Here is a good article from mercola.com. I posted the link at the end, it's really better to read it at that site because there are a lot of pictures.

Fear the Squat No More! Part I

By Paul Chek, HHP, NMT
Founder, C.H.E.K. Institute

While most articles written about the squat are aimed at the sweat-covered "big boys" in the gym, or at athletes trying to improve their performance, I'll show you that anyone, with at least one good leg, can use the squat to achieve improved health and function. I will teach you why we must learn to cherish and use the squat exercise, and how to perform several variations for excellent results.

In the elite circles of strength sports, the squat exercise has long been referred to as "The King of All Exercises." Many respectable strength and conditioning experts feel if they had to choose only one exercise to condition an athlete, the squat would provide the greatest overall benefit.

This is because the squat is a free-body movement that requires use of every muscle in the body. Given enough load and/or intensity even small muscles in the face will contract.

Although the squat has been considered a keystone exercise for as long as people have been writing about strengthening and conditioning, it's beginning to show serious signs of becoming extinct. Having traveled and lectured all over the world for many years, I've been in a fair share of gyms and it is astonishing to me how few people are squatting anymore. It has come to the point that even finding a squat cage in a gym is difficult because they are being replaced with the shiniest new machine!

Squatting is a Primal Pattern

As developmental beings, the majority of our activities were ground-based activities that demanded physical readiness and the ability to get down to the ground easily. As I discuss in my book, "Movement That Matters," there are seven specific movements that we would have to be able to perform in order to ensure our survival during that era. I call these seven basic movements the Primal Patterns™ and they are:

Squatting
Lunging
Bending
Pushing
Pulling
Twisting
Gait (walking, jogging and running)


Until very recently, we lived in harmony with nature and involved ourselves in hunting, gathering (see Figure 1), building shelter (see Figure 2), tending to crops (in the recent 10,000 years) and using fire to make tools and keep warm. The squat pattern was crucial for survival and, I believe, just as important today as it was then.

The Physiological Importance of the Squat

Digestion and Elimination

Most of you don't think of the squat exercise as being beneficial to digestion and elimination. However, I would like to point out a few unique anatomical features of the human being in this regard. First of all, human beings are the only animals who must push feces uphill.

In our natural environment, where we were squatting repeatedly throughout the day as dictated by a ground-based living environment, this was not a problem because of our anatomical design. Whenever we squatted to work, socialize or defecate, we would naturally squat until our hands reached the ground, (since that's where everything was) or until our torso was fully relaxed and supported by our thighs (see Figure 3).

The full squat results in compression in the lower abdomen from the thigh. The right thigh will compress the cecum (the origin of the colon), mechanically pushing the feces uphill into the transverse colon, while the left thigh compresses the descending colon, moving feces into the sigmoid colon and ultimately the rectum (see Figure 4).

With this understanding in mind, it is not surprising many early naturopathic physicians attributed the massive increase in constipation in the late 1800s and early 1900s to Thomas Crapper who has often been mistakenly identified as the inventor of the modern seated toilet. He was actually a plumber who popularized the toilet, but didn't invent it. To combat the fact that the modern toilet doesn't require a full squat, and therefore doesn't facilitate evacuation of the colon, Colon Hygienists recommend the use of a footstool ranging from 6-14 inches in height.[1]

The addition of the full squat to your exercise program, along with a footstool can dramatically improve digestion and elimination. The reason I say "digestion" and elimination is that when the body is chronically constipated, the entire system gets backed up, literally from stomach to anus. When this happens, the stomach is forced to hold onto its contents, often leading to reflux, heartburn and poor digestion.

Digestion and elimination are further facilitated by the full squat as a result of both pressure changes in the abdominal and thoracic cavities and improved motility of organs. Whenever you repeatedly perform the full squat, a pressure wave is created by the thighs, compressing the abdominal viscera. Additional pressure waves are created by the action of the abdominal muscles as they contract to stabilize your body, and by the action of the diaphragm as you breathe.

These pressure waves, coupled with the mechanical action of the thighs, literally mobilize the viscera. They also pump blood and lymphatic fluids as well as mechanically aiding the intestinal system.

By using "Breathing Squats" (see Figure 5), you can also facilitate the parasympathetic nervous system (PNS). The PNS is also called the anabolic or digestive nervous system because it regulates these activities. Implementing PNS stimulating activities like breathing squats is probably more important today than ever, due to the typical American diet and lifestyle.

It is not only stressful to the body, it also encourages activation of the sympathetic (catabolic) nervous system, which is the functional antagonist to the PNS. Too much SNS activity results in poor recovery from exercise, poor digestion and poor elimination! Try some breathing squats today.

Many athletic types, Type-A personalities and those who cannot relax or calm their mind will very likely find breathing squats to be a valuable addition to their daily routine. To get the most from your breathing squats, make sure you go as low into the squat as you can without any discomfort, fully exhale on the way down and pause briefly at the bottom.

To keep your mind from wandering, simply focus on counting your breaths. Keep the effort low and the movement slow. The most common mistake is to try and make it too athletic which defeats the purpose.

One way to make sure you do your breathing squats correctly and get the most benefit is to do them right after eating or after drinking two glasses of water. If you are doing them correctly, you will not feel uncomfortable with a full stomach. In fact, as I show you in my book, "How to Eat, Move and Be Healthy!," squatting can actually improve your digestion and overall physiology.

I recommend that you commit to performing at least 50 breathing squats a day. If you are unable to do 50 in a row then do as many as you can. Then, at intervals throughout the day, do a set of 10. This is an effective way to energize the body and combat the effects of sitting, which is an activity that the body is not designed for and is stressful to the lower back. Many of you will find that as you get better at breathing squats, your flexibility, digestion, elimination, energy, appearance, concentration and mental clarity all improve.

Spinal Health

The discs of our spine have no direct blood supply. They receive their nourishment and fluids through a process called "imbibition." This is a process whereby the jelly-like structure of the nucleus and collagenous outer rings of the anulus absorb fluids from the porous bone of the vertebra. The process of nourishing the spinal discs is improved by movement, which results in pressure changes in the disc tissues.

During our developmental years, we didn't have chairs. If we wanted to stop and socialize, we simply went into a full squat and rested our trunk on our thighs[2] (see Figure 3). This process, along with our sleeping postures, naturally facilitates rehydration of the spinal discs (see Figure 6). Today, most people have such a poor diet and exercise program that performing a loaded squat places them at risk of ligament or disc injury, which has led to most exercise and rehabilitation professionals teaching maintenance of lumbar lordosis (curve) during a squat.

Unfortunately, while the lordotic squatting posture may be beneficial among the injured and for those training at more than 60 percent maximum intensity (~ 21 rep load), use of the lordotic posture when it is unnecessary, such as during light squatting or during functional activities, results in static loading.

This reduces pumping and accelerates the rate at which you dehydrate your disks, shortening your spine (see Figure 7). When the spine shortens due to disc dehydration and desiccation, the spinal ligaments become progressively more lax (see Figure 7-A), encouraging spinal instability. Surely, what we need is to use the natural full squat at low intensities in the gym, or during activities of daily living where the load is not threatening to the spine.

I recommend to my patients that they use a natural full squat if the load is light enough to comfortably lift more than 20 times or light enough they can easily breath naturally. However, they must have no orthopedic restrictions, such as an existing disc bulge.

For Those Who Have Been Injured by a Squat

Many people have been told by doctors, physical therapists and personal trainers squatting is dangerous, but there are some real physiological consequences that must be faced when following such short-sighted advice.

First and foremost, when it comes to squatting, if you can't, you must! Having spent 21 years of my life in the fields of orthopedic rehabilitation and sports conditioning, I can assure you anyone who was injured performing a squat movement and did not learn to squat correctly and/or develop adequate strength in the pattern, is a re-injury waiting to happen.

Just look at what it takes to get into your car. You must perform the equivalent of a single-legged squat with a lateral shift and a twist, particularly if you own a sports car. All the while, you are being told to avoid an opportunity to reestablish optimal motor skills and strength in what can be considered key movement pattern in anyone's life even today.

Whenever you injure yourself, an electrical charge is created in the injured tissues, often referred to as the healing current of injury. This is one of the mechanisms by which the body knows where to send the repair materials.

Initially, a random application of serofibrinous exudate forms at the injury site. You may know this as the semi-clear fluid that forms and turns into a scab. Within 24 hours, fibroblast cells start laying down collagen, being guided by micro-currents called streaming potentials. It is the movement of the injured tissues, via internal and external forces, that initially stimulates the production of micro-currents as streaming potentials. It is these streaming potentials that tell the fibroblasts how to align the new collagen fibers.

Therefore, from a wound-healing perspective, it is important for anyone that has been injured while performing any type of squat to begin carefully loading the tissues in as close a pattern as possible to that of the injury. Failure to return to squatting as soon as possible only results in a weak wound repair and a greater likelihood that you will injure yourself again, when you have to squat and least expect it!

Part 1: Conclusion

As you can see squatting is a very important Primal Movement Pattern™. Initially, the squat movement need not be performed under a greater load than that afforded by your body weight. Body weight squats offer the following benefits:

Improved respiration of all working tissues used in the squat. The squat uses almost all the muscles in your body
Improved pumping of body fluids, aiding in removal of waste and delivery of nutrition to all tissues, including organs and glands
Beneficial physiological stress to your hormonal system. Properly performed breathing squats actually shift the body away from sympathetic nervous system dominance and encourage parasympathetic activity. This aids in tissue repair and cultivation of Chi, or life-force energy
Improved movement of feces through the colon and more regular bowel movements
Breathing squats and functional squatting can be performed anywhere, anytime. No equipment needed
Body weight squatting prepares your body for more advanced training
When you are capable of performing at least 100 breathing squats in a row, you will have mastered the squat with body weight and conditioned your tissues to effectively handle greater intensities as achieved with resistance training.

In Part II of this article, I will show you how to squat properly and safely with free-weight resistance. I will also show you some variations to the standard squat that will add some variety to your exercise program. Adding muscle mass and increasing your metabolic rate are among the many benefits available to you by applying this information and the information in Part II of this article.

Fear the Squat No More!