Squats and Sprints

Part III: When are Partials Valuable?

I made the case in part II for including full-depth squats in a training program for sprinters and jumpers by exploring the numerous benefits they can provide to an athlete. While I do make the argument that full range of motion squats can and should be a part of sprint and jump training when taught properly, I don’t make the argument that many dogmatic coaches in this box often make – that partial ROM movements in general and 1/4 squats specifically have no value, and thus should be avoided entirely.

In fact, there are many short range of motion variations of back squats that can add value to a training program and enhance athletic performance for sprinters and jumpers. I touched on a few circumstances where partial ROM can be valuable in part 1 – when training around an injury or when mobility restrictions and body type join forces to make certain depths inaccessible.  

Though partials are useful in these two scenarios, they are implemented as a stop-gap measure until full-depth training can commence or resume. It doesn’t speak to whether there are situations where partial ROM can be beneficial for a sprint or jump athlete who can otherwise perform full-depth squats normally.  As it turns out, there are other scenarios where 1/4 squats and other partial ROM movements can be useful tools for athletes who can still perform full squats. Let’s take a look at some of them:

When To Use Partial Range of Motion

1. When Peaking

   One of the reasons full squats are so beneficial is because of the systemic impact they have on the body. Increasing the weight used over a longer range of motion is more work, and in the process of developing strength, power, motor control, or inducing hypertrophy, we want to do more work. We also want to reap the benefits conferred on joint and tendon health. This is true for most of the year. But there are some periods – like when we are peaking for important competitions, that we don’t want to do more work. We aren’t developing strength and power, we are focused on managing fatigue to maximize the expression the qualities we have already developed. 

   When peaking for the most important competitions, the goal is essentially to reduce fatigue while improving neurological output. We limit muscular, neurological, and psychological fatigue by reducing training volume while carefully dosing in exposure to high intensity movements to maintain neurological output and technical efficiency. Reducing training volume creates an environment where the body recovers from the psychological, neurological, and muscular fatigue accumulated during the training period leading up to high-priority competitions. But we don’t want to remove all exposure to stress as the body will begin to see high-intensity scenarios as a novel stimulus, which can lead to performance degradation fueled by muscular soreness.

   Pin squats, high box squats, 1/2 squats and1/4 squats are viable candidates to help athletes meet these goals. A more detailed discussion of nuances between each variation is beyond the scope of this article, but the short range of motion with each limits the potential for muscular soreness and further accumulation of central nervous system fatigue while allowing the intensity to remain relatively high to maintain nervous system output. Provided that overall training volume is kept low, we create a scenario where athlete output is amplified during the time of year when it matters most. This also leaves athletes with more in the tank – physically and psychologically – to perform and recover from the work being done on the track.

   Another benefit of partial ROM late in the season is that the stimulus for hypertrophy is extremely low. This allows a high central nervous system stimulus while minimizing the potential for growth when an athlete has closed in on their optimal bodyweight.

   How to use: Around 4 weeks prior to a major competition, spend a few weeks performing a heavy partial range of motion squat variation before de-loading. Similar to the training on the track prior to the championship portion of the season, total volume should be relatively low but intensity kept relatively high. 80-90% of the athlete’s back squat max is a good range to start with. Occasionally I will work up to 100-110% for an athlete with excellent control.  8-10 total reps (4x2, 3x2 + 2x1) is optimal.

2. To Potentiate

   Contrast and complex training are both training methods that usually combine a heavy strength movement with a lighter power or plyometric movement. They take advantage of what’s known as PAP, or Post Activation Potentiation. The idea of PAP is summed up simply with the idea that “the contractile history of a muscle influences the mechanical performance of subsequent muscle contractions.”(1)

   While there is some debate about how long the effects of potentiation last, the idea is that by performing the heavier movement first, the central nervous system (CNS) is primed by recruiting more motor units – particularly high threshold motor units (HTMUs)– to perform the work. This priming, or activation, then allows the plyometric or power-based movement that follows to be performed faster and with more force as the HTMUs recruited in the strength movement increase their contribution to the work.

   The reason this works is because there is a force requirement that needs to be met for HTMUs (which contain a higher percentage of fast twitch fibers) to be activated. For most activities in our lives, low threshold motor units can cover the work demand. In order to include those capable of producing the most force, we need to expose them to high force activities. Once that threshold is met, those neurological pathways continue to be accessible for other activities that follow.

   For an extended conversation on how motor units work, read this article on why distance runners should lift heavy.

   Contrast or complex training can be pretty fatiguing when used as a training method, such as the popular French Contrast training. Methods like this often involve a combination of full ROM and partial ROM movements to be performed back-to-back, each one training a different portion of the force-velocity curve with the end goal of increased force production over a smaller amount of time that can be applied to the specific demands of a given sport.

   The science of PAP can also be manipulated to improve performance using partial ROM movements prior to competitions. Using 1/4 squats or other short range of motion options can minimize the potential for CNS and muscular fatigue to negatively impact performance while still allowing a high-intensity stimulus to access HTMUs. Essentially, we can “turn on” neurological pathways without taking the movement through a full ROM.

   When this is done before a practice or competition, the squat variation serves as the primer while sprinting, jumping, or even throwing on the track serves as the secondary movement that is being primed. A recent example of this method at work was Ryan Crouser performing 700 lb pin squats prior to unleashing a massive 23.51 meters in the shot put – the 2^nd farthest throw of all time - en route to winning the World Championship in Budapest this summer.

   I will caution that this method of preparation also comes with risks as high intensity movements with athletes who lack the motor control and technique to perform the movement safely can create soreness, fatigue, or injury with no time to recover.

   How to use: This method should be experimented with in practice sessions prior to use in a competition to gain familiarity and confidence with getting under a load before competing.

   Prior to a high-intensity jump or sprint session, use 4-5 warmup sets to work up to 1-2 heavy sets of 1 or 2 at around 90% of the athlete’s back squat max. This is different than the peaking method in that only 1 or 2 top sets are necessary for the activation we are looking for, meaning only 1-4 of the heaviest reps will be performed.

3. As Assistance Movements

   Another way partial ROM squats can be used are as assistance movements - movements designed to target a weakness through a smaller range of motion to improve performance in the full range of motion. For example, if an athlete has a sticking point – a weak point or technical breakdown that prevents lockout at the top of a back squat - partial range of motion movements that overload the top portion of a squat are sometimes used to build strength to help break through the sticking point.  This strategy can also help inspire confidence with an unfamiliar weight - both of which can be limiting factors in the successful completion of the full movement.

   These movements can also be helpful if someone has particularly weak quads as it can be easier for some athletes to maintain constant tension in the muscle when the range of motion is kept shorter.  This longer tension with a heavier weight can be a useful tool in developing hypertrophy of the quads for athletes who tend to lose tension towards the bottom of a full squat, as well as teach them how to maintain tension all the way down.

   Other examples of short range of motion movements implemented to enhance performance of the full range of motion movement are board presses or floor presses for bench press, and rack pulls for deadlift. These are common in the sport of powerlifting, and while there can be nuances in how they are performed to address individual goals, the short range of motion in these movements allows them to be overloaded to address a technical breakdown or positional weakness that prevents the successful completion of the full lift.

   How to use: For athletes who struggle with a sticking point or maintaining posture on the ascent, set pins or a box at a height where the bar can descend just below the sticking point. Then use 12-16 reps broken into small sets (4x4, 6x2, 2x6 etc) with a challenging weight where no technical failure occurs. Increase the weight as long as technical efficiency can be maintained. The aim should be to maintain posture and to accelerate the bar through the sticking point above the weight that would typically induce an exaggerated deceleration or technical breakdown in the same rep range.

A Word on Assistance Movements

Yes, athletes can handle more weight in the upper portion of a squat where they a.) have a biomechanical advantage and b.) haven’t created any fatigue by moving through a longer range of motion on the eccentric portion first. They will get even stronger in these squat variations when they perform them more frequently.

The idea that they can continue to get stronger within short ranges of motion without assuming the “risk” of going all the way down tempts many coaches to opt for partial ROM squat variations year-round and to load them significantly beyond the athlete’s full ROM squatting ability. Essentially, short range of motion squat variations cease being assistance movements for full squats and become primary strength movements with assigned intensities that have nothing to do with full squat ability.

When the relationship between full and partial squatting is severed, many well-intentioned practitioners opt for loading athletes dangerously beyond their ability. I’ve already described a scenario where 110% of a full squat max could be appropriate for partial ROM. But it isn’t uncommon to see athletes who can’t perform a 225 lb squat to depth with 400-500 lbs on their back for their chosen partial variation. This is potentially over 200% of their full squat max, and in my view simply trades one risk for another.

This philosophy on loading partially comes from the idea that athletes will encounter several times their bodyweight upon ground contact when sprinting and even more when jumping. Attempting to re-create these momentary forces on ground contact with load on a barbell is incredibly dangerous. I’m not convinced the trade is worth it. Those forces are better addressed with sprint and jump practice and various methods of plyometric and ballistic training. This is a crucial distinction between using partial ROM squats as assistance movements vs using them as primary strength movements.

Speaking Of Ballistics

Different versions of ballistic movements generally and ballistic squats specifically are great variable use tools that can improve force production at different points along the force-velocity curve. These help to bridge the gap between highly specific sport practice and general strength training, ensuring strength is expressed quickly. These includes movements like weighted squat jumps, where the main goal is to violently accelerate all the way through the end range of motion to where the body actually leaves the ground. Even some variations of medicine ball throws, box jumps, and double-leg plyometrics could be considered ballistic versions of a squat pattern.

Though these are excellent tools, I haven’t included a detailed discussion of them as partial ROM squats because they generally are not performed with near-maximal squat weight. I would caution that some coaches - particularly jump coaches - will include these as a part of their sport training at practice. If this is the case, it is critical to collaborate with the sport coach to ensure the combined training demand from practice and the weight room is manageable.

Context Matters

An important point to understand with all these examples is that partial range of motion is implemented as a tool to manipulate nervous system output, manage fatigue and soreness, or improve the execution of the full squat. They don’t replace full squats on a permanent basis and are typically performed alongside, rotated with, or temporarily replace the full movement.

Additionally, partials in all these scenarios are typically not included for a lifter who isn’t already proficient in the full movement - especially for an athlete with a young training age who still adapts rapidly to linear loading progressions. Trading the strength and skill development of full squats for partial squats in these athletes deprives them of important opportunities to build qualities that can serve them for the rest of their careers.

Which Mechanism Is It?

I include partial range of motion movements for all the athletes I train in some capacity because I believe they are a valuable tool when implemented at the right time and managed appropriately.

But I believe sometimes we inaccurately attribute the success of 1/4 squats and other short ROM variations to the mechanism of specificity, when they were simply used as an effective peaking or priming tool during the late part of the season. When we get used to using “specificity” as a catch-all justification for avoiding full range of motion, we can lose sight of other beneficial processes occurring in the body that help elevate performance. It is possible that matching the angles of sprinting and jumping under a bar is less important than using a tool that allows for the effective reduction of fatigue and soreness, as well as a dosing of intensity to perform well at the right time. It is a wholistic process the body goes through involving the manipulation of neurological, muscular, and psychological output. Not just matching the angles of the event.

As I discussed in part II, specificity of training is absolutely essential to improving performance. But the problem with attributing event success to weight room specificity is that when we get the mechanism wrong, we can be tempted to constantly pursue short ROM all year long and load them far beyond what is safe.  Neglecting full squats or limiting them to the off-season can cause us to miss out on the numerous benefits they offer for performance enhancement.

When we get the mechanism right, we can reap the benefits of a full spectrum of training tools and methods, rather than getting pigeon-holed into chronic discomfort avoidance and the overuse injuries that tend to follow.

Putting It All Together

We’ve come to the conclusion of this 3-part series on squatting for sprinters and jumpers. In the three parts I’ve covered:

-How to adapt and coach back squats to the typical body type of sprinters and jumpers

-The benefits of learning to squat as low as possible safely

-The consequences of chronic partial squats and deep squat avoidance

-The scenarios where partial squat variations can be valuable tools for performance enhancement

If you’ve followed along to this point, its should be clear that I’m both pro-full ROM and pro-partial ROM. The critical ingredient in determining when different variations are appropriate is the context of how the squat variation is being applied.

An important theme woven throughout all these ideas is the importance of teaching. Even I have been surprised at what athletes who have been convinced they can’t or shouldn’t squat can do when they are given the opportunity to learn how to do it and progressively loaded through a full ROM. It is crucial for any coach tasked with designing strength programs to emphasize teaching their athletes to expand their abilities, rather than simply accommodating inabilities. I’ve been surprised not just at how strong they get in the weight room, but how much their performance improves when combined with effective event training. When this happens, they have many more options when it comes to managing the demands of a competitive season, including the effectiveness of other methods that use partial ROM variations or emphasize higher power and velocity movements.

Deep squats are fantastic, but the skill must be developed. Making athletes do them without regard to proximity to competition and without taking steps to develop the skill is a recipe for injury, distrust, and constant tension with athletes and sport coaches. Partials can be great tools to augment performance at the right time, but doing them at the expense of full squats and under unreasonable loads deprives athletes of important opportunities to grow and creates its own injury risks. Let’s expand the proverbial “box” and figure out how to use them both.

Sources:

1. Lorenz, D. “Postactivation Potentiation: An Introduction.” International Journal of Sports Physical Therapy. 2011;6(3):234–240.