We’ve all been there. You’re driving out of the hole on a heavy squat. The bar is moving like a knife through warm butter. And BAM. You hit a brick wall and the bar stops. No matter how hard you strain, you can’t get the bar to move any higher. After a fight, you dump the bar behind you and get up wondering what happened. That is the power of hitting your sticking point. It’s like the bar gets stuck in mud, and can’t get out. Luckily though, having an understanding of why sticking points happen can help you train to minimize their impact.
Sticking points happen in all types of lifts. However, I’m going to focus on the big three (squat, bench and deadlift). But the same principles will carry over from the big three to any other lifts you are performing.
There are a number of things that can impact sticking points, including changes in lever lengths, the mechanical advantage of muscles and fatigue. So, let’s dive in a check out why we hit sticking points.
Overall strength can impact sticking points too – check out my article on optimizing strength training to maximize gains.
If you are looking for tips to overcome sticking points, check out my article explaining 4 key ways to change your training to blast through sticking points.
Sticking Point – A Definition
It makes sense that we start this off with a definition of “sticking point”. If we are going to spend a whole article on the topic, we should all be on the same page before we get going.
Surprisingly, it is hard to get a solid definition by going through scientific literature. Every paper and every author seems to have a different definition depending on what they are specifically looking at in their research.
A couple of different definitions include
- “The point in the range of motion during an exercise at which the upward velocity of the load decreases or reaches zero”
- “Where the lifter experiences apparent difficulty in exerting effective force against the load”
- “The weakest point in the range of motion of an exercise, probably where the external resistance has the greatest mechanical advantage”
Additionally, some authors consider it to be a ‘sticking region’. This is “the part of the range of motion in an exercise between the first peak in velocity of the load [speed of the bar] and its first local minimum thereafter [where speed hits a low point and goes back up].”
There are a number of issues with the above definitions. Such as #1 not taking into account that at the end of a lift the bar’s velocity has to slow down and reach zero in order for the lift to stop.
Or #2 failing to understand the force-velocity relationship, whereby as the speed of the bar increases force actually decreases. So, definition 2 suggests that the sticking point is when the bar is moving the fastest (and thus the force is lower).
And #3, which actually comes from the National Strength and Conditioning Association, failing to line up the definition with what is seen in real life. During the bench press, a lot of people have a sticking point near the end of the lift, just prior to lock out. However, the bar does not have a mechanical advantage there. So, the NSCA definition doesn’t match what happens in the real world.
My favourite definition comes from a paper by Kompf and Arandjelovic:
“the point at which failure occurs when exercise is taken to the point of muscular failure”
More broadly, the same authors suggest that the sticking point is: the part of the range of motion in a resistance exercise in which a disproportionately large increase in the difficulty to continue the lift is experienced.
Now that we are all on the same page, let’s take a look at what causes sticking points.
Biomechanical Disadvantage
There are two types of biomechanical disadvantages that come into play when we are lifting. The first is the force-length relationship and the second is the force-velocity relationship. I’ll spare you the in-depth dive into muscle mechanics and physiology (although my master’s work is based on this and I could talk about it forever).
Instead, we’ll talk about why it matters in your lifts.
Force-Length Relationship Intro
Muscles produce force actively and passively.
Active force production is through muscle contraction.
A surface-level explanation of muscle contraction is that we have muscle fibers, or cells, that make up our muscles. In these muscle fibers, there are contractile elements that do the work that results in our muscle contracting.
These contractile elements have two different proteins that interact with each other and slide past each other when they contract. The bigger protein (myosin) has heads protruding off of it that attaches to the smaller protein (actin). Each myosin interacts with two actin molecules. When the muscle fiber contracts, the myosin heads pull on the actin towards the midline. This leads to a shortening of the muscle fiber.
As muscle fibers contract, myosin heads pull actin filaments toward the center of the sarcomere (source)
You might have heard of the sliding filament theory. This is where that comes from.
How Muscles Produce Force
When these proteins overlap optimally all (most) of the myosin heads are able to reach out and pull on the actin to move it. This is what happens when we would consider the muscle to be at an optimal length.
However, when the muscle is already shortened the myosin pulls on the two actin molecules, but they end up running into each other. This means that the full force of the muscle can’t be expressed.
When the muscle is too stretched out, the opposite happens. The actin molecules are too far away, and the myosin heads can’t reach out to pull the actin into the middle. This leads to decreased force.
On the other hand, we have passive force production. This is essentially due to non-contractile elements in muscles that are stretched as the muscle is stretched.
You can think of it like a bungee cord. If you and a friend are each pulling different ends of the bungee, you are being active while the bungee is passive. The more that you pull the bungee, the more tension it has in it and the harder it is to continue to stretch it. Basically, the same thing is happening in your muscles.
If you’re curious about how muscles respond to workouts, then check out my article on the SAID principle. I dive into neurological and muscular adaptations, why having a plan is key, and how goals can inform your gains.
Force-Length Relationship and Sticking Points
So, why does this matter?
The active and passive forces add together to make up the total force of a muscle. As you can imagine, the total force possible changes at different points in a movement.
When the muscle is very short (i.e. the pec close to lockout on a bench press), the active force available is fairly low. And because the muscle is short, there isn’t much passive force to help out. Therefore, total force production is pretty low in the pec near lock out. This shifts more of the load of the bar to other smaller muscles. And because smaller muscles are as strong as larger ones, we often see people fail the bench press just before locking out.
Fatigue
As soon as a muscle starts to contract, it also starts to fatigue. We have all experienced this. As we perform more work, either increased reps or increased weight moved, we lose strength. This may represent itself as decreased bar speed or feeling of being ‘powerful’.
The amount of intramuscular fatigue is dependent on the force produced by the muscle and the duration of the contraction.
Muscular fatigue is a multifactorial process. Fatigue is experienced as a result of changes in nervous system signaling size and frequency to the muscle, decreased concentration of contractile enzymes, decreased excitation-contraction coupling and blood flow. All of these factors either inhibit contraction or decrease the strength of contraction.
Additionally, if you are working with heavy weights you will be recruiting type II muscle fibers. Type II muscle fibers are large, fast-twitch fibers that contract more forcefully than type I (slow-twitch) fibers. Although type II fibers produce significantly higher force than type I, they also fatigue much quicker.
You may be experiencing fatigue because of going too hard for too long. In that case, you need to take a break from training. Click here to check out some key signs that you need a deload week.
If you hit your sticking point and are fighting to break through, the duration of the lift is increasing. This is where type II fibers can become inhibited. As a result, you aren’t able to produce as much force.
Coupling this decrease in force production with the sticking point occurring when you are at a biomechanical disadvantage, means that a sticking point can stop you dead in your tracks.
Hearing about muscular fatigue might have you wondering why muscles get sore after working out. If so, check out my article on it here.
Torque
Torque is a way that force is expressed around a joint.
If you have ever used a wrench, you will have experienced the phenomenon of torque. Your wrench is around a bolt (the joint center). You apply force, some distance from the joint center, to the wrench handle. If you apply enough force far enough from the joint center, the bolt will spin.
The amount of torque produced is a result of the amount of force applied, the angle of the force and the distance from the joint center.
t= r * F *cos(angle)
We can change the amount of torque produced by changing the amount of force applied, the angle in which the force is applied, or by changing where the force is applied in relation to the joint center.
The same principle exists in the body.
Our muscles attach to bones at certain distances from the joint. For instance, our biceps tendon attaches a certain distance from our elbow on the ulna.
Read More: how often and how intense you should train to maximize strength.
Torque and Sticking Points
If we consider the biceps curl, we can investigate how torque and range of motion affect muscular force, and thus sticking points.
The angle of pull changes at different points of lifts. The closer the angle of pull is to 90°, the more the force will be converted into torque. However, if the muscle is pulling on a bone at an angle close to 180°, it won’t convert to as much torque.
This means that the biceps may produce the same force when the elbow is extended as when the elbow is bent to 90°. However, there will be significantly less torque produced when the elbow is extended.
This is relevant to sticking points when you consider multiple muscles that work together to make a movement happen. For instance, my sticking point in the biceps curl is just after the beginning of the movement from an extended elbow position.
In this position, the biceps brachialis muscle isn’t very effective at bending the elbow. Therefore, the majority of the torque production load is put onto other muscles. My synergist muscles aren’t as strong as my biceps brachialis. Therefore, they need to work at a higher percentage of their max capacity to get the weight past my sticking point.
As a result, they fatigue quickly, and I eventually fail in curls. This fail is a result of an increased load on other muscles that contribute to the curl than due to biceps fatigue.
Similar force shifting occurs in exercises like the squat, bench and deadlift as well.
Now that you know why a sticking point happens, check out four training tips to overcome sticking points.
References:
Kompf, J., & Arandjelović, O. (2016). Understanding and Overcoming the Sticking Point in Resistance Exercise. Sports Medicine, 46(6), 751–762. https://doi.org/10.1007/s40279-015-0460-2
Kompf, J., & Arandjelović, O. (2017). The Sticking Point in the Bench Press, the Squat, and the Deadlift: Similarities and Differences, and Their Significance for Research and Practice. Sports Medicine, 47(4), 631–640. https://doi.org/10.1007/s40279-016-0615-9