The Science of Squats

 / 4.9

Please log in to rate this article! Log in/Registration


The squat is considered a pretty simple exercise by many bodybuilders and other athletes. On the surface, all you need to do is put a bar on your shoulders, bend your knees until your thighs are parallel to the ground and stand up again. But, the squat and all of its variants are actually very complicated. To do this exercise effectively, squats require the following:

  1. Maximum ability to stabilize the spine, the upper body and the hips, so that you can support and move the weight;
  2. Maximum flexibility in the hips and the ankles to enable you to make the most of the appropriate motion range in the knees, the hips and the ankles;
  3. An appropriate tilt of the trunk and the shins;
  4. A great power of the muscles around the hip and the knee joints and a similar power in the lower back.

In this article we are going to examine several variants of this wonderful exercise in detail, including proper performance for maximum effectiveness.


The squat follows one basic performance pattern. Variants include different leg and trunk positions including dumbbells or barbells, and different depth levels as well. Let’s start with the basic exercise before taking a look at the variants. Stand in a shoulder-wide stance or wider, with your feet looking straight ahead or slightly outwards. The accurate positioning depends on your natural standing position. Pull the upper part of your back backwards (by pulling your shoulders back). Hold the bar behind your neck and across your shoulders. It should be supported by your traps, not your spine. Your grip should be 15-20 cm wider than your shoulders, depending on your individual comfort. Your elbows should be pointing downwards, not backwards. Pull your lower back muscles together to fix your trunk in its position. Take a breath and hold it. Then, lower your hips downwards and backwards, as if you were sitting down on a chair. As soon as your hips are moving downwards, tilt your trunk slightly forward. You hips will move backwards beyond your heels, your knees pointing straightly outwards above your feet, and the bar should remain in a vertical plane above your knees. Look straight ahead, as you are lowering your body. Lower your body until your thighs are parallel to the ground or slightly lower. As soon as you reach the lowest position, slow down and, using your muscles (never by swinging!), simply change to the opposite direction while pushing the heel/midfoot area against the ground (technically, directly downwards, along your shins, the main bones of your shanks). Then, stand up with your hips tilted forward. Exhale as soon as the most difficult part of the rising stage (the halt) is over. Bodybuilders should stand somewhat wider than a shoulder-wide stance. Doing so, they do not need to balance that much and can work with heavier weights. Plus, if you stand slightly wider than shoulder width, you’ll need somewhat less flexibility in the hip and ankle joints, which enables proper trunk positioning, a key to safe performance. However, to reach the optimum angle for your trunk while maintaining the slight arc in your lower back, you’ll need excellent flexibility in your hip joints, especially in your hamstrings. If your feet are closer to each other while your are lowering your body to the squatting position, your hamstrings will undergo strong excentric contraction, forwarding this pull to your hips, forcing them to turn under your spinal column. To balance this force, the erector spinae muscles need to be strong enough to keep the lower back in a firm, stable and arched position. This position exerts even more tension to the hamstrings. However, at the same time, it enables them to play an important role in the initial phase of the rising stage, especially if you lower your body further than the position in which your thighs are parallel to the ground.



Your eyes should look straight ahead, and the plane of your chin, head and neck should be naturally in line above your spine. This is important for the proper position of your spine and also for ensuring balance and maximum safety. If you are keeping your head straight, your straightening reflexes will automatically pull the erector spinae muscles together, which will keep your spine in a safe and stable position. Looking upwards may cause problems with balancing, while looking downwards will bend your back. Therefore, both positions should be avoided.


Keep your back straight; pull your shoulders backwards and keep your lower back firm (naturally slightly arched). However, “straight back” doesn’t mean you have to keep your upper body in a perfectly vertical position. When squatting with free weights, you will inescapably bend slightly forward so you can keep the balance and keep the weights above your knees. The trunk will tend to move together with the hips and the knees to keep the bar above the knees. The movement range of the trunk depends on the strength of the lower back muscles and the flexibility of the hamstrings. If the hips are continuously moving downwards, it will be easier to keep the proper trunk position, provided that the flexibility of the hamstrings or the Achilles tendons is not limited.


Considering the development of the hamstrings, the position of the bar is best when it is above the shoulders and exactly under the 7th cervical vertebra so that it is supported completely by the traps. If you position the bar too high on your spine, it will not only be uncomfortable but may cause spine problems as well. A towel or pillow can make this exercise more comfortable. However, do not twist the towel too tight because it might slip and change the center of mass relative to your body, causing balance problems. If you feel discomfort, move your hands slightly towards your midline. Doing so, you can pull your shoulders back and the bar can rely on a larger surface. If your grip is too wide, the bar is laid on the middle of your traps and the weight is concentrated to one small surface.


In general, the motion itself should be slow, especially if you are still learning how to squat. To maximize the weight, muscle development and safety, it is inevitable that you focus on proper performance. The key factors are the following: keeping your back straight, with a small natural arch at the lumbar area and between your shoulder blades; keeping your thighs and back firm while “sitting down” (imagine you are a spring which is being pressed together); slowing down the downward motion using muscle power, similarly to pressing a spring gradually; never bounce in the lowest position but focus on your body position, the position of the bar or the dumbbells and maximum muscle efficiency along the axes of your shins (tibia) and through flexing your glutes persistently, pressing directly downwards to force your hips to tilt forward as you are rising. So, in order to master all this, you need to move slowly. As you grow familiar with this exercise and get more comfortable with it, you can increase the speed of performance. Knee injury (the most serious of all dangers associated with squats) is definitely a result of inattention, when changing direction at the lowest point (following from bouncing and overexertion of the connective tissues of the knees). The greatest power is exerted in this phase (when changing direction of motion at the lowest point). And, at the same time, the muscles are the most tired and the knees and the surrounding connective tissues are the most vulnerable in this position (most favorable biomechanical position).


Proper breathing is as follows: inhale (to about 75% of your maximum capacity) and hold your breath while lowering your body until the most difficult part of the rising stage is over. Then, exhale. Holding your breath is very important, as this creates higher pressure within the chest and the abdominal area, which helps keep the spine and the upper body in a stable position. Doing so, you can exert a greater force safely, and, consequently, develop larger and stronger muscles. Between reps, feel free to breathe as you like.


Apply thumb grip (your thumbs should cross your fingers), grabbing the bar so that both hands are in an equal distance from the middle of the bar. It is a common mistake frequently made by beginners, that their hands or arms are above the bar or they hold on to the weight plates. These methods are not recommended because the dumbbells or the bar may rotate during the exercise, which may lead to loss of control above the weights or even injury. A somewhat narrower grip will help you keep your body firm and your upper arms pressed tight to your back, with your elbows facing downwards (twisting your shoulders outwards to the maximum).


Beginners often use heel plates or small weight plates which can help them keep the balance, often by compensating insufficient flexibility of the ankles/Achilles tendons or the hips. If you are unable to squat comfortably with your heels touching the ground, you need more flexibility training. In this case, heel plates can be useful, because they will enable you to push through your whole soles, particularly through your heels instead of your forefeet (which may happen often if you are not flexible enough, or if your heels are actually not touching the ground). Pushing downwards through your shinbones instead of your forefeet will not only enable you to use heavier weights, but it will also reduce the load on the knees and the risk of injury. More experienced bodybuilders usually use heel plates if they want to maximize the work and development of the quadriceps. Lifting your heels can have several different consequences. If you are squatting deep as mentioned above, with your shanks and upper body in a similar angle, the bend (and stretch) of the knees is enhanced, therefore, more load is exerted on the quads and less on the hips and the trunk. The angles of the shins are often the same and, if you are not careful, your knees may stretch beyond your feet. This way, more tension is exerted on the knees, which can easily lead to tendinitis or other serious issues in the knees or the surrounding connective tissues. Furthermore, since heel plates or weight plates are not fixed to the ground and tend to slip when you are stepping back on them, they can lead to balance issues and increased risk of serious injuries caused by misstep, slipping or twisting your body, especially if you are tired or using heavy weights. If you lift your heels while squatting, you should consider using strong weightlifting shoes, trainers or even boots with good heel and ankle support, and with heels thick enough.

“How deep you lower your body while squatting does not matter as much as the way you reach that position and come back from it.”


The depth of squats has been a controversial topic for a long time. However, there is a general consensus we can rely on, concerning safe and effective performance. It is actually not clear why the knees would be the only joints which cannot move safely in the full motion range. Olympic weightlifters who squat really deep (their butts almost touch the ground) do not suffer more injuries than bodybuilders or other athletes who only lower themselves until their thighs are parallel to the ground. Therefore it doesn’t matter that much how deep you lower yourself, but the way you get to that position and rise back, and the way you perform the exercise overall. If you meet the necessary physical prerequisites, you should lower your body until your thighs are parallel to the ground or lower. The depth of squats also determines the contribution of your muscles. If you are physically capable, you can lower your hips even deeper, while maintaining proper spine position and keeping your heels on the ground, without your knees going ahead of the plane of your shanks. We can say it is a general rule that the knees never get injured in this position. Injury only occurs if the knees get ahead of the soles. Therefore, when defining the ideal squatting depth for you, you should take proper body positioning into account. Medical and professional bodies have too often deemed several exercises harmful because of the injuries that have occurred, without actually having examined the reasons. Similarly to other exercises, in the case of squats, the key to safety is strict performance and proper body positioning.



This exercise differs from the basic squats in several aspects. The bar goes lower on the back, which will automatically make the trunk tilt forward and remain tilted for longer than in the case of any other variant. This changes the upper body’s center of mass. The effect is similar to the case when the head of an axe is moved downwards, towards the handle. This itself makes it easier to lift the same weight or even more. Concentrating the mass will make it easier and more natural to keep the bar in the middle above the knees, and also makes it easier to exert force downwards, through the heels or the midfoot area. A tilted trunk and related biomechanical changes require strong glutes and quads to work hard. Legs are in a wider stance; the feet and the knees are pointing further outwards. A wider stance reduces the distance of moving the weight, and strong adductors will be involved in the work, too. As a result, you will be able to use considerably heavier weights and develop your glutes, hamstrings and back to the same extent as the quads or better. So, you can generally achieve bigger growth for the thighs with this method.


The Hack squat has several variants. The first one is doing Hack squats with free weights. In this variant you keep the dumbbells tight next to your body, under your glutes. You stand with a straight upper body, often on a foot holder to help you keep in balance and center the effort to the quads, especially to the lower parts. The key is that you should push downwards through your heels. Even moderately heavy weights will make the exercise very exhausting and effective. In the case of Hack machine squats, the weights are also positioned behind your body, but there is no problem with the balance. This will enable you to slightly change your position, adjust the weight on your shoulders and target specific areas or muscles. The feet are usually positioned at the front of the foot holder and the lower back area (the hips in particular) is pushed backwards, into the sliding cushion. Pushing your hips into the cushion as you are rising up will fix the hips and the lower back. This way, even sufferers of lower back pain can perform this exercise without feeling any pain. In the case of this exercise (similarly to the Smith machine), experimenting with feet position and focusing on different areas enable you to develop any part of the thighs upon necessity. If you pull your hips away from the sliding cushion, the exercise will look more like Sissy squats, exerting more load on the quads and less on the glutes and the hamstrings. For keeping your feet directly under your shoulders (similarly to the basic squats), you’ll need good flexibility in the ankles and the hips. And again, you need to make sure your knees do not go ahead of your feet when going down.


Knee supports are quite misinterpreted and often used in the wrong way. However, they can have many benefits if used properly, including higher temperatures in the joints, which improves blood circulation, the “lubrication” of the joint surfaces and the flexibility of the tissues; enhanced joint stability, including the maintenance of proper knee position, which can help protect the joints and enables higher force transfer; and finally, enhanced effort. A study has shown that one single diagonal bandage across the knees created a pulling (holding) power equivalent to about 5 kilos. So, 6 to 9 overlaps you can make of a 2-meter bandage can provide an extra power equivalent to about 30-40 kilos, which will be helpful when you are stretching out your knees. Plus, there is an enhanced awareness of one’s own movement. This psychological state will enable you to be more alert to the position of your knees, feet and upper body. And, doing so, you can make the necessary adjustments, be more relaxed and confident, which will all contribute to maximum effort. Hazards also entail both physical and psychological aspects. Too tight knee bandages often cause the softening of the knee cartilages (a wear on the inner surface of the knee-cap which occurs when two bony surfaces are pressed together with a great force and at the same time they are moving to and fro as the joint is being opened and closed) and/or a “scratching” effect when the muscle tissues are injured near the edges of the bandages. Apart from this, the bandage can also cause psychological dependence just like drugs, to an extent that users are unable or unwilling to lift heavy weights and/or exert maximum power without bandages. All in all, for most people, bandages are simply tools which enable them to apply the Weider cheating principle. Bandages will enable you to get over the most exhausting (lowest) position so that you can use weights that are heavy enough to overload the thigh and hip muscles for real, at other, harder points of the motion range. Bandages will not ensure strict form and the connective tissues can get seriously injured—and they actually will, if you are still careless while wearing bandages. The key factors of using bandages are as follows:

  • Use high quality bandages which will keep their flexibility.
  • Warm up your legs thoroughly by easy exercises like cycling and stretching, massage, if necessary, and rubbing your muscles locally before hard leg exercises.
  • Use bandages only for higher load (higher than 80% of the maximum load). Very tight bandages should only be applied occasionally and for short periods of time; this means, you should only use them on an ongoing basis for a few weeks, before and during competitions.
  • Put on the bandages before each set and take them off after each set.
  • Do not use bandages (and do not lift heavy weights) if you have a knee injury and do not treat the symptoms with pain killers, as these won’t restore the health and performance of your muscles and bones.
  • Apply strict form and a cyclical workout routine to enable full recovery and healing.


Squatting in a Smith machine limits the plane on which the bar is moving. At the same time, it offers a range of different leg positions, using different areas of the legs and hips. Similarly to the Hack squats, the knee and the hip joints should be bent in 90 degrees. If you are flexible enough, you may bring your feet closer to one another. If you aren’t, you should position them wider and/or on the front to make the exercise safer and more effective. As the limited plane of the motion helps keep your back straight and balanced, this can be one of the best solutions for those with lower back injuries. You can use such a wide stance that your hips can fit in between your legs in the lowest position, which reduces the tilt of the hips, but at the same time, exerts more load on the lower back.


This type of squat used to be very popular in the past, but nowadays it is not used as often as it should be. During the front squat, the bar is supported by the fingers, far from the chest, with the elbows pointing forward. If this position is uncomfortable, you may hold the bar higher, laid across your delts, with your arms crossed to prevent the bar from rolling down. Since you are holding the bar on the front, your upper body is forced to keep its vertical position; thus, more load is exerted on the quadriceps. Front squats work especially well in the development of the quadriceps.


This exercise separates the quadriceps completely. During this squat type you hold on to a stable rack with one hand and raise your heels when lowering your body to stretch your knees far ahead. This is another rarely used exercise with a lot of potential. Try to add 2 or 3 sets to your leg workout several times. You can do Sissy squats anywhere you can find something to hold on to, or a machine built specifically for this purpose.


To maximize safety and performance, every muscle and connective tissue around the knees should be well developed. This includes not only the quadriceps and the hamstrings (which provide lateral stability for the knees), but hip abductors and adductors as well. For example, one of the abductor muscles, the tensor fascia latae crosses the knee from the outside, and connects to the shinbone and the knee-cap as well. It helps pull the knee-cap outwards, and this movement should be constantly balanced by the vastus medialis. Most injuries occur when the knee joint is bent and is exposed to external lateral or twisting forces. Accordingly, you should avoid positions and forces which exert unfavorable load on the knees. Such situations occur frequently, even without you noticing it. For example, when you do not make sure your knees remain in the vertical plane which crosses the midfoot area throughout the full motion range. Working out too often and with too many exercises may lead to injuries related to overuse. Such injuries occur particularly if the load is increased too fast. For example, if you suddenly start using too heavy weights compared to the small weights you used to work with in the past. Using a rough simile: imagine that you run 5 km every day, then, one day you switch to 10 km all of a sudden. It doesn’t matter if you increase weights or kilometers this way. The point is, you are risking injury doing so. Furthermore, you should not squat either with your feet pointing too far inwards or outwards. The latter position may be of some value; however, the more you twist your feet, the more it will affect the activity of the knee-caps related to the thigh-joint structure, which exerts a heavy load on the knees and is likely to lead to pain and injury. Further causes of injury can be unbalanced muscle power; doing speed/strength exercises when you are exhausted; or, doing extreme bending, stretching or twisting moves which exceed the flexibility of your tissues. As mentioned earlier, the most common cause of knee injuries is bouncing in the lowest position. Doing so, you actually rely too much on your connective tissues in changing the direction of the movement of your body and the weight. This is the point when the knees are the most vulnerable and exposed to the biggest forces. In order to keep your knees stable and avoid injuries, you need to develop the muscles around your knees in a balanced manner. Do each exercise involving your knees in a strict form. And, most of all, always be fresh when doing explosive leg exercises or a lot of squats. Leg extensions (should rather be called “knee extensions”) are often not the best for strengthening your knees. The compressive forces which emerge during this exercise may cause injuries. To make leg extensions more effective, you should be able to tilt your trunk to and fro during the exercise, so that you can change the load that is being exerted on the knees. Locking out can be effective for the vastus medialis and the lateralis, but only if you can keep the load fully under control. For the lower back, the best exercises are back stretches with the center of motion crossing the lower back. Such exercises strengthen the erector spinae throughout the full motion range. The “good morning” exercise is also great for this purpose. Do it in a motion range of 90 degrees or higher, provided that you are flexible enough.


Single-leg squats are performed with one leg at a time. Exercises with free weights or machines are involved in this group. The leg which is not being used at the moment is stretched ahead or behind the body. Each variant is focused on the development of the quadriceps. These exercises often enable you to develop the mind-muscle connection, i.e. the ability of muscle perception at areas that are more difficult to “access” (for example, the upper-external part of the quads). Try all variants, first without weights. Make sure you warm up thoroughly, because, even without weights, you have to lift your full bodyweight, using a much smaller muscle mass than what you normally use. Single-leg squats are great for developing the quadriceps. Similarly to other single-leg exercises, they are suitable for sufferers of back problems, are great for developing balance and spice up any workout routine.


This exercise is performed exactly like the basic squats. The only difference is the limited motion range. If you do not go that low, most of the work will be done by the quadriceps. For more intensity you may use heavier weights and further decrease the motion range. This will overload the quadriceps to the maximum, while being safe for the knees. Be careful with placing the bar on your back. Do not rise to the highest point so quickly that makes the bar move upwards on your back. Use your common sense when adding these exercises to your routine, and do not use heavier weights than those you can use for 2-3 full back squats. Partial exercises are good for rehabilitation; if you want to increase the weights you use, or spice up your routine and bring in some motivation for other exercises in your leg workout or for other routines.


Use light resistance during the first workout and focus solely on the mechanics of the movement. This means, you should use 25% of your bodyweight when mastering the performance of the exercise: a 20-kg Olympic bar without weight plates, or a standard bar with the required amount of extra weight, to ensure a sense of resistance as you are moving up and down. In the beginning, focus on the form. And this can be developed best by doing more repetitions. As soon as you have mastered performance, you can start training with 50-75% of the weight you can handle for one rep. As you are getting stronger, you may gradually increase the weight by 5% or smaller installments.


While you are still learning proper squat technique, you do not need a weightlifting belt. The key is to focus on developing the right body positioning, learn to “keep firm” (like a spring) and develop a “narrow channel” within the full motion range. Wearing a belt at this stage is unnecessary, as the weights used are relatively small, and a belt would only interfere with self-perception and mastering the sense of motion. However, once you start working with heavier weights, the weightlifting belt will play an important role. The weightlifting belt increases the pressure within the abdominal cavity, which is crucial for keeping proper spine position. Fixing your spine is important to ensure that each movement of the legs is transformed into moving the weight. If your spine is loose, it will work like an accordion and damp part of the force exerted by the legs, which is extremely dangerous.


This unusual variant comes from Olympic weightlifting. The performance is the same as in the case of the basic squat, only holding a bar above your head with your arms stretched. This requires flexibility and strength in the shoulders, the hips and the knees. Plus, it demands extra balancing ability from the whole body. The squat is similar to explosive basic exercises, therefore it is highly valuable for Olympic weightlifters. However, if you lack the necessary flexibility or balance, this exercise is not for you. On the other hand, it is great for learning. And, if performed with small weights, it has many benefits, most of which develop the muscles of the upper body and the flexibility of the hips and the lower body.


  1. Let’s take 1-3 sets and 10-12 reps with maximum resistance (this is the maximum weight you can lift 10-12 times). After a 6-10-minute workout on a stationary bike and a few minutes of stretching, perform the first set with 12 reps, with about 50% of your 10-rep max. weight. In the next set do 10 reps with 75-80% of your 10-rep max. weight. Finally, do as many reps as you can, with your 10-rep max. weight.
  2. If you can do 12 reps, next time increase the weight so that you can only do 10 reps in the last set. Use this new weight until you can do 12 reps again. Then, slightly increase the weight again.
  3. Allow yourself 3-4 minutes of rest between sets so that fatigue won’t cause any problems in mastering the exercise. As your skills are developing, reduce rest time to 1-2 minutes in order to develop the endurance of your muscles, if this is your goal. Or, if your goal is strength and performance development, you may rest longer, use heavier weights and try to change resistance as fast as you can, even if the load is too big and the actual movement is very slow.
  4. Do this initial phase of the training for 8-12 weeks. For further strength development, change intensity (the weight used for the squats) regularly between very heavy (3-5 RM), moderate (6-8 RM) and relatively light (12-12 RM) load.


Manta Ray is a cutting-edge product of the 90’s. This plastic piece of equipment slides on the shoulders and enables the user to squat without pain which might emerge during squatting because of the heavy bar or a shoulder problem. Manta Ray divides the pressure evenly between the upper part of the back and the large area of the shoulders. So, as the pain is gone, retired squat experts like Muscle and Fitness Chief Editor Tom Deters, who cannot squat without it, could return to hardcore squatting again.


This exercise is performed on a vertical squatting machine which is set horizontal. It is also called leg press. The benefit of horizontal squats is that you are lying horizontally on your back and, unlike in the vertical position, you don’t need to hold the bar on your shoulders. Although the cushions are pressed against your shoulders, your trunk is pressed to the back cushion all along. The key of safe performance is that you should place your feet high enough so that your knee and hip joints are in a right angle when you are in a squatting position. Plus, just like in the case of Hack squats, make sure that you are pressing your hips into the sliding cushion while you are pressing downwards through the heel/midfoot area. Doing so, you will stabilize the hips and the lower back and prevent your lower back from taking up a round shape or overstretching, which may cause pain in this area or make existing pains worse.


There are also other kinds of squats which require special equipment, for example, weights hung on a belt around the waist. A high platform is also required for this exercise. Plus, you may use special bars for squats, or devices like Manta Ray, which can help you divide the weight evenly between your shoulders.

Most popular this month
Scitec AmiNO Xpress test: Editorial experience at Shop.Builder! You know, we always tell frankly what’s on our minds. So, if you are curious...
Bench press is one of the most popular exercises. But if you do it wrong, that can be not only ineffective but dangerous as well. Let’s see ...
Here we are again, with an offbeat training method, because we dig these quasi heretic approaches. The concept is as follows: super-strict ...
Getting muscles ain't easy, we know that by experience. But only a few people know that with the most underrated area of bodybuilding and fi...
Many gym-goer do the same training routine over and over again, that's why they can't grow their biceps. Let us show you some tricks which w...
A champion can always say something new. You can always learn some new tricks you can incorporate in your training program. Some of these mi...
Okay, that must have hurt. Don’t be nervous, rhymes are over. Pectoralis muscles are the most problematic muscles for many. But problems are...

Ask your question about this article here!

You can ask questions after registration and login!
Please log in!