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donescobar2000
11-03-2003, 06:03 PM
Is it possbile to deplete your glycogen stores in one day? I am asking because this past saturday I helped my dad out all day on some construction work. I did this for around 6 hours or so. I was mainly hauling cinder blocks all day. The day before the work I did a refeed. I did my regular cut diet on the day that I worked. I am asking this because as of right now I find myself craving carbs.

harryhoudini66
11-03-2003, 10:53 PM
Take a piss on a kitostix so you know for sure.

bradley
11-04-2003, 03:12 AM
Originally posted by ultra150
Effect of glutamine supplementation combined with resistance training in young adults.

Candow DG, Chilibeck PD, Burke DG, Davison KS, Smith-Palmer T.

College of Kinesiology, University of Saskatchewan, Saskatoon, Canada.

What does this have to do with glycogen depletion?:confused:

ultra150
11-04-2003, 06:07 AM
Originally posted by bradley


What does this have to do with glycogen depletion?:confused:

My bad I posted the wrong thread.Here is a study on Glycogen Replenishment After Exhaustive Exercise.



Glycogen Replenishment After Exhaustive Exercise
Gregory Tardie, Ph.D.


Throughout the centuries, dietary intake has been a source of concern to athletes in search of an ergogenic edge over opponents.

It wasn't until 1866 that it was demonstrated that there was insignificant, if any use of protein as a fuel during exercise. Since that time, innumerable studies have refuted the notion that a high protein intake will enhance athletic performance.

Since the conclusion of the Kraus-Weber Tests in the 1950s, there has been ever- increasing awareness and concern for cardiopulmonary fitness and health in Americans. Endurance type activities such as Nordic skiing, cycling, running, triathalons, and swimming have become in vogue, and as a result, more intense attention has been devoted to dietary manipulations which may provide an ergogenic effect, thus prolonging time to exhaustion, or delaying the onset of blood lactate accumulation (OBLA) in an attempt to compete at a higher intensity, longer.

The classic study by Christensen and Hansen in 1939 established the effect of a high carbohydrate diet upon endurance time, and that pre-exercise glycogen levels exerted an influence in time to exhaustion. Subsequently, it was discovered that if an athlete after depleting glycogen reserves, consumed a high carbohydrate diet for two to three days prior to an athletic event, there would in fact be higher glycogen levels than prior to exercise. This "supercompensation" effect became the basis for carbohydrate loading undertaken by endurance athletes.

Therefore, the concentration of muscle and liver glycogen prior to exercise plays an important role in endurance exercise capacity. In exhaustive exercise many studies have observed significant depletion of both liver and muscle glycogen. It is interesting to recognize that the point of exhaustion seems to occur upon the depletion of liver glycogen. Conversely, muscle glycogen reserves, though significantly lower are only 65-85% depleted, versus the 85-95% depletion exhibited for liver glycogen. This should make it readily apparent that liver glycogen is an integral determining factor in an athlete's time to exhaustion. It follows that endurance athletes who maintain a daily regimen of endurance training without glycogen repletion may severely deplete their glycogen reserves.

Glycogen, the major reservoir of carbohydrate in the body is comprised of long chain polymers of glucose molecules. The body stores approximately 450-550 grams of glycogen within the muscle and liver for use during exercise. At higher exercise intensities, glycogen becomes the main fuel utilized. Depletion of liver glycogen has the consequence of diminishing liver glucose output, and blood glucose concentrations accordingly. Because glucose is the fundamental energy source for the nervous system, a substantial decline in blood glucose results in volitional exhaustion, due to glucose deficiency to the brain. It appears that the evidence presented in the literature universally supports the concept that the greater the depletion of skeletal muscle glycogen, then the stronger the stimulus to replenish stores upon the cessation of exercise, provided adequate carbohydrate is supplied.

Though most of the evidence presented on glycogen is related to prolonged aerobic exercise, there is evidence that exercise mode may play a role in glycogen replenishment, with eccentric exercise exhibiting significantly longer recovery periods, up to four days post-exercise. Muscle fiber type is another factor implicated in the replenishment of glycogen in athletes, due to the enzymatic capacity of the muscle fiber, with red fiber appearing to be subjected to a greater depletion, but also undergoing repletion at a significantly grater rate.

Though early literature appeared to indicate that the time course of glycogen replenishment after exercise-induced depletion was 48 hours or more, more recent data have controverted this thought. One study reported that a carbohydrate intake totaling up to 550-625 grams per day was found to restore muscle glycogen stores to pre-exercise levels within the 22 hours between exercise sessions. The findings of this study were supported by second study in which a carbohydrate intake of 3100 kcal resulted in complete resynthesis of glycogen within 24 hours.

There also appears to be a two-hour optimal window immediately after the cessation of exercise for the administration of carbohydrate. Simple carbohydrates appear to be the preferred replacement during this replenishment period.

Normally, 2% of glycogen is resynthesized per hour after the initial 2 hours immediately after exercise. With administration of 50 grams of carbohydrate every 2 hours, the rate rose to 5% per hour, but did not rise when additional carbohydrate was administered. Administration of .7grams per kg body weight every two hours is another strategy that appears to maximize the rate of glycogen resynthesis. There is also some evidence that even smaller loads (28 grams every 15 minutes) may induce even greater repletion rates.

Therefore, at least 20 hours are required to recover muscle glycogen stores, even when the diet is optimal. So, athletes working out two times per day should complete one workout at a diminished workload to relieve the reliance on glycogen reserves.

The principle of glycogen resynthesis and supercompensation have great practical implications, not only in athletics, but also within industry for workers who consistently undergo depletion of glycogen stores due to prolonged bouts of exertion, or extended lifting tasks which would be glycolytic in nature; due to the duration, and also the myofibrillar ischemia induced by static contractions.

ultra150
11-04-2003, 06:18 AM
You can deplete your glycogen in a day and when your levels are low already from your cutting diet which is usually low carbs to begin with.It will make you crave carbs you could drink a serving of dextrose after your workout to get your levels back up to a normal range faster and eat low glycerin carbs like brown rice,oatmeal etc.... through out the day like you are already but maybe a little mor a day before you think you will be useuing more energy then normal but if your cutting thats part ot the game.lol But the extra work will deplete your levels considering you are at a fine line with your diet and anymore work can be enough to deplete it.

bradley
11-04-2003, 07:33 AM
Originally posted by donescobar2000
Is it possbile to deplete your glycogen stores in one day? I am asking because this past saturday I helped my dad out all day on some construction work. I did this for around 6 hours or so. I was mainly hauling cinder blocks all day. The day before the work I did a refeed. I did my regular cut diet on the day that I worked. I am asking this because as of right now I find myself craving carbs.

It would depend on your initial glycogen levels, but it is possible to deplete your glycogen levels significantly over the course of one day. Another factor would be the amount of carbs that you took in while performing the work.

The lower your bf%, the more frequent your refeeds will need to be, so I am not surprised that you feel the need to refeed. Especially since you are at a low bf% currently.

bradley
11-04-2003, 07:35 AM
Originally posted by ultra150
You can deplete your glycogen in a day and when your levels are low already from your cutting diet which is usually low carbs to begin with.It will make you crave carbs you could drink a serving of dextrose after your workout to get your levels back up to a normal range faster and eat low glycerin carbs like brown rice,oatmeal etc.... through out the day like you are already but maybe a little mor a day before you think you will be useuing more energy then normal but if your cutting thats part ot the game.lol But the extra work will deplete your levels considering you are at a fine line with your diet and anymore work can be enough to deplete it.

While I agree with your statements above, but glycogen levels should not be low, due to the fact that he performed a refeed the previous day.

ultra150
11-04-2003, 07:59 AM
when he reefed the day before is was probably just enough to get him through his normal workout.the extra work load he did probably took him below his normal range that he was used to SO it made him crave the carbs more then normal.Usually cutting diets are so low to began with that its hard enough to stay away from the extra carbs lol.one of the studies say when you consume 500g of carbs it takes 22 hours to get levels back to normal.On a cutting diet he probly is goiong no higher then 200g of carbs a day.

donescobar2000
11-04-2003, 08:42 AM
Thats true on dieting days I do about 200 or less grams of carbs and on the refeed I did maybe a little more than 600 grams.

aka23
11-04-2003, 09:56 AM
It is definitely possible to deplete your glycogen levels in a day. This is a common problem in extended endurance events. In some sports running out of glycogen is called "hitting the wall" or "bonking." A key factor in the rate of depletion is exercise intensity. Hultman found that liver glycogen became depleted after ~140 minutes at 85% VO2 max, ~190 minutes at 75% VO2 max, and ~220 minutes at 70% VO2 max. Muscle glycogen depletion takes longer since it does not occur in a linear manner. The body starts emphasizing alternative sources of fuel such as fats, as glycogen levels decrease. It takes much less time to deplete half of the glycogen than all of the glycogen. Muscle glycogen might get depleted by 75% in ~15 minutes at 150% VO2 max, ~25-30 minutes at 120% VO2 max, ~90 minutes at 85% VO2 max, ~150 minuts at 75% VO2 max, ~230 minutes at 70% VO2 max, and more than 12 hours at 50% VO2 max. The greater than 100% VO2 max speeds are above the lactate/anaerobic threshold, so they cannot be sustained for more than a couple minutes. This might occur with the sprint portions of HIIT. In these types of patterns, The most rapid glycogen depletion occurs with longer sprints or short recovery periods. There is little glycgogen depletion in a 10s work, 20s rest pattern since the phosphocreatine and ATP systems dominate the energy source, and the glycolysis system is not placed under heavy stress.

As others have mentioned initial glycogen levels have also have a large effect on time to depletion. Diet and training history play a large role in the size of glycogen stores. A higher carb diet generally increases the size of glycogen stores. Depleting glycogen, then refeeding can increase stores to beyond normal levels. Many types of athletes and bodybuilders have larger glycogen stores than the average person. Also note that if there is inadaquate time to recovery, then glycogen stores may become more depleted over time.

ultra150
11-04-2003, 11:26 AM
Originally posted by donescobar2000
Thats true on dieting days I do about 200 or less grams of carbs and on the reefed I did maybe a little more than 600 grams.

On that day that you did extra work you probably burnt more fat off.lol

Shao-LiN
11-04-2003, 11:34 AM
It is possible, but I'd imagine you'd be dead tired and worn out. The depletion workouts and diets associated that I've read say you can double up a depletion workout to deplete in one day, but for convenience, sanity, and to overcome possible boredom, they split it into a 2-day depletion.

I also have a question related to depletion workouts though. To save an extra thread, I was wondering if you would still do a pre- and post-workout shake consisting of only protein immediately before and after the workout...or would you forego the shakes and just eat whole food 2-3 hours before and directly after a workout, or an hour after...or what not.

ultra150
11-04-2003, 11:52 AM
Originally posted by Shao-LiN
It is possible, but I'd imagine you'd be dead tired and worn out. The depletion workouts and diets associated that I've read say you can double up a depletion workout to deplete in one day, but for convenience, sanity, and to overcome possible boredom, they split it into a 2-day depletion.

I also have a question related to depletion workouts though. To save an extra thread, I was wondering if you would still do a pre- and post-workout shake consisting of only protein immediately before and after the workout...or would you forego the shakes and just eat whole food 2-3 hours before and directly after a workout, or an hour after...or what not.

For myself I like 32 oz of skim milk before my workout or cottage cheese.for a post workout A protien shake with dextrose and ala seems to work well with me.

bradley
11-04-2003, 01:26 PM
Originally posted by Shao-LiN
I also have a question related to depletion workouts though. To save an extra thread, I was wondering if you would still do a pre- and post-workout shake consisting of only protein immediately before and after the workout...or would you forego the shakes and just eat whole food 2-3 hours before and directly after a workout, or an hour after...or what not.

I think it would depend on how many calories you have to work with. If I remember correctly you are using UD 2.0, in which I would just go with whole food meals pre/post workout, since shakes are not very calorie "effecient" so to speak. Lyle does not give you many calories to work with on the depletion days.:p

If you are taking in a whole food meal preworkout and a whole food meal shortly after training, I do not think you are going to see much, if any benefit over consuming pre/post workout shakes (protein only). Consuming a whole food meal will ensure that you have aminos available when they are needed (during and post workout).

Shao-LiN
11-04-2003, 04:19 PM
Cool, yes I'm using UD2 and am consuming around the minimum amount of calories suggested on depletion days.

I've done 2 trial cycles just to iron out workouts and the diet. Was just curious because the first week I stuck to whole food throughout the depletion days, not necessarily geared towards pre and post workout...while the second week I re-worked it to include a 15 g pre-workout whey shake and a 40 g post-workout shake.

I just wasn't sure if the timing really mattered surrounding the depletion workouts. Whether or not I should eat a meal immediately before and/or after and what not.