top of page
  • Writer's pictureCoach Paul Kuck

Should you do half or full squats?

This topic bothers me a bit because I often see people dispensing and accepting bad advises, without checking to see if they are sound or well-researched. This is especially so in the internet age where people can easily find any exercise routine online. People will follow as long as the program is from someone who looks good and/or is a famous personality, never mind their fitness credentials if they have any in the first place. These followers would then forward the same thing to the rest. Blind leading the blind.

Before I go into the discussion, I need to clarify what exactly are the half squats and full squats.

A correctly done full squat is one that at the lowest point of the descend, the hamstrings are touching the calves and the butt is close to the floor like this:

A half squat is one where the lowest part during the descend, the thighs are running parallel to the ground, like this:

Note the depth difference.

Back to the question: is half-squat better than full squat because the former puts 'less' stress on the knees and safer as claimed by many 'experts'? Such 'experts' include many fitness trainers, fitness enthusiasts, and medical doctors who often teach people to avoid full squats, in order to prevent injuries to the knees. The prevalence of such advice is so common that it can be heard everywhere.

Just google 'squat exercise' and you can see almost all exercisers and drawings are demonstrating 'half squats'. Rarely can I find a photo depicting a properly done full squat ( I did eventually after scanning through like 100 pics).

Every exerciser's doing half squat
Google search: Everyone's doing half squat

Look! Everyone is doing half or partial squat. Surely 99% of the fit-looking models and their writers can't be wrong. (Oh btw, speaking of fitness models, you would be surprised many of them don't even exercise, they just happened to look good. How do I know? I have written for many health magazines, worked with such models on many occasions and they self-admitted).

Ya, right.

Now, if one has a case of bad knee due to ACL/PCL, meniscus, flexibility issues etc, such advice is warranted. Otherwise, doing half squats consistently may do you more harm than good in the long run, ending with the knee issues just mentioned. Such irony.

Hear me out.

Full squats, done properly, are one of safest and the healthiest thing you can do for your leg muscles and your body, for that matter. Even if you can only do half-squat or even only quarter-squat, one should progressively work towards increasing the depth of the squat.

Here are the reasons why going deeper is better:

Full squats build more shape in your butt.

Full squats activate more glute muscles, hands down [1]. So, if you want a fuller-looking, sexy set of bums, squat low and deep.

Full squats build stronger legs all round.

Full squats activate the hamstrings, adductors, and glutes, so exercisers will develop a balanced set of leg muscles. In contrast, partial squatting contributes to an imbalance in the quadriceps to hamstring strength ratio. This imbalance increases the risk of hamstring tears.

Full squats are better for knee health.

This is an important part of the argument.

This imbalance caused by doing partial squat also increases the risk of an ACL tear. An increased quadriceps to hamstring ratio is a major factor in increasing the amount of anterior tibial sheer. Research suggests that “the deep squat presents an effective training exercise for protection against injuries and strengthening lower extremities” [3].

In addition to knee pain, the squatting depth can affect the amount force put on the knee. The amount of force put on the knee can cause an individual to not squat as low as they desire due to discomfort. Individuals have various squatting depths to produce more or less force on the knee.

There two major forces acting on the knees.

  • Shear force. It is force acting from the sides. In the case of the knee, shear force would be loads that go crosswise to the shinbone

  • Compression force. It is force acting downwards. In the case of the knee, compression force would be loading along the length of the bone.

Important: Joints are better able to withstand compressive forces than shear forces. Imagine this: if you apply a large compression force on a spring (which mimics the meniscus as it is the only concern for compression force), would it cause much damage to the integrity of the spring?

The answer is an obvious no.

On the other hand, if you apply large shear pressure to knee, the damage exerted would be great as it could hurt the ligaments (anterior cruciate ligament, the ACL, and posterior cruciate ligament, the PCL) and the meniscus. High shear force is the reason why leg extension exercise causes knee pain. Ouch!

The diagram suggests that the greatest shear forces on the knee will occur with a squat at different knee angles.

Different squat depth and their forces
Different squat depth and their forces

As you can see, the forces acting on the ACL peak at between 15-30 degrees and then reduce considerably past the point of 60 degrees. Similarly, the forces acting on the PCL rise gradually to a knee angle of 90 degrees, and then drop significantly thereafter. Furthermore, when holding a squat position at 90 degrees, as often occurs in transition between the eccentric and concentric phase of the exercise, the time the knee is exposed to the maximum levels of shear force is also increased. Thus for many, deep knee squatting may indeed be better for knee health than squatting to 90.

Full squats are safer for the spine.

"Concerns about degenerative changes of the tendofemoral complex and the apparent higher risk for chondromalacia, osteoarthritis, and osteochondritis in deep squats are unfounded. With the same load configuration as in the deep squat, half and quarter squat training with comparatively supra-maximal loads will favour degenerative changes in the knee joints and spinal joints in the long term" [3]

We were meant to squat fully

Every single human being knows how to squat perfectly right from the young. Here, my daughter and her cousins show you how it's done (circa 2008).

That is until we have chairs, toilet bowls and stools. If you look at certain cultures that have not had exposure to seated in chairs from an early age, you will see that they rest and eat in a full squat position, even as they grow old. This where 'Asian squats' come from. If going by the logic of full squats can damage knees, explain this:

Or this.

Asian men squatting
Asian men squating

Everybody used to squat fully. Even westerners.

American western men doing full squat
American men squatting

And now, I have met many Asians who can't even do Asian squats! People need to undo their unhealthy behaviours and relearn what's natural for them. Doing half squats consistently is teaching you NOT to do full squats, and what happens? Your body adapts by becoming less flexible over time! No brainer, right?

Let's not forget Yoga practitioners, who often do Yogi squat, Malasana pose, in their routines.

Also, the human lower digestive system, like those of most mammals, excretes better when we squat, as it mildly compresses the bladder and bowels, forcing out the waste [4]

Full squats are a natural movement. They are great, safe and can be done by most people. Period.

Another issue surrounding Squats - knees shouldn't go pass toes?

For lunges, yes, knees mustn't go beyond the toes. For squats, this is another myth with a poor understanding of the biomechanics of the knees.

Read this:

My personal experience and what qualifies me to preach about full squats.

Firstly, my mechanical engineering background and previous job as a product designer say that I know a thing or two about mechanical forces.

Secondly, I have been doing squats in all my exercise routines all my life since I was 7. It has been 4 decades and counting! I must have done a couple of millions of squats in different variations. It is the most performed exercise in my routines. I was called 'Iron Legs' by a Former Mr Asia for my superior leg strength. But this is not without issues.

There was a period where I had only done exclusively half squats. It was when I first got serious in weight training, at around 14, no thanks to some half-baked instructions I found in books and magazines, just what we see on the internet today. After religiously squatting as taught for 2-3 years, my knees had taken serious punishment and damaged to the point when I found extreme pain from trying to get up from a normal lunge or squat position. The specific cause of the pain was unknown as I didn't see any doctor.

Good thing I was young still and the knees got well with the help of corrective full squatting technique for another few years. It has been another 2 decades since. At my current age, my knees feel great and I can still sprint, jump, and handle heavy poundages. Had I continued doing the half squats, I probably would need a knee replacement by the time I was 25!

If you need more understanding about why full squats are superior, please see the writings of other fellow fitness writers {5,6,7,8] who are also squat experts.

Thirdly, I have been a fitness coach for twenty-odd years, with tens of thousands of coaching hours, armed with a 'Gold' Standard Medical Exercise Specialist Cert and an MSc in Exercise & Nutrition Science. On top of that, I constantly read latest research articles, as any researcher would.

I do not preach out of thin air.

What about my clients?

Every few weeks another client tells me how his/her knee pain has gone away since training with us and performing full-depth squats. Not only that, a few can even do 'pistols', another name for one-legged squats.

One such client and good friend is Prof Jacob Lee, one of the 'go-to' corporate coaches. He had painful and weak knees when he first came to me. Now he can even do pistols with added weights for reps, and he's approaching 60!

Full squats work. They work very very well, for me and all my clients who do them.

Are half squats all that bad?

There are merits to doing half squats. Half squats can be beneficial for certain sports requiring explosive quadriceps strength like sprinting and basketball. Also as mentioned, full squats can aggravate pre-existing knee issues, which is why for them it is better to avoid the full version for the time being. In addition, half squats can isolate your quadriceps (thigh muscles) better.

That said, the ability to achieve deep squats should be the ultimate goal of everyone.

Need help?

If you have knee pain, can't do a full squat or just want to own a pair nice looking legs, we will fix them in no time. Email us for a free assessment.

P/s: this article was written with me in a fully squatted position.


  1. Kubo, Keitaro, Toshihiro Ikebukuro, and Hideaki Yata. “Effects of squat training with different depths on lower limb muscle volumes.” European journal of applied physiology (2019): 1-10.








bottom of page