My Wife's Butt Got Flat... So I Fixed It In 90 Days

We both have no butts.

That's my wife. She's trained with one of the most jacked personal trainers for 10 years. From the outside, her life looked perfect, but there was one thing stopping her from being truly happy. 5 years ago, she hurt her back badly doing heavy squats, and ever since then, her butt got flat. Sorry, flatter than she'd like. But she's not alone. I've gone from cake to pancake because I not only sit more than I used to, but I also find glute training extremely uncomfortable, so I got lazy with it. But strong glutes don't just make your butt look better in clothes. They help you move better, lift stronger, and can even help with back tightness and knee pain. So for the next 90 days, we're on a mission to build our glutes. She'll build hers with no squats, no deadlifts, and no heavy loading on her spine, whereas I'm free to use whatever I want. And if my injured wife outgrows me, I go vegan for 30 days. Without crazy heavy weights, without squats, without deadlifts, can she still grow her glutes?

Yeah, this is a piece of cake. I know it sounds impossible to you because you built your glutes with heavy squats and deads.

That's Bret Contreras, the man who literally invented the hip thrust and has dedicated his life to studying and growing glutes.

So first exercise we're going to try is the glute dominant step up. Okay, I want you leaning forward a little more. And reach back right there. Tap, come back up.

To build well-rounded glutes, Brett recommends doing 4 movement patterns: a lower body press, a lower body hinge, a squeeze, and abduction. He's used this simple approach to transform even the flattest of butts. But because of Tawny's sensitive back, we do have to find workarounds for the heavy barbell exercises Brett would normally use. Starting with the lower body press, where most people would simply squat.

This looks like a squat. This looks like a glute dominant squat, a box squat with mostly vertical shins. So you're training the glutes as if you were doing a squat anyway. So now that we see that bodyweight was tolerated well, we have a 15-pound dumbbell. So about a 7 kg dumbbell. It's a little harder now.

Yeah.

Yes, this is great. What I want is shin mostly vertical, thigh parallel. This creates the most requisite hip extension torque being furthest out. So she's getting the stretch. She's getting the torque loading, and then this foot maybe a little back right there.

But now we needed a safer hinge movement instead of traditional deadlifts. This is a single-leg dumbbell deadlift, which challenges the glutes as much as normal deadlifts but requires much less weight. But Brett emphasized the key to activating the glutes rather than the hamstrings is to keep that knee slightly bent.

Yes, come up. Don't even straighten it out. Yep.

That's—

yes.

Right there, just like that. Perfect.

Okay, so I'm not coming like full stand up.

Yep, exactly.

How's it feel, babe?

I feel it.

Another one, another one.

So weak. I'm so weak.

So far we're 2 for 2 as we moved into our third type of exercise, the squeeze, which in this case happens to be the exercise Brett actually invented, the barbell hip thrust.

All right, so already I'm thinking, all right, feet back a little. You want the knee at around a 90-degree angle. Crawl up a little higher on this bench. Right there. Okay, now bust out a couple reps. Let me see your natural form. I'm watching to see if she naturally has a tendency to hyperextend the spine. She doesn't. So you might be okay doing regular hip thrusts.

What Brett's watching for as she reaches the top of each rep is whether she's overextending her hips and creating pressure in her lower back, which is the most common cause of back pain when performing this exercise. To avoid this, Brett recommends trying the scoop method, where you tuck your chin down and move from the chest down, tilting your pelvis upwards by by squeezing your glutes. Now you won't be able to get as high, but that's a point.

8. Great form, good lockouts. Yes.

Okay. And with Tawny already lifting heavier than she has in years, we just needed one more exercise to round out her training: a hip abduction movement.

I always call this penalty-free volume. You add it in, it doesn't beat you up, adds to the glute hypertrophy stimulus without fatiguing you much. We're going to put these pads right here so that you get more active range of motion. Now you can hold on the handles. Let's see how this feels. Tap. Make sure you come in and tap.

Oh, for this exercise, you first target your upper glutes while sitting upright, but if you lean forward at the end of your set, you then switch tension to your lower glutes. So by pairing both sets back to back, you can target multiple areas of your glutes to finish off your workout.

General rule of thumb, if you have low back pain, if it feels off If you feel anything during the movement itself, don't do it. Skip it.

With the trip to Brett being a success, here is a workout plan Tawny is going to now be using, training her glutes twice per week and tracking it all in our Built with Science Plus app. As for me, while I will be stealing some of these exercises, I'll still be doing heavy compound exercises like squats and deadlifts, so we'll be able to see if that gives me a huge advantage or not after the 90 days of training. On day 1, Tawny's glute circumference comes in at 92 centimeters, while mine is just slightly bigger at 92.5. But while most people glutes are just about making people turn their heads, your glutes are actually one of the biggest drivers of power, speed, and force production. The most explosive athletes almost always have incredibly powerful glutes. And then there's mine. Slitherin, watch out, watch out, watch out! Okay, so I also want to see if by training my glutes more seriously, it'll lead to any improvement in how high and how far I can jump without actually practicing it, which on day 1 is coming in at— I think that's a winner, right? 51.9. Oh wow, look how far I can jump! And with our baselines recorded, it's time to start training.

Whenever I get close to failure, I get really angry and really mean. Ow! Ow, I hate this one.

Week 1 was rough. For the past 6 months, I've honestly just been lazy with my glutes training, and so they're struggling to keep up.

As for Tawny, I'm a little concerned because I've just finished my first few workouts and my glutes aren't really sore. And to me, soreness means growth and development, so I don't know what that's about.

But multiple studies have actually shown that soreness is not an indicator of growth. Which is actually why Bret chose some of these exercises. He's found that they don't lead to nearly as much soreness or muscle damage as squats, deadlifts, or bulgarians do, helping Tawny recover faster and feel less beat up. However, one proposed advantage of heavy squats is they boost your testosterone levels. Sounds like a serious advantage, right? Well, there is some truth to this. Heavy squats do actually provide a 10-20% spike in testosterone. And the boost we see with squats is higher than it is with other leg exercises like leg press. However, this boost only lasts about 15 to 45 minutes after a workout before returning to baseline. So while it might explain why heavy squats make me feel like an absolute beast, it's not going to provide me with any hormonal advantage over Tawny. But speaking of hormones, I am noticing a big spike in dopamine as it's the first time in years that Tawny and I have trained together. Although she says all my enthusiasm can be a bit much. You want a hug?

No, get away from me.

Which makes it difficult when I offer coaching or push her to train harder.

Ah! Implementing my last set where I did 13 reps, and I would say I did max effort, like that was my max.

I have to tread very carefully. You can put it as max. You did push hard that set.

I did, so I pushed to my max.

But so far, things weren't going quite as smoothly as we expected. Despite doing every exercise correctly, Tawny was very scared of pushing harder, just in the fear of hurting her back again.

My left leg, like my glute, it feels like it's cramping, but also my left side is where I have an issue with my SI and piriformis. So it's hard for me to decipher if I'm having a glute cramp or if I've slightly hurt myself.

And on top of that, she was struggling to eat enough, not because she wasn't hungry, but because she was scared of gaining fat.

If I'm laying it all out on the table here, I'm on my period. Whenever I'm on my period, I always gain a few pounds, usually like 2 to 3 pounds. Like, I can see the water weight. It sits in my stomach, it sits like heavier in my face. So the thought of having to put weight on isn't a pleasant thought for me.

As for me, my glutes were finally getting used to the new volume, and it actually started boosting my squats, making them feel smoother and much stronger. So today I got squats on the menu, and one thing that I'm actually doing is just a very subtle tweak with my form. To emphasize the glutes a little bit more, and you guys can try this too. One way of performing the squat is a bit more quad dominant, and so your back is upright and you let the knees drive forward. But what I'm doing is, since I want to focus on the glutes a little bit more, I'm actually going to focus on keeping my shins more vertical and pushing my hips back, leaning forward a little bit. All it does is it shifts the emphasis a little bit from the quads more so to the glutes, and hopefully that gives me a little bit more of an edge to help win this challenge. And while you might be thinking squats are giving me a huge advantage Jo Bertani. Back in 2023, Brett actually ran a study comparing squats against hip thrusts, and while squats did grow the quads and inner thighs more, for glutes growth, they were both equal. And based on Tawny's progress so far, it honestly seems like I'm the one that was starting to lag behind. I'm telling you, the glutes are popping. Holy—

I don't see it, so I don't know.

What do you mean you don't see it? The camera definitely sees it. Look Good. By week 3, Tawny was setting mad PRs and the gains were clearly coming in. Babe, you just did 135 pounds. That's a plate on each side.

I know. I'm really proud, to be honest, because I haven't done this weight in like 6 years. My girls are proud of me too. And it actually felt really easy. Like, that was 12 reps.

However, Tawny is not the only one getting the cake. Week 3. Oh, whoa, whoa, whoa. Dennis, you see that?

Yeah.

Wow. If this is week 3, can you imagine what week 10 is going to be like? Go. Go. I recently watched Heat to Rivalry, where the actor's glutes blew up online, showing the world just how much ladies appreciate a strong butt. How important would you say glutes are on a guy?

I like athletic glutes on a guy. I don't want, like, a big booty. But I want you to have like something there. Yeah.

Okay.

Like we don't want a guy that can just do like bicep curls. Like go do a squat.

Now technically, Tawny actually has two big advantages over me. First, based on Brett's experience, he's noticed that women seem to recover faster from lower body workouts than men do and can train their glutes with more volume and frequency. While the heavyweights I'm using may be a factor, I am noticing that by the time Tawny's ready to go for her next workout, I still need another day or two to recover and I just can't keep up with how many sets she's been doing. But Second, and this is the biggest factor, about 80% of Tony's training right now is dedicated purely to glutes. Meanwhile, I'm still doing a lot of volume for my quads and my upper body. And although this has yet to be actually studied, when I wanted to grow my shoulders in the past, I scaled back everything else and poured more volume into my shoulders, and it led to the fastest growth I've ever seen. Because when your body has fewer competing priorities, it can move more resources towards one area. So if that same principle applies here, Tawny should be able to outgrow my glutes, which is concerning because I love my meat. And if she wins, I'm going vegan for 30 days. Let's see what measuring tape says. 30 days, your booty is up exactly 1 centimeter.

Oh, is that good?

That's very good. And now it's my turn to measure my glutes after 30 days. The result was not what I was expecting. Come on, what are we at? Ooh, 93.5. No way. Okay. My glutes have also grown 1 centimeter. We are tied. But I may start outgrowing her because based on her tracking in our Bitwise+ app, she wasn't reaching her target calorie intake. If that continued, her progress might eventually stall. So to motivate her, I decided to do something I honestly hadn't done for her in years. I cooked for her. We'll see what she thinks in just a sec, but Tawny and I actually met about 10 years ago at the gym. But as my work got busier and with her back injury, we started spending less and less time together. So my hope is this experiment gives us more to do together and rebuild more than just our bodies. Hopefully I didn't ruin all my chances by butchering this food. Mm. Oh my God. Oh my God, you actually like it? Mm-hmm.

Oh, it's really good. It's like a restaurant.

Really?

Mm-hmm. I'm so happy.

It's the first time in a while that we actually sat down at home and enjoyed a meal together. Now, some of you might be thinking, Tawny has a huge disadvantage with her diet, that you need to live off chicken breast to build muscle. And I used to think that too. But the latest research is making me rethink that. A new study took two groups of lifters, vegans and meat eaters, and had them both eat 0.7 grams of protein per body weight per day. And the vegans ate a variety of protein sources like tofu, soy, and lentils. Whereas the meat eaters obviously relied on meat, protein shakes, and eggs. Now you'd expect the meat eaters to have at least a small advantage, but after 12 weeks, both groups ended up building the same amount of muscle and strength. So as long as you're getting enough protein, it doesn't seem to matter too much where that protein is coming from, which honestly makes me slightly less terrified of going vegan for 30 days. But I still really do not want to give up my favorite foods. And even though we're only 30 days in, I do want to see if we can pass the bar test.

Oh, you're back.

Stop it.

Unfortunately, we both couldn't stop the bar, but if you watch closely, I kind of did manage to stop it a little bit. And that is when Tawny decided to take her glute training to the next level. So far, Tawny's been doing around 20 sets of glutes per week and seeing some pretty good progress. Holy shit, wow, that's crazy. But for Brett's clients that want the most growth possible, he takes this all the way up to 30 to 40 sets per week. That extra volume seems to speed up their growth. And so for Tawny, this means ramping up her glute training from 2 to 3 days per week.

And that makes me really nervous because I'm not going to lie, with my back injuries, so it's just like a fear thing for me. And I really, really hope that I don't hurt myself, hurt my back, because I really want I want to reach my glute goals. I don't want to let Jeremy down. I don't want to like get frustrated and let myself down.

Now, first everything felt fine, but slowly tightness started building up in her upper left glute and then into her lower back. And eventually this happened. And so we decided to put the challenge on pause for a few days.

Oh, so I hurt my back at the gym yesterday and I came today to try to work out and it's very clear that I'm going to need a few days off, which is really frustrating for me.

Tawny is at work right now, but she just sent me a text and just saying how she's not feeling too well. She's a bit sad. And I think what's going on is that this challenge is putting a lot of pressure on her. I think like she not only wants to win, obviously, but she just doesn't want to let you guys down. After a few days of rest, thankfully her back started feeling better.

I feel so good.

Do you want to go back on the challenge? Totally fine if you want to drop out, no hard feelings.

Why are you scared you're going to lose?

No, I'm trying to be nice, okay? But fine, I'll take that as a sign as you are ready to go back, and I'm just going to say I'm not going easy on you, okay? Okay. All right, all right, let's go. But after just a week off of training, Tawny's glutes felt and looked a bit flatter than usual. And she started worrying she was losing muscle. And she wasn't just imagining it. When you stop training for a week or two, your muscles store less glycogen. And since glycogen pulls water into your muscles, they'll look less full. It's kind of like letting air out of a balloon. But while your muscles might look flatter and your strength might also dip because you just haven't practiced your exercises, most research suggests it takes at least 3 weeks or more of no training to start losing actual muscle. That said, we definitely do not want her to hurt her back again. So even though we might see a bit more growth training her glutes 3 times a week, it was a no-brainer to dial her training back to just 2. And to help keep her consistent, we even found some creative ways to do her workouts at home, which we've even added to our Built With Science+ app. That way our members don't need to always rely on the gym to make progress. And with only a few weeks left, Tawny's glutes were making the fastest progress ever. And if I'm gonna be honest, Even if I lose and have to go vegan, this challenge really is a win-win for me. While Tony's glutes were blowing up, all of my glute training was actually leading to some unexpected benefits. Today that felt more like a jog. My treadmill can't even go any faster, but definitely feels like my glutes are contributing more to the run. Like it's helping me with my run. And all these benefits weren't from actually changing much to my leg workouts. I mainly just started doing hip thrusts again and experimented with some of Brett's exercises. Which helped my other exercises feel stronger, and more importantly, just helped my body move and feel a lot better than it used to. So if you've been neglecting your glutes like I was, just start by adding 3 hard sets of hip thrusts to your leg days. But with 1 week before our final results, we decided to take a trip to Hawaii to show off our glute gains. Holy moly, what the heck do we have here? And on the final day of the experiment. She didn't just bring the heat to the beach, she broke another PR. First time ever, 2 plates on the hip thrust.

I am finally done my glute video with Jeremy Ethier. I am so grateful that Brett Contreras let us come into his home. He showed me a bunch of lower back-friendly glute exercises, and I'm forever grateful for him for that, because doing this challenge just showed me that I am capable and there are ways of getting a booty.

As for me, I've got one more final test. After 90 days, did these glute gains actually improve my jump performance? So that is pretty much a 5 centimeter increase, which is pretty impressive. I wasn't sure if my glute strength growth would impact vertical jump at all, but that honestly motivates me even more than just the growth, is seeing the athletic performance there, because I love playing sports too. So my vertical jump went from just beating average to now being on the high end of above average, though still not enough for my Asian mom to be proud. But broad jump scored excellent on day 1, and I still managed to increase it by 2 cm. Not bad, not bad. But now it's time to measure the glutes and see who actually grew them the most in the past 90 days. Final day is here. I am extremely nervous, especially after seeing what I'm, what I'm up against today. I'm done. There's no way. So you started at 92 centimeters and today you are at 94 centimeters. 2 centimeters of growth. Good job, baby.

I wanted 95. Now, did I win?

Please, God. There's no way.

That's where you are.

Yeah, it means you. There's no way.

You can't. All right, do it again.

You're right here. All right, guys, we have measured and I am what?

Plus 2.

Which means?

I am plus 1.5.

Which means?

Which means I'm cooked. You won, you won, you won, you won. I also won. I also won. But it wasn't until I tried on my wife's shorts that I truly appreciated my new glute gains. So while this does mean I have to go meatless for 30 days, at least this gives Tania and I a chance to enjoy more dinners together. Oh, and she's got some serious cake that I could stare at all day. So still feels like a win for me. I'm honestly just so proud of Tania. She's overcome like some of her biggest fears and she's genuinely enjoying the gym again. And she did all of this without lifting crazy heavy. I think it goes to show you that there's no must-do exercises. What matters the most is good form and choosing exercises that actually fit your body and feel good. And that is actually why we created the Built with Science Plus app. Both mine and Tony's workouts are in there, but the program adjusts based on how your specific body responds to your plan, so you're not just copying somebody else. And if you want to try it, you can test it out completely free for 2 weeks. Just scan the QR code here or head to builtwithscience.com. And if you guys want to simplify your glute training and focus on the only 2 exercises you actually need to fix your flat butt, give this video a watch next, which we recorded with Brett. Thank you so much for watching, and I'll see you next time.