Muscle glycogenolysis vs ATP use during low rep sets

[gijoe985]

Well, this isn't directly nutrition, but it is a question I have came upon while diet planning. And the information gathered would be used to develop appropriate nutrition. I just need a guru to help me...

My simple, but difficult, question-

During low rep sets (@85%+ of 1RM), I have read that the body recruits more ATP than musle glucose. This would be for sets that last less than 20 seconds. Though sets lasting over 30 seconds (I guess it is mixed in the middle?) will depend on muscle glucose, muscle glocogenolysis. Glucogenolysis happens at a rate of .35mmol/kg/sec, with weights at approximately 70% of 1RM.

My questions- At what rate does ATP get used? When would it get depleted, or what levels do we start at? And lastly, how much, if any, glucogenolysis takes place during a short (under 20 sec) set? None, some?

Sources-
*Training on the Cyclical Ketogenic Diet: Effects of Cyclical Ketogenic Diets on Exercise Performance (http://www.thinkmuscle.com/ARTICLES/mcdonald/training-on-ketogenic-diet.htm)

*Eric Hultman "Fuel selection, muscle fibre" Proceedings of the Nutrition Society (1995) 54: 107-121. (http://journals.cambridge.org/action/displayFulltext?type=1&fid=789420&jid=PNS&volumeId=54&issueId=01&aid=789412)

*Robergs, RA et. al. "Muscle glycogenolysis during different intensities of weight-resistance exercise" J Appl Physiol (1991) 70: 1700-1706.

*Tesch, PA et. al. "Muscle metabolism during intense, heavy resistance exercise" Eur J Appl Physiol (1986) 55: 362-366.


P.S. If it makes more sense to you than me, you might find the answers in the second link...

[in10city]

ATP hydrolysis is what drives the cross-bridge movement, not glucose per se. That means it needs to be used from available ATP or generated / regenerated from substrate in a 'continual' manner.

ATP consumption rate varies with the number of cross-bridges in a force generating state, contraction velocity [isometric vs. dynamic] and a number of other factors. And not only that, it will vary individually with the fiber isoform based upon the ATPase hydrolysis rate. There is also a reserve capacity of ATP consumption such that it often will not reach the upper limit of consumption - the Vmax ATPase.

[gijoe985]

Well, then I guess what I really want t know is, how much glocognolysis takes place at those lower reps... I guess it isn't a huge issue, but I am tracking glocognolyisis to determine my carbohydrate needs... I don't know if I should count power sets or not...

[xAlphax]

Well, then I guess what I really want t know is, how much glocognolysis takes place at those lower reps... I guess it isn't a huge issue, but I am tracking glocognolyisis to determine my carbohydrate needs... I don't know if I should count power sets or not...

You should prolly count anything that would recruit type 2s/quick/explosive movement, don't think it will make a difference in determining how many carbs you'd need for/in a single session though.
...I'm not positive on what you mean by "glocognolysis," but if that were a simple possibility, then I think it'd be a step closer to a few less people asking "How many calories (moreso with carbs?) do I need??" and "Is this enough?? (also probably the same)" type questions. I'm guessing what you're asking would require a high degree of statistics/a few estimates over at least a span of a few months (fixed diet & training plan, muscle growth measurements & biopsies, on top of how well you'd adapt to lifting program for a given span of time). That aside I'll bring up one important point:

This is not necessary AT ALL. If you're that concerned with how many carbs you'd need then just do the next best thing and estimate your BMR + count cals/track macros for a few weeks, & add a few carbs, or not (I won't elaborate because like so many freaking things like these, it depends).

[gijoe985]

You should prolly count anything that would recruit type 2s/quick/explosive movement, don't think it will make a difference in determining how many carbs you'd need for/in a single session though.
...I'm not positive on what you mean by "glocognolysis," but if that were a simple possibility, then I think it'd be a step closer to a few less people asking "How many calories (moreso with carbs?) do I need??" and "Is this enough?? (also probably the same)" type questions. I'm guessing what you're asking would require a high degree of statistics/a few estimates over at least a span of a few months (fixed diet & training plan, muscle growth measurements & biopsies, on top of how well you'd adapt to lifting program for a given span of time). That aside I'll bring up one important point:

This is not necessary AT ALL. If you're that concerned with how many carbs you'd need then just do the next best thing and estimate your BMR + count cals/track macros for a few weeks, & add a few carbs, or not (I won't elaborate because like so many freaking things like these, it depends).

My "research" is pretty specific and having to do with ketogenic dieting. I am basically trying to fine tune certain aspects of a Targeted Ketogenic Diet, to incorporate into the foundations of the Anabolic Diet.

That being said, I am trying to calculate the rates of glycogenolysis (the rate that muscle glycogen is burned as fuel) in order to determine the amount of carbohydrates to include in a pre workout shake. For every 5.6mmol/kg of glycogen you burn, you can intake 1g of carbohydrate in order to create no net gain/loss. This will help maintain a level of muscle glycogen throughout the week.

I brought these questions here because this is the advanced nutrition forum, and my questions seemed pretty advanced.... I like science and I like figuring things out. Our body is a machine that can be fine tuned. I understand that we don't know a lot about our bodies and that many "facts" are guesses at best. But knowing certain things can at least help point us in the right direction...

Check out my links above for more info on what I'm doing...

[rhizome]

Your complete lack of knowledge of exercise physiology is your Achilles heel. Any time there is a drop is ATP glycolysis is ramped up. So where does the glucose come from?

I refuse to feed this overthinking festival with "numbers" since there are SO many variables that affect fuel usage. Hell you completely ignore lactate generation being used for gluconeogensis and muscle glycogen sparing and even liver glyogen use and sequestering. lol. You fail to see the forest through the trees.

[gijoe985]

Well I am just trying to research the same stuff that Lyle McDonald covers. I guess him and I are both stuck in the forest...

If I made my questions simpler, maybe that would appease more people.

Lyle McDonald plainly states, in his ketogenic diet/exercise book, that studies have shown that when doing reps at 70% of 1RM, you use up about .35mmol/kg of muscle glycogen per second. He uses that for most of his workout numbers. That is what I use. I don't really question it, I just use it as a general number to work off of. He also states that 1 carb replenishes 5.56 mmol/kg of glycogen in his discussion of the TKD.

My question, and reason for starting this thread, is basically, how does this affect lower rep/higher weight workouts that, according to Lyle McD, rely more on ATP than glycogen.

I don't think I am going to be coming up with any revolutionary discoveries, nor do I think that any of my conclusions will be concrete. But if I were doing a TKD workout, and I needed to supply myself with pre workout carbs, how would my carb intake differ if I was doing 70%of 1RM workouts, vs. 85%+ where I am only doing 2-5 reps.

As for now I figure I can just count it at the rate given above, but if it is true that lower rep sets rely more on ATP, then I don't want to be overfeeding myself carbs...

[NorwegianBadass]

Well, this isn't directly nutrition, but it is a question I have came upon while diet planning. And the information gathered would be used to develop appropriate nutrition. I just need a guru to help me...

My simple, but difficult, question-

During low rep sets (@85%+ of 1RM), I have read that the body recruits more ATP than musle glucose. This would be for sets that last less than 20 seconds. Though sets lasting over 30 seconds (I guess it is mixed in the middle?) will depend on muscle glucose, muscle glocogenolysis. Glucogenolysis happens at a rate of .35mmol/kg/sec, with weights at approximately 70% of 1RM.

My questions- At what rate does ATP get used? When would it get depleted, or what levels do we start at? And lastly, how much, if any, glucogenolysis takes place during a short (under 20 sec) set? None, some?


Sources-
*Training on the Cyclical Ketogenic Diet: Effects of Cyclical Ketogenic Diets on Exercise Performance (http://www.thinkmuscle.com/ARTICLES/mcdonald/training-on-ketogenic-diet.htm)

*Eric Hultman "Fuel selection, muscle fibre" Proceedings of the Nutrition Society (1995) 54: 107-121. (http://journals.cambridge.org/action/displayFulltext?type=1&fid=789420&jid=PNS&volumeId=54&issueId=01&aid=789412)

*Robergs, RA et. al. "Muscle glycogenolysis during different intensities of weight-resistance exercise" J Appl Physiol (1991) 70: 1700-1706.

*Tesch, PA et. al. "Muscle metabolism during intense, heavy resistance exercise" Eur J Appl Physiol (1986) 55: 362-366.


P.S. If it makes more sense to you than me, you might find the answers in the second link...

I dont know if this will answer your questions, or you might allready know this. I just finished the medical carbohydrate biochemistry parts so my brain just wants to puke out some information. Sorry if its not related to exactly what you are asking for!!!

It is rather the limitations of oxygen that sets the standard for low rep isotonic excersises than the ATP storage. You will continously produce ATP from free blood glucose, but the reduced oxygen levels will stop the convertion to pyruvate and rather produce lactic acid. This will give you only +2 ATP for every glucose molecule that is biosynthesized rather than 38 (under aerobic conditions).

Since isotonic (strenght) training will always be anaerobic you will always have a quick drop in ATP levels and quick rise in lactic acid.

These are also some the reasons why isotonic traning DO NOT BURN FAT! Fat burning is max at low to medium aerobic workouts like jogging.

[RealMenDeadLift]

As for now I figure I can just count it at the rate given above, but if it is true that lower rep sets rely more on ATP, then I don't want to be overfeeding myself carbs...

Huh? ATP is generated primarily by the TCA cycle which relies on glucose and fatty acid catabolism in order to provide the necessary amounts of acetyl-COA and oxaloacetate.
In a nutshell, use of glycogen leads to ATP production, they aren't exclusive fuel sources.