Today’s Ask-Bret-Contreras question was forwarded to me from my friend Marianne; a fellow trainer from Ireland. Marianne felt that I’d be better suited to answer this question than her. While I probably have more biomechanics knowledge about this exercise, she definitely has the greater booty! Check it out below. She also has a much better accent than me, but I digress.
Hi Marianne, ready for one of my technical questions? I was discussing with my trainer this morning and told him that I wanted to do single-leg hip thrusts the way you demonstrate them in this video (elevated shoulder and elevated foot, on the bench). He was telling me that by doing the single-leg hip thrusts on the floor I could obtain exactly the same results. Do you agree? (I don’t, but I would like to hear your opinion). Thanks, Bianca
Hey Bianca, you show great instincts by wanting a second opinion regarding this topic. Here is my answer:
1. Proficiency in the single leg glute bridge and bilateral hip thrust should be reached before progressing to the single leg hip thrust. If you progress too quickly and jump ahead to single leg hip thrusts when you haven’t built up a base of strength on easier variations, tissues in the lumbar spine, sacroiliac joint, or anterior hips could be irritated because your form will be compromised as you try to fling and contort your body to conduct the lift. You must be able to control your body through a full ROM, which means that the tempo is smooth and the body stays in the sagittal plane, with no compensatory movement in the frontal and transverse planes. The single leg hip thrust is an advanced exercise and is not suitable for 80% of beginners. Athletes are exceptions to the rule, but even many of them aren’t able to properly perform single leg hip thrusts until they’ve gained strength and coordination from single leg glute bridges and barbell hip thrusts.
2. Range of motion increases by 250% when you elevate both the shoulders and the feet. Think about it like this. If I started doing bodyweight squats and push ups, but I only went a third of the way down, I could probably get a hundred reps of both lifts. But I wouldn’t be getting a stretch in any muscle, I wouldn’t be strenthening the initial ranges (only the end ranges), and I’d be using mostly my quads in the squat and my triceps in the push up. On the same line of reasoning, if I wanted to do bodyweight glute bridges, I could probably bust out 200-300 reps. But I’d be focusing on end range strength, the hamstrings wouldn’t receive a stretch, and I’d be using mostly the glutes.
Initial range hip extension involves a higher proportion of hamstring and adductor magnus contribution (as well as other adductors and the posterior fibers of the gluteus medius and minimus), while end range hip extension involves a higher proportion of gluteus maximus contribution. When full range of motion is used, suddenly the exercises become much more challenging. Switching from bodyweight partial squats to bodyweight full squats and from bodyweight partial push ups to bodyweight full range push ups, I’d probably struggle to get 50 reps in a row without stopping. And switching from bodyweight glute bridges to bodyweight hip thrusts… well…I actually know how many I can get. Back when I owned my training studio Lifts, one of my trainers challenged me to see if I could get 100 bodyweight hip thrusts off the Skorcher, a machine I invented that is similar to a shoulder and elevated hip thrust but let’s you use barbell and/or band resistance. I ended up getting 100 reps (he beat me and got 110 reps), but my glutes and adductor magnus were crippled for three to four days due to the fact that my muscular tissues weren’t accustomed to that rep range. I certainly won’t be doing that again anytime soon!
I could probably perform 50 single leg glute bridges, but I’ve “repped out” before on single leg hip thrusts and 20 reps absolutely destroys me. Based on my experience, highly fit individuals can often perform over 30 repetitions of single leg glute bridges but only 10-15 repetitions of single leg hip thrusts (done properly where the body is controlled through a complete ROM and no lateral or rotational energy is leaked).
3. Due to the fact that full range bodyweight lifts are more difficult than partial range bodyweight lifts, they allow most individuals (especially beginners, heavier individuals, and people who aren’t that fit) to stay in more suitable rep ranges for strength, power, and hypertrophy rather than muscular endurance.
4. Muscle activation is far higher for the hamstrings and higher for the glutes in a single leg hip thrust compared to a single leg glute bridge, due to the increased ROM and increased stability demands. For example, a foot elevated single leg glute bridge and single leg glute bridge may get one’s glute activation up to 30% of MVC, whereas a shoulder elevated single leg glute bridge might bring glute activation up to 35% of MVC. But when you elevate both the shoulders and feet, now activation levels of 40% of MVC might be reached. Everyone is different regarding muscle activation, but in general elevating the feet increases hamstring activity, while elevating the shoulders increases quad activity. Elevating both the shoulders and the feet is definitely the most difficult variation, especially if you perform the “bottoms up” method shown below where you touch your butt to the ground.
5. The increased functional demands of the single leg hip thrust lead to excellent rotary stability and full range hip extension strength, which carries over to other lower body activities. The same cannot be said of the single leg glute bridge, which doesn’t challenge the rotary stability system as much and doesn’t move the hips through deep levels of hip flexion. For sports that require speed and power, full range hip extension strength is critical, which makes the single leg hip thrust a much better choice over the single leg glute bridge.
6. My guess is that the trainer has never performed the movements himself and he’s too naive to realize that the increased ROM makes the exercise much more challenging. Many times I’ve been guilty of making assumptions about exercises, only to find out that I was wrong when I finally got around to performing the exercise for the first time. This is why it’s so important for trainers to experiment and stay in good shape, so they can evaluate new exercises, methods, and programs. It’s also why trainers and coaches should not make assumptions!
I hope that answers your question! -BC