Recent Blog Posts
Ab Training
July 27, 2011
No exercise has been more maligned in recent years than the abdominal crunch. That’s right, the good old crunch, a staple exercise in almost every athletic program, is constantly dissed by certain fitness professionals as being non-functional and, worse, a potential hazard to spinal health. I have co-authored a peer-reviewed article with my good friend and colleague Bret Contreras that evaluates the current research on spinal flexion exercises such as the crunch and draws relevant conclusions based on the evidence. The article appears in the current issue of the Strength and Conditioning Journal. You can view the article at the following link: To Crunch or Not to Crunch.
One of the more attention-grabbing criticisms on the topic is that crunches have a negative effect on posture. The theory goes something like this: Crunches shorten the rectus abdominis (i.e. the “six pack” muscle). Since the rectus abdominis spans from the sternum/rib cage to the pelvis, continually shortening the muscle will pull down your ribcage, ultimately resulting in kyphosis (i.e. a roundback posture). It’s an interesting theory. It’s also completely unfounded.
As with many theories, its basis has a kernel of truth. Specifically, placing a muscle in a shortened position for a prolonged period of time does in fact cause it to assume a shorter resting length. For example, if you immobilize your arm in a cast at a flexed position for several weeks, your arm will tend to remain flexed once the cast is removed. This is due to an adaptive response whereby the elbow flexors (i.e. biceps, brachialis, etc) lose sarcomeres in series (Toigo & Boutellier, 2006). This has been coined “adaptive shortening.”
There also is some evidence that certain types of exercise can affect the number of sarcomeres in series. Lynn and Morgan (1994) showed that when rats climbed at an incline on treadmill (i.e. repeated shortening contractions), they had a lower sarcomere count in series than those who walked at a decline (i.e. lengthening contractions). This suggests that repeated concentric-only actions lead to a decrease in the number of sarcomeres in series while exercise consisting solely of eccentric contractions results in a serial increase in sarcomere length. Similar results have been noted by other researchers (Butterfield et al. 2005; Lynn et al. 1998).
Perhaps you can see the flaw in hypothesizing that performing a crunch will shorten the rectus abdominis: namely, crunches are not solely a shortening exercise! Rather, the movement also involves eccentric actions where the rectus abdominis is returned to its resting length. Thus, any potential negative effects of shortening contractions on sarcomere number are counterbalanced by the lengthening effect of the eccentric actions (Butterfield et al. 2005; Lynn et al. 1998). The net result is no change in resting length and thus no negative effect on posture.
Some anti-crunch proponents take an alternate hypothesis, claiming that performing spinal flexion exercises (i.e. crunches) overly strengthens the rectus abdominis to the the point that it overpowers its antagonists and thereby pulls down on the ribcage. Again, this is a straw man argument. Certainly it’s true that an imbalance between muscles can cause postural disturbances. I’m sure you’re familiar with guys who perform the “nightclub workout” (chest and arms every time they hit the gym) and end up so internally rotated that they have difficulty scratching the back of their head. Does this mean you shouldn’t perform chest presses and arm curls? Certainly not! The issue here is one of poor program design, not an indictment of presses and curls. Simply train the antagonistic muscles and there’s no postural problem.
With respect to crunches, the same principle holds true. Sure, if you perform a gazillion crunches every day and don’t train other muscle groups then you’re setting yourself up for a postural deviation. But this is a non-issue as long as you adhere to a balanced routine that emphasizes strengthening of the back extensor muscles (Sinaki et al. 1996; Mika et al. 2005). And performance of virtually any standing, non-machine based exercise will heavily involve the posterior core muscles that antagonize the rectus abdominis (Schoenfeld, 2010; Lehman, 2005). This will negate any potential “over-strengthening” of the rectus abdominis associated with the crunch. In fact, the average person tends to have weak abdominals (Morris et al. 2006), so they could very well benefit by directly strengthening the anterior core musculature.
To sum things up, there is no convincing evidence that performing crunches as part of a total body resistance training routine will have any negative effects on posture (assuming there is no inherent postural issues to begin with). This is yet another instance where a theory can seem logical on the surface but have little basis of support once you look deeper into the facts.
Stay Fit!
Brad
References
1. Butterfield TA, Leonard TR, Herzog W. Differential serial sarcomere number adaptations in knee extensor muscles of rats is contraction type dependent. J Appl Physiol. 2005 Oct;99(4):1352-8
2. Lehman GJ, Gordon T, Langley J, Pemrose P, Tregaskis S. Replacing a Swiss ball for an exercise bench causes variable changes in trunk muscle activity during upper limb strength exercises. Dyn Med. 2005, 4:6.
3. Lynn, R and Morgan, DL. Decline running produces more sarcomeres in rat vastus intermedius muscle fibers than does incline running. J Appl Physiol 77: 1439–1444, 1994
4. Lynn R, Talbot JA, Morgan DL. Differences in rat skeletal muscles after incline and decline running. J Appl Physiol. 1998 Jul;85(1):98-104.
5. Mika A, Unnithan VB, Mika P. Differences in thoracic kyphosis and in back muscle strength in women with bone loss due to osteoporosis. Spine (Phila Pa 1976). 2005 Jan 15;30(2):241-6.
6. Morris CE, Greenman PE, Bullock MI, Basmajian JV. (2006), Vladimir Janda, MD, DSc: Tribute to a Master of Rehabilitation. Spine, 31(9), 1060-4
7. Schoenfeld, BJ (2010). Squatting kinematics and kinetics and their application to exercise performance. Journal of Strength and Conditioning Research, 24 (12), 3497–3506
8. Sinaki M, Itoi E, Rogers JW, Bergstralh EJ, Wahner HW. Correlation of back extensor strength with thoracic kyphosis and lumbar lordosis in estrogen-deficient women. Am J Phys Med Rehabil. 1996 Sep-Oct;75(5):370-4.
9. Toigo, M and Boutellier, U. New fundamental resistance exercise determinants of molecular and cellular muscle adaptations. Eur J Appl Physiol 97: 643–663, 2006
Personal Appearances, Speaking
July 25, 2011
I will be speaking at next month’s CanFitPro International Fitness Conference. The conference will take place at the Toronto Convention Centre in downtown Toronto, Ontario Canada from August 17 to 21, 2011. This will be my fifth straight year presenting at the conference, and it always is one of the best fitness venues I’ve had the pleasure to speak at. The following is a list of the sessions that I will be presenting. I’m particularly excited to be co-presenting with my friend and colleague Bob McAtee on the science of PNF stretching. Hope to see you there!
Program Design for Muscle Hypertrophy: Muscle development is of primary interest to those who lift weights. This workshop will elucidate the science behind optimizing muscular hypertrophy. It will detail the effects of manipulating intensity, sets, repetitions, and rest intervals on growth, as well as exploring the roles of factors such as exercise modality, training to failure, speed of movement, and recovery. The significance of acute hormonal fluctuations and lactate production and their effects on increasing protein synthesis will be addressed. Sample routines are offered in the context of a periodized approach to help the practitioner with perfecting program design.
Optimal Fat Burning Strategies: Losing body fat is the # 1 reason why people work out. This seminar will explore the science behind fat loss, debunking several of the more common myths on the subject. A research-based approach is taken to present the most effective exercise strategies for optimizing fat loss in a safe and efficient manner.
Facts and Fallacies of Fitness: The fitness field is rife with folklore that often leads to questionable practices. This lecture helps separate fitness fact from fiction to reveal the real truth about many myths and misconceptions associated with exercise and sports nutrition. An evidence-based approach is taken to examine the validity of many long-held fitness beliefs in this informative and entertaining seminar. An interactive question and answer session is provided to address specific questions on the topic.
Scientific Stretching: Mechanisms and Application of PNF Techniques: Flexibility is an integral component of a fitness routine, and can help to improve functional capacity and athleticism while reducing the potential for injury. Proprioceptive neuromuscular facilitation (PNF) is one of the most popular and effective techniques for improving measures of flexibility. This combined lecture/workshop details the mechanisms of PNF while reviewing the research into its effects on joint range of motion and sports performance. Participants will learn and practice specific PNF techniques to illustrate practical application.
You can register at the following link: Register for CanFitPro
Uncategorized
July 13, 2011
The NSCA national conference was held this past week at the Paris Hotel in Las Vegas. For me, this was a particularly special event as I was named the NSCA Personal Trainer of the Year at the awards banquet ceremony. I also got to catch up with many friends and colleagues, some of whom I haven’t seen for a while, as well as meeting with some of the top researchers in the field about my doctoral work.
Throughout it all, I spent the majority of the days attending various presentations. Here are some of the highlights from the sessions I attended:
- JC Santana gave two presentations. His first was a hands on presentation on bodyweight training. Lots of cool variations of exercises such as pushups, squats and lunges that could be used to alter muscle recruitment and energy system development. His second presentation was called “Combat Spartan Training.” Here JC discussed an approach to fitness that he uses with MMA fighters, discussing applications for general fitness training. JC is one of the most dynamic presenters in the fitness field, and both sessions were highly entertaining.
- Dr. Dan Bernadot presented on nutrient timing. Certainly Bernadot has good credentials–professor of nutrition, multiple research publications, etc. His primary contention, however, was the importance of consuming multiple, small meals throughout the day to optimize fat loss. As I mentioned in a previous post, this claim is contrary to the majority of research that I’ve seen. He did provide several references to support his contention, so I need to go back and review these studies. I’ll have more to say on this in a future post.
- Dr. Joe Weir presented on customized supplement approaches for the future. This was an extremely interesting lecture where Weir discussed the role of genetics in response to nutrition. He presented evidence, for example, that a certain percentage of the population has been shown to be susceptible to weight gain from saturated fat intake while others are at a considerably less risk. The take home message is that the time is rapidly approaching where we can get a genetic printout of our bodies and then individualize a nutritional regimen accordingly. We should be able to do the same with exercise, too.
- John Cissik presented on evidence-based core training. This was one of my favorite presentations of the conference. As the name of the discussion implies, John discussed the research on the benefits (or lack of such) of core training. As John points out, there is a surprising dearth of evidence to support the need for a core training regimen with respect to improving sports performance and aiding in rehabilitation. Now some apparently misinterpreted John’s message to mean that core training is a waste of time. This isn’t the case. Rather, it simply implies that we should take a closer look at the evidence and not be so quick to assume that the standard advice about the subject is substantiated by research. Look for an interview with John in a future blog post.
- Dr. Andy Fry did an excellent presentation titled “Back to the Basics about Strength and Conditioning.” Dr. Fry provided a template that could be used to create a strength training routine from scratch. What I liked best about his approach is that he did not advocate a particular method of training. Rather, he presented a modifiable way to systematically create a routine. It was a highly practical session and his technique should be standard reading for trainers and fitness enthusiasts alike.
- Dr. Chad Kerksick co-presented on the importance of training to failure. This is a heavily debated topic and Kerksick did an excellent job reviewing the literature and presenting recommendations on the topic. Bottom line is that training to failure is an important component of a training routine, but it’s use should be balanced by recovery issues. Some failure training is necessary, but it should be periodized in a routine depending on the goal’s of the lifter.
There were many other excellent presentations, but I’m running short of time. Next year’s conference will be in Providence, RI. Hope to see you there!
Stay Fit!
Brad
Uncategorized
July 10, 2011
I’m honored to report that I was named 2011 NSCA Personal Trainer of the Year at this past National Conference. I’ll post some pics from the awards ceremony soon…
Brad
Fitness
July 1, 2011
There are a lot of terrific fitness blogs in the blogosphere. Here are 10 that I’ve found to be highly informative, entertaining and, most importantly, scientifically based. No offense to any that aren’t mentioned here–I hope to cover another round in a future blog post. Read and enjoy!
Bretcontreras.com: This blog is authored by fitness guru Bret Contreras. Pure and simple, Bret is one of the most learned and well-read fitness pros I’ve ever encountered. I’ve collaborated on numerous articles with him, and am proud to call him a good friend. Bret’s blog is an eclectic mix of great training info on a wide variety of subjects. The breadth of material that he covers is a testament to his expansive knowledge base. You’ll always learn something new from reading his blog.
Nicktumminello.com: This blog is authored by Nick Tumminello. Nick is a highly knowledgeable fitness pro who is consistently creative in his exercises and routines. I’ve gotten to know Nick well over the past year and have been highly impressed with his approach to fitness. His blog includes videos, training routines, and guest posts. Always a good read.
Ben’s Blog: This blog is authored by Ben Bruno. Ben is an up-and-coming fitness pro who is adept in discussing a host of fitness subjects. What’s particularly interesting about Ben’s blog is that he posts a weekly “good reads” and “good videos,” which covers dozens of good articles recently posted on the internet. This alone is a terrific resource, not to be missed!
Mark Young Training Systems: This blog is authored by Mark Young. Mark is dedicated to research-based information on fitness. His posts often challenge rigidly held beliefs about exercise and nutrition, and he regularly solicits guest posts from those in the know.
Exercise Biology: This blog is subtitled “The Science of Exercise and Nutrition.” You can bet it keeps its promise. The blog is authored by Anoop Balachandran, an extremely bright and well-read fitness pro. Anoop always takes an evidence-based approach in his posts, citing applicable studies to support his views. The site also has an active forum where scientifically-minded fitness people discuss a wide spectrum of topics. Highly recommended reading.
Ericcressey.com: This blog is authored by Eric Cressey. Eric is popular strength and conditioning specialist who has made a name for himself by training many athletes, particularly baseball players. Eric has an excellent grasp of the science of exercise as well as the practical experience to properly implement the relevant principles. He posts regularly on a variety of subjects and does so in an interesting and informative manner.
Louschuler.com: This blog is authored by Lou Schuler. Lou is the former fitness editor for Men’s Health magazine as well as a popular fitness author. Lou’s training is as a journalist, but that doesn’t mean he isn’t knowledgeable about fitness. Quite the contrary, he’s dedicated himself to reading and understanding research and it shows. As you might expect from a journalist, his posts are extremely reader-friendly, sometimes funny, and often thought-provoking. A consistently enjoyable read.
Alanaragon.com: This blog is authored by nutritional expert Alan Aragon. I’ve previously reviewed Alan’s Research Review newsletter, which is one of the most educational publications on the topic that I’ve seen. Alan’s blog covers various nutritional topics and related info on fitness, and does so in a no-nonsense, enjoyable fashion. My only qualm is that he doesn’t post enough!
Weightology.net: This blog is authored by James Krieger. James is an incredibly bright fitness pro with a particular focus on exposing fitness myths. You may remember his guest post on my site a couple of months ago where he debunked some of the misconceptions about fructose. James’ posts are extremely well researched and you can always count on their accuracy of facts. The only downside is that some of the content is only available to premium subscribers. That said, the free content is highly informative and, if you like what you see, you might consider opting for a subscription.
NSCA Blog: Those who read workout911.com will know that I’m a huge supporter of the National Strength and Conditioning Association (NSCA). They are clearly the leading authority on strength training, which is borne out by their mission statement “To disseminate research-based knowledge and its practical application, to improve athletic performance and fitness.” The NSCA blog is evolving into an excellent resource, both for information on fitness as well as keeping abreast about what is going on in the association. Read the blog and, while your at it, consider joining the NSCA if you already aren’t a member. It’s a worthy investment.
Stay Fit!
Brad
Uncategorized
June 26, 2011
Want to give a shout out to Advanced Physical Medicine for naming Workout911.com as one of the top 10 fitness blogs to bookmark in 2011. It’s always nice to be recognized for a commitment to excellence. You can read the post at the link below:
Top 10 Fitness Blogs
Stay Fit!
Brad
Nutrition
June 19, 2011
A recent New York Times article took to task the all-too-often-expressed claim that high protein diets are bad for the kidneys. After citing some of the relevant research on the topic, the article goes on to conclude: “…studies show that in healthy adults, increased protein intake does not put excess strain on the kidneys.” Hooray for the New York Times for finally acknowledging what those of us who keep abreast of research have known for years! The real question is, What took so long?
The myth that protein is detrimental to the kidneys dates back to the early 1980’s when Dr. Barry Brenner, a nephrologist at Brigham and Women’s Hospital, published several research papers linking high protein diets to the progression of renal disease (1). In short, Brenner claimed that a high protein intake increased glomerular filtration rate (i.e. the volume of fluid filtered in the kidneys), ultimately leading to renal dysfunction. This came to be known as the “Brenner Hypothesis” and was adopted as gospel by a large segment of the nutritional community. To this day, most college nutritional texts continue to espouse the dangers of a high protein consumption on the kidneys.
The problem with the Brenner Hypothesis is that it was based almost entirely on data from animal subjects and those with existing kidney disease. Extrapolating results from such populations to healthy humans is a classic case of improperly generalizing findings. Research 101 dictates that external validity (i.e. generalizability) is limited to the population studied. That’s certainly the case here.
As noted in the New York Times article, research on healthy individuals has continually failed to find any negative correlation between protein intake and kidney problems. While a higher protein consumption does lead to changes in renal size and GFR, these have proven to be normal adaptations with no adverse effects on kidney health (2). And this is not a case of cherry picking studies; results have held true in multiple research trials across a wide variety of demographic groups including athletes, the elderly, and the obese.
In fairness, it should be noted that studies on the topic have been limited to examining an intake of under 3 grams/kg of protein a day. Thus, it is not known if intakes above this amount might cause detrimental effects. However, 3 grams/kg/day is a substantial amount of protein, equating to a daily intake of about 250 grams of protein for a 180 pound guy. What’s more, there’s a large body of anecdotal evidence from athletes who consume extremely high protein diets (sometimes in excess of two times body weight) without displaying associated kidney issues. This would seem to indicate that higher intakes are not an issue but further research is needed for confirmation.
In sum, it’s about time to put to rest the myth that a high protein intake will harm your kidneys. Given that higher protein diets have been shown to be metabolically advantageous for those who are trying to lose weight and/or maintain a healthy body weight, we should be encouraging people to adopt such nutritional practices, not scaring them off with baseless claims.
Stay Fit!
Brad
1) Brenner BM, Meyer TW, Hostetter TH. Dietary protein intake and the progressive nature of kidney disease: the role of hemodynamically mediated glomerular injury in the pathogenesis of progressive glomerular sclerosis in aging, renal ablation, and intrinsic renal disease. N Engl J Med. 1982 Sep 9;307(11):652-9
2) Skov AR, Toubro S, Bülow J, Krabbe K, Parving HH, Astrup A. Changes in renal function during weight loss induced by high vs low-protein low-fat diets in overweight subjects. Int J Obes Relat Metab Disord. 1999 Nov;23(11):1170-7
Uncategorized
June 14, 2011
On July 9th and 10th, my friend and colleague Joe Dowdell will host the first annual Peak Performance Training and Diet Design Seminar. This a two-day intensive seminar covering a wealth of material. I’ve gotten a sneak peak at the content and I can say without hesitation you won’t be disappointed. It’s an excellent blend of theory and practice, extremely thorough and well-researched, that is sure to enhance your knowledge base.
Joe is covering the training material. As I’ve mentioned in a previous interview, Joe is one of the most astute trainers around. I’ve gotten to know him quite well, and have been extremely impressed with his ability to harness the science of exercise and apply it to training program design. In short, the guy knows his stuff!
The nutrition component of the seminar is being handled by Dr. Mike Roussell. Although I don’t know Mike personally, his credentials are outstanding and, based on the articles I’ve seen from him (he is a writer for many popular websites), he shows keen insight into the complexities of nutrition with respect to body composition.
The seminar will conclude with an expert panel of fitness professionals who will share their knowledge in a question and answer session. It is a rare opportunity to interact and learn from some of the leaders in the industry. The event is being held at Joe’s facility, Peak Performance, in New York City. You can check out specifics at the link below:
First Annual Peak Performance Training and Diet Design Seminar
Stay Fit!
Brad
Uncategorized
June 10, 2011
The NSCA National Conference will take place from Wednesday July 6 to Saturday July 9, 2011 at the Paris Hotel in Las Vegas. The national conference is always a terrific event and this year should be no exception. There are a host of great speakers lined up, including Stu McGill, JC Santana, and many others. My good friend and colleague Jay Dawes is doing a pre-con presentation on athletic assessment that’s sure to be highly informative.
For those who have attended the national conference in the past, you know what a great time it is. If you’ve never been to the event before, you owe it to yourself to check it out. Here’s a link to check out the schedule of events:
NSCA National Conference
Hope to see you there!
Brad
Exercise
June 8, 2011
One of the most widely held exercise beliefs is that you should never let your knees go past your toes when squatting. You’ll hear this “rule” echoed like a mantra over and over by the majority of personal trainers: “Keep the knees behind the toes!”
Fact is, though, there’s little evidence to back up such a claim. It is true that as the knees move anteriorly (i.e. forward) during the squat, the forces acting on the knee joint increase. However, there is no “magic point” where these forces suddenly become dangerous. The plane of the toes has been misguidedly used as a line of demarcation despite a complete lack supporting research. What’s more, intentionally preventing the knees from going past the toes can create additional problems at other joints that are potentially more injuries.
An eloquent study by Andy Fry and colleagues (2003) looked at this very topic. Seven recreationally-trained males performed 3 unrestricted squat lifts and 3 restricted lifts where a wooden board was placed immediately in front of both feet so that the knees were prevented from moving forward past the toes. As expected, knee torque was greater when the knees went past the toes compared to restricted squatting (~150 vs. 117 newton-meters). Sounds like intentionally keeping the knees behind the toes is a good thing, right? Not so fast…
Restricted squats resulted in significantly greater torque at the hip joint compared to unrestricted squatting, with the differences here much greater than those seen at the knee joint (302 vs. 28 newton-meters). Perhaps even more problematic is that results were attributed to a greater forward lean when performing restricted squats. Why is this an issue? Well, in order to squat while keeping knees behind toes, lifters tend to compensate by increasing their forward lean. Studies have shown that an increased forward lean is associated with greater lumbar shear forces. And since the lower back is more susceptible to injury than other joints, this would seem to be a poor tradeoff.
So what’s the take home message? I’ll quote directly from the Fry et al. study as they sum things up very nicely: “While it is critical to protect the knees from unnecessary forces, it is also important to avoid unnecessary forces acting at the hips. These hip forces will ultimately be transferred through the lower back and therefore must be carefully applied. The net result is that proper lifting technique must create the most optimal kinetic environment for all the joints involved. Exercise technique guidelines should not be based primarily on force characteristics for only one involved joint (e.g., knees) while ignoring other anatomical areas (e.g., hips and low back).”
I would note that the same rules do not apply for lunges. Since the lunge involves stepping forward, there is no issue with maintaining an erect posture during performance. The biggest mistake I see is that people tend to push forward on their front leg, which significantly increases shear at the knee joint. Instead, your focus should be centered on dropping the rear leg. In doing so, your front leg will stay perpendicular to the ground, minimizing stresses to the knee joint without negatively impacting the hip or the spine.
Stay Fit!
Brad
Fry AC, Smith JC, Schilling BK. (2003). Effect of knee position on hip and knee torques during the barbell squat. J Strength Cond Res. 17(4):629-33.
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