Refocusing My Efforts – Subscribe to My Newsletter

Since I launched Science for Fitness, the regularity of my posts has been fairly frequent and over the past several months new posts were going live nearly every week. This is a lot of content and I’ve been thinking about how much is too much. I know some of my readers have had a hard time keeping up, so that’s one issue. Another issue is that the posts take time, especially if they are to be accurate and of good quality (and I don’t want to post anything that isn’t). The risk of losing quality when you ramp up the quantity of your material was impressed upon me recently when I came across a review of the Paleo literature. My previous post on this site addressed the problems with this review, so if you haven’t read it, check it out. I don’t want to succumb to the kind of problems this review had.

Another consideration is that I want to refocus my efforts a bit. There is more to Science for Fitness than just my articles. There are of course the clients I train that need my attention, but I also need to spend more time working on seminars that I will be giving, as well as on a book that I am trying to put together. What this means is that the frequency of posts to will drop a bit. You will still see at least 1-2 posts per month, but posting dates will be variable. This means that the best way to keep track of what’s going on is to sign up for my monthly newsletter (on my homepage). This will go out at the beginning of each month and recap everything from the month prior, so you won’t miss a beat.

Thanks for reading,

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Quality vs Quantity: A Paleo Review That Doesn’t Quite Add Up

Not too long ago I came across Led by Dr. Greger, the organization’s goal is to “present you and your doctor with the results of the latest in peer-reviewed nutrition and health research, presented in a way that is easy to understand.” We certainly need more people out there doing this. The videos the organization puts out are very slick (as you will see below in a moment) and it’s a format I’ve been considering adopting for quite some time. However, I soon noticed that videos were being released every other day and they were each discussing the primary literature (scientific studies). It takes time to read and interpret scientific studies. I was puzzled. And then I came across one of the organization’s videos on Paleo research. The video is below, give it a watch:

The video threw me for a loop because it was espousing things I had understood to be different. In short, I felt the data wasn’t being interpreted properly. This happens all the time in the popular media when they summarize science, but here a doctor was interpreting (or at least speaking the interpretation) and citing the actual studies. So, I went through the article piece by piece and here is what I found:

  • At 1:10: Here Holt et al., 1997 is referenced and in the video’s bar graph a serving of meat was shown to increase insulin the most. But this isn’t what the study showed. As seen in Table 4 of the study, the beef insulin came in at 7910 pmol(min/L) and the apple came in at 8919 pmol(min/L). The study showed the apple raised insulin more than the beef.
  • At 1:37: Here a graph is shown indicating that beef causes the same insulin spike as pure sugar (glucose). But the study isn’t cited, so I don’t know where it comes from. But if we look back at the Rabinowitz et al., 1966 paper which is cited in the very beginning of the video, we see a lot of data on this – data that actually looks at the insulin levels after various times post-ingestion. This data does not indicate a similar insulin spike between meat and glucose. In all the graphs shown in Figures 4&5, insulin levels during the 1st two hours after ingestion are greater for glucose than meat (click to see an example here).
  • At 3:37: Bueno et al., 2013 is cited comparing a low-carb diet to a low-fat diet is cited to indicated that dropping carbs does not lower insulin. But this is a Meta Analysis study. It is collating data from many studies and the “low-fat” groups are not necessarily high carb diets and the types of carbohydrates consumed is also not accounted for.
  • At 4:00: The Smith et al., 2014 study is cited to close the video. In the video we are told that the paleo diet worsened LDL cholestrol (“bad cholesterol”) and reduced HDL (“good cholesterol”) in individuals who were exercising (CrossFit). The narrative has now, only at the very end, switched away from insulin, to cholesterol to address an interaction effect with exercise. I’ve posted numerous times about how the cholesterol literature is riddled with problems, so I won’t go into it again. But I will note that this study is problematic for another big reason – the participants didn’t strictly follow a Paleo diet as indicated in the study’s methods. For a write-up on this, check out this blog post by The Russells.

As you can see, the above video is problematic. There is some interesting data in the video, such as the fact that Holt et al., 1997 saw white pasta spike insulin less than meat, and the fact that vegetarians tend to have lower insulin levels (despite eating more carbs than non-vegetarians), but there are many key points that just don’t add up and the viewer is given the impression that the “case is closed” when we are really still putting the pieces together.

I posted several of my above-mentioned corrections to the video in the comments thread (because of course maybe I was missing something), but didn’t get any response. I then suspected that Dr. Greger wasn’t reading all the social media himself and that he probably wasn’t reading the actual studies himself either. It made sense, because for me to really pick apart one study and make sure I get it right, it takes several hours. In this video alone, there were more than 5. He must have been using a team to go through the studies.

It turns out I was right. Earlier this month February Dr. Greger put out a call for “fact checkers” to work freelance for the organization. It’s also revealing that he tested applicants on their fact-checking skills and during the first round everyone was under 80% (out of 100%). has a great mission statement, and many of their videos are great, but interpreting scientific studies is hard, even for the scientists. It’s very demanding and requires a lot of training, thought and focus.

As scientists and doctors we have to remember this and not get caught up in trying to give the public large quantities of information covering all topics all the time. Quality suffers when quantity goes up. Not to mention, our understanding of science (e.g., nutrition, health, fitness), does not change every time a new study comes out. It’s an aggregate of studies over time, shown to be repeatable, that have meaning and putting this message together requires quite an enormous investment of thoughtful consideration.

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Scientists Need to Give Lectures More Like This

Starting Strength Coach Association Series: Exercise Science Presentation 2014, Part II from Starting Strength on Vimeo.

It’s a rare occasion that I see a scientific lecture that excites me and leaves me thoroughly satisfied in the end. The above video is one of those rare occasions. In the above video Starting Strength Coach Dr. Sullivan gives a review of literature on the topic of concurrent training and exercise interference. That is, does endurance training interfere with strength training? His answer to this question is the least interesting part of this lecture. In my opinion, the video excels for a number of other reasons:

  • Dr. Sullivan references specific studies
  • The studies are given a level of scrutiny that matches my own (which is quite rare)
  • Discussion of limitations and weaknesses is bold, colorful, and up-front.

As a scientist I spent nearly two decades attending conferences and listening to lectures. Many of those lectures were topical reviews like Dr. Sullivan’s and yet not one of them was like his. The vast majority of the time, scientists review literature in a positive light. Supporting studies or pieces of data within the studies are chosen and then simply referenced with virtually no consideration of the study as a whole nor the limitations of the study. It’s as if researchers at conferences turn a blind eye to limitations or maybe they just want to be everybody’s friend. Or maybe a bit of both. Yes, Dr. Sullivan’s tone might be a bit too harsh for a conventional scientific meeting, but it was a breath of fresh air for me, and this is a clear indication that a better balance is needed.

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Low-Bar vs High-Bar Squat

Image from Starting Strength, Rippetoe and Kilgore

I’ve been wanting to write about low-bar and high-bar squats for quite some time and now that I am programming for a large number of individuals, it seems like the time is right. I’ve gotten some questions from my members at CrossFit Solace and they’ve also forwarded me the writings and thoughts of others. Let me begin by saying this topic is not new; there have been many articles written on it, However, I have a few points that I’ve not seen mentioned elsewhere and perhaps more importantly, how I approach the issue is, I think, different.

The Difference in the Squats: There are 3 squats that come into play in this argument: the low-bar squat (pictured above right), the high-bar squat (pictured above middle), and the front squat (above left). The front squat is the squat position needed to rack a bar on your shoulders to complete a Clean in the sport of Weightlifting. Standing up from rock bottom in this vertical torso position emphasizes glute and quadriceps activation. The high-bar squat has the bar resting on the shoulders. The torso is still largely upright and standing up from rock bottom in this position is also largely glute and quadriceps driven. The low-bar squat as you can see above has the hip angle much more closed and the finish position is taught with hip crease just below parallel. The difference here is notable as more leg muscles are being worked with this version of the squat (quadriceps, glutes, hamstrings, adductors, abductors). I don’t really know of anyone that disputes this difference and anyone who has never low-bar squatted can verify for themselves, by seeing where they are sore the day after they first try it.

The Weightlifting Argument: First and foremost, the low-bar vs high-bar argument arose in the context of Weightlifting movements. So let’s stay within this context for a moment. This argument concerns which is “better,” the low-bar squat or the high-bar squat. The front squat is generally left out of the argument because it is a movement that is part of the sport of Weightlifting. You have to do this movement if you want to perform Cleans. So, training it is by definition useful. But for the other versions, you generally only see high-bar squats being used. People often ask why Weightlifting coaches don’t use the low-bar squat. Greg Everett was asked this question and he responded with, “That’s like asking why baseball players don’t use footballs.” In short, he’s saying that the low-bar squat does not have carry over to the functionality of Weightlifting. But this isn’t entirely true:

  • The position of the bar and the back angle for a high-bar squat is not the same as a front squat. It is more similar to a front squat than a low-bar squat, yes, but it is not the same. There is a difference. So, in terms of form, saying the high-bar carries over and the low-bar does not, is a matter of drawing a line. You are of course welcome to do this, but the differences are not black and white.
  • A low-bar squat does in fact have carry over to weightlifting in that is develops strength. Strength is a general adaptation. Just being stronger will make you better at Weightlifting. I have seen this time and time again with my clients and myself. For example, after just a month of low-bar squatting I PR’d my Clean and front squat. Perhaps you can say my PRs would have been better if I high-bar squatted instead, but you can’t say the low-bar had no carry over. It did. This point is an important one. It goes beyond just squatting. Years ago, after 2 months of only upper body strength training (with no technical work), I PR’d my Snatch.
  • The low-bar squat does a better job of strengthening your lower back through isometric contraction than the high-bar does. This is a particularly important adaptation for Weightlifting as most lifters try their best to keep their shoulders over the bar during the first pull. This loads your hamstrings and requires a very strong lower back. Again, I am not saying you can’t train this other ways (heavy Clean pulls work well for this too). I’m just saying that for this adaptation, low-bar squats are more effective than high-bar.
  • One thing I found when returning to performing Cleans after low-bar squatting, was that my legs felt stronger in the transition out of the bottom of the squat to above parallel – they didn’t cave in as much. Your hamstrings, abductors, and adductors are largely “turned off” in the bottom of the low-bar and front squat (or Clean) and they need to kick in at the transition. You can see this by watching a lot of lifters Clean heavy weights. In the video of Ilya below, you’ll see his knees cave in a bit (at about 0:02):

    This is purely personal observation, but I had less knee cave-in at even heavier weights after low-bar squatting. I’m not saying low-bar squatting will prevent this knee movement in Weightlifting, but I suspect it is a very efficient way to strengthen/improve this transition position in the Clean, at least for less advanced athletes.

The Weightlifting Argument Wrap-Up: As you can see, I in no way tried to discredit the high-bar squat. It’s a great exercise and more similar to the front squat than the low-bar, but the Weightlifting argument really needs to be about strength. It can’t be about technique carry over, because if you are training Weightlifting you will always still be training the front squat and the Clean. You will have plenty of technique work for that upright vertical torso position. And along these lines, there are Weightlifting coaches, like Mike Burgener, who don’t use either the low-bar or high-bar squat – they just use front squats and Clean pulls. So, if you’re incorporating any squat that is not a front squat, you’re really doing so to build strength. Strength is paramount in Weightlifting, and low-bar squats build strength exceedingly well. Might high-bar squats do it better, possibly, but that’s a harder argument to make as so few Weightlifters have low-bar squats as a staple of their routine.

The CrossFit Argument: This section is why I really wanted to write this article. I think the major problem with the low-bar vs high-bar argument is that it has morphed from being just an argument about training Weightlifters to an argument for and against the lift regardless of the situation. More specifically, you are now seeing CrossFit coaches saying the low-bar squat is not appropriate because it does not carry over to the functionality of Weightlifting. But a CrossFit coach is not a Weightlifting coach. In response to this, writers have said, yes, but there are so many Weightlifting movements in CrossFit, that you should focus on the lifts that carry over best to these movements. By analogy, if you don’t train with emphasis for this carry over, you’re leaving a lot on the table. Well, I don’t see this as entirely accurate. My points in the Weightlifting argument above are relevant in response, but here are a few other key points:

  • CrossFit having a lot of Weightlifting is relative. It certainly can. If you follow Outlaw CrossFit, then there will be a ton of Weightlifting. Outlaw has basically morphed into a Weightlifting program where its followers also do some CrossFit (see Outlaw Way). However, performing Weightlifting every day is not CrossFit as it was originally designed, nor is it how it is taught and programmed now by HQ. Don’t get me wrong, I’m a huge fan of Outlaw and I program a lot more Weightlifting than traditional CrossFit would suggest. But this is because the lifts are very technical and require lots of practice (and because they are fun). It is not because CrossFit is now largely Weightlifting.
  • A CrossFit coach saying a low-bar squat has no carry over to Weightlifting is an even weaker argument. It fails on the general strength point I noted above in the previous section. The hardest thing for CrossFitters to develop, and what takes the longest to achieve, is strength. If they can get stronger, it will carry over to many of the CrossFit movements and their overall performance. Strength aside, the carry over argument fails because we don’t always use perfect carry over in CrossFit. If we wanted perfect carry over we would never let people learn handstand push-ups against a wall first as this doesn’t have good carry over to a proper, stacked freestanding handstand/handstand walk. Different motor patterns have to be trained for these, and they are. But that is what CrossFit is all about. It’s about being very good at many different things. It’s about being a master of many different movement patterns. Saying you won’t train the low-bar squat because the movement pattern is different than a Clean, is like saying you won’t train the Push Press because the movement pattern is different than the Split Jerk. But of course, most coaches in fact do train both.
  • As a CrossFit Coach you are going to have a wide mix of clients with varying skill and strength levels. I have found that the “knees caving in” phenomenon at the bottom of the squat can be a result of very weak abductors and adductors. Cuing “knees out”, often isn’t enough. I’ve found that even in relatively strong squatters, this can be a problem and that cycling in some low-bar squatting solves the problem nicely.
  • High-bar squatting actually leaves a fair bit on the table for a CrossFitter. In particular, hamstring strength. Ask a typical CrossFitter to perform a Glute Ham Raise with no bend in their hip. Odds are they won’t be able to do it. Low-bar squats help build your hamstring strength.
  • As a CrossFit Coach you are going to have clients that will want to be competitive and compete in either the Open or higher levels. As soon as this comes into play, they are going to want to be as efficient as possible in performing movements such as the squat. A full depth squat as trained in the front squat or high-bar squat is no longer advantageous when the workout requires air squats or wall balls at high repetitions for time. The range of motion requirement is hip crease below parallel, not all the way down, and this will get the reps completed faster. When does this movement pattern get trained? Almost never, and it’s hard to hit just right if you’ve never trained it. But if you have experience low-bar squatting, you will know where to stop intuitively.

The CrossFit Argument Wrap-Up: The CrossFit argument against low-bar squatting is a very weak one. By definition CrossFitters should be above average in a wide array of skill sets and motor patterns. This is the essence of CrossFit. Why the argument even arises is because CrossFit Coaches are doubling as Weightlifting Coaches these days. I think this has been great for CrossFit and the sport of Weightlifting (I am a Weightlifting Coach as well as a CrossFit coach). But not every CrossFitter wants to be a Weightlifter. So, if low-bar squats are being programmed for CrossFit in addition to other key movements (e.g., Clean, front squat and possibly low-bar squats), you’re getting the best of all worlds. And this is why I rotate low-bar squats into my programming. In a Barbell Club class, which focuses solely on Weightlifting, the decision to use low-bar squats is more complicated for the reasons discussed above in the Weightlifting section. For our class, I do not program in low-bar squats (or any other pure strength developer) as we offer a separate strength class and the time is better spent training Weightlifting technique. But again, this decision depends on your class structure and demographic.

So, next time this argument arises, you have a different perspective on why low-bar squats might be incorporated in training. And most importantly, you will have an appreciation for how the argument against low-bar squats must be placed in a specific context. Who you are training, (age, experience, individual movement patterns/deficiencies) and the goal of the training (strength, technique, etc.) must be considered. There is no one-size fits all answer to training.

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10 Science-Backed Tips to Help Prevent Hip Fractures

My latest article appears as a guest post on The article presents 10 tips that may help prevent hip fracture and gives scientific studies in support of each. Click here to read the article.

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The Importance of Proper Dosing

When I review scientific studies on this website, I always end my review with a “limitations” section. The section is a list of factors or issues that may limit the reproducibility of the study (i.e., self-reporting for food intake), limit who the study is relevant to (e.g., men, women), and so on. When dealing with studies of chemical compounds or drugs, dosing is a very important variable and must be taken into account. I haven’t reviewed a lot of studies where this was an issue, but there were two instances I wanted to point out as they slipped under the radar.

The first pertains to my previous post, “No, a Glass of Wine Does not Equal 1 Hour of Exercise.” This study was overinterpreted by the media, but in my discussion, I left dosing off my limitations list. One of my readers noted that the dose of resveratrol (the compound of interest found in wine) administered to the rats was 4g/kg of body weight. If we take the average rat to weight 300 g (.3kg), then rats were getting about 1.2g of resveratrol. For humans, if they drink a medium sized glass of wine, they are consuming about 0.175 liters of wine. If we are generous and say that the amount of resveratrol in a liter of wine is 7 mg (0.007 g), then one glass of wine gives a human a dose of 1.2x10e-6 (or 0.0000012 g). You can see here that by drinking a glass of wine you are getting nowhere near the amount of resveratrol the rats were getting. In comparison to a human drinking a glass of wine, the rats were overdosed. This is not a fair comparison.

The other instance arose in the article I wrote for entitled, “5 Supplements That Science Recommends for Fitness.” In the article I noted that science backed the use of caffeine to improve performance, which it does. But the original version of the post didn’t have any mention of dosing. Of course the articles I cited in the article give the dosings used (3-4mg/kg body weight), but most readers likely wouldn’t look for that. This equates to around 320 mg for a 180lb person. Most caffeine supplements on the market are pills of 300 mg or less and suggest taking only 1 tablet, so this is in line with the studies. But caffeine is a stimulant. What if you took more than this amount? Well, it turns out this is exactly what a number of teenagers have been doing and a number of them have died. It appears they were using caffeine as a supplement, but taking it in powdered form. In this form, measurement was up to them and made in teaspoons – and 1 teaspoon is about 5 grams. This is over 15 times the amount of caffeine adults were given in the studies I cited. You can see how this might be a recipe for disaster.

The limitations of studies are extremely important. Virtually every study has one or more limitations that make the findings impossible to directly apply to human health and fitness without additional studies to support their claims. Dosing is a common limitation in studies of chemical compounds and supplements, so keep this in mind the next time you read a headline that seems too good to be true…it probably is.

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Understanding the Impact of Epigenetics (Podcast)

I was recently part of a Breaking Muscle panel discussion on Epigenetics in health and fitness. To listen to the podcast click here.

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5 Supplements That Science Recommends for Fitness

I was asked to write an article for on fitness supplements. There are thousands of fitness supplements out there, but the number with scientific support for their effectiveness is far less. I narrowed my list down to 5 supplements that have scientific studies (in humans) supporting their use. You can check out the article here:
5 Supplements That Science Recommends for Fitness

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Removing Personal Bias – A Quiz for My Readers

From Schoenfeld et al., 2014

Today I came across a summary article reviewing a scientific study on intermittent fasting (skipping one or more meals to promote fat loss). The original article can be read here. The summary article was interesting for two reasons. First, the writer of the article was using the study to “debunk” intermittent fasting and second, the writer brought into play the concept of Bayesian Inference as a major reason why our personal bias can get out of hand.

This is a perfect opportunity for my readers to test their ability to interpret scientific studies and the way those studies are portrayed in the media. Take a few minutes and read the original summary article here. Once you’ve read it, continue reading here…

Now that you’ve read the summary article, what did you think? More specifically:

Quiz Question #1: Do you feel the article satisfies the scientific requirements for “debunking” a theory (i.e., intermittent fasting)? Why or why not?

Quiz Question #2: Do we have to stop using Bayesian Inference in order to achieve unbiased results?

Here is my take on the answers to the above questions:

Answer to #1: This is the easier of the two questions, if you’ve been reading my critiques to scientific studies and have read my Science 101 page, one of the major points is that you cannot take a single study and say “this is how it is.” Science rests on multiple-studies verifying an existing hypothesis or theory. It is the reproducibility of a phenomenon that makes us more comfortable in saying the phenomenon exists. So, contrary to what the summary article says, one study on intermittent fasting cannot rebuke the entire phenomenon. If you’ve been reading my articles you also have a good idea of why one study cannot be used. This is because all studies have limitations. The summary article in question did not highlight any of the study’s limitations, but there were several: the study period was only a month, the fasted group got a protein shake right after their training, the fasting was only removing around 250 calories (what about individuals who normally eat more than 250 calories during the fast period?), and the study only examined women (women are known to be less responsive to intermittent fasting).

Answer to #2: This is a tough question as it requires to reader to understand Bayesian Inference. The writer of the summary article frames it as a process that is loaded with bias and often leads us astray. In truth, it is a statistical approach. Yes, it has its limitations, but it is used in numerous disciplines inducing science, medicine, and law. I think the risk lies not in the approach of Bayesian Inference, but how it is applied. The author of the summary article sates, “My inclination to believe the efficacy of this [intermittent fasting] method grows stronger as my understanding of the science behind it is reinforced by my own experiences.” In other words, if my experiences keep reinforcing the science, then I’m likely to give the science far more credit that it deserves (i.e., personal bias). But it doesn’t have to be this way. And if you think like a scientist it won’t be. Instead you will keep accumulating an understanding of what multiple studies show and then weigh these findings in the context of your own experience. This is a better approach to Bayesian Inference and this is how new hypotheses are generated and theories are refined.

As scientists, clinicians, therapists, etc., we cannot completely remove personal bias. To do so would be to remove us from the situation completely and that cannot be done (the studies won’t perform themselves!). Regardless, science begins with a question. In this question, the questioner invariably has an opinion as to the what the answer will be (a prediction). They just need to be open to the possibility that their prediction might be wrong. As long as we are open and make an attempt to consider all of the available information, then we are doing our due diligence.

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Book Review – Shred It!

And now, my very first book review. My review is of the book “Shred It!” which I read to assist in the training of one of my clients (it was a book they were referring to in our discussions). The book advocates a whole food, plant-based diet for optimum health and fitness and claims to be a step-by-step guide to burning fat and building muscle using this approach.

Unfortunately, right in the Introduction it makes claims that are hard to substantiate, such as 1) the diet being the best diet to prevent and even reverse disease. 2) the diet and lifestyle that yields the most energy, 3) the best diet to aid in recovery after exercise, 4) that fiber is only found in plants and of paramount importance, 5) that cholesterol should be avoided. It seems these claims stem from the author being a disciple of Dr. Campbell and the science given in the Forks Over Knives documentary (which I review here). The science just isn’t supportive though: Studies haven’t properly compared plant-based diets to other diets like Paleo. Arctic peoples have and continue to eat all meat (no-fiber) diets. The cholesterol data has been picked apart by Gary Taubes in Good Calories, Bad Calories. Because I place a premium on how science is presented, all of these points have a major influence on my review.

Regarding the rest of the book, the Getting Started chapter is good. It touches on motivation, goals, and being specific. The Basic Nutrition and Fat Burning chapters are also good. There is then a brief chapter on gaining muscle which focuses on making sure you ingest the right mount of calories. The estimations are certainly reasonable, but they don’t address balance of macronutrients. Indeed, the book espouses a 70/15/15 percent split of carbs, protein, and fat. For everyone. But scientific support for this is not given. The author says these numbers are within healthy ranges, as close to ideal for energy production, muscle recovery/growth, joint care, digestion/assimilation ease, and disease prevention as you can get. But the proof is not given. The book eventually shifts away from scientific claims and focuses more along the lines of how the diet should be chosen because “it works.” I am all for discussing things that one observes to be true, but there is a lot of this. More than 30 pages are devoted to convincing the reader of the diet’s effectiveness with different success stories. This would have been a great opportunity to delve into variations of this diet as clearly the different case studies presented were a mix of men and women of different ages and body types. We get tidbits of how they had to individually alter their diets and training, but not enough to put together a comprehensive picture. The book then concludes with meals, exercises, recipes, and yet another case study section, this time featuring athletes.

In the end this book gets off on the wrong foot scientifically, and although it has some good sections, they are few and far between. It reads more like a sales pitch than a guide, which may have been the intent given how difficult it is for vegans to obtain mainstream acceptance (a reality that baffles me). But for those that are not biased against a plant-based lifestyle, you aren’t getting a whole lot of information that can’t be found elsewhere. There were a lot of missed opportunities here, so Shred It! is not a book I would recommend.

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