How bigger glutes may improve the squat and deadlift
“Strength is a product of muscular action initiated and orchestrated by electrical processes in the nervous system of the body. Classically, strength is defined as the ability of a given muscle or group of muscles to generate muscular force under specific conditions.” (Verkhoshansky 1)
– Verkhoshansky and Siff
There are so many factors that contribute to how a person expresses strength. Some factors cannot be changed, such as limb length. For example, short arms would be beneficial for the bench press but not the deadlift (Keogh). Other factors can be controlled such as muscle hypertrophy and more effective nervous system stimulation.
Several months ago I was at the Fitness Summit in Kansas City. Bret Contreras, one of the speakers had a presentation entitled “Contributing Factors to Displays of Strength”. In one of his slides he covered how gluteal hypertrophy can lead to increased hip extension torque. He stated that, “increasing gluteus maximus hypertrophy by 32% leads to 50% increase in torque potential”. As a competitive powerlifter, anything to do with increasing strength peaks my interest so I decided to dig deeper into the biomechanical rational behind that statement. This article is going to examine why increased gluteal hypertrophy may help to increase torque (strength) in the squat and deadlift. First here’s what you need to know:
“A muscle action describes the potential direction of rotation of the joint following its activation by the nervous system; a muscle torque describes the “strength” of action” (Neumann).
Internal Torque = muscle force (N) within a plane of interest times the muscles associated moment arm length (cm). The larger the moment arm the greater the torque. The moment arm is calculated by taking the perpendicular distance from the joint center to the muscle’s line of pull..
Greater cross sectional area means greater force production. Bigger muscles also increase the internal moment arm of the muscle which means it can produce more torque.
There are two different types of torque, internal and external. External torque is caused by the lifter acting on an object. The moment arm is measured by the horizontal distance between the external load and the pivot point. Internal torque is created by the muscle or elastic force. Moment arm is calculated by the distance between the center of the joint and the perpendicular distance from the muscles line of pull (Beardsley) Larger internal moment arms are desirable whereas smaller external moment arms are desirable. Here are two visuals from “Hip Extension Torque” to help explain moment arms and torque:
This article is going to focus on internal moment arms and how increasing gluteus maximus size effects torque. For more information on this I recommend reading Hip Extension Torque by Bret Contreras and Chris Beardsley.
Gluteus Maximus Hypertrophy to Increase Moment Arm
Increased muscle hypertrophy not only leads to greater force production but also can create an increased internal moment arm therefore increasing torque. Beardsley and Contreras state that, “the degree of hypertrophy affects the length of the moment arm, most likely at all joint angles tested, because a bigger muscle belly changes the muscle’s line of action and pushes it further away from the joint center” (Beardsely). Therefore, ways to maximize gluteal hypertrophy should be of interest to those attempting to lift more weight.
Muscular hypertrophy is created by mechanical tension, muscle damage, and metabolic stress (Schoenfeld). Working at varying intensities, varying exercise selection and progressively increase the work volume is the best way to bring about hypertrophic responses.
While working with lighter weight for higher repetitions may cause metabolic stress, loads should be higher than 65% of 1 rep max to induce hypertrophy. Lower rep ranges can be used to build up strength but moderate rep ranges of 6-12 seem best for hypertrophy. Moderate rep ranges also work to elevate testosterone (Schoenfeld).
Applying exercise variation and progressive overload to gluteus maximus training will help with hypertrophic responses. Even within certain exercises, such as the squat, increasing depth (Caterisano) and increasing stance width to 140% of shoulder width (McCaw) can increase gluteal activity.
Aside from the squat, the hip thrust and deadlift are two great exercises to develop the glutes. The hamstring muscles are a bi-articular joint, meaning they flex at the knee and extend at the hip. During the squat on the eccentric portion the hamstrings are shortened at the knee but lengthened at the hips so there isn’t really too much of a change in muscle length. During the concentric portion the joint is extending at the knee and the hip, so once again one side is being lengthened while the other is being shortened, same concept with the deadlift.
During the hip thrust the hamstrings are shortened at the hip and shortened at the knee so there is a change in muscle length. At this point the hamstrings are their weakest and the gluteus maximus must take over (Beardsley). Contreras et al. state that, “ because the hamstring muscles are shortened during knee flexion their force production capacity necessarily will be reduced during performance of the hip thrust, consequently increasing the contractile requirements of the gluteus maximus musculature” (Contreras). The authors also state that because of muscular tension throughout the entire range of motion of the exercise, the hip thrust would increase the hypertrophic stimulus.
Lastly, the deadlift and variations such as the Romanian deadlift are also great exercise that train the glutes in end range hip extension.
In order to get the most out of the squat and deadlift, maximizing hip extension torque could play a role. Increasing gluteus maximus hypertrophy and thereby increasing the internal moment arm seems to be one mechanism to increase torque. While training for strength the lifter may want to consider adding in hypertrophy work in their program or following their main strength movements. Exercises like the squat with full range of motion and increased stance width, hip bridges, and deadlifts in the rep range of 6-12 would be appropriate exercises to increase gluteus maximus hypertrophy.
Images: permission granted for use from Contreras and Beardsley- http://www.strengthandconditioningresearch.com/specials/hip-extension-torque/
(1) Beardsley C ., & Contreras B. (2012) Hip extension torque: The scientific guide to the posterior chain.
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