further blunting of insulin at the muscle cell.

Although this could be way off base, I'm no scientist!