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What's a young, hip, well-dressed guy like John doing, finishing up a PHD with a specialization in exercise and nutritional biochemistry this fall? Well, John Berardi is world renowned for his nutrition, supplement and training advice. After 8 years of working in this industry, John has made a big splash with his numerous nutrition and supplement contributions to www.t-mag.com . Now, after 10 years of nutrition and exercise consultation, and over 100 published articles on these topics, John has founded Science Link, Inc. - Translating Research into Results and www.johnberardi.com - Human Performance and Nutrition Consulting. Through his consulting businesses, John works with a diverse client population from supplement companies wanting to design cutting-edge products for high-level athletes who want to win medals and championships. To say that this guy knows his stuff is an understatement.

Two other guys that have made a big impact on me have been Dr Tim Ziegenfuss and Dr Lonnie Lowery. While these two are more like nerdy frat brothers, they have both made meaningful contributions to my work and view of this industry.

 

 

THE SMACK DOWN ON PROTEIN

Maki R: How much protein does a bodybuilder/athlete need on a day-to-day basis?

Dr Berardi: Here's where I always get into trouble. This is usually the first question I get asked and with my response, I usually piss everyone off. Oh well, here goes nothin'.

With respect to athletic needs, the work of Lemon, Tarnopolsky and colleagues has given some indication that athletes do require more protein (Lemon et al 1981, Tarnopolsky et al 1988, Tarmonpolsky et al 1992, Lemon et al 1997). This classic research indicates that during intensive training, strength and endurance athletes may need somewhere between 1.4 - 2.0 g of protein per kg of body mass to maintain nitrogen balance.

But what about all the athletes and weightlifters out there that consume fewer protein grams than the recommended 1.4 - 2.0 g of protein per kg of body mass? If they really needed those 1.4 - 2.0g/kg, wouldn't they be wasting away and dying? Since they're not, they must not need all that protein. What's the deal?

As Michael Rennie and colleagues have pointed out, there are several problems when trying to apply the Lemon and Tarnoposky data to habitual exercisers. First, the studies by Lemon and Tarnopolsky were done on athletes undergoing new training programs. While they were recreationally active before the study began, the training stimulus (strength training in some studies, endurance training in others) was novel, most likely causing a short-term increase in protein need, an increase that would not persist in the long-term (Rennie et al 1999, 2000). In other words, Rennie argues that while a new exercise program (whether strength or endurance exercise) may increase protein need acutely, chronic exercise probably doesn't increase protein need at all.

Maki R: Say what?

Dr Berardi: Hold on now, before you start hatin' on Rennie, it's important to understand that this guy is a protein research legend. Type his name into Medline and you'll get a couple hundred protein-related research publications. Beyond his excellent reputation, his ideas do have both theoretical and research support. Specifically, the research of Butterfield and Calloway suggests that athletes may actually need less protein due to an increase in protein efficiency that may accompany chronic training (Butterfield and Calloway 1984). What this means is that athletes may actually get more efficient in their protein use (i.e. increased anabolic efficiency) and therefore may need less protein than the 0.8g/kg required for sedentary individuals!

Actually, the Butterfield study suggests an exact number: 0.65 g/kg. In calculating the exact amount of protein they might recommend to maintain nitrogen balance, a 200lb athlete who trains consistently would find that they only need a measly 59g of protein to prevent nitrogen losses and protein malnutrition. So, for those of you who staunchly believe that you're only required to eat enough protein to meet your needs, go right ahead and reduce your protein intake from 2.g/kg to 0.65g/kg. In the meantime, I'll be encouraging everyone else to actually increase his or her protein intake beyond the current 2.0g/kg recommendation.

Is this Rennie guy crazy? Butterfield? Me? Probably not! Then why do these comments fly in the face of what athletes and weight-lifters know; namely that a higher-protein diet helps pack on muscle mass and helps promote a favorable body composition? Well, actually, they don't! If you think so, you don't understand the difference between need with optimization.

An athlete may need less protein to stay alive but he/she should consume more protein to optimize performance and body composition. Therefore, when I'm asked how much protein an athlete needs, my best response is that it doesn't matter! Asking "How much protein does an athlete need?" is much like asking the question "How much does a student need to study for an exam?" Since a student only needs to pass their exam to remain a student, the proper answer would be "however much it takes to score a 60%." However, very few students want to earn only a 60%. Therefore the best question would be "How much does a student need to study to get an A on their exam?"

Maki R: Great, you hate my question - how about this one. How much protein should a bodybuilder/athlete consume to maximize muscle and strength gains?

Dr Berardi: Now that's better! I usually recommend that protein intake be in the neighborhood of 3-4g/kg. If this recommendation seems excessive and you think that you should stop this interview right now, hang on one second. Again, I'm not crazy. Basically the reason someone might think this intake is excessive is because they have a narrow view of how protein fits into one's dietary strategy. They're looking at protein in the same narrow way that people used to look at vitamin C; essential at a specific dose but conferring no additional benefits with a higher intake.

With vitamin C, we all know it's important to consume enough of it (at least 10mg/day) to prevent scurvy. However, it's also commonly known there are a host of health benefits associated with much higher doses (200mg/day or more) including a reduced risk of cancer, increased HDL cholesterol, reduced risk of coronary artery disease, and a reduced duration of cold episodes and severity of symptoms.

Like vitamin C, instead of thinking of protein as a macronutrient that provides no benefit beyond preventing protein deficiency, we need to recognize the benefits of eating protein (at any dose).

Increased Thermic Effect of Feeding - While all macronutrients require metabolic processing for digestion, absorption, and storage or oxidation, the thermic effect of protein is roughly double that of carbohydrates and fat. Therefore, eating protein is actually thermogenic and can lead to a higher metabolic rate. This means greater fat loss when dieting and less fat gain during overfeeding.

Increased Glucagon - Protein consumption increases plasma concentrations of the hormone glucagon. Glucagon is responsible for antagonizing the effects of insulin in adipose tissue, leading to greater fat mobilization. In addition, glucagon also decreases the amounts and activities of the enzymes responsible for making and storing fat in adipose and liver cells. Again, this leads to greater fat loss during dieting and less fat gain during overfeeding.

Increased IGF-1 - Protein and amino-acid supplementation has been shown to increase the IGF-1 response to both exercise and feeding. Since IGF-1 is an anabolic hormone that's related to muscle growth, another advantage associated with consuming more protein is more muscle growth when overfeeding and/or muscle sparing when dieting.

Reduction in Cardiovascular Risk - Several studies have shown that increasing the percentage of protein in the diet (from 11% to 23%) while decreasing the percentage of carbohydrate (from 63% to 48%) lowers LDL cholesterol and triglyceride concentrations with concomitant increases in HDL cholesterol concentrations.

Improved Weight-Loss Profile - New research by Layman and colleagues has demonstrated that reducing the carbohydrate ratio from 3.5 - 1 to 1.4 - 1 increases body fat loss, spares muscle mass, reduces triglyceride concentrations, improves satiety, and improves blood glucose management (Layman et al 2003 - If you're at all interested in protein intake, you've gotta go read the January and February issues of the Journal of Nutrition. Layman has three interesting articles in the two journals).

Increased Protein Turnover - All tissues of the body, including muscle, go through a regular program of turnover. Since the balance between protein breakdown and protein synthesis governs muscle protein turnover, you need to increase your protein turnover rates in order to best improve your muscle quality. A high protein diet does just this. By increasing both protein synthesis and protein breakdown, a high protein diet helps you get rid of the old muscle more quickly and build up new, more functional muscle to take its place.

Increased Nitrogen Status - Earlier I indicated that a positive nitrogen status means that more protein is entering the body than is leaving the body. High protein diets cause a strong positive protein status and when this increased protein availability is coupled with an exercise program that increases the body's anabolic efficiency, the growth process may be accelerated.

Increased Provision of Auxiliary Nutrients - Although the benefits mentioned above have related specifically to protein and amino acids, it's important to recognize that we don't just eat protein and amino acids - we eat food. Therefore, high protein diets often provide auxiliary nutrients that could enhance performance and/or muscle growth. These nutrients include creatine, branched chain amino acids, conjugated linoleic acids, and/or additional nutrients that are important but remain to be discovered. This illustrates the need to get most of your protein from food, rather than supplements alone.

Looking over this list of benefits, isn't it clear that getting lots of protein would be advantageous to anyone's training goals? Since a high protein diet can lead to a better health profile, an increased metabolism, improved body composition, and an improved training response, why would anyone ever try to limit their protein intake to the bare minimum necessary to stave off malnutrition?

Maki R: Ok then,how much protein is too much?

Dr Berardi: I can't answer that definitively.

Maki R: But, but Dr Berardi, I thought you knew it all?

Dr Berardi: Well listen to this. Interestingly however, Dr Loren Cordain (of Paleo Diet fame) shared with me some data suggesting an upper limit of protein intake in the 2.6g/kg - 3.6g/kg range. These data are based on studies by Rudman and colleagues (Journal of Clinical Investigation, 1973) in which urea synthesis (urea is a byproduct of protein metabolism) was compared against maximal urea excretion rates. According to the logic presented here, if you eat so much protein (and make so much urea) that your body can't excrete all of the urea, a more chronic hyperaminoacidema and hyperammonemia can result. Therefore, for intakes higher than 3.6g/kg, one might not be able to all of the protein nitrogen from the body in a timely fashion.

Maki R: Is this a bad thing?

Dr Berardi: Some scientists and doctors speculate so. Since nitrogen is a compound that is considered "toxic" (or at least "stressful") to the body, a chronic build-up of nitrogen can't be good. However, the human body is more adaptive than most of us give it credit for and since the Rudman studies were relatively short in duration, I wonder if maximal urea excretion rates might climb with habitual high protein consumption.

Maki R: With those high intakes, I wonder how much protein the body can assimilate in one sitting?

Dr Berardi: 30 grams.

Maki R: Really? But I thought. . .

Dr Berardi: Ok, ok, I'm just kidding. Got your attention though, didn't I? Actually, my real answer is this. No one's done the studies to answer this question. So we can't know for sure. What we do know is this. Protein digestion depends on a number of factors including the protein source, how the protein source was prepared, whether or not you are on any drugs that affect the GI tract, and probably a host of other factors.

Let's tackle the digestion issue first. When a food is ingested the food first must undergo the digestive process. Since the larger the meal, the slower the GI transit time, it stands to reason that most (but not all) of the protein in any given protein meal (small or large) will be digested and absorbed across the intestinal mucosa eventually. You see, the enzymes for protein digestion aren't limiting so most of the protein thrown down your gullet will be digested and absorbed if it hangs out long enough. Let me say that in another way. If you eat a meal containing 30g of protein and 95% of the protein is digested and absorbed through the intestinal mucosa, does that meal if you ate less protein, 100% would have been absorbed and if you ate more protein only 90% would be absorbed. Not at all. If you ate less protein, the time this protein sits in the GI tract would be shorter and fewer enzymes would be released so you'd probably digest and absorb 95%. And if you ate more protein, the time that this protein sits in the GI tract would be longer and more enzymes would be released so you'd probably digest and absorb about 95% of the protein. So my speculation is that digestion is more contingent upon other factors (as discussed above) than protein meal size.

To this end, Gibson and colleagues published a study in 1976 (British Journal of Nutrition) showing that an increasing protein intake did not lead to increased fecal nitrogen loss. This means that higher protein diets did not lead to more un-digested protein in the gut. These data are supported by further studies suggesting that most proteins have somewhere between 85% and 98% digestibility (meat and cheeses are around the 85-90% range while protein powders are closer to 95%). Interestingly, Pieter Evenepoel and colleagues published a nice study in the American Journal of Physiology showing that when subjects ate 25g of cooked egg protein, 93% of the protein was assimilated. However, when the eggs were not cooked, 65% of the eggs were assimilated. So it appears that food preparation is important; in the case of eggs, probably more important than meal size.

Evenpoel and colleagues also published a nice review of protein digestion and assimilation indicating, "Protein digestibility depends both on characteristics of the ingested meal and on the digestive and absorptive capacity of the upper gastrointestinal tract. The latter is significantly impaired in pancreatic disease but is also compromised by some drugs often used in clinical practice. We moreover confirmed that a substantial amount of even easily digestible dietary protein escapes assimilation in the small intestine."

So it's clear that protein type and preparation are critical to protein digestion. Unfortunately, I can't find any other studies comparing protein meals of different sizes. So the question as to how much protein can be digested in one sitting has to remain unanswered.

Beyond protein absorption through the intestinal mucosa, the protein (or, more appropriately, peptides and amino acids) must then pass through the liver en route to the blood. This is where things get can get even murkier. The liver can do a number of things with an influx of amino acids and peptides including letting them through unmolested, making glucose or glycogen out of them through deamination (gluconeogenesis), or oxidizing them. What the liver decides to do is probably dependent on the instantaneous load that it's faced with. This is probably why more protein is oxidized with a fast digesting whey than with slow digesting casein.

So, in the end, the question has to go unanswered. There's not enough data to draw definitive conclusions. Regardless, from real world experience, it's clear that weight-lifters eating even 3-4g/kg do very well. For a 100kg guy, that's an upper limit of 400g of protein. Assuming 6 - 8 meals per day, that's between 50 - 70g per meal. Assuming varied protein sources, proper preparation, and slower digesting proteins (like whole foods), at these intakes, I can't imagine any real assimilation problems. 

 

 

TO CHEAT OR NOT TO CHEAT?

Maki R: Do you believe in following a strict eating plan year round?

Dr Berardi: In response to this question I have say that no one should try to eat 100% on point year-round. Furthermore, unless one is on a strict contest-type diet, no one should try to eat 100% on point every week. Expecting 100% adherence is not only a recipe for psychological disaster; it's plain old physiologically dumb. Would you train 7 days a week if you could get the same results from training 5 days a week? If so, you need some hobbies!
Sure, a lot of you hardcore young'ins are sitting there thinking that only the weak cheat, or miss a meal, or eat something not listed in their diet sheet on the fridge. Well, come back in 10 years and tell me the same thing. I've been training for 11 years without an unplanned break and during this time I've learned that 90% is all you need to reach your goals. The extra 10% is only for the most intolerable zealots among you who are misguided enough to think that only the very strictest and most disciplined individuals are worth a damn (i.e. what I call "weightlifting snobs"). I assure you of this - if you try to follow a diet to the 100% level all year, you won't last very long in this game. You'll be another one of those guys who looks at me and says, "When I was your age, I was in great shape too" (only to learn that they are my age!).

Think about it this way. I have a diet posted on my fridge. This diet tells me to eat 8 specified meals per day. Multiplied by 7 days in a week, that means I have 56 meals (or feeding opportunities) per week. Now, if I can be perfect during 50 of the 56 (90%) feeding opportunities, I consider that week acceptable. Some weeks I hit my goal at 100%. Other weeks I fall somewhere between 90% - 100%. I never hit below 90% unless I'm on vacation or away for the week.

Make no mistake, hitting 50 out of 56 requires a great deal more discipline than most people have. But to suggest that someone isn't doing enough if they follow their diet to the 90% mark is just absurd.

Maki R: I hear ya. Do you believe in 'cheat days' or in 'cheat meals'?

Dr Berardi: My classic cheat meal joke/response usually goes something like this: "You know, before today I wasn't sure if the cheat meal existed but the empirical evidence located around your waistline has made me a believer."

Maki R: Uh, haha, good one John.

Dr Berardi: Smart ass.

More to the point though, before we proceed, I think we should define the concepts of cheat meal, planned overfeeding, and refeed for our discussion (of course, these are my definitions).

Cheat meal = unplanned dietary transgression in which someone eats foods not on their diet (and not considered "clean") and/or over consumes these foods. Cheat meals are usually the consequence of getting hungry and not having good food options available. An example of a cheat meal is being on the road and not having a chicken breast and vegetable dinner available so you stop at a restaurant and eat a burger, fries, and a milkshake.

Planned overfeeding = planned increase in calorie intake for a single meal. Planned over-feedings usually occur when eating maintenance intake or above since this meal will probably bump your calories up above the maintenance or habitual level of intake. Planned over-feedings can be carried out with excess amounts of "clean" foods or with other foods not considered bodybuilding friendly and are usually in place to allow time to eat "fun" foods so that athletes don't feel so deprived as well as to help with recovery. An example of a planned overfeeding is ordering 4 large pizzas for yourself and 3 friends every other Sunday afternoon when in the midst of a serious strength and power phase.

Re-feed = planned increase in calorie intake that lasts 8 - 12 hours and usually consists of a large increase in carbohydrates. Re-feeds usually occur when dieting and are planned in order to provide a brief day of psychological relief as well as a number of physiological benefits that we'll discuss later. An example of a re-feed is following a strict diet of 1500kcal 5 days per week and consuming 2500kcal of clean bodybuilding foods (the additional kcal coming mostly from carbohydrates) on the other 2 days.

Now that we have our terms defined, it should be clear that the re-feed and the planned overfeeding can be useful parts of any athlete's eating regimen as long as they don't have dramatically negative consequences on body composition. If an overfeed or re-feed sets you back too far, then you either have to reduce the intake during these meals/days or drop them altogether. Cheat meals, while some are bound to happen, don't really provide much benefit physiologically and certainly can wreak havoc psychologically.

Maki R: I've heard that you like to take advantage of the "second meal effect" during planned overfeeds. What is it, exactly?

Dr Berardi: Studies since the early '80s have demonstrated this "second meal effect." Basically, if you eat a "first meal" that's low in fat and contains a high percentage of low-glycemic index (GI) carbohydrates, resistant starch (RS), and dietary fiber (DF), your responses to your "second meal" are improved. Specifically, you'll remain satiated longer between meals and during your next meal and you'll have decreased glucose and insulin responses as well as reduced serum triglyceride (TG) levels. In fact, this is the case whether your "second" meal has a high GI or a low GI.

Now, not only is this effect valid for a low GI/high DF carbohydrate breakfast followed by a high or low GI lunch, it also operates overnight as improved glucose tolerance is seen during a high GI breakfast if you eat a low GI/high DF carbohydrate meal the night before.

In addition, although this isn't exactly a "second meal effect" recent data has also shown that post-prandial glycemia (blood glucose rise) is reduced if a piece of fruit (a small amount of fructose) is consumed prior to a meal. This probably occurs as a result of an up regulation of glycogen storage in the liver as a result of the fructose ingestion. We can call this the "fruit effect".

Maki R: Fruity!

Dr Berardi: Obviously the "second meal effect" and the "fruit effect" have implications for planned overfeeds or dietary transgressions. If you were going to have a meal that's not necessarily "bodybuilding friendly", my recommendation would be to consume a low GI/high fiber carbohydrate meal a few hours before your big feast. Then, have a piece of fruit about ½ an hour before the big binge. These dietary strategies will help control the glucose and insulin responses to your gluttonous meal as well as keeping high triglyceride levels at bay. The "second meal effect" and the "fruit effect" may also prevent you from going overboard during that "second meal".

Maki R: What time of day would be best for an overfeed?

Dr Berardi: If I had to pick a "best time", I would say the morning; perhaps after a glycogen depleting workout. For starters, glucose tolerance is slightly better during the morning hours vs. the evening hours. Furthermore, if you binge in the morning, you have all those afternoon and evening hours to workout again or to just move around and be active. So if you're concerned with body comp during your cheats, you might choose a breakfast buffet over a dinner buffet.

However, most shameless binges aren't done in a conscientious attempt to improve body composition. They're done in order to let out the restrictive reins, to partake in a little dietary debauchery. It's only reasonable and sane to do so from time to time. Therefore if you're going to cheat, do it up right. Don't get too caught up in the timing of your cheat meal. After all, who's going to order and inhale a few large pizzas at 9am or hit the Chinese buffet for breakfast? Once in a while, enjoy yourself!

Maki R: What supplements do you recommend during an overfeed?

Dr Berardi: If we're talking about a big-time overfeed here - the kind where caution is thrown to the wind and there isn't even a cursory "reefed" justification for it, there are a few tricks to minimize the damage. In addition to the nutritional strategies listed above, there are a few supplement strategies you can employ. Before I share them, however, it's important to remember that different individuals handle big meals differently. Those who respond to overfeeding by upregulating something called NEAT (non-exercise activity thermogenesis) or spontaneous physical activity, can probably get away with doing nothing but slugging down that whole pizza. In these individuals, the sympathetic nervous system gets jumpy, their thermic effect of feeding shoots up, they get more active, their thyroid hormone output increases, and the insulin response blunts some (but not all) of the lipid mobilization. With all this good stuff happening, these people might actually lose fat from an occasional binge! (Bastards!).

However, there are others who binge and just get fat.
Maki R : Oh, it sucks to be them.

Dr Berardi: Yes, you could say that. In these individuals, the responses seen above don't occur. Their sympathetic nervous systems stay constant, they don't get much of a thermic effect of feeding, they actually get sleepy, they don't get a thyroid boost, and almost all of their fat mobilization is blunted. Bad news!

Fortunately, in this latter group, certain supplements can mimic what's happening in their leaner counterparts. In order to upregulate sympathetic nervous activity, in come our good friends ephedrine and caffeine. In addition to upregulating sympathetic activity, ephedrine alone can increase the thermic effect of a meal by 30%. Finally, ephedrine and caffeine will probably increase spontaneous activity. It's just hard to sit around when you're hopped up on stimulants. While the thyroid effect may be difficult to acutely mimic, diiodothyronine might make a good choice with its rapid mechanism of action. I'm not sure if it's being sold any longer, though.

Finally, an herbal diuretic might help keep those high carb and sodium meals from swelling your ankles up so much that you need compression socks for adequate circulation and venous return.

Maki R: Is there any kind of training that would help prior to a cheat meal?

Dr Berardi: I would say that if you were going to train on a big cheat meal day, you should probably train after the cheat meal. In head to head studies, exercise done after eating leads to a greater metabolic cost than when exercise was done before eating. However, for the ideal exercise and cheating strategy, a few hours before the meal, I would perform a glycogen-depleting workout. This could be a 60-minute cardio bout or a 30-minute bout of high-intensity interval training. Then, a few hours later, I would eat the big meal. Then, as soon as I can button up my pants again, I would hit another workout. This one could be another cardio bout (if it's an "off" day) or a weight-training bout if it's my lifting day.

Maki R: Do you believe that refeeds should be administered to increase leptin levels. If so, why?

Dr Berardi: Lyle McDonald (more of a leptin expert than I'll ever be) and I just had a discussion about this with David Greenwalt and his coaching group over at leannesslifestyle.com and we both pretty much concluded that re-feeds probably won't do much for dieters in terms of leptin. For starters, leptin kicks up and down very rapidly as energy intake fluctuates. Therefore, while leptin may kick up with a 10-hour carbohydrate reefed, it's likely to drop back down just as rapidly after the reefed is over and another 10 hours of dieting are accomplished. Therefore, a dieter may just end up with a bigger positive energy balance during those 24 hours of re-feeding and subsequent return to dieting.

Since there is no data, one way or the other, illustrating what happens in dieting weight lifters when re-feeding, there's only speculation. Of course, leptin itself aside, if there were some prolonged increase in leptin, we should be able to measure the effects of this leptin increase by observing increases in metabolic rate the day after the re-feed. Unfortunately, metabolic increases as a result of acute overfeeding aren't observed a day after the overfeed (or re-feed). Remember, we're not so much interested in what's happening with leptin itself but what's happening to metabolism. Leptin doesn't impact fat loss. The effects of leptin do. And it doesn't appear that re-feeds impact metabolism for any longer than the day of the re-feed.

However, make no mistake about it. I am not saying that re-feeds are useless. In fact, I do see other good reasons (i.e. a psychological break from dieting, increased adherence, better glycogen status, more intense workouts, suppression of the catabolic hormonal cascade associated with dieting) for re-feeding besides the leptin issue. A common strategy that I use with dieting bodybuilders is to have them do a 1-day re-feed once per week. This re-feed usually contains 50% - 100% more energy than their daily intake from the other 6 days. Therefore if the bodybuilder is eating 1000 kcal per day, he/she will re-feed on 1500 - 2000 kcal. Likewise, if the bodybuilder is eating 2000 kcal per day, he/she will re-feed on 3000 - 4000 kcal. The magnitude of the re-feed is dependent on their leanness, on how low their energy intake is, and on their rate of fat loss.

In addition to this refeeding on the micro- scale, I will usually have the same bodybuilder re-feed on a macro- scale by eating 50% - 100% more energy for a full week after every 4 - 6 weeks of dieting. The frequency and size of this macro- re-feed is dependent again on the bodybuilder's leanness, on how low their energy intake is, and on their rate of fat loss. You can think of this re-feeding strategy as calorie periodization. We do it for training, why not for nutrition?

While I have just discussed my strategies for dieting bodybuilders, I use similar strategies for most of my other athletes as well, especially the ones trying to maximize their power to weight ratios. In these athletes, however, their calories are cycled according to their recovery needs. On hard days the calories are higher while on easy days the calories are lower. Re-feed weeks are used when performance starts to suffer or when fat loss slows.

 

 

POST-WORKOUT PERFECTION

Maki R: You've written a lot about post-workout nutrition. How important is it to take advantage of insulin post workout?

Dr Berardi: It depends on your goals. For starters, just so that everyone is up to speed, insulin plays important roles in both carbohydrate and amino acid uptake across the muscle cell membranes as well as acts as a key signaling molecule to stimulate protein synthesis. The insulin signaling pathway is an elegant one because once the insulin molecule binds to the cell membrane, it sets in motion two different chemical messenger systems that accomplish three goals. 1) This system increases transcription (RNA formation), 2) Increases glucose uptake into the cell, and 3) Increases the translation of the cellular RNA into protein. Although there are other pathways that stimulate translation of RNA into protein, the insulin pathway is one of the most important nutritional ones.

I hope it's clear, therefore, that insulin plays a critical role in post-workout recovery of protein balance. Now, whether or not we need a HUGE insulin burst depends on our goals. If someone is interested in maximum growth and recovery, lots of carbohydrate, protein and insulin should flood the body immediately after a workout. With respect to glycogen synthesis, once you get enough glycogen resynthesis to pass the insulin independent threshold (see below), you'll need that extra insulin to boost cellular uptake of nutrients. My research shows that when full glycogen depletion is induced, carbohydrate only drinks and carbohydrate plus protein drinks perform similarly with respect to glycogen resynthesis. However, when full glycogen depletion is not induced, drinks containing protein and carbohydrates offer much more glycogen resynthesis. I think this happens because anything will help restore glycogen when glycogen is very low (due to upregulation of glycogen synthetic enzymes and even the branching structure of the glycogen itself) but when glycogen isn't fully depleted, it takes a strong signal to drive synthesis and the insulin signal (from protein and carb drinks) is strong enough to do it. Of course, these drinks also give a better insulin response than either protein or carbs alone. Furthermore the protein is critical for flooding the muscles with amino acids for enhancing the translation of RNA into new proteins.

On the other hand, if someone is interested in getting as ripped as possible, topped off glycogen isn't a goal. Since a huge insulin response might be counterproductive to fat loss and therefore a simple amino acid flooding may be all that's needed. But before I move on I have to say that I often go back and forth on this one in my mind (that's why I say "might" above) especially in the case of very low carb diets because a big post-exercise boost in insulin (as a result of a carb plus protein drink) may rapidly promote recovery and muscle preservation as well as rapidly bring blood glucose down and bring you right back into ketosis. Furthermore, studies show that the body shifts toward fat oxidation during the post exercise period even in the presence of high insulin. This means that even in the presence of hyperinsulinemia, lots of fat is still burned, leaving all the carbs to be stored preferentially.

So I'm not totally sure which is a better strategy for dieters. Usually I just try the carbohydrate and protein drinks in all trainees during the post exercise period and if there is a noticeable stagnation in the rate of fat loss (at very low body fat percentages), I have them drop the carbs and use protein only to minimize the insulin response while still providing amino acids.

Maki R: If one were insulin resistant, would consuming a larger amount of whey protein minus carbohydrates suffice for post workout?

Dr Berardi: Again, it depends on their goals.

Maki R: Soooo...

Dr Berardi: Hold your horses.

In this situation it also depends on what we mean by insulin resistant. If we're talking clinically measured insulin resistance, the individual is probably in need of serious weight loss (because obesity and heart disease are characteristic of true insulin resistant) anyway so in their case, the latter suggestion of just amino acids is probably warranted. Interestingly, type 2 diabetics (people with real insulin resistance) see an equal insulin response whether they ingest protein or carbohydrate - so perhaps a smaller protein only drink is warranted.

While I'm no expert on diabetes, it is important to note that insulin resistance is characterized by a larger insulin release in response to a normal carbohydrate or protein load. In other words, because muscle and fat cells are partially resistant to the effects of insulin, a whole lot of insulin needs to be released for it to do its job. Fortunately for diabetics, exercise can dramatically increase the sensitivity of the muscles for glucose uptake and overall insulin sensitivity. Therefore the postworkout period is one time where diabetics are more normal.

With your question, though, I suspect that you are more interested in those weightlifters or athletes who think that a slight propensity to gain more fat on a higher carb diet means that they are insulin resistant. In this case, it's become clear to me that a lot of athletes have just enough knowledge to be dangerous. Somehow they think that they can diagnose their own insulin and glucose tolerance by how they "feel" after a carb meal. That's nonsense. Therefore if someone suspects some sort of carbohydrate or insulin problem, they need to get their doc to check them out by doing a 3-hour oral glucose tolerance test complete with insulin measures as well as blood glucose measures. That's the only way to be sure if there is a legitimate problem or if they are just eating poorly and that's why they're too fat.

However, with that said, it's important to note that insulin resistance is a sliding scale. You don't need to have full-blown diabetes to be on the road to it. If your blood work shows some impairment in glucose and insulin tolerance, you need to start managing your overall nutritional plan with a higher protein, lower carbohydrate (low GI carb) diet. In addition, supplements like fish oil and rALA can help out too.

In this situation, with respect to post-workout nutrition, the great thing is that the person with borderline insulin resistance can do the same thing as someone with normal insulin tolerance. Here's why. First of all, if someone is insulin resistant, they need more insulin to do the same job (in terms of lowering blood glucose). Therefore the synergistic insulin release associated with protein and carbohydrate consumption should drive insulin high enough to do its job with respect to stimulating protein synthesis and increasing glycogen storage. Interestingly, since recent data has demonstrated that there are insulin dependent and independent stages of glycogen recovery during the post workout period, it's important that insulin resistant people get their carbohydrates during the early stages of recovery when glycogen recovery is insulin independent. You see, in any given muscle fiber, if glycogen concentrations are low enough (below 35mmol/L for anyone who cares), even in the presence of low insulin concentrations, glycogen resynthesis is maximal when enough carbohydrate is around. Therefore after exercise, especially high intensity strength exercise (where type II fibers may be very depleted) or high intensity aerobic exercise (where type I fibers may be very depleted) the provision of carbohydrate can assist with glycogen recovery during the insulin independent phase of glycogen resynthesis. During this phase of glycogen resynthesis, even type 2 diabetics have normal glycogen recovery. However, once above the glycogen threshold, during the insulin dependant phase, the synergistic insulin response associated with protein and carbs can help pack those fibers full of glycogen again.

So although it's customary to prescribe low carb (especially low GI) diets for those with some degree of insulin resistance, the post exercise period is the one time of the day when insulin tolerance is much better than the rest of the day. So use this time to promote growth and recovery. You can use the rest of the day to avoid carbs and take supplements to improve glucose and insulin tolerance.

Maki R: Alright, last question, I swear. How effective is ALA or R-LA in terms of being an effective nutrient partitioner during the post-workout period.

Dr Berardi: Recent data is demonstrating that the r- isomer of ALA is a very effective nutrient partitioner in terms of reducing blood glucose response to a meal (it does this by increasing glucose disposal into target tissues). While I think it is a good idea to consume ALA if your insulin sensitivity is poor (again as diagnosed by a 3 hour blood glucose tolerance test), if your insulin sensitivity is normal to good, it's probably unnecessary. Furthermore, as indicated above, the post-workout period is marked by excellent insulin sensitivity. Therefore ALA will probably have very little additional effect during the post workout period. It's a matter of redundant systems. It's kind of like pushing your gas pedal to the floor. When the car is going as fast as it can go, another gas pedal isn't going to do anything but waste gas.

Maki R: Thanks for taking the time to share some of your knowledge with us, John.

Dr Berardi: No problem, my pleasure.

Maki R: For more information about Dr Berardi, Science Link team or their services, please visit www.johnberardi.com. Also, be sure to check out www.johnberardi.com/seminars right now. Here you will find out how to purchase and/or attend one of Dr Berardi's dynamic and information-packed seminars.