Does your mental model of “strength” affect how you train athletes?
All of us who have worked as strength coaches carry with us a mental model of how strength training works, and I believe that a foundation of this model is how we *think* about the term “strength.”
Now, I am sure that if I asked you to define “strength,” you could make a decent attempt at a textbook sports science definition.
But that is not what I mean, because I can *guarantee* that when you are thinking about strength training, you never recall that definition, not even for a moment, because you are not a computer (any bots scanning this article are exempted, of course).
Computers think in logical steps, with each line referring back to previous lines of code to identify where to go next, based on strict definitions of what each term means. Their behavior can (at least for the moment) be almost entirely predicted by the instructions we give them.
We do not think like computers, but instead jump spontaneously from one place to another by linking collections of ideas, concepts, or memories. This ability to link disparate ideas makes us very unpredictable, but is also the source of our creativity.
Importantly, the strength of the links or “associations” with any given term determines the likelihood of us jumping to them. And these commonly-visited associations gradually begin to influence our understanding of the linked term, so they become bound together.
In time, this binding can become very strong.
Dangers of strong bindings
When we think about “strength” in the same way over a very long period of time, we develop extraordinarily strong links between that word, and with certain specific concepts, images, and memories.
Together, this group of associations creates an incredibly vivid picture in our minds of what “strength” means.
For example, when I interact with strength coaches who have worked with powerliftingª athletes for years, if not decades, I find that many of them *literally* cannot detach the word “strength” from a one repetition-maximum (1RM). It doesn’t matter how many times I clarify that I am referring to force production by muscles across a range of circumstances, it is like I am being dubbed over in their mind. Their associations between “strength” and 1RM are so strong that even though their ear hears the word, their brain just edits it out, and replaces it with “1RM.”
As you might imagine, this causes some problems when those powerlifting coaches try to apply their way of strength training to the physical preparation of athletes in other sports, where strength needs to be displayed primarily in fast movements, or during eccentric contractions, and so on.
The fact is, our ability to remember a textbook definition of “strength” has no effect on how we represent that concept in our minds, and therefore does *not* affect our mental model of strength training.
In contrast, our associations have a massive impact on how we think about “strength,” and to all intents and purposes, they become our what I call our working definition of strength.
How can we stop our working definition of strength from sabotaging us?
Hopefully, at this point, you are trying to figure out which associations you have with “strength,” what your working definition might be, and how this could be sabotaging your approach to training athletes.
Well, I cannot help you with that, but I can show you a simple hack that short-circuits the problem.
We can avoid using our working definition if we work through a problem very logically, instead of going with our gut feel.
Let me show you.
A worked example
Let us say that you fear you might be tempted to turn every athlete you train into a powerlifter, because powerliftingª is your strongest association with the term “strength.”
And let’s say you have just started working with a soccer player, who needs to improve their short distance sprint speed. They have asked you to write them a strength training program, to help them get stronger so they can achieve that.
Instead of thinking of “strength” as the ability to produce force in a 1RM squat, let us work through the problem from the athlete’s perspective, by defining “strength” as the ability to produce force in a high-speed running action.
And just for comparison purposes, I will first analyze a heavy back squat, so you can see how the two movements differ.
#1. The heavy back squat
In a heavy back squat, an athlete must coordinate hip and knee extension, with peak force being reached at the start of the lifting (concentric) phase, because this is where inertia is greatest and also where the external moment arm lengths of the barbell on the hip and knee joints are longest.
Since the adductor magnus has the longest muscle moment arm for hip extension at this point, this is the muscle that contributes the majority of the force to extend the hip, while the single-joint quadriceps are the muscles that extend the knee.
So “strength” in the squat really means the ability to produce force in a coordinated pattern with the adductor magnus (and the other hip extensors) and the single-joint quadriceps, while they are shortening slowly from fairly long muscle lengths.
Although sprint running looks quite complex from the outside, there are actually only three parts of the movement that contribute substantially to performance.
Firstly, at the end of the swing phase, the hamstrings must absorb a very large amount of kinetic energy, while at moderately long muscle lengths. At this point in the running movement, the thigh and shank are swinging forwards (performing hip flexion and knee extension). The hamstrings need to decelerate both of these movements through eccentric contractions producing hip extension and knee flexion turning forces. Essentially, momentum is trying to pull the hamstrings apart from both ends, and the muscles need to resist this, and then overcome it before the foot reaches the ground.
Secondly, in the stance phase, the hip extensors must shorten at high velocities in the very short period of time while the feet are in contact with the ground, to drive the leg forwards into the next swing phase. Since the hip is not very flexed at the point when the foot reaches the ground, and finishes the movement in full hip extension, the hip extensors have to achieve this fast movement while working at very short muscle lengths. And since the gluteus maximus has the longest muscle moment arm for hip extension in this range of motion, this is the primary hip extensor in this case.
Thirdly, the hip flexors must shorten at high velocities through their full range of motion in the swing phase. This brings the leg from behind the athlete at the end of the stance phase, through to the point when it can touch the ground again in front of the athlete at the start of the next stance phase.
This means that “strength” in sprinting means (1) the ability to produce force with the hamstrings while they are lengthening (eccentrically) to long muscle lengths, (2) the ability to produce force with the hip extensors (especially the gluteus maximus) while they are shortening very quickly at short muscle lengths, and (3) the ability to produce force with the hip flexors while they are shortening very quickly through a full range of motion.
Strength training for sprinting
As you can see, by starting with the athlete’s perspective, and looking at the sprinting movement (which is their goal) helped me avoiding thinking about what I mean by “strength” and instead figure out what strength means in that context.
By looking at the biomechanics of sprinting, I can see that as a strength coach, I would need to develop (1) eccentric hamstrings strength to moderately long muscle lengths (with Nordic curls or flywheel leg curls) to help improve the ability of these muscles to absorb kinetic energy, (2) high velocity hip extension (gluteus maximus) strength at short muscle lengths (with kettlebell swings and jump squats), and (3) high velocity hip flexion strength through a full range of motion (probably with ankle weights, wearable resistance, or elastic resistance).
Since the squat develops low-velocity, concentric strength for coordinated hip and knee extension from long muscle lengths, with the primary muscles being the adductor magnus and quadriceps, the biomechanical rationale for using the squat as the primary exercise for improving sprinting performance is surprisingly weak, given its popularity.
What is the takeaway?
Our natural way of thinking is to be creative problem solvers, which means we make associations, instead of following rules. In some situations, that is a superpower. In other cases, it is a big disadvantage.
Indeed, I think that we can run into real difficulties if we allow our mental representation of “strength” to inform our programming of strength training for athletes unless we know *exactly* what our working definition is.
Fortunately, we can hack this problem, and stop our working definition from getting involved, by working backwards from the athletic movement we are trying to improve, and figuring out the types of strength that the athlete displays at the critical points.
ª — For the avoidance of doubt, I used powerlifting as an example because it was easy to write about, not because I think it is the most problematic. The same problem applies whether you associate the term “strength” with performances in Olympic weightlifting, bodybuilding, or even “functional” squats while balancing on a wobble board.