The barbell squat is one of the most misunderstood, or otherwise neglected, exercises in strength training. Many trainees perform it incorrectly, while others avoid it like a painful pandemic. The importance of intense leg exercises cannot be undermined in resistance training programs, since muscle growth throughout the body can be negatively affected. While genetic limitations differ between individuals, in general, human muscular systems require symmetry. They will stop responding to growth cues if an extreme imbalance starts to unfurl, in order to remain a fully functional organism. Learning how to squat correctly is essential for building a stronger and more muscular body. Squats also help promote a greater tolerance to the stress of intense exercise.
Free-weight squats are a functional movement. Unlike leg presses and hack squats, they work the body’s largest muscular systems through a natural range of motion. Squatting primarily recruits the quadriceps, a large mass of muscles covering the front and sides of the femur, to include: vastus lateralis, on the lateral side of the femur; vastus medialis, on the medial side of the femur; vastus intermedius, between vastus lateralis and vastus medialis on the front of the femur. As the weight is lowered, significant support is offered by the gluteus maximus (glutes), inner thigh adductors and soleus. The movement is counter balanced and stabilized with activation of the hamstring, calf, lower back and abdominal muscles.
In November 2008, researchers published a meticulous look into muscle function during the pushing phase of a full (deep-knee) barbell squat in the Journal of Applied Biomechanics. Muscle function in six experienced weightlifters was examined using joint kinematics, inverse dynamics, electromyography and changes in muscle length. Analysis revealed that the glutes and quadriceps are the prime movers during ascent; to a lesser extent, the soleus muscles as well. The hip extensors (glutes and hamstrings) produced the greatest force, followed by the ankle plantar flexors and then the knee extensors (quadriceps). The biarticular muscles function mainly as stabilizers by transferring energy among segments of the ankle, knee and hip joints.
All this muscle activation is exhausting! When barbell squats are performed correctly, the movement is mentally and physically draining. It causes extreme central fatigue, decreased plasma PH levels (acidity), dehydration, depleted glycogen stores and a drop in blood glucose. Remaining disciplined during a nauseating condition is a true testament of character. The human body naturally resists moments of extreme fatigue and metabolic strain – as a survival mechanism. For that reason, many trainees lose sight of proper form and execution. Giving up and moving over to the Smith Machine isn’t a commendable retreat; it results in less stabilizer and supporting muscle activation while using a fixed path that acts against the body’s natural arc of movement. Moreover, allowing one’s self to continually lock out knee joints is not beneficial to performance gains; since the load is subsequently transferred from the muscles to the skeletal system.
A free-weight squat should be performed in a rack with safety bars. In preparation, position the barbell so it’s racked at shoulder level. Dismount the bar by resting it behind the head, nestled inside the meaty part of the upper back, and carefully take a step or two away from the hooks. With a firm grip securing the weight across the shoulders, sit back through the decent, until the knees are fully bent and hips are parallel to the floor. This depth is often referred to as “going to parallel” in powerlifting circles. Over-zealous lifters often wrap their knees in a rush to ego lift greater loads – they often drift from full- to quarter-range squats in their misguided efforts. Wrapping the knees can prevent required adaptations form occurring, resulting in system imbalances. If proportionate development, training longevity and injury prevention is important, the safest route is to avoid knee wraps and simply train to parallel with a lighter load until hip and ankle flexibility improves.
After the decent, immediately reverse direction with the head and shoulders moving first – not the hips. Lift until the legs extend enough to contract the quadriceps, but remain bent to avoid placing the load on the skeletal system. Don’t look down at feet placement as the load is forced against gravity. In every sport, athletes look where they want their efforts to be applied – golfers gaze off to the green and bowlers keep an eye on the pins. When squatting, weightlifters should look up, maybe forward, but never down. For the best structural support during the lift, the back should remain straight and erect while the feet stay flat on the floor. The weight should share equal distribution across the soles. To avoid a repetitive stress injury, the knees must always remain pointed in the same direction as the feet.
The movement should be continuously repeated until the leg’s extensive network of muscles gives in to the load. Muscle failure should occur at around 10 to 20 repetitions; high repetitions are advocated since the legs generally have a slow rate of fatigue. If possible, position safety bars so the weight can be dumped at any point without injury. They help encourage pumping out more repetitions while eliminating the need for spotter assistance.
Squatting isn’t easy, especially as fitness thresholds increase and greater loads add to each workout’s intensity. However, handling heavier loads shouldn’t be the only method for applying a progressive overload. Altering program design to permit sets with short rest intervals will dramatically increase the training stimulus. Twenty-repetition “widow maker” sets are well known as an effective method for stimulating growth in the leg muscles. To further ramp up intensity, a load heavier than a 20-repetition maximum can be used with brief moments of rest. Around 65 percent of a trainee’s one-repetition maximum frequently fits the bill. The increase of intensity helps maintain reliance on the explosive anaerobic energy system during the agonizing climb to 20 repetitions.
The massive muscles of the lower extremities should never be neglected in bodybuilding program prescription. When performed correctly and consistently, free-weight barbell squats are a great muscle growth stimulator. They also provide an edge in sports where sprinting and jumping is necessary. Most strength coaches consider squatting as a fundamental exercise for greater total-body muscularity and physical competence.
D. Gordon E. Robertson, J.M. John Wilson, Taunya A. St. Pierre. Lower extremity muscle functions during full squats. JAB, 24(4), November 2008