The ideal moment arm of the gluteus maximus is closer to hip extension than hip flexion, and there could be value in a purer hip extension exercise that isolates the glutes closer to the end of its range of motion. Nonetheless, moment arms are relative to other muscles involved in the exercise, so a squat or leg press done properly will certainly emphasize the glutes, with more active and passive tension for muscle growth. Classic natural bodybuilding also means not overdeveloping the hip muscles to promote a dramatic V-taper, with wide shoulders and lats alongside narrow waist and hips, so apply the hip thrust thoughtfully.
The hip thrust is similar to a bridge but with more range of motion, which comes from raising the back on a bench. You can also lay a weight across the hips to add a load such as with the barbell hip thrust.
The hip thrust has caught on as one of the best exercises to focus on your rear and to boost your sprinting speed.
Like many ideas that catch in fitness, the hip thrust has caught on for reasons that go beyond its value.
An expert will show some research and state their points on as many sources as they can. Other gurus then pounce on it with their own gains in mind, endlessly praising it so that the idea takes hold. This sways the masses and the concept sticks.
The hip thrust defies how our bodies evolved to work. The argument for this and a whole host of bad exercises tends to state:
- Isolation allows for a better contraction.
- The exercise primes the muscle for a more functional movement.
- It hits the muscle uniquely, perhaps with a different loading pattern throughout the range of motion or some change in position that adds variety.
These arguments have flaws. Any exercise that works a muscle through enough range of motion will lead to lactate buildup though. This may cause a feeling of working it well, but that does not makes it worthwhile.
Whenever a man does a thoroughly stupid thing, it is always from the noblest motives.
– Oscar Wilde
- It causes active insufficiency of the hamstrings and calves.
Active insufficiency gives us a clear signal of how poorly this exercise works.
Your muscles have an ideal length. They work strongest in the middle portion of any good movement. They form more connections here due to allowing a better overlap for your contraction sites. At the endpoints of any motion, the sites that allow for these connections stretch too far apart or overcrowd.
Though you may feel stronger or weaker at the endpoints due to leverage, these positions always involve less tension. Tension is the main stimulus for size and strength.
This also does not always occur at resting length. For example, the resting length of your biceps when assuming anatomical position is a stretched and weak position. When you stand, your glutes rest in a shortened state. This calls into question favorably comparing the standing position with the hip thrust.
The hamstrings act on the hips and knees. When moving normally, you shorten this muscle group over one joint and lengthen them over the other. This keeps the ideal length for tension.
With a non-functional movement such as the hip thrust, you shorten the muscle over more than one joint. This allows too much slack and can cause the muscles to cramp. Your body would never allow you into this position, unless you command it to behave otherwise.
The large calf muscles act on the ankles and the knees. When you hip thrust on your toes, they also bunch up. They shorten over each joint as well.
The hamstrings and the calves try to work during the hip thrust, so you cannot just turn them off. Experts will tell you this is an advantage. You do not get a better contraction by limiting these muscles though, you get a harmful exercise. Muscles in fact work harder when allowed to work together.
As a final point to consider, know that the best exercises work our muscles similar to how they had to overcome gravity or perform everyday tasks.
- The weight fails to match the strength curve.
The hip thrust loads the glutes as they bunch up. This is a bad effect from too much range of motion on any exercise, loading the working muscles about the same even at this weak moment. You may hip thrust a decent weight because of the short moment arm, but this matters not since it loads the muscles poorly.
- It relies upon a bad setup.
When loading the hip thrust, the barbell, even with a pad, rests on the bone of the front hip without any muscle support.
- It encourages hyperextension of the spine and hip.
Just because your muscles can move through a range of motion does not mean you should load it throughout that full range.
Hip thrusts lead to hyperextension of the hip. Loading hyperextension can place harmful forces on the joints. The joints are in odd positions and the muscles work weakly.
Hyperextension may feel like a strong contraction due to the bulge you see and feel when your butt tenses up. This results from shortened fibers that create less force. It may happen when you sprint in the final phase but you do not launch yourself from this position.
Hyperextension of the lower back should never occur, at least with a load. You should maintain a neutral back during all exercises. The hip thrust can cause a posterior pelvic tilt too.
It brings a host of problems beyond these examples since it is not a natural movement. Hip thrusts force you into these poor positions by its very nature.
- It is an isolation exercise that matches no function.
- is inefficient.
- places shearing forces on the joints.
- allows less tension for growth.
- removes synergy.
- supports muscle imbalances.
Some differences in using each portion of the glutes do exist. The upper and lower parts have different functions. They work together for hip extension though.
Instead, you just use an exercise that develops these muscles less effectively. Become strong and then transfer that strength toward sprinting. Achieve this by practicing sprinting itself.
Squat Instead of Using the Hip Thrust
The barbell squat will build up your rear. It improves lower body power best since it also best allows hip extension with a load. Using good form, which means avoiding extremes, then brings all of the muscles into play.
Avoid having a long list of exercises. You either work the muscle at a weaker or stronger length, with the best range close to the middle, if you choose the right ones. The best movements use many muscles at once and safely load the joints mostly through compression.