Every day, millions of people ask Google some of life’s most pressing questions, big and small. And I’ve taken it upon myself to provide you with the answers.
Today, I tackle some of the most popular questions on the subject of squats, what muscles they do (and don’t) work, and whether they’ll make your glutes bigger.
1. Do Squats Work Your Abs?
Squats do work your abs. However, they don’t work them to the extent that you can get away without doing any direct work for your abdominal muscles.
Let me explain.
When they talk about the abs, most people are referring to rectus abdominis, which is the muscle that extends down the stomach from your ribs to your hips.
Alongside rectus abdominis, there are several other muscles that make up your abdominals, including the external obliques, the internal obliques, as well as transverse abdominis.
All of them, transverse abdominis and the internal obliques in particular, play an important role in generating intra-abdominal pressure.
They work in tandem with your spinal erectors, those cable-like muscles that run up both sides of your spine, to stabilize your spine and keep your upper body rigid when you squat.
Rectus abdominis certainly plays a role in keeping your upper body stable when you squat, and the contribution it makes to the stability of your torso will increase as the load you’re squatting goes up .
In short, while squats are primarily a lower body exercise, various muscles in the upper body are also involved to varying degrees.
Even just maintaining a standing position with a heavy barbell across your shoulders is going to involve some level of core muscle activity. Without those core muscles working to keep your torso stable, your upper body would collapse.
However, that doesn’t mean you can get away without training your abdominal muscles directly.
That’s because there’s a difference between recruiting a muscle and stimulating a muscle. A muscle needs to be both recruited and stimulated to a degree that’s sufficient to trigger some kind of positive adaptation.
And most research to look at core muscle activity during the squat shows that rectus abdominis activity is relatively small.
The figure below comes from Dr. Jeffrey McBride, a Professor in Biomechanics at Appalachian State University. It shows the extent to which rectus abdominis was activated during a variety of exercises, including the barbell squat and deadlift.
Even when subjects were lifting a heavy weight that was around 90% of the maximum weight they could lift once, rectus abdominis wasn’t doing much.
Similar results are reported in a trial involving a group of elite male rugby union players .
These were reasonably strong guys, sitting roughly halfway between “intermediate” and “advanced” in terms of squat strength. Not the typical “untrained beginner” often used in this type of study.
The researchers used electromyography, EMG for short, to measure muscle activity in various upper and lower body muscles during the barbell squat, overhead squat, as well as various ab exercises.
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Once again, rectus abdominis didn’t have to work very hard during the squat – only around 10% of its maximum. In fact, the researchers found “substantially larger” abdominal muscle activity during ab exercises like the plank, sit-up and jackknife.
The overhead squat did work some of the core muscles harder than the regular back squat, but the difference between the two exercises was relatively small (between 2-7%).
With all of that said, the research on the subject does come with some important limitations.
For one, most studies use electrodes placed on the surface of the skin to measure trunk muscle activity.
But during the lowering phase of the squat, you will lean forward. As a result, skin in the stomach area can fold, moving the electrodes further away from the abs, which may lead to measurement error .
The extent to which the various core muscles are involved during the squat also depends on who’s doing the squatting.
If you’re squatting with heavy loads, wearing a lifting belt, performing the valsalva maneuver and pushing your stomach out when you squat, rectus abdominis is going to be working harder compared to squatting with a lighter weight, not wearing a belt and using a different bracing pattern to create intra-abdominal pressure .
But all things considered, if getting a six-pack is high on your list of priorities, I’d suggest doing exercises that work your abs directly.
When I go for a walk, my quads are active. They’re working. They’re doing something. But they’re not being stimulated to a degree that’s sufficient to generate the adaptations I want.
It’s the same with rectus abdominis when you squat. It’s certainly involved and active, but not to the extent that you can get away without training it directly.
2. What Muscles Do Squats Work?
Barbell squats work mainly the muscles in your thighs (the quadriceps and adductors rather than your hamstrings), your arse (the glutes) and your lower back (erector spinae).
There was an interesting study that looked at the rate of growth in various muscles after 10 weeks of squatting twice a week .
Three of the four muscles that make up the quads (with the exception of rectus femoris) grew by around 5%. The adductors and glutes grew by 6-7%. In contrast, the hamstrings didn’t grow at all.
The relative contribution of each muscle is going to vary depending on how deep you squat, how wide your stance is, how far forward you lean as you descend, and so on.
But in most cases, the quads, glutes, erector spinae and adductors are doing the majority of the work involved in moving the weight from point A to point B.
3. Do Squats Make Your Thighs Bigger or Smaller?
Squats work many of the muscles in your thighs. Assuming that your training program ticks the right boxes in terms of the number of sets and reps you do, the amount of weight you’re lifting, and the number of times each week that you squat, it’s highly likely that your thighs are going to end up getting bigger.
What if you’re squatting with just your own bodyweight or a couple of light dumbbells, stopping well short of the point where your muscles hit fatigue, and just going through the motions, trying to crank out as many squats as you can without paying much attention to how those squats are being done?
In this case, any increase in the size of your thighs is going to be minimal.
Can squats make your thighs smaller? Squats, in and of themselves, aren’t going to make your thighs smaller. Squats can certainly form part of a diet and training program that leads to fat being lost. And, if some of that lost fat ends up coming from your thighs, your thighs may well end up getting smaller.
But that wasn’t because of the squats by themselves. It was because of all the other things you were doing (diet in particular) to get rid of the fat.
A lot depends on you and how you’re put together. Genetics play a big part in determining where you store fat, and where it comes from when you lose it.
Let’s say that you’re someone who tends to store a lot of fat in your thighs, your muscles respond well to resistance training, and they’re growing from all the squats you’re doing.
In this case, even if you’re on a diet and losing fat from other areas of your body, your thighs may well end up getting bigger rather than smaller.
4. Do Squats Make Your Arse Bigger or Smaller?
Glutes… buttocks… booty… butt… arse… call it what you will. If you’re doing them properly, squats are an effective way to work your gluteus maximus. And, as with the thighs, if your training program ticks the right boxes in terms of volume, frequency and effort, your gluteus maximus is going to end up getting bigger.
5. Do Squats Burn Fat? Can You Use Squats for Weight Loss?
Squats will certainly lead to some amount of fat being burned, particularly if you’re doing multiple sets, lifting heavy weights, and pushing yourself hard. They can also form an effective part of a diet and training program geared towards weight loss.
However, the contribution that squats, in and of themselves, make to weight loss is relatively small.
If you’re wondering whether this exercise or that exercise burns fat and can be used for weight loss, you’re asking the wrong question.
When it comes to losing weight, the food you eat is a lot more important than the exercise you do. Strength training… HIIT… steady-state cardio… metabolic training… all can be useful at different times, and for different people.
But they’re not going to help you lose fat if your diet isn’t set up properly.
6. How Many Reps of Squats Should I Do?
That depends a lot on you and your goals. In most cases, somewhere between 5 and 20 reps will get the job done.
If you want to focus on getting stronger, keep your reps near the lower end of that range. If hypertrophy is the main objective, you can use a variety of reps, from low to medium to high.
Put differently, sets of 5, 10 or 15 repetitions will all make your muscles grow. But it’s the sets of 5, done with heavier loads, that will typically lead to faster strength gains.
These 30-day squat challenges that involve cranking out hundreds of air squats aren’t going to do much. They’re certainly better than nothing, particularly if you’re a complete newbie. But there are far better ways to work your quads and glutes than doing hundreds of bodyweight squats every day.
RELATED: High Reps vs. Low Reps for Muscle Growth: What the Science Says
7. Do I Need to Do Squats?
Squats are often referred to as the king of all exercises. But unless you’re a powerlifter who needs to squat because it’s one of the exercises used in competition, there’s no rule that says you have to do it.
The same holds true for deadlifts, the bench press and every other compound exercise that you’re told is critical to your progress.
Yes, the squat is an effective compound exercise for working the muscles in your hips, thighs and lower back. But there’s nothing magical about it, and no good reason why you can’t replace it with something else. There are plenty of other squat alternatives you can use to work the exact same muscles.
If you can’t seem to get the hang of squatting, but you still want to work your quads and glutes, use the leg press. If you don’t have access to a leg press machine, do split squats. If you want to train your glutes with minimal involvement of the quads, try hip thrusts.
8. Do Squats Burn Fat in Your Thighs, Belly or Arse?
You’ve got an area of your body that you’d like to lose fat from, be it your belly, thighs, arse or wherever. And you want to know if squats are going to help you get rid of the fat from that area. If you’ve got fat thighs, for example, will doing squats make them smaller and slimmer?
Squats can certainly form part of a diet and training program that leads to fat being lost. And some of that lost fat may happen to come from whatever area of your body you want to lose it from. However, doing exercises targeting a particular body part is no guarantee that fat will be lost from that specific area of your body.
When you work a specific muscle group, you develop the muscle that sits underneath the fat. But you’re not shrinking the fat cells in that area.
Researchers from Chile discovered as much when they looked at how training just one leg affects body composition .
There was no significant difference in the amount of fat stored in each leg, even after 12 weeks and tens of thousands of leg presses.
Fat was lost from the arms and trunk. But the leg that was exercised contained no less fat at the end of the study than it did at the start.
Squats may well lead to fat being burned in your thighs. But burning fat and losing fat are an entirely different thing. When it comes to getting rid of fat, what counts is the difference between the amount of fat that gets stored and the amount of fat that’s burned off.
If you’re eating more calories than your body needs to maintain its weight, any fat that’s burned off will end up being replaced.
Training a particular muscle may appear to lead to spot reduction.
However, what looks like a reduction in the thickness of subcutaneous fat is nothing more than an increase in the size of the underlying muscle. This leads to the compression of the extracellular space between fat cells, creating the illusion of spot reduction [7, 8].
The total amount of fat under the skin remains the same. It just takes up less space because the muscle underneath has got bigger.
In summary, squats do work your abs. But do they work them hard enough that exercises like crunches, planks or rollouts can be left out of your workouts?
That depends a lot on you and your goals. Do you want a six pack? If so, squats alone are unlikely to do the job, and your workouts will need to include exercises that work the abs directly.
But if all you want is a strong core, a program of heavy strength training built around compound exercises like the squat, deadlift and overhead press will be sufficient for most people.
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