December 2010: Interview with Jeff Volek, PHD (Part 1)

by on December 24, 2010

JOHN: I am very excited about this month’s expert interview as we have the one and only Jeff Volek. Jeff wrote one of my favorite books called the “TNT Diet”. Pick p a copy if you want to learn more about low carb diets, it’s an awesome read. Also, if you have already read my review of the NSCA Nutritional Symposium, you’ll understand why this is so exciting to me. Jeff has much he can teach us all. So Jeff, first of all, please tell everybody about yourself. Don’t be humble. Also, what are the things that you are most passionate about in terms of nutrition?

VOLEK: I started out in school studying dietetics and completed my master’s and doctoral work at Penn State University in Exercise Physiology. I have been a professor and researcher for 11 years. I’m currently an associate professor in the Department of Kinesiology at the University of Connecticut. I have managed to accumulate over 200 scientific publications mainly because I have surrounded myself with extremely talented and productive people. I have published in a variety of areas but the majority of studies dealt with issues in sports nutrition and nutritional aspects of obesity, diabetes and heart disease. So my interests in nutrition span the gamete from using cutting edge techniques to enhance athletic performance to using nutrition to combat obesity and chronic disease. In graduate school as a master’s student I did some of the seminal work on creatine supplementation and its effects on resistance exercise and adaptations to resistance training. This was at a time when creatine supplementation was just becoming popular in the early 90s. I published a few key papers including a comprehensive review and quickly became one of the ‘experts’ on creatine supplementation. That was empowering and gave me a lot of confidence as a researcher. I have not done a lot of recent work with creatine. We know it works and I moved on to other things. My team now is doing a lot of work with carnitine and whey protein, and we have examined many different dietary supplements over the last decade.

But my real passion, which has been the case since I started graduate school nearly 20 years ago, is studying how humans adapt to carbohydrate restriction. I have done over a dozen experiments examining how low carbohydrate diets affect a broad spectrum of physiologic adaptations in different groups including men and women ranging from young to old, thin to obese, sick to healthy, sedentary to active. My team has learned a lot about how these diets impact health and performance. Let’s suffice it to say the 4 decade obsession with low fat diets has been unfortunate and we are suffering the consequences in an out of control obesity and diabetes epidemic. The good news is restricting carbohydrate is a powerful weapon to combat these problems. Even when it comes to sports nutrition there has been an overemphasis on the obligate nature of carbohydrate for athletes. A strong case can actually be made that lower carbohydrate intake or slow release forms of carbohydrate are preferred for active individuals seeking improvements in metabolic health and performance. In brief, the things I’m most passionate about are the role of carbohydrate in the diet for general health and sports nutrition.

JOHN: Thank you Jeff. Now before we get into the interview, I have to ask if you are some geeky researcher that has never seen the inside of a weight room, or do you know the pain and pleasure of an all out set of squats?

VOLEK: First, I kind of like geeks, but yes I have seen the inside of a few weight rooms. In fact, there was a good chunk of my life when you might say I was obsessed with the iron. It took me awhile to catch my stride mainly because my main source of training information in high school and college was Muscle & Fitness. Being an overachieving passion zealot trying to follow championship bodybuilder programs was a great formula for being constantly inflamed and overtrained, but not so good for increasing strength. It wasn’t until I started graduate school and began to understand the science of strength training that I changed my routine. I also met a non-traditional (aka older) graduate student in the laboratory who was a former collegiate strength coach and trainer of elite strong men who took me under his wing. Having a coach gave me the confidence and tools to compete in powerlifting. I had a blast and did OK. Nothing to out of the ordinary for a decent powerlifter but managed to squat and deadlift well over 3x body weight in the 82.5 kg class which is probably better than the average geeky researcher.

JOHN: Very impressive! Let’s talk creatine. We all know that it works. Can you shed some light on the following questions?

Do you believe a loading phase is necessary? The protocols I have seen were 20 grams in 4 divided doses over 5 days, followed by 5 grams a day after. What kind of protocol do you recommend?

VOLEK: That’s a pretty good loading regimen. Most of the loading will actually occurs on the first and second day and after that your just topping off the tank. Average increases in muscle creatine after 5 days are about 20-25% although there is quite a bit of variability among individuals. If you don’t want to load, you can achieve the same degree of muscle creatine loading with a lower dose but it takes longer.

JOHN: What do you think is the best time to take it? Pre or intra or post training?

VOLEK: I don’t think timing around a workout is a big factor in creatine uptake, although it has not been adequately studied. One might make a case for increased blood flow during exercise as mechanism to deliver greater amounts of creatine to active muscles, but that is theoretical. All the early studies, and most of the studies for that matter that have measured muscle creatine, used a protocol that involved taking multiple doses per day…usually 5 grams at a time with no reference to ingesting it around a workout. Five grams was selected as a dose because it elicited a peak blood level of creatine that was about 10-fold higher than basal. That level is required to cause the muscle to take up creatine. The half-life is relatively short so taking multiple 5 gram doses is logical to keep a gradient for muscle creatine uptake over the day.

JOHN: What do you think of all these new fancy creatine formulas? Are they really better than old school monohydrate?

VOLEK: The benefits of creatine supplementation on exercise performance are directly related to the increase in muscle creatine. I have not seen a creatine product that increases muscle creatine to a greater extent than creatine monohydrate.

JOHN: Do you think creatine can affect someone’s lab work, specifically their creatinine levels, and other measures of kidney stress?

VOLEK: Creatine supplementation is very safe and not associated with abnormal lab values. Creatinine, the breakdown product of creatine, will increase slightly but remains within normal levels. Creatinine is spontaneously (nonenzymatically) formed at a constant rate from muscle creatine and phosphocreatine, and thus if you have more creatine in your muscles then it makes sense that blood and urine creatinine levels would increase as well. This is a physiologic increase, not a pathological response indicating renal problems.

JOHN: Do you take anything with it in order to get a synergistic effect, such as Alpha Lipoic Acid or Waxy Maize starch?

VOLEK: Again, there is not a strong literature base to support synergistic effects of other substances with the exception of fast acting carbs to spike insulin. Although I advise against using this tactic on the basis of a high cost/benefit ratio. The cost of spiking insulin repeatedly is to wreak havoc with carbohydrate and fat metabolism, especially the latter. Insulin is a potent blocker of fat breakdown and fat burning. Continually pounding the pancreas has many other adverse health implications as well. And the benefit of spiking insulin on creatine uptake is rather small.

JOHN: Do you think that a post workout window exists or is it smoke and mirrors? If yes, is it more for carb uptake, better protein synthesis or both?

VOLEK: The post workout period is extraordinarily complex involving an inter-related sequence of biochemical events not limited to simply carb uptake and protein synthesis, although researchers have focused on these physiologic processes. Exercise is also a strong perturbator of inflammatory, oxidative stress, and immune processes. All these processes determine how fast and complete recovery takes place. Is it a window? I’d say that is an oversimplification. Each process has a unique temporal timeline where it may or may not be more sensitive to nutritional input. At this point I must apologize for not answering your question directly, but I think Einstein had it right when he said “Make everything as simple as possible, but not simpler”. We tend to make things too simple in nutrition, and in the process we make inappropriate interpretations and lose sight of the big picture. For example the majority of research on the post exercise period has focused on glycogen synthesis, and for sure there is a rapid phase of glycogen synthesis for an hour or 2 after exercise after which it slows down. This does not mean however you should be shoveling in as many fast acting carbs as humanly possible in order to maximize glycogen synthesis. Maybe we should be asking whether glycogen synthesis should be a priority? What about the effect on lipid metabolism. If you try to optimize glycogen synthesis you will have the undesirable side effect of blocking access to fat, shutting down fat oxidation, and this can have far reaching effects on performance and health.

JOHN: I think the concern that people have is two-fold, number one they feel that they have to refill glycogen or they will lose size, strength, and the ability to pound through hard training sessions. Secondly, they feel that they will get catabolic without the carbs. What is your thoughts around those two questions?

VOLEK: There are several potential factors to consider here. For one, some people confuse the water retention associated with carbohydrate consumption with muscle mass. You can exercise intensely while on a low carbohydrate diet and maintain muscle mass during weight loss, and even build muscle. There is a misconception that glycogen levels are completely depleted on a very low carbohydrate diet, but even when carbs are very low muscle glycogen levels remain about half full. This is because the body can make glucose from other substances such as lactate or glycerol that can be used to resynthesize glycogen. If you follow a well formulated very low carbohydrate diet with attention to mineral balance there is not a catabolic stimulus. In fact the adaptations in fat oxidation are profound and this actually protects the body from catabolizing protein.

JOHN: Many people think that carbs are the most preferred form of energy? Any response to that?

VOLEK: Again there are misconceptions here that get perpetuated because of a lack of understanding of the metabolic details. What is true is that carbs are burned first, that is on the hierarchy of fuel choices they get selectively oxidized. So if carbs and fat are both available, the body will choose to burn the carbs first and store the fat. Why is this? It probably has to do with the fact that we cannot store carbohydrate in large amounts. We can pack about 100 grams in the liver and perhaps another 300-400 in skeletal muscles. That is about 2000 kcal worth of carbohydrate fuel. Compare to the total amount of fat available in adipose tissue, that is a drop in the bucket. So since the body cannot store carbs well, it tends to oxidize them first and if carbs are consumed in excess of the body’s ability to burn them they get converted to fat.

JOHN: What about fat consumption post workout? Does post workout fat do anything positive? Since it slows down the entry of glucose into the blood stream, should that matter to us? I guess that depends on if you are trying to elicit the “insulin spike” huh?

VOLEK: I have to admit I don’t have the answer to that question, mainly because there has been very little attempt to study the role of dietary fat in the post-exercise period. By far the majority of work has focused on carbohydrate and protein supplementation, alone and in combination. The number one priority in my opinion is to consume some form of essential amino acids containing ideally 2-4 grams of leucine. If you don’t consume any source of protein, you are in a negative protein balance which is hard to believe is good for recovery. The role of carbohydrate post-exercise depends what you are trying to do. Generally speaking carbs are OK if you are healthy and weight stable but I’m a big proponent of using slow absorbing forms. However, if you are trying to improve metabolic health and/or attempting to lose weight and body fat, then carbs are counter-productive so use them judiciously if at all. In respect to fat, my guess would be it is more important if you are following a very low carbohydrate diet. In the keto-adapted state, muscle triglycerides will be used for energy during exercise and ingesting fat would be expected to be needed to help replenish those stores. Fat may have other positive effects during recovery, but again there is a dearth of studies addressing the importance of fat in the post-exercise period.

JOHN: So given what you know via your research, please share with us your finding on the benefits of fat intake. I don’t necessarily mean post-workout, I mean just in general, and I don’t mean just EFA’s. So what do you feel comfortable saying the benefits are for:

Saturated Fat:

VOLEK: SFA are important fuels especially when consuming a low carbohydrate diet, and they are important for flavor in foods which becomes important when we talk about long-term sustainability of low carbohydrate diets. The atherogenic nature of saturated fat has been way over done. The evidence linking saturated fat to disease is weak at best and whatever truth there is to this common belief it would likely only manifest in the presence of high carbohydrate intake.


VOLEK: MUFA are also great fuels. In fact most of the fatty acids that make up triglycerides in our fat cells are oleic acid, the most prevalent MUFA and the predominant fatty acid in olive oil and canola oil. MUFA and SFA should make up the bulk of fat on a low carbohydrate diet because they are better fuels than PUFA.


VOLEK: These are the essential fatty acids and they come in two forms, n-6 and n-3. It is important to balance intake because they compete for elongation into longer chain PUFA (>20 carbons) that serve as important substrates for eicosanoids that exert widespread effects in the body. Traditional diets are much higher in n-6 (think soy bean, corn and safflower oils) whereas n-3 intake is low. The optimal ratio may be close to 1-1 in the diet, but current intakes are probably closer to 10 to 1 (n-6 to n-3).

Stay tuned for part II next month!