Straight Bar Deadlift versus Hex Bar Deadlift

Here’s a study that’s fresh off the press. In fact, it was just posted online around one hour ago. How’s that for fast service on my part? The study compared the straight bar deadlift to the hex bar deadlift.

Straight Bar Deadlift versus Trap Bar Deadlift

Many coaches (including myself) have theorized that the trap bar deadlift allows lifters to:

1. Lift more weight
2. Place less loading on the spine, and
3. Get more knee extensor involvement

These findings were all shown to be true in a brand new study by Swinton et al. (2011) titled A Biomechanical Analysis of Straight and Hexagonal Barbell Deadlifts Using Submaximal Loads. Here is the abstract:

Swinton, PA, Stewart, A, Agouris, I, Keogh, JWL, and Lloyd, R. A biomechanical analysis of straight and hexagonal barbell deadlifts using submaximal loads. J Strength Cond Res 25(7): 2000-2009, 2011—The purpose of the investigation was to compare the kinematics and kinetics of the deadlift performed with 2 distinct barbells across a range of submaximal loads. Nineteen male powerlifters performed the deadlift with a conventional straight barbell and a hexagonal barbell that allowed the lifter to stand within its frame. Subjects performed trials at maximum speed with loads of 10, 20, 30, 40, 50, 60, 70, and 80% of their predetermined 1-repetition maximum (1RM). Inverse dynamics and spatial tracking of the external resistance were used to quantify kinematic and kinetic variables. Subjects were able to lift a heavier 1RM load in the hexagonal barbell deadlift (HBD) than the straight barbell deadlift (SBD) (265 ± 41 kg vs. 245 ± 39 kg, p < 0.05). The design of the hexagonal barbell significantly altered the resistance moment at the joints analyzed (p < 0.05), resulting in lower peak moments at the lumbar spine, hip, and ankle (p < 0.05) and an increased peak moment at the knee (p < 0.05). Maximum peak power values of 4,388 ± 713 and 4,872 ± 636 W were obtained for the SBD and HBD, respectively (p < 0.05). Across the submaximal loads, significantly greater peak force, peak velocity and peak power values were produced during the HBD compared to during the SBD (p < 0.05). The results demonstrate that the choice of barbell used to perform the deadlift has a significant effect on a range of kinematic and kinetic variables. The enhanced mechanical stimulus obtained with the hexagonal barbell suggests that in general the HBD is a more effective exercise than the SBD.

It should be mentioned that subjects were allowed to rise up onto their toes at the end of the movement in order to facilitate more acceleration through the exercises. What was very surprising is the amount of peak power that occurred in the submaximal deadlifts. Previous work by Escamilla et al. 2000 showed that elite powerlifters took 4 seconds to complete the concentric portion of the rep, which equated to only .2 m/s of velocity. And since power equals force x velocity, despite the large forces seen in the max deadlift, power output is not very impressive. Here’s an excerpt from the article discussing the peak power output:

In the current investigation, peak power for the SBD and HBD reached 4,388 and 4,872 W, respectively, with individual values as high as 6,049 and 6,145W recorded. Studies quantifying power during Olympic weightlifting exercises have reported maximum peak power values similar to those obtained here. Winchester et al. (33) and Cormie et al. (6) reported maximum peak power values of 4,230 and 4,900 W, respectively, for college athletes performing the power clean.

One issue I have with using traditional strength exercises for the purpose of power production is the fact that the barbell must be decelerated toward the top of the movement. The researchers mentioned this in their article:

Some researchers have asserted that performing traditional resistance exercises with submaximal loads is an ineffective method for developing muscular power (25). This position is based on previous studies reporting extended periods of deceleration and reduced force production to slow the barbell velocity to zero at the end of the movement (8,25)

The researchers go on to say:

The results from this study show that even with very light loads the majority of the exercise duration can be used to accelerate the load (Table 4).

In looking at the table around 60% of the lift was spent accelerating the load with a 10% 1RM load, which climbed up to over 80% for the 80% 1RM loads.

For practical advice, the authors stated:

If the training objective is to target the lumbar area and maximally recruit the erector spinae muscles then it is recommended that the SBD is performed. Because the HBD more evenly distributes the load between the joints of the body, practitioners may find deadlifts performed with the hexagonal barbell to be an effective alternative to the squat and an appropriate exercise to use in the final stages of low back rehabilitation.

In addition, they mentioned that:

This is the first study to demonstrate that the deadlift can be combined with submaximal loads to generate large power outputs. The finding suggests it may be advantageous to include the deadlift in structured periodized models aimed at developing muscular power. The results of the study also demonstrate that the HBD can produce significantly greater peak force, peak velocity, and peak power values than the SBD. Strength and conditioning coaches should be aware of the enhanced mechanical stimulus created with the hexagonal barbell when selecting a deadlift exercise.

My Take (but you should form your own conclusions):

1. The hex bar deadlift is clearly the safer lift as it reduces the moment on the lumbar spine.

2. That said, it also reduces the moment on the hip joint (while increasing the moment on the knee and ankle joints).

3. As I mentioned in my Topics of the Week article that I linked above, I still prefer the conventional deadlift because I use the full squat as my knee dominant exercise so I want a deadlift variation that complements the full squat and acts more on the hips.

4. Although the peak power levels are very impressive for the submaximal deadlifts (where you rise up onto the toes), you still spend a large percentage of the time decelerating the load which means reduced muscular tension through end range hip extension (though 87% of the 80% 1RM deadilft was indeed spent accelerating, so only the last 13% of end range hip extension is spent decelerating).

5. For this reason elastic bands could be used to increase tension on the hip extensors toward end range hip extension.

6. For this reason I like the jump squat and hang clean (or even the trap bar jump and possibly the deadlift plus shrug/calf raise) as I don’t believe they’d involve any deceleration at the top of the lift (though I confess that I haven’t located studies that address this issue…but nonetheless studies addressing this likely exist).

Check out this video from Joe DeFranco…scroll to :42 seconds into the video and you can see an example of trap bar jumps.

Whenever I watch a DeFranco video I get all jacked up and want to train!

28 thoughts on “Straight Bar Deadlift versus Hex Bar Deadlift

  1. Matt

    Brett, in #1&2 did you mean movement instead of moment?
    I know we are supposed to work on our Mind-Muscle connection, but I would think sharing a touching moment at the beginning of a deadlift might look a little strange in a gym setting

    1. Bret

      Haha! Matt, a moment is also called torque. It’s a measurement of force that describes a tendency to rotate a joint. For example, let’s say there was a very high moment on the hips in the direction of hip flexion. Your hip extensors would have to resist that moment (or counteract that moment) during isometric or concentric movement.

      Using your definition, Ronnie Coleman and Brian Dobson share a touching moment before his 800 lb deadlift!

  2. ben

    great post. this study is making the rounds and you jumped right on it. I’m still with the conventional but its interesting to read the quantified difference. As an aside, I have always thought that the trap bar DL is pretty much a different exercise than the conventional DL. I mean, as you mention in your post, the trap version is much more akin to the squat – or, rather, it IS a squat. You are clearly squating down and then lifting a weight directly under you more or less straight up. While a conventional DL you are clearly bending over and then lifting/pulling-back a weight. I feel like they should not be necessarily either-or but rather considered almost fully different exercises. Am i totally off base?

    1. Bret

      Ben, it’s definitely a different lift, with many individuals “squatting down more.” Some don’t, though. They simply use high-hips and pull like a regular deadlift, only with the hex bar more aligned with their center of mass. But even in those who squat down more, they still have much less knee flexion and ankle dorsiflexion than they would in a regular squat exercise (assuming you go down to parallel or deeper), which is why it’s been deemed by some as a “squat lift;” half-way between a squat and a deadlift. So you’re definitely not off-base. Cheers!

  3. James de Lacey

    Hi Brett

    So by Trap bar having an increased peak moment at the knee means it is more quad dominant while conventional is more hip dominant??

    Thanks and nice post!

  4. Mat Herold

    Great post tying in the research to the real work once again Bret. As for the knee dominance of the hbdl, they can also be performed as RDL variations and the like. I have found hbdl to be much easier to implement with most of my athletes, especially those with limited ankle and hip mobility and lifting experience.

  5. Jay

    Hey Bret, great article.

    I have always thought of trap bars being particularly useful for athletes. I was reading some more stuff from Louie Simmons, he famously qouted “Why do an exercise that takes more than it gives”. I here at Westside they have a no deadlifting program to increase their deadlift. I understand this is due to CNS fatiguing because the weight is being pulled, rather than pushed, and from a dead stop. But it seems a lot of the newer guys, you, Cressey, Robertson, Defranco, all program it routinely.

    Another thing Louie said about doing round back 100% straight leg deadlifts or good mornings to increase hamstring flexibility. Wondering what your take is on that. I have always liked Gray Cook’s quote ” Don’t add length if your not going to add strength somewhere else” So stretch hams, and make your glutes stronger. But using weights to stretch the hams? Also loaded flexion to strengthen the erector spinea?

    Cheers Bret,


    1. Bret

      You have to keep in mind that Louie’s goals are for powerlifting purposes, not athletic improvements. I think that some of the Westsiders have achieved success by pulling more often than they did a decade ago, though I could be wrong. I believe that even top powerlifters should deadlift every week, even if it’s just speed pulls (like what Andy Bolton does). For athletic improvements, deadlfits are huge, but of course you need to be able to perform them properly. Sure they can fatigue the nervous system but you can work around that…avoid grinding reps, just do speed pulls, limit the volume, etc. As for round back sldl’s, I have no dout that they’d be great for increasing ham flexibility, but why round the spine? You can do them with an arched back, albeit with a much shorter ROM, and achieve the same benefits. And the Cook quite is great. Cheers Jay! -BC

      1. Jay

        Hey Bret, thanks for getting back to me, about the rounded back deadlifts and good mornings, I meant do you think its a good way to build back strength, I have tried it with low weights, and my erector spinea gets pumped, unlike other more isometric back exercises, but I know McGill thinks loaded spinal flexion is a big no no.

        1. Bret

          Jay, if we didn’t have to worry about disc and other spinal injuries, then no coach would disagree that roundback lifting was extremely effective in strengthening the erector spinae. However, we do have to worry about these factors so most coaches instead try to strengthen the erectors isometrically via arched back lifting including deadlifts and good morning variations. I’d like to say two things about this. First, it matters where the rounding is coming from. If the rounding is shared between motion segments and none of the motion segments approach end-range flexion (especially in the lower lumbar region), then it wouldn’t be consider so dangerous. However, few lifters possess this kind of kinaesthetic awareness and motor control to know where the rounding is coming from. Second, it all depends on your goals. If you’re a sport athlete or bodybuilder, why risk it? If you’re a powerlifter or strongman, then maybe it’s worth the risk. Hope that helps! -Bret

  6. Thomas Kurz

    I wonder what would be peak moment at the lumbar spine and peak power in a SBDL on Hise’s deadlift hopper? That assuming the weight is such as to take advantage of the hopper (if too heavy then no bounce).

  7. jon heisinger

    love to round. it depends how you are built. i am 5’11 220 long legs and arms short torso. by low bak stays netural not arched works for me lots of upper back rounding though

  8. Steve

    Hi Bret, great article! just wondering what your thoughts were on what weight to use for trap bar deadlift jumps, would it be the same as westsides dynamic squats (i.e 50-70% roughly). your advice would be greatly appreciated. Many thanks!

  9. David

    I’m a rower and thinking of swapping out front squats for HBDL as my knee dominant exercise because the arm position is more akin to the start of a rowing stroke than the clean position I use on front squats. I’ll still keep conventional DLs, RDLs, and hip thrusts as my hip dominant exercises. Oh, great podcast you did recently critiquing Rip’s recent T-Nation article.


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