The king of strength exercises: can it be made loads better?

There are few sports where improving lower body strength doesn’t produce performance gains, which explains why athletes seeking optimum performance often undertake lower limb (ie leg) strength training. And when it comes to this type of strength training, the squat exercise is just about the single most effective strength exercise there is, which is why it is sometimes dubbed the ‘king of exercises’. That’s because it simultaneously targets the largest muscles in the body, including the buttocks, front and rear of the thigh and to a lesser extent, the muscles of the lower back.

Benefits of squats

The powerful electrical stimulation generated by high-intensity squatting is extremely effective at helping to develop power and strength in the leg and buttock muscles, which explains their popularity with sprint and power athletes. However, it turns out that the same type of muscle stimulation can produce significant performance gains for endurance athletes such as runners, cyclists, triathletes, rowers etc too.

Over the last decade or so, evidence has steadily accumulated that performing heavy weight lower body exercises such as squats can benefit both power and endurance performance. For example, studies on cyclists who squat looking at cycling economy (how efficiently the muscles use oxygen to produce power – good cycling economy is a characteristic of all top cyclists) and other attributes of performance have found^(1,2):

•    Increased cycling economy.
•    Increased peak power during incremental tests to exhaustion and longer times to exhaustion.
•    More power produced at lactate threshold (4mmol/L).
•    Increased average power produced during a 40-minute all-out time trial.
•    A better spread of force (torque) applied to the cranks.

The same squat training benefits – ie improved muscle economy and time to exhaustion have also been found in road runners⁽³⁾, cross-county runners⁽⁴⁾ and rowers⁽⁵⁾.

Why squats?

Why is the squat exercise rather than equivalent machine exercises such as leg extensions and leg presses the choice of athletes seeking improved leg strength? This is a pertinent question, especially given machine exercises require less skill and technique, are quicker to perform and are supposedly safer. It turns out that the evidence for using squats is actually quite compelling; research shows that compared to machine exercise, free weight squats are superior for increasing knee stability and strength, especially hamstring strength⁽⁶⁾. Perhaps even more importantly, the strength developed by performing free weight squats seems better able to translate into the kinds of sports performance gains needed by athletes - for example, the ability to jump high or long⁽⁷⁾.

Squat technique

Before we go on to discuss how variations in loading and movement patterns affect squat mechanics, we first need to define what constitutes a good standard technique when performing the squat exercise (see figure 1). Although there are no absolutes in squat technique the consensus among many athletes and coaches (and supported by evidence in the literature) is that squats should performed pretty much as shown in figure 1, with the thighs parallel to ground at the lowest point of the movement (ie between around 100 degrees of knee flexion)⁽⁸⁾.

Figure 1: The back squat (standard technique)