Carbs not Required post workout
- 12-21-2010, 06:51 AM
Carbs not Required post workout
The recent study shows that carbs are not required in post workout protein shake:
Carbs Not Required for Your Workout Protein Shake
- 12-21-2010, 07:07 AM
I'm sure it's an interesting read....but I can't bring myself to open it and read. Long live my carbs.
- 12-21-2010, 08:23 AM
The belief that carbs are required in your post workout protein shake is so established that the debate has been more about whether to take high gi or low gi carbs, if waxy maize is better than dextrose. and so on. But this recent study shows that carbs may not be required in the first place.
Why carbs were needed in your protein shake?
Protein break down: Protein breakdown is increased after workouts. Carbs increase insulin levels and can blunt protein breakdown after your workouts. This is the major reason why carbs are added with protein shakes.
Protein Synthesis: Carbs can increase insulin levsl and slightly increase protein synthesis.
Glycogen: Restore glycogen in the muscle. Unless you are doing a lot of high reps, glycogen is not really depleted with weight training.
What was the study design?
9 recreationally active subjects were randomly assigned to a Protein only group and a protein + carbs group.
Participants performed 2 trials seperated by 7 days of 4 sets of leg extenions ( 8-12) for failure after an overnight fast.
The protein group consumed 25 gms of whey protein while the protein+carbs group consumed the protein with 50 gms of malto dextrin
What were the results of the study?
As predicted, the glucose and insulin levels was significantly greater for the protein +carbs group
But, guess what, there was no difference in protein synthesis or protein breakdown between the protein only group and the protein plus carbs group.
Are there other studies to support?
30 gms vs 90 gms: Another recent study looked if 90 gms of carbs +amino acids can decrease protein breakdown compared to 30gms+amino acids after resistance training. But they didnít find any significant difference between the groups.
Though study lacked a group with only protein to see if there is any difference if only protein was ingested, the results are consistent with this study.
There is no reason to add carbs in your post wrokout shake to decrease protein breakdown or increase protein synthesis.
The protein itself in the shake is enough to increase insulin levels and decrease protein breakdown to the maximum extentA-Minds HYPE-SLAYER! All posts & feedback are guaranteed to be unsolicited and legit
"The fear of the LORD is the beginning of knowledge. Fools despise wisdom & instruction" Proverbs 1:7
12-21-2010, 08:34 AM
12-21-2010, 08:46 AM
Carbs aren't 'required' post workout. Glycogen levels are shown to replenish in study groups who drank just water.
I like to look at it the other way. If you are building muscle, why would you not take advantage of your workout by loading up on nutrients post workout?
The insulin spike can used to blunt cortisol and improve the cortisol:testosterone ratio.
If I was solely trying to lose fat then I would go with a high dose of glutamine and glycine.
12-21-2010, 10:24 AM
Glutamine ..oi vey.
The studies done with glutamine that have yielded positive results in skeletal muscle have generally incorporated an IV drip and more often than not were in burn or accident victims.
In the studies where glutamine was ingested orally, the increase in muscle mass was SMOOTh muscle (i.e.: intestinal).
Further, there is a lack of well set up studies that show glutmine aids in recovery or muscle growth.
As to the study, I would be interested to see levels of protein synthesis and degradation up to 24 hours following resistance training.
Secondly, for those consuming carbohydrates, simple nutrient partitioning theories state that the best time to consume CHO is post workout. Glycogen is partially depleted (4 x 8 leg extensions is not a very demanding lower body workout), glycogen synthase is increased, and Glut-4 proteins are translocated to the surface of the muscle cell. Together, this creates an ideal environment for optimal glucose disposal into the muscle cell.
12-21-2010, 10:50 AM
Supplementing with glutamine enhances muscle glycogen synthesis.
by Paul Cribb, B.H.Sci HMS
Muscle glycogen is the storage form carbohydrate and the primary fuel of intense exercise. For bodybuilders, glycogen-full muscles mean a greater work capacity, faster recovery and muscle growth. Many bodybuilders restrict their carbohydrate intake in an effort to remain lean, this can create low muscle glycogen levels that limit recovery and the ability to train intensely. This study demonstrated that taking glutamine straight after training stimulates glycogen synthesis in muscles and appears just as effective at restoring glycogen levels as a high-dose of carbohydrates.
The participants in this study completed three glycogen-depleting weight training sessions. After each session they received one of three different drinks (by a systemic rotation), a carbohydrate solution (61-grams), a glutamine solution (8-grams), or a combination of both. The muscle biopsy results revealed that 8 grams of glutamine was as effective as 61-grams of glucose for restoring muscle glycogen levels, while the combination of glucose and glutamine restored whole body glycogen levels more effectively than either supplement taken separately.
These findings are fantastic for competitive bodybuilders, wrestlers, and other athletes that may restrict carbohydrate intake yet require high muscle glycogen levels for optimal performance. These results also have important implications for those that follow a low-carb diet. Taking an 8-gram serving of glutamine after exercise will restore muscle glycogen levels as effectively as a high dose of glucose. This means bodybuilders and other athletes can replenish vital muscle glycogen levels with minimal amounts of carbohydrates! Pre-contest bodybuilders can use glutamine in their carb loading phase to enhance muscle glycogen accumulation.
Bodybuilders and other strength athletes should aim for rapid replenishment of muscle glycogen stores straight after exercise. By adding glutamine to your post-workout meals you will enhance the replenishment of vital muscle glycogen and whole body energy stores.
This research demonstrates more important benefits of glutamine supplementation for athletes. Glutamine remains one of the most underrated, research-proven performance enhancing supplements an athlete can use.
12-21-2010, 10:57 AM
Glutamine increases glycogen synthesis and replenishes glutamine levels which is a strong indicator for overtraining.
In low carb scenarios it works well.
12-21-2010, 10:58 AM
12-21-2010, 11:09 AM
12-21-2010, 11:21 AM
Why wouldn't you take a high amount of carbs/calories post workout if you can afford it? It is the only time of the day I can take that much sugar without falling asleep afterwards.
You can get nutrients post workout if you went with fresh fruit juices (which I have done). I wouldn't drink a vast amount of grape juice at any other time of the day for the reason above.
12-21-2010, 11:22 AM
M.Ed. Ex Phys
12-21-2010, 11:27 AM
12-21-2010, 11:31 AM
I've never found a study showing that carbs + protein is better than protein alone after workouts other than fasted first thing in the morning workouts.
12-21-2010, 11:37 AM
12-21-2010, 11:41 AM
I use it to take advantage of the anabolic nature of insulin at the time when I am most insulin sensitive.
I can say wholeheartedly that I am leaner doing this than consuming my carb ration in smaller amounts of carbs throughout the day.
12-21-2010, 11:49 AM
12-21-2010, 12:04 PM
"The results suggest that delaying the ingestion of a carbohydrate supplement post-exercise will result in a reduced rate of muscle glycogen storage."
This was comparing an identical carbohydrate solution taken immediately post workout to two hours post workout.
12-21-2010, 12:33 PM
The original article posted is garbage, and basically someone summing upmtwo studies they dont understand. The point of post workout carbs is for the resynthesis of glycogen, not to blunt protein degradation. Several studies have shown the benefit of adding protein To pwo carbs following endurance training leads to faster recovery of glycogen and reduced protein degradation than carbs alone.
So basically in regards to post workout carbs it's going to depend on your training. If your doing 5x5 workouts with long rest periods, your not using up alot of glycogen, and won't need to pound them with your shake. High volume high rep workouts, you burn up glycogen rapidly and will want to replace it pwo. However, i agree with easyej that you don't need mass quantities of carbs, just 20g or 30g to provide enough substrate til urnnext meal. It's not a free formall pwo, u still will get fat.
As for glutamine, it's an awesome compound that can be converted to glucose and be used for energy, or stored as glycogen. It also helps with them clearing of toxic nitrogen
During periods of high protein breakdown (pwo). Definitely a great addition after an intense training session.
12-21-2010, 12:49 PM
But then again the research we have mostly pertains to athletes trying to maximize performance on a daily basis,'and cannot be directly related to bodybuilding,'where body comp is the main goal.
12-21-2010, 12:56 PM
Surprised this hasn't been added, too: there is a huge difference in eating for performance and eating for aesthetics. If you're training 2x/day for a sport, then you'll need a lot of carbs after training (simple and complex).
M.Ed. Ex Phys
12-21-2010, 01:03 PM
12-21-2010, 01:08 PM
so a) cyclists not weight lifters b) was only measured at 0,2 + 4 hours post exercise.Twelve male cyclists exercised continuously for 70 min on a cycle ergometer at 68% VO2max, interrupted by six 2-min intervals at 88% VO2max, on two separate occasions. A 25% carbohydrate solution (2 g/kg body wt) was ingested immediately postexercise (P-EX) or 2 h postexercise (2P-EX). Muscle biopsies were taken from the vastus lateralis at 0, 2, and 4 h postexercise.
Yes thats valuable if you are doing endurance sports, and may have more than one session a day (where you need to replenish glycogen before the next event). Meaningless from a bodybuilding perspective where you don't likely in 90 minutes of lifting hit 50% of V02max for more than a couple minutes total. Your glycogen reserves are rather large, and a normal lifting session doesn't clip 25% off the total.
12-21-2010, 01:16 PM
Of course I read the study.
My point is that there are benefits to timing of carbohydrate ingestion and it isn't necessarily equal to 'spreading them throughout the day' as you suggested. The laws of thermodynamics stand but there is no denying the hormonal influence.
Once again, if I am trying to build muscle and I can afford to ingest that much sugar for a highly anabolic insulin spike without putting on fat then I will do that. At the moment I can ingest 150g of carbs dextrose/maltodextrin usually without my bodyfat going up, if my bodyfat isn't going up I am going to consume as much as I can post workout.
12-21-2010, 01:20 PM
12-21-2010, 01:26 PM
I must be communicating badly?
Regarding glycogen replenishment in bodybuilding. I wrote this in post #5- "Carbs aren't 'required' post workout. Glycogen levels are shown to replenish in study groups who drank just water."
Regarding time of day comment. In post #11- "Why wouldn't you take a high amount of carbs/calories post workout if you can afford it? It is the only time of the day I can take that much sugar without falling asleep afterwards." -
12-21-2010, 01:32 PM
12-21-2010, 03:53 PM
12-21-2010, 03:56 PM
12-21-2010, 08:38 PM
If it doesn't show the benefits on beginners, I don't expect to see anything in trained. Trained athletes are shown to have much less damage than beginners.2 trials of leg extensions on "recreationally active" participants is hardly an applicable sample size. The study was also not calorically controlled, which makes a huge difference (duh).
The study just like any other protein study is obviously calorie controlled. these acute studies are much better than long term studies where we got no clue what they ate during a 12 week period unless you give them food packets. And they all came after an over night fast too.
I have bolded my answer in your post. Resistance training is different from endurance training. I don't see to much glycogen getting depleted unless you are doing lot of volume and high rep sets.The point of post workout carbs is for the resynthesis of glycogen, not to blunt protein degradation. Several studies have shown the benefit of adding protein To pwo carbs following endurance training leads to faster recovery of glycogen and reduced protein degradation than carbs alone.
And just so that people know glycogen do not build muscle unless it does something to protein synthesis or protein breakdown.
Only thing I can see problematic is they only did 4 sets of 12. In real world most people, do a lot more sets for legs. There was a study which showed 9 sets of 12 depleted 36 % of muscle glycogen.
12-21-2010, 09:04 PM
M.Ed. Ex Phys
12-21-2010, 09:28 PM
"Participants were asked to refrain from heavy leg exercise for 72 h prior to each of the trials, and to refrain from alcohol, caffeine, and other drugs for 24 h prior to each of the trials. Participants kept a food record for the day before their first trial and were asked to replicate the diet and approximate eating times before the second trial. Participants were only permitted to consume water during the 10h before each trial, and they were asked to obtain a full night of sleep on the evenings before each trial."
And what has long term study got to do with the sample size n?
And read it again what I wrote: I meant you cannot completely control someones diet in long term study unless you are feeding them food packets or lock them up in a building which is usually a problem with body composition studies.
12-21-2010, 09:50 PM
M.Ed. Ex Phys
12-21-2010, 10:16 PM
This study is cross over design. you do one sets of measurements and the next time after a washout period you do the other one.Within subjects designs like these eliminate problems with genetics and motivation factors since you are using the same subjects.
The sample size is determined by a power analysis before the study (which they did). You need just enough sample to see if you can find a significant difference. You can make any difference statistically significant, if you have a high enough sample size. So more doesn't mean good.
12-21-2010, 10:25 PM
If you can't understand why n should be large, then you should stop making making broad conclusions on a given study. Understanding n is covered on the first day of any decent experimental design class, which I gather you have never taken.
M.Ed. Ex Phys
12-21-2010, 10:36 PM
Second, where did i say more n do not mean more statistical power. Read my post again.
You can make even a 5 lb difference in strength statistically significant if you have a large sample size. So the goal of a study is not find the LARGEST sample size, but just enough to have it significant to prove that there is a meaningful difference.
And no reason start being condescending in your posts.
12-21-2010, 10:49 PM
For example: if you have a test group of 10 and 4 show an improvement, then that is an impressive statistic; however, if you expand the sample size to 100 and only 13 show improvement, then it is not nearly as effective or as high of a ratio. Why else do you think there are 1000's of trials done on medications? You want to weed out the data and find out if you can reject the null hypothesis or if the p-value is too high to reject the null hypothesis.
M.Ed. Ex Phys
12-21-2010, 11:03 PM
Have you heard about power analysis?
Here is the definition for it: Power analysis can be used to calculate the minimum sample size required to accept the outcome of a statistical test with a particular level of confidence.
I hope you understand that it is SINGLE study and by "trial" means the 2 separate groups for carbs and carbs +protein.
12-21-2010, 11:54 PM
Your not understanding the definition of statistical power, and reading the definition on wikipedia doesn't do your argument justice. Statistical power is basically how much you can rely on a statistical test to support or reject the hypothesis. It is related to sample size, and the larger the sample size (n), the more statistical power you have. You don't want to have the minimum sample size needed to Accept an outcome, you want the largest sample size possible to maximize validity.
This is the only study I've been able to locate looking at this matter. one study involving 13 recreational subjects performing considerably less volume than most on this website, is not enough to make the claim that post workout carbs aren't needed after weight training. But it does spark interesting debates, and opens the door formmore research,'so it's still a good post.
12-22-2010, 12:42 AM
Restoring muscle glycogen is important only when doing endurance events. Normal eating will restore glycogen for regular weight workouts. If you need to carbo-load before a bodybuilding contest, for example, to look as cut as possible you would then carbo-load. But this is not a recommended practice for normal weight workouts.
One of the belief is that carbo loading or glycogen loading increases your power or maximum aerobic output. The amount of glycogen in your muscles does nothing for strength, power or V02 max. it simply enables you to continue longer at your maximum aerobic pace. Far from increasing power, for short events (less than 2 hours), glycogen loading is a definite liability. 1. There is insufficient exercise to use the extra glycogen. 2. More important, doubling your glycogen store will increase your water and glycogen weight by 4-5lbs which will reduce your performance for shorter workouts. Extra glycogen will also create tightness and stiffness of muscles. -Colgan Institute
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