1) Happy to say that I’m entering the final year of my PhD program at Rocky Mountain University. So far it’s been an extremely rewarding experience. Sure, the coursework has been a bit overwhelming at times, but I’ve become a much more astute fitness professional as a result–particularly in my ability to assess and scrutinize research. Very much looking forward to carrying out my dissertational research and furthering our understanding about the mechanisms of muscle hypertrophy and their application to resistance training.
2) I recently collaborated with my good friend Bret Contreras on another T-Nation article, this one focusing on the Weider Principles. In case you don’t know, the Weider Principles are a set of exercise guidelines compiled by Joe Weider, who built a fitness empire that includes many of the popular fitness magazines and bodybuilding contests. Joe has been maligned by many in the field (and in some cases rightly so) for perpetrating a variety of exercise and nutritional myths. But Joe was a visionary and in our article, 6 Lessons Learned from the Master Blaster we objectively delve into recent research that has validated a number of Joe’s principles and provide recommendations for practical application of the relevant principles.
3) Speaking of Bret Contreras, he has teamed up with physical therapist Jonathan Fass for a new podcast venture called, The Strength of Evidence. It’s a really great listen filled with top-notch info from two really smart guys.
4) Here is a video clip from my lecture at the recent Fitness Education Institute conference in New York City. In this clip, I discuss the importance of adopting an evidence-based approach to training. Many people have a misconception as to what “evidence-based practice” really entails, and here I clarify its meaning and discuss why it is so vital to optimal fitness results.
5) My new book, The MAX Muscle Plan is set to be released next month. The book details a six month periodized routine designed to maximize muscle development, providing both the scientific basis of how muscles grow as well as detailing every exercise, set and rep of the program. I’m really pumped (no pun intended!) for its release. Much more on this over the coming weeks.
The stiff-legged deadlift (a.k.a. straight-legged deadlift) is one of the most popular resistance exercises for developing the glutes and hamstrings. Unfortunately, it’s also one of the most misunderstood. Many lifters have misguided notions about the risks of the movement. Others simply have the wrong idea as to how it should be performed. Here’s a primer on what you should know.
There’s a misconception that the stiff-legged deadlift is dangerous to the knee joint. You’ll hear people say that you should never perform a movement that requires locking out your knees. Nonsense. To understand why, a little applied anatomy is in order. Although people tend to think of the knee joint (i.e. tibiofemoral joint) as a hinge joint, this is only partially true. In actuality, it’s a modified hinge joint (in geek speak, it’s technically classified as a trochoginglymus joint) given that a small amount of internal and external rotation takes place during flexion/extension. Specifically, when the knee begins to flex from a fully extended position, the tibia internally rotates to “unlock” the joint. During extension, the tibia then externally rotates to “screw home” so that the knee can fully lock out. This mechanism is necessary to achieve proper alignment of the tibial and femoral condyles. And herein lies the rub. Knee flexion is associated with rotation while there is no appreciable rotation of the knee during extension. Given that increased mobility results in decreased stability, which do you think is the more stable position? Full extension, of course. This is supported by in vivo (i.e. in the living) human research which shows that that anterior/posterior laxity of the knee is greatest at 20 degrees and tightest at lock out (Markolf et al. 1978). Bottom line: There is no detriment to locking out the knees when performing the stiff-legged deadlift.
There actually is a potential benefit to keeping the legs straight. You see, the hamstrings are a biarticular muscle, meaning they span two joints: the hip and the knee. By keeping the knees straight, the hamstrings remain in a fully lengthened position. Why is this important? Well, studies show that muscle force is optimized when a two-joint muscle is stretched at one end while acted upon at the other. This seems to be particularly important to an element called titin, which has been shown to act as a mechano-sensor for anabolic signaling. Thus, if your goal is to maximize hamstrings development, the straight-legged version will tend to heighten activity in this musculature. As an aside, there is reason why you generally shouldn’t lock the knees during performance of multi-joint lower body exercises like the squat as this diminishes constant muscular tension, but this is a topic for a different day.
Another issue with the stiff legged deadlift involves performance. Namely, I all-too-often see lifters get up onto an elevated platform or box so they can stretch down to the floor. Unfortunately, this extra range of motion generally occurs by flexing the spine. Problem is, this can place an extreme amount of undue stress on the discs, potentially leading to injury. Realize that the stiff-legged deadlift is a hip extension movement designed to target the glutes and hamstrings. Hopefully you know that the glutes and hams do not attach to the spine, so spinal movement will have zero effect on activation of these muscles! Bottom line: Bend only as far as your hips will allow. In most people, this generally means you won’t lower the bar much past your knees. You’ll feel an intense stretch in the hamstrings and this will be the limiting aspect to how far down you can go.
As far as performance, here are a few important cueing tips. First, always maintain a neutral lumbar/thoracic spine. To facilitate this posture, keep your head up throughout the move. I encourage lifters to see themselves in the mirror at all times (a tip I learned from the late, great Mel Siff). As soon as your head drops, your spine will reflexively tend to round. I’ve heard some coaches say that keeping the neck slightly hyperextended is problematic, but there is no evidence this is the case. In almost two decades of training clients, I’ve never had anyone complain of neck pain and, most importantly, no one has ever injured their lower back during performance. Second, try to push your butt backward as you descend. This will maximize activation of the hip extensors. Finally, actively squeeze your glutes at the top of the movement. The idea is to generate a powerful contraction that maximizes muscle activation in this position.
Here is a video explaining performance of the exercise. Enjoy!
My review article titled, “Does Exercise-Induced Muscle Damage Play a Role in Skeletal Muscle Hypertrophy?” has just been published ahead of print in the Journal of Strength and Conditioning Research. For those who want the cliff notes, here is a synopsis of findings:
Exercise-induced muscle damage (EIMD) occurs primarily from the performance of unaccustomed exercise, and its severity is affected by the type, intensity, and/or duration of training. Concentric and isometric actions contribute to EIMD, but the greatest damage to muscle tissue is seen with eccentric exercise, where muscles are forcibly lengthened. Although EIMD can have detrimental short-term effects on markers of performance and pain, it has been hypothesized that the associated skeletal muscle inflammation and increased protein turnover are necessary for long-term hypertrophic adaptations. A theoretical basis for this belief has been proposed, whereby the structural changes associated with EIMD influence gene expression, resulting in a strengthening of the tissue and thus protection of the muscle against further injury. Other researchers, however, have questioned this hypothesis, noting that hypertrophy can occur in the relative absence of muscle damage.
An extensive review of the scientific literature showed that there is a sound theoretical rationale supporting a potential role for EIMD in the hypertrophic response. While it appears that muscle growth can occur in the relative absence of muscle damage, potential mechanisms exist whereby EIMD may enhance muscle development including the release of inflammatory agents, activation of satellite cells, and upregulation of the IGF-1 system, or at least set in motion the signaling pathways that lead to hypertrophy. Although research suggests that eccentric exercise has greater hypertophic effects compared to other types of actions, however, a causal relationship directly linking these gains to EIMD has yet to be established. Moreover, if such a relationship does in fact exist, it is not clear what extent of damage is optimal for inducing maximum muscle growth.
Evidence seems to show that threshold exists beyond which damage does not further augment muscle remodeling and may in fact interfere with the process. Given that a high degree of EIMD causes a reduction in the force-producing ability of the affected muscle, excessive damage can impair an individual’s ability to train, which necessarily would have a detrimental effect on muscle growth. Moreover, while training in the early recovery phase of EIMD does not seem to exacerbate muscle damage, it may interfere with the recovery process. Thus, current research indicates that a protocol that elicits a moderate amount of damage would be most appropriate for maximizing the hypertrophic response.
A big gap in the literature is that the vast majority of studies have been carried out on untrained subjects. Considering that a ceiling effect slows the rate of muscle growth as one gains training experience, it is possible that muscle damage may become an increasingly important factor in promoting hypertrophy in highly trained individuals. This area needs further study.
A dozen or so years ago, I was given a book to read called “The Antioxidant Miracle.” The book, written by researcher Lester Packer, discussed the (apparent) plethora of benefits of taking antioxidant supplements–benefits that included a reduced incidence of heart disease and cancer, healthier skin, and even better sex! The skeptic that I am, I decided to look into the research and assess the validity of these claims.
First a little background info on the topic: In case you don’t know, antioxidants scavenge unstable molecules called “free radicals” that have been implicated in disease and aging. Here’s a short-course in how the process works: Your body is made up of billions of cells held together by a series of electronic bonds. These bonds are arranged in pairs so that one electron balances the other. However, in response to various occurrences (such as oxygen consumption), a molecule can lose one of its electron pairs making it an unstable free radical. The free radical then tries to replace its lost electron by stealing one from another molecule. This sets up a chain reaction where the second molecule becomes a free radical and attacks a third molecule, which becomes a free radical and attacks a fourth molecule and so on. The main culprit: oxygen. Every time you breathe, oxygen uptake causes free radical production. Environmental factors such as pollutants, smoke and certain chemicals also contribute to their formation.
To prevent rampant free radical production, your body has a sophisticated internal antioxidant system. Various antioxidant enzymes combine with antioxidants from the foods you eat to help keep free radicals at bay. But when free radical activity reaches a critical level, the system can become overwhelmed, causing extensive damage to cellular tissues.
Given my role as an exercise scientist (as well as the fact that I’m an avid exerciser), free radical buildup was of particular concern. After all, free radicals are generated by oxygen consumption and when does oxygen consumption skyrocket? During exercise, of course!
So I began poring over the peer-reviewed literature in an attempt to evaluate the potential benefits of supplementation. Lo and behold, the research seemed pretty compelling. There were numerous studies showing that taking antioxidant supplements had a positive effect on a multitude of health issues. Vitamin C, vitamin E, alpha-lipoic acid, co-Q 10 and other antioxidants all had shown efficacy with respect to improving health and preventing disease. Moreover, there seemed to be a synergistic effect of combining supplements. A red flag was that the studies were almost all observational and thus low on the hierarchy of evidence-based practice. Nevertheless, the studies included several large-scale trials and the sheer number of positive studies gave credence to positive benefits. I jumped on the antioxidant bandwagon…
As it turned out, this was an important career lesson for me. Subsequent studies (including a number of randomized clinical trials–the top of the evidence-based hierarchy) failed to find support for benefits of taking antioxidant supplements. In fact, some recent studies actually showed a *negative* effect of supplementation on markers of health and wellness. A 2008 systematic review published in the Cochran Database (Bjelakovic et al., 2008) refuted the claims that antioxidant supplements could prevent mortality in healthy people or patients with various diseases. The authors went on to conclude: “We found no evidence to support antioxidant supplements for primary or secondary prevention. Vitamin A, beta-carotene, and vitamin E may increase mortality. Future randomised trials could evaluate the potential effects of vitamin C and selenium for primary and secondary prevention. Such trials should be closely monitored for potential harmful effects. Antioxidant supplements need to be considered medicinal products and should undergo sufficient evaluation before marketing.” A pretty sobering rebuke of earlier research.
For those who exercise, things become even murkier. Turns out that reactive oxygen species (ROS) actually function as key cellular signaling molecules in the response to exercise, and serve to bring about important training-related adaptations. They seem to be particularly important in adaptations to aerobic exercise, where oxygen is utilized at a very high rate. In accordance with this theory, a number of studies have shown that antioxidant supplementation can actually cause decrements in athletic performance. In a recent letter to the editor at the American Journal of Physiology Endocrinology and Metabolism, Gomez-Cabrera et al. cite some of the research on the subject and point out that antioxidant supplementation may be worse than useless for aerobic athletes–it has the potential to be detrimental.
Although the effects of antioxidants on resistance training have not been as well studied, there is good reason for concern. ROS have been shown to promote growth in both smooth muscle and cardiac muscle, and they are theorized to have similar hypertrophic effects on skeletal muscle. Interestingly, transgenic mice with suppressed levels of selenoproteins, a class of proteins that function as potent antioxidants, display increased exercise-induced hypertrophy, suggesting that the higher levels of ROS may play a role in muscle growth.
Now before we say case closed and demonize antioxidant supplementation as useless, realize that research on the subject is still in its infancy. There is still much we don’t know about the relationship between antioxidants, health, and exercise performance. Could it be that certain antioxidants are beneficial while others are not? Or could it be that a threshold of intake is beneficial while beyond this amount detrimental effects occur? We simply don’t know yet. So based on current evidence (which is all that we can go on at this point), it seems prudent to avoid taking supplemental antioxidants and instead focus on getting these nutrients from the foods you eat (vegetables and fruits are replete in antioxidants and other potentially beneficial phytochemicals). When future research comes out on the topic, we can then reevaluate recommendations.
Bjelakovic G, Nikolova D, Gluud LL, Simonetti RG, Gluud C. Antioxidant supplements for prevention of mortality in healthy participants and patients with various diseases. Cochrane Database of Systematic Reviews 2008, Issue 2.
Here is a link to an excellent article by Marta Montegro titled What’s the Best Time to Exercise? that appears on FOX News Latino. She does a great job delving into the science of the topic and dispelling some of the myths that continue to be perpertrated.
Finally, here is a terrific article by my buddy Bret Contreras aptly titled, The Contreras Files: Volume II. As always, Bret tackles some controversial fitness subjects and backs up his opinions with solid research. You can read Part I of this series here.
I recently co-authored an article with Bret Contreras on the barbell hip thrust. The article, which is published ahead-of-print in the NSCA Strength and Conditioning Journal, describes the performance of the barbell hip thrust and its application in strength training programs. It’s a terrific exercise for targeting the glutes in a manner that traditional exercises such as squats, deadlifts, and hyperextensions simply cannot approach. Here is a video of Bret demonstrating the exercise:
The seated row is one of the best exercises for building muscle in the mid-back region. Most people perform the move with excessive hip flexion (and often spinal flexion, too). Big mistake! Check out this video to learn correct performance.
Here’s a link to an article I was quoted in on fitness time-wasters. As I stated in the article, I’m of the opinion that for the most part there are no “bad” exercises–just poor application of a given movement based on an individual’s goals, abilities, and medical history. That said, I did manage to come up with a few moves that I find to be pretty much useless. I should also note that I don’t necessarily agree with some of the choices of the other experts quoted in the story. What are your thoughts on the topic?
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.
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.