Most people own a key chain, but do they possess an adequate posterior chain? That's the question. You can easily perform back extensions or reverse hypers until you're blue (or more appropriately "red") in the face, but to truly work the posterior chain in a functional movement pattern, consider these two variations of the deadlift – the Romanian deadlift (RDL) and the Stiff-legged deadlift (SDL).
Classically, these lifts are used by European men as a diagnostic tool to ass-ess whether a female would make a good wife! Nah, actually, the RDL in particular is used as an assistance exercise to the Olympic lifts (i.e. snatch and clean.)10 This is a difficult exercise to grasp for many beginners and the SDL tends to be an easier option. Once you get the hang of them though, they're addictive. It's like owning an Apple computer in that, "Once you go Mac, you never go back!"
Done regularly, you'll quickly find out that leg curls are not the only way to build a set of hamstrings. In fact, many including yours truly consider the deadlift as a far superior exercise that recruits many more fibers at a far higher tension and utilizes the hamstrings in their primary role as hip extensors.9
Remember, the hamstrings are a biarticular muscle, meaning that they cross two joints – the hips and the knees. So, you don't necessarily have to perform knee flexion with some fancy machinery to get at these bad boys. A simple barbell set will do. 'Nuf said.
The Romanian Deadlift is Born.
Okay, let's break 'em down. We'll start with the RDL. There's some debate as to the origin of the name. Some feel that the RDL isn't even a true deadlift and that its origins are not Romanian at all. Apparently, American lifters witnessed a world champion weightlifter from Romania perform this exercise way back in the 1950's so they dubbed it this catchy name and it stuck around for years.1
Others specifically pinpoint Romanian-born and now US weightlifting coach, Dragomir Cioroslan, as the man who brought this exercise to North America. He experienced great success with the RDL as a lifter and a coach so why not share the wealth!2,3,11
Here's how it goes. Start with a shoulder-width stance and use a "clean" grip – an overhand (pronated) grip set just outside the legs. Stick your chest out and retract the shoulder blades while maintaining natural curves in the spine. Initiate the movement by pushing the hips backward.
The knees will naturally bend (slightly that is) as you descend and the shins should remain vertical. Make sure to keep the bar close to the body (even dragging along the thighs)3 and the back flat, which will minimize the risk of injury.8
Keep the arms straight throughout the movement. If you're doing it right, you'll feel it in your hamstrings. For most people, the bar will just cross the knees before the back loses form. At this point, it's time to reverse the movement and come back up. Don't allow the back to round and don't hyperextend the spine at the top of the movement. In other words, stand tall at the top, but don't lean backwards.2,10,17,20
The Romanian Deadlift
Think of this more as a horizontal movement with the hips moving forward and back rather than merely raising the bar up and down in a vertical fashion. Now, read this carefully because this is very important. The one thing you should never say while spotting the RDL is: "Let me know if I'm standing too close."
I've noticed that many smokers have difficulty with this exercise in that they have a problem with the concept of butt out! Actually, Pavel Tsatsouline has a great tip for those experiencing problems jackknifing at the hips. He suggests that you "press the ridges of your hands over the hip joints, in the creases formed when you lift your legs. Imitate the RDL [first] without a weight by trying to hinge your torso and legs around your hands."20
Try it – it should help, especially if you smoke!
Enter the Semi-Stiff-Legged Deadlift?
The start position is the same for the SDL as the RDL, but then things get a little different. Before we go any further, the words stiff-legged and straight-legged are used interchangeably. Either way, they're both a misnomer. It is more appropriate to use "semi-stiff-legged" as coined by Olympic strength coach, Charles Poliquin, since the knees should be slightly bent throughout for safety and effectiveness.
Since 70-85% of the gluteus maximus fibers attach to the illiotibial band (IT band for short) and the IT band is taut around 15-20° of knee flexion, the semi-stiff position will bring the powerful glutes (your butt!) into play.5,11,17 If you bend the knees too much, though, the overload on the hamstrings and glutes is reduced.20
On the other hand, most bodybuilders do this exercise on a bench with stiff (straight) legs.21This is the traditional SDL which involves spinal flexion as opposed to spine neutrality in the versions discussed above. The glutes don't get as involved since the IT band remains somewhat flaccid, and this increases the stress on the lower back.5,11
As an example, the force of lifting a 20 kg load from the ground with your knees bent is 3 times your bodyweight on L3 (a vertebrae in your low back). Lift that same load with your legs straight and all of a sudden you have 4.85 times your body weight acting on L3 – that's a significant difference!23
So where does this incorrect advice of keeping your legs straight come from anyway? Glad you asked – here's an excerpt from Joe Weider's Ultimate Bodybuilding:
In order to increase the range of motion, this exercise [the stiff-legged deadlift] is normally performed while standing on a flat exercise bench or thick block of wood. Your feet should be placed fairly close to each other, toes pointed directly forward. Take a shoulder-width overgrip on the barbell. Stand erect and keep both your arms and legs completely straight throughout the movement. Slowly bend forward at the waist and lower the barbell down until it touches either your toes or the bench/block right in front of your toes. (Weider, 1989)
Incidentally, the close stance works more of the biceps femoris (the outer/lateral hamstrings).
Anyhow, rumor has it that the most you can achieve with a Romanian is a semi-stiff condition anyway, which is at least true in the weight lifting world! In other words, the RDL is a semi-stiff-legged deadlift (SSDL) since the knees are slightly bent!
Confused yet? The real difference between the RDL and SSDL is bar position. During the RDL, the hips move backward, thus keeping the bar close to the body. However, during the SSDL, the butt stays somewhat put (it will move back slightly). You'll still rotate around the hips, but the bar is now further away from the body.20 This, of course, will place greater stress on the lumbar erectors (your lower back.)17
The Semi-Stiff-Legged Deadlift
Let's go over that just to make sure you get it right. During the SSDL, the knees are slightly bent and stay rigid throughout as you rotate around your hips. The bar will be positioned below and in line with the shoulders. Bend forward to lower the weight. The shoulders (and the directly suspended bar) will move forward, out over the toes as opposed to the RDL where the shoulders and bar stay over the ankles.17,20 Try it unilaterally (single leg) as well.
Option A – opposite foot on plate
Option B – opposite foot free floating
Overall, there's less stress on the low back and greater weight can be used with the RDL since the load is closer to the axis of rotation and over the base of support.3 For this reason, you can go pretty heavy with RDL's as long as you maintain strict form.
However, since the lever arm is longer and the potential for injury greater, avoid low rep work with heavy poundages on the SSDL and definitely during the SDL where the spine is flexed (more on this later) – but then again, don't go too high in your rep work either–all that will do is fatigue your grip before anything else and the intensity may be too low to elicit a true training effect!10,17
This is not a trampoline!
As mentioned above, your back will dictate how far down you go. If it starts to round and you lose the arch in your lower back, you've gone too far! Here's an excerpt on the topic from Gardner and Cole, 1999:
During the SDL, the spine is put under enormous stress. Once trunk flexion begins, the intervertebral disc pressures increase significantly throughout the range of motion. When one moves from full flexion into extension with the weight supported by the hands, the lumbar discs are under tremendous torque because of the long lever arm between the weight and the low back. This weak mechanical leverage causes the muscles to produce forces in excess of 10 times the amount of weight lifted. In full spinal flexion, the lumbar discs are at the most vulnerable position for injury to occur. (Gardner & Cole, 1999)
Also, it is very important that you don't bounce at the bottom of the movement.10
Keep an open mind and a flat back!
Traditionally, as a safety precaution for the spine, especially when using heavy loads, the RDL and SSDL are performed with what some would call a "flat" back. In reality, since flat equates to a posterior pelvic tilt, you want to actually encourage a natural concave curve in the lower back when viewed posteriorly. If this is difficult for you, stick your chest out and tilt your head up (i.e. cervical extension) as you descend.
The opposite effect occurs when you look down and flex your neck – the back tends to round. Use this approach with the SDL. It may also be advantageous during supine knee-ins or leg raises to emphasize the abdominals over the hip flexors.18,19
Rehabilitation specialist Paul Chek makes a good point in saying that we routinely perform this movement pattern everyday. How else do you pick up a tissue from the ground?5 And Ian King's philosophy of no exercise is "bad," it's just the way you perform it (it is not uncommon for the Aussie strength coach to prescribe round-back good mornings or deadlifts) does make sense, but in both cases, light loads should be used at least initially until sufficient strength is acquired. Even then, be careful! Once the back starts to round, the forces on the lumbar spine are at least tripled and it's the ligaments (not the muscles) that support most of the load.10 If you have a herniated disk, you may want to avoid the SDL.14 I mean, it's just common sense!
The SDL involves rounding the back – be very careful and use light loads!
Also, keep in mind that round-back versions utilize the back extensors (i.e. Erector spinae) as prime movers instead of their role as stabilizers during the flat-back versions.
Ever heard of butt punches?
You can use barbells, dumbbells, cables (low pulley), and even the Smith machine to do the RDL and the SSDL. Jerry Telle, a man familiar to Testosterone readers for inventing some unique exercises, recently introduced an interesting one called "butt punches." No, it's not a Richard Simmons move nor is it a special Greek tradition. Originally described as a good morning variation using the Smith machine, it can also be performed with the bar low as in the RDL. The premise is to basically punch the butt backwards while keeping your back flat. To encourage the weight over the heels, small plates are placed under the forefoot.19
Butt Punch Good Mornings
Butt Punch RDLs
Dirty tricks for clean results.
There are some dirty tricks to increase recruitment of the posterior chain. Pavel Tsoutsaline advises that you dig your heels into the ground and squeeze a dime between your cheeks.20 Just make sure that you don't lose it! Along the same lines, powerlifter Tom McCollough recommends that you "claw" the ground with your feet during the ascent.22
I've also heard of the "aerobic" technique of scrunching a carpet under your toes, but this may not be the best method if you're training with masculine types on concrete floors. Catch my drift? Much of this advice applies to good mornings as well.
To focus on your legs and not your grip, use straps, especially as the weight starts piling up. Of course, if you want to build your grip, don't use straps and favor fat bars like the Apollon's Axle from IronMind. Whatever you do, make sure that your grip is centered evenly. "If it is positioned off-center on the barbell by even a small amount, it creates an asymmetrical distribution of forces throughout the lumbar spine – where 85-90% of disc herniations occur."10
The pinch test is a trick I picked up from Paul Chek. If you still have problems maintaining a tight arch in your lower back, have a partner pinch the skin (i.e. form a vertical skinfold) directly over one of the lumbar erectors. Once the back starts to round, you'll lose the pinch. It's a nice proprioceptive cue.5
According to sprint coach, Charlie Francis, an overemphasis on exercises such as good mornings or deadlifts can result in weakness of the quadratus lumborum muscle which is considered by some to be the most important stabilizer of the spine! This will lead to an unbalanced core. If this is indeed true, then a variety of side bridges, bends, and flexions should cure the problem.9
Quit sucking in your gut!
If there's ever a time NOT to draw in the navel, it's during these exercises. In fact, this act should be abandoned altogether unless there's a specific reason to do so (i.e. motor reeducation). I find that drawing in the navel – or the act of "sucking in your gut as if you're putting on a tight pair of jeans" – tends to detract the emphasis from the posterior chain.
Yes, I do believe that it is necessary to keep the core tight without the aid of a belt, but overemphasis on the Transversus abdominis (or TVA for short, which is basically the internal girdle that keeps your organs from spilling out) can negatively affect performance. The advice to activate the deep abdominal wall was well-intended, but unfortunately, you cannot extrapolate information from a pathological population (i.e. low back patients) and apply it to healthy individuals – it just doesn't work that way!12,19
I won't mention any names but one authority on the subject actually contradicts himself twice on this matter:
- In his writings, he states that "if you reduce (contract) a muscle, you thereby inhibit it." Take the leg curl for example. We all know by now that pointing the feet away (plantarflexion) throughout the movement causes us to use less weight but places greater stress on the hamstrings. As Croce et al., 2000 contend, "The reason for decreased knee flexor peak torque with the ankle fixed in plantarflexion is probably due to the gastrocnemius muscle being in a too shortened position, thereby preventing it from effectively producing force at the knee joint."7 So, if that's the case, wouldn't full contraction of the TVA throughout any movement actually inhibit it? Instead of helping to stabilize the spine as it does naturally (along with other abdominal and torso muscles), you've now taken it out of the picture! Think about it.
- In one of his early videos (and a good one at that), he notes that fixating the scapula during lat pulldowns or rows alters mechanics. This predisposes the lifter to shoulder problems (such as impingement syndrome, capsular laxity, tendonitis, etc.) because the humerus is driven up into the acromion during the eccentric action if the scapula is not allowed to move. "Basically, this is a misuse of an isolation technique – you must integrate appropriately, and in order to do so, all links have to move! By stopping one link in a system, you get an overflow into other links or joints."
That's great information, so why doesn't it apply to abdominal hollowing as well?
You want further proof? Alright, I'll keep going.
Early in my career, I tried this approach with several clients. The report from most of them was that it felt uncomfortable, almost as if their lungs were being pushed out of their throat while descending! The body doesn't lie. If something doesn't feel right, don't do it! Dr. Stuart McGill, a spinal biomechanist and professor at the University of Waterloo, points out that there's a clear distinction between abdominal bracing and hollowing12 :
There appears to be some confusion in the broad interpretation of the literature regarding the issue of abdominal "hollowing" and "bracing". Richardson's group has evaluated hollowing – observing that the "drawing in" of the abdominal wall recruits TVA. Given that TVA has been noted to have impaired recruitment following injury (Hodges and Richardson, 1996), Richardson's group developed a therapy program designed to re-educate the motor system to activate TVA in a normal way in low back pain (LBP) patients. Hollowing was developed as a motor re-education exercise and not necessarily as a technique to be recommended to patients who require enhanced stability for performance of the activities of daily living (ADL), which has perhaps been misinterpreted by some clinical practitioners. Rather, abdominal bracing, that activates the three layers of the abdominal wall (external oblique, internal oblique, TVA), with no "drawing in" is much more effective at enhancing spine stability. (McGill, 2001)
In summary, he recommends that you brace the abdominals – as if you're about to accept a punch – but don't suck 'em in if you want spinal stability. And guess what ... after adopting this method, no more complaints and performance started to improve.
Still not convinced?
I remember Poliquin once commenting on this practice. He said, "Why rob the neural drive from the extensor chain by drawing in the navel?" Bottom line, it makes you less stable, so why do it? The analogy I like to give is that of chopping down a tree. Visualize the side profile of someone sucking in their gut. Now, where will that "tree" fall if "chopped" down?
Louie Simmons and Dave Tate of Westside Barbell (these guys are renowned for producing world-caliber strength athletes) have stated numerous times that if you want to increase core stability, do the opposite – push out your gut!
Low back specialist and lecturer, John Casler, admits that the abdominals themselves cannot push out – they can only be pushed out by the forces of intra-abdominal pressure (IAP). "If you don't believe me just go stand in front of a mirror and force all the air out of your lungs and try to push your abs out," says Casler. "Won't happen! What Louie or Dave are describing is the creation of IAP that will push the tensioned abs out – this creates a very rigid torso."19
It's pretty interesting, too, that kids naturally push their tummies out when lifting an object from the ground!19
And don't get Dr. Mel Siff, coauthor of the mighty Supertraining text started on this subject–he's got a mouthful to say. Here's just a morsel from Siff that you might find interesting:
It is far too inadequately understood (even to most sports scientists and coaches) that the pressure of the distended belly is not only used to support the spine in any form of squatting, deadlifting or cleaning movement, but also to enhance stability of the body by the contact between the lower abdominal region and the upper thighs. This contact, especially if the lower abdomen is thrust explosively against the upper thighs can very significantly enhance the strength of the starting drive from one's lowest position, especially in the squat (and also in the squat snatch).
Although geared more towards squats, this advice alone could improve performance instantly!
Despite all the evidence against it, there are still coaches and personal trainers who continue to endorse abdominal hollowing on practically every movement. Unfortunately, when you're in too deep, it's hard to get out! Jon Barron, in his book, Lessons From The Miracle Doctors, made a similar argument about the continued support of mercury amalgam fillings by the American Dental Association (ADA): "If you're in for an inch, you're in for a mile. What would the legal ramifications be if the ADA suddenly announced that they, and all the dentists connected with them, had been wrong for well over 100 years and had been slowly poisoning all Americans? Can you spell tobacco?"4
The decision is yours.
Variety in training is important – here a low pulley is being used.
Every breath you take, every move you make...
Breathing is another issue. Cioroslan recommends that you take a deep breath at the start of the movement and hold it while you lower, exhaling only when you complete the movement.2 Siff supports this advice stating, "Russian research cited in Vorobyev (Textbook on Weightlifting) shows that filling one's lungs to about 75 percent of maximal capacity before a heavy effort appears to be optimal for producing maximal force and power." This provides optimal support for the spine with the fewest side-effects. There is also evidence that this action coincides with increased athletic performance.18,19
In an old weight training post, Chek revealed that sprinters do not take a breath for the first 15 meters since the body must stabilize for the maximal force of acceleration provided by the drive of the legs and explosive swing of the arms. According to Chek, "If this stabilization does not happen, the core is soft and power is not optimally directed, resulting in dissipation of energy and loss of performance."22
This is also true in archery and pistol shooting as stability and accuracy are connected with brief phases of breath-holding.18 It is even common among combat pilots to hold their breath and perform the Valsalva maneuver (exhaling against a closed glottis) to prevent blackout during high G-force aerial maneuvers.6 In fact, we all perform a Valsalva maneuver unconsciously when confronted with near-maximal efforts!16
Actually, fellow T-Mag contributor, Charles Staley, put it best in a past article when he stated that we breathe quite well by instinct alone. Messing around with this could negatively affect performance. With that said, you will notice that you reflexively hold your breath to increase both intra-thoracic and intra-abdominal pressures.23 While I'm on this point, I never discuss so-called "proper breathing" when demonstrating an exercise because, like Staley, I feel that it detracts concentration and will negatively affect performance.
Both McGill and Siff agree that the common recommendation of exhaling upon exertion (or raising of the weight) and inhaling on the lowering is a mistake.13,18 Much like the discussion of the TVA and abdominal hollowing, Siff states that the "careful instruction as to the technique of a given exercise will automatically result in the body responding with the optimal muscle recruitment strategy throughout the duration of the movement."18,19 This also applies to breathing. Let it occur naturally.
A Valsalva maneuver or even a partial Valsalva (holding your breath until you clear the sticking point) will help to maintain IAP to stabilize the spine and make you stronger.18,19,22
If you want proof, try this experiment, courtesy of strength coach, Lorne Goldenberg. Next time you squat or deadlift with a heavy weight, try to hold your breath for at least the first 3/4 of the concentric action, and then on another lift begin to exhale as you initiate from the floor. What will you discover? Easy, you'll be able to handle a much higher load when you hold your breath and blow it out at the end of the movement.22 In case you didn't know, relaxation is associated with gentle, controlled exhalation18 – not something you want coming out of the hole now, is it? And if you decide to perform heavy squats or deadlifts with improper breathing patterns, expect a sore spine!22
Just to clear up any misunderstanding, the Valsalva maneuver should be permitted primarily during short-time ultimate efforts.23 Submaximal loading should be executed with longer phases of normal exhalation-inhalation and shorter phases of breath-holding.18 I thought I'd add that last sentence in case you're part of the SuperSlow cult! And here's another really important point: make sure you breathe between reps! It might seem obvious to you, but beginners often stop breathing during repetitive lifts of low intensity, so remind them if necessary.23
Of course, there's also a concern in hypertensive and cardiac patients–these individuals should breathe through pursed lips or hum out through the nose when lifting submaximal loads.15,18,19,22,23 This is mentioned in greater detail in my Abdominal Rollout article.
Wow, what a stretch!
Remember to work the range! Don't try to achieve full range of motion (ROM) on your first rep; instead, aim to increase the range just a touch (even by a mere millimeter, or for you Americans, a "hair") each rep.
Assuming that you're following a slow, controlled tempo without bouncing at the bottom, this is a safe approach that will ensure you reap the benefits of these exercises without experiencing any silly injuries. For extra ROM as you progress, use small plates and/or perform them on top of a step,21 but don't sacrifice form!
If you shift to one side as you descend, your hams on that side are probably tight. To even things out, use PNF stretching on the tight side with either a Swiss ball or bench, or have a partner perform the traditional ham stretch with you lying on the ground. Either way, make sure they use a lumbrical grip and do not return in the same pathway (more on this in a future article.)
This picture below shows a stretch-position exercise for your hamstrings as described by Ironman Magazine Editor-in-Chief Steve Holman in his Positions-Of-Flexion (POF) program. It sure is a stretch-position exercise. Mr. Legs himself, Tom Platz, was able to kiss his knees from regular performance of this exercise. And it definitely is a killer. You should see the look of pain people display as they complete a set ... kinda reminds me of my honeymoon!
Stretching your hamstrings with a Swiss ball.
As a final point, and to echo what Charlie Francis indicates in his great book, Training For Speed, the more prominent the gluteal fold, the more you should concentrate on training the hamstrings as hip extensors! In other words, there should be no indentation at the gluteal/hamstring junction; rather, the hams should flow into the glutes indicating a high hip extension strength capability.9 Whether you use the SDL, SSDL, RDL – whatever deadlift you choose – you're working that posterior chain. The RDL targets the hamstrings while the SDL stresses the lumbar erectors more, but both nail the glutes (other options include glute pull-throughs and reverse hypers).
To summarize, I've discussed two types of deadlifts in this article: a flat-back and a round-back version. The former can be further divided into a SSDL or RDL depending upon the shoulder and hip position.
During the classic RDL, the hips move backward; whereas, with my definition of the SSDL, the shoulders (and bar) move forward. They both involve a slight bend in the knees that's held rigid throughout the set while maintaining a neutral spine. Furthermore, the lumber erectors act as stabilizers as opposed to prime movers in the round-back version.
The latter, of course, is the traditional SDL. I may have portrayed it earlier as a "bad" exercise. Well, it is! Expect your spine to snap and a lightning bolt to the head as soon as you round your back! Okay, maybe it's not that bad–the bolt may hit you elsewhere. Just keep in mind that it poses a greater risk to the spine so use with caution!
So who wins this heavyweight match? Nobody! They're both great exercises. Going extra rounds with either lift should provide the knockout punch to your muscular development!
Special thanks to Jerry Telle and John Casler for their assistance with the article; Nelson Da Silva (professional bodybuilder), John Kitchen (skier), Mike Bester (windsurfer) and Trionne Moore (competitive salsa dancer) in order of appearance for modeling the exercises; and John Clark for his photography.
- Andres, PS. Romanian Deadlifts: Training the Other Half of Your Leg. http://www.protraineronline.com
- Askem, JV. The Romanian Deadlift. http://www.olympus.net
- Ballantyne, CS. The Deadlift: 1 Exercise, 18 Variations. Issue #75. http://www.cbathletics.com
- Barron, J. Lessons from the Miracle Doctors – A Step-by-Step Guide to Optimum Health And Relief from Catastrophic Illness (e-book). http://health1st.healingamerica.com
- Chek, P. Scientific Back Training. La Jolla, CA: Paul Chek Seminars, 1994.
- Cresswell AG, Blake PL, Thorstensson A. The effect of an abdominal muscle training program on intra-abdominal pressure. Scand J Rehabil Med. 1994 Jun;26(2):79-86.
- Croce RV, Miller JP, St Pierre P. Effect of ankle position fixation on peak torque and electromyographic activity of the knee flexors and extensors. Electromyogr Clin Neurophysiol 2000 Sep;40(6):365-73
- Escamilla RF, Lowry TM, Osbahr DC, Speer KP. Biomechanical analysis of the deadlift during the 1999 Special Olympics World Games. Med Sci Sports Exerc. 2001 Aug;33(8):1345-53.
- Francis, C. "Training for Speed." Australia: Faccioni Speed & Conditioning Consultants, 1997.
- Gardner, PJ, Cole, D. The Stiff-Legged Deadlift. Strength and Conditioning Journal, 1999, Vol. 21, No. 5, pp. 7–14.
- Goldenberg, L. Strength Training Q&A. Ironman Magazine. June 2000, Vol. 59, No. 6, pg. 150.
- McGill, SM. Achieving Spine Stability: Blending Engineering And Clinical Approaches. 4th Interdisciplinary World Congress on Low Back Pain & Pelvic Pain. Montreal, Nov. 2001.
- McGill, SM. Enhancing Low Back Health Through Stabilization Exercise. http://www.ahs.uwaterloo.ca
- McGill SM. Low back exercises: evidence for improving exercise regimens. Phys Ther. 1998 Jul;78(7):754-65. Review.
- Narloch JA, Brandstater ME. Influence of breathing technique on arterial blood pressure during heavy weight lifting. Arch Phys Med Rehabil. 1995 May;76(5):457-62.
- O'Connor P, Sforzo GA, Frye P. Effect of breathing instruction on blood pressure responses during isometric exercise. Phys Ther. 1989 Sep;69(9):757-61.
- Piper, TJ, Waller, MA. Variations of the Deadlift. Strength and Conditioning Journal, 2001, Vol. 23, No. 3, pp. 66–73.
- Siff, MC., Verkhoshansky, YV. Supertraining 4th Edition. Denver, CO: Supertraining International, 1999.
- Supertraining Forum (moderated by Dr. Mel Siff). http://groups.yahoo.com
- Tsatsouline, P. Full Range of Motion or Joint's Demolition Project? Parrillo.com, February 1999.
- Weider, J. Joe Weider's Ultimate Bodybuilding. Chicago, IL: Contemporary Books Inc., 1989.
- Weight Training Posts (compiled by Tom Griffin). http://www.staff.washington.edu
- Zatsiorsky, VM. Science and Practice of Strength Training. Champaign, IL: Human Kinetics, 1995.