Today, we’re going to be talking about the key mechanical demand factor that everyone seems to be talking about and that everyone obviously refers to within strength, which is:

The Load that we lift…

…And how we can actually implement that within both, a rehab and a strength development practice; where the gap bridges between the two, and ultimately understand how it applies to each of the clients and the patients that we have in front of us.

Why Lifting Heavy?

So the first question that we need to ask is, why would we want to be lifting heavy?

Obviously coming from a strength coaches background, being a strongman myself, I’m pretty obsessed with lifting heavy and the moving of pretty much any heavy weight from A to B – but there obviously needs to be some kind of empirical backing there.

It can’t just be a subjective bias.

To give you a little bit of an insight, my original training, From an academic point of view at least, actually came from being interested in the science of training before I actually got into lifting heavy.

And it was in light of the vast, pretty much insane, amount of empirical evidence that was available that I actually committed myself to strength.

So it wasn’t the other way around where it’s this kind of confirmation bias where I look to find all of the research that shows the strength is a feasible and very effective method of training for everyone – but it was actually the inverse.

And irrespective of what it is that you look at whether it’s:

• Prevention of injuries.
• Delaying the effects of aging
• Enhancing sports performance

The stronger you are, the better off you are.

Now that’s not to say that there is a direct causation at play, but the evidence is pretty overwhelming and it’s difficult to dispute that strength and lifting heavy puts you in a better position for any athletic performance endeavor.

With that in mind, the key focus here is the effective implementation and prescription of strength and not a bastardized version that is subject to these biases that we tend to see within the industry.

Taking an example within the rehab setting,  noncontact injuries, particularly within like young women in stability based sports of ones that have high repetitive impacts, jumping, that type of thing.

They often stem from faulty mechanics.

So there is a whole swathe of corrective exercises out there, exercises or drills that mimic or create, “functional patterns” that will obviously translate to movements such as change direction mechanics and skill based exercises.

But ultimately, that still falls into the line of strength training, because as we’ve said before – all strength is, is….

The ability to effectively produce and coordinate force.

Whether that’s in the form of resistance, whether that’s an excess range motion, it doesn’t matter – it’s about the control and production of force.

So, again, keeping that in mind, faulty mechanics tend to come about as a result of a lack of appropriate passive and or active tension. 

Whether it’s the passive structures and their ability from a tissue resiliency standpoint to tolerate the loads during cutting mechanics or whether it’s the ability to effectively activate your glute medius and the lower limb musculature to control triple alignment (Hollman et al., 2009) – it’s pretty irrelevant.

The point is, at least a meta level, the stronger the individual is and through the process of lifting heavy, the greater the potential they have to reduce the prevalence of things like noncontact injuries in sport (Khayambashi et al., 2016).

And there’s a really simple quote,

“If you don’t take the slack out of your body, the barbell, the weight or gravity will”.

And that’s just a really simple way of kind of analogizing to the patients and/or the clients – the importance of what it means to be strong because something is going to take the slack out the body.

And typically when you can’t withstand that force, that’s what results in these types of injuries.

Now, this is obviously a very general overview, but it’s important to lay the conceptual groundwork.

Whether it comes from a standpoint of you guys having to get on board for the understanding of why strength is so important or whether it’s being able to deliver the rationale to the client and break down a lot of these issues that we still, to this day, tend to see within the typical sports setting or if it’s a general population client, the subjective cultural views towards lifting heavy.

It’s important that you need to break that down and create a lower barrier of entry for the people that you’re going to be working with.

So let’s dig right in and first of all, look into what we would actually use to classify load.

What is – ‘Load’ ?

Personally, I like to rephrase this. When I’m breaking it down as a topic of discussion and as a mechanical demand factor and look at ‘load lifted’ as a more appropriate term in the form of:

A line of force.

It’s important because the action of the force on the body is ultimately the thing that determines the outcome when we’re lifting heavy. Whether it be the tissue stress – looking at it from a muscular hypertrophy standpoint and we’re optimizing joint angle position to create regional hypertrophy (Zabaleta-Korta et al., 2020) – or whether it is in powerlifting – where we’re looking at optimizing leverages to maximize the weight that’s moved from A to B. 

Or whether, again, as I said earlier, we are utilizing what we would typically classify as a “functional exercise” – Either way, the important factor is the line of force.

One of the key things that you’ll have to have when you have a patient or a client work with you, is, first of all, understanding how you’re going to apply that force to the individual.

Now, there are typically three types of resistance.

This isn’t to be confused with isotonic or isokinetic.

This isn’t to be confused with machines versus free weights.

It’s a different way of looking at things that I tend to find is a really simple way of categorizing the exercises that you’re going to use – purely to scale up or scale down the load that you’re going to be applying to that individual when you’re lifting heavy.

And this comes in the forms of:

• Fixed
• Fluid
• Bodyweight

So we’ll talk about in inverse order.

Bodyweight Exercise

Bodyweight exercise – the clue is kind of in the name, really.

That is where we adjust body position to manipulate the line of force. 

A really simple example would be obviously going from a split squat into a reverse lunge into a Bulgarian split squat, into a pistol squat.

All we’re doing is adjusting body position. Altering a few of the mechanically less favorable positions to require more force to act through the muscles and the overall structure within the body.

We then have fluid resistances.

Fluid Resistances

So this is when we can actually adjust to the line of force, adjust the weights or the implements that you’re using in order to suit the body position of the individual.

And this is a really useful distinction to make, because if you’re coming at it from a rehabilitation setting, you’re going to come across morphological restrictions.

You’re going to come across psychological barriers, you’re going to come across tissue tolerance issues, whether it be rehabilitation tendinopathy, whether it be knee replacements or whether it be rehabilitating someone through a triple flexion based injury, such as an ACL rupture…

Having an understanding of fluid resistances allows you to still provide overload to the tissues in the individual when lifting heavy but in this scenario, the mobility demand is much, much lower.

An example of this would be a goblet squat; using a sandbag, using resistance bands etc. we can adjust the line of force and where the resistance is actually acting on our body to effectively implement or create a stress to the tissues without necessarily having to conform to a certain movement pattern.

Now, the trade off with this is because we are in control of the load, with regard to the position, to a greater extent than the fixed exercises, typically means that less force is going to be applied.

So this is what we would look at from a standpoint of early stage rehabilitation.

If you can squat 200 kilograms doesn’t necessarily mean you’re going to be able to goblet squat 100 kilograms – far from it.

OK, again, load position is obviously something that we would talk about and we will talk about the mechanical demand factor in its own right – so it’s important to make the distinction and being aware of the trade off – having slightly less flexibility to scale the exercise purely from a standpoint of the absolute load that is acted upon the body.

Now with fixed resistances.

Fixed Resistances

This I would classify as a barbell or a machine.

You have to mold the individual around the line of force.

For those of you that don’t necessarily understand this, you might not have come across powerlifting or strength sports at a high enough level to initially understand.

Basically, when we’re looking at lifting heavy from a physics standpoint, without going into too much detail, to optimally (and again, the key word there is optimal) recruit the maximum amount of muscle and therefore the maximum amount of leverage within a barbell squat –

The bar must be over the midline of the foot.

If it isn’t, that’s not to say that you’re going to be weak…far from it.

It just means that certain energy is being wasted in order to control the trajectory of the bar.

The same with the deadlift. It needs to be coming in towards the hip joint and the bar path as a result, traveling in roughly a vertical line.

And again, it’s not to say that everything has to be perpendicular, but in essence, the bar path is the thing that determines optimal leverage.

Keeping that in mind – we have to then adjust the body position and control for any kind of morphological restriction that we have, to be able to fit round the line of force.

With a barbell back squat, if you’re looking at optimizing the position that that individual is going to get into, you’re going to have to make sure you have a certain degree of thoracic extension.

You’re going to have to have a certain degree of ankle mobility.

Because it might be that an individual has really long femurs but has really poor ankle mobility, in which case they’re going to struggle with a barbell back squat. 

And a lot of the origin of this “mobility work” that we have is the whole, what I like to call a square peg into a round hole analogy; of molding an individual to an exercise that, although it will allows them to lift heavy, might not necessarily be the most suitable thing from a range of motion or a mobility standpoint.

So we have those three methods of implementing load through the body and understanding the kind of trade off between all three, again, body weight, fluid and fixed resistances.

The next thing that we’re going to talk about is the idea of a strength curve within any loaded movement.

Strength Curves

So with strength curves, we’re essentially referring to the force that is required and when lifting heavy, throughout the range of motion of a movement (Kulig, 1984).

So we actually have four, but today we’ll talk about the three primary ones:

1. Bell shaped.
2. Linear ascending
3. Linear descending curve.

1. Bell Shaped

Now, a bell shaped curve basically means that we experience the exercise at its most difficult within the middle or approximately the middle of the range of motion. Really simple example of this would be a bicep curl – the hardest point is halfway through the range of motion because of the internal moment arm is at its greatest.

2. Linear Ascending

A linear ascending strength curve, is where the exercise is at its most difficult at the start of the concentric phase of the movement. So most strength exercises that we tend to see when lifting heavy, follow roughly a linear ascending path, which is something like a barbell back squat. The bottom position is the hardest position for that range of motion.

3. Linear Descending

We then have a linear descending strength curve, which is essentially the inverse where the exercise gets progressively harder throughout the range of motion. Really simple example of this would be a dumbbell lateral raise – it’s why it’s so difficult to hold a pause at the top position unless a very light weight is used because it gets progressively harder as the as the joint goes through that range motion.

And again, it’s important to be aware of each of those strength curves because different exercise selections will allow us to elicit different stresses on a tissue dependent upon either what stage of the rehab process they’re in or what the weakness is that we are working on developing with the individual.

Example Application – Tissue Tendinopathy

Let’s take a classic example with a tissue tendinopathy. Again, this is entirely down to your individual exercise prescription modalities, but it may be that the individual experiences pain when loading a tendon in a stretched position.

If we’re taking an individual during a squat pattern and want them to be lifting heavy, yet we are finding that when the individual is under significant stretch, that’s when they experience this kind of painful response – giving them an exercise that has an ascending strength curve is almost counterintuitive because we are maximizing the force application at its weakest point and in its most stretched position.

Within any strength exercise – you are limited by the actual difficulty and the most difficult part of the movement.

For example, in a lateral raise, if you have to go through that full range of motion and the position of the top is so difficult that you would only be able to do 4 kg dumbbell – even though the deltoids and all the muscles that are involved in that exercise are so much stronger at the bottom phase – it doesn’t matter – they’re only getting “4 kilograms” worth of overload – they’re only getting 4 kilos worth of resistance, so to speak, throughout that range motion.

And it’s a similar scenario within the squat. Because you are limited by the painful response at a stretched position in the bottom of a squat, you’re not getting any overload to the tissue throughout the rest of the range of motion where:

And this is where we can start to manipulate strength curves, add what’s known as variable resistances (in the forms of bands and chains that we tend to see within the scary powerlifting world with lifting heavy) – we can actually use them when we’re bridging the gap between a rehabilitation setting and a performance setting, because we can continue to provide a significant amount of overload, continue to implement and progress the mechanical demand factor that is “load”, without necessarily being hindered by the injury that is at play.

And that’s just a really important distinction to make.

So, one other point that we need to talk about before we look into programming is essentially the contraction mode that we’re going to be utilizing.

Contraction Type

It’s pretty conclusive now that most skeletal muscles, irrespective of the movement, irrespective of the task at hand, are stronger within an eccentric contraction – some muscles are up to 60 percent stronger (Komi et al., 1986; Higbie et al., 1996) – passive resistance (Leonard et al., 2010), more optimal motor unit recruitment strategies (Howell et al., 1995) all these different factors that you want to talk about – it’s pretty conclusive that eccentric contractions are stronger.

Then obviously, you get the isometric positions that we can produce a significant amount of force there and we can concentric.

And in the weakest muscle action when lifting heavy typically comes in the form of concentric contractions.

So, again, if we have an injury or even if we have an athlete that is looking for optimal performance and they are limited – at the moment – by the load that they can lift, because every single exercise you give them typically goes through the isotonic protocol of having those three phases at play (eccentric, isometric and concentric) and that’s where the overall is applied – You’re only as strong as your weakest link.

Eccentric Contractions

I might be able to eccentric squat and provide overload to my patella tendons, for example, with a 300 kilogram weight. Yet, if I can only squat 240, my tendons, during an eccentric contraction at least are only getting force stimulation from the 240 kg squat.

Again, when it comes to exercise selection, this is what’s birthed the idea of exercises such as the Nordic hamstring curl to be able to provide a significant amount of low to the hamstrings there and essentially utilizing isometric positions, To not only teach optimal movement strategies, but also to provide a significant amount of overload on neurological level and tendon level.

And looking at that – we can actually see distinct benefits from each of the contraction types if we were to bias them in movement.

Within an overload eccentric one of the biggest benefits that I tend to see – at least in an anecdotal practice – is that it teaches tension, it teaches an individual to be able to hold a position.

This idea of being able to take the slack out of the body – nowhere is it better than under a really, really heavy eccentric load.

On top of that, a lot of noncontact injuries that we were talking about earlier tend to come from “landing based” activities, which is obviously very heavily eccentric based.

If you can provide overload both in a rehab and a performance setting to that you eccentric mode and be able to get the individual to develop strength in that very specific capacity, you are able to progress the load lifted, purely within that contraction mode and not necessarily limiting the stress that’s place to the tissue purely by what that individual can lift in a concentric manner.

A classic example of this would be working up to having your testing set – instead of working up to one rep max squat, where there might be a limited correlation with that individual athletes and also within that sport – where having a stronger squat might not necessarily yield greater adaptations and/or provide diminishing returns – but eccentric capacity is important – You could do a three rep max/five second lower on an overload eccentrics.

So get that individual to work up to the heaviest way they can possibly do – lowering for five seconds, literally recorded on a stopwatch – that is now your new baseline.

And you would look to develop eccentric strength rather than always focus in on this very one dimensional view of an isotonic movement having to require all three parts.

Again, with that in mind, eccentric contractions also provide a greater amount of proprioceptive feedback from the muscles of the brain (Matthews, 1991; Yue et al., 2000).

We get this overload from a cognitive standpoint and reinforce an optimal movement patterns when we overload eccentric contraction.

We can push the load again, as I said earlier, without being limited by our concentric capacity and also reinforce the positions that we want to get better within.

Isometric Contractions

Moving on from eccentrics onto isometric. This is absolutely fantastic for mechanical injuries – an injury that is typically as a result of a lack of tissue tolerance and the stress exceeding tissue tolerance. Simply because, there is no movement that is occurring. You can subjectively get that individual to reduce their intensity based off the pain that they are reporting, but also without causing any movement that is typically the cause of a lot of injuries.

A really good example of this that I’ve actually seen in anecdotal practice is the analgesic effect that we typically get from sustained isometric contractions (Rio et al., 2015).

Yes, as a disclaimer, I’m saying they’re not a fix for a lot of the issues that you have. But if that individual is presenting with an overuse injury that will typically just take a little bit of time and you don’t want them to have a significant amount of time away from practice, because we know that the worst thing you could do for a tendon is de-load it chronically.

Providing a sustained isometric and (particularly in overcoming isometric, if you can do that) is a really, really effective way of providing pain relief and also provide an overload effect to the tendon that will then serve a greater purpose within rehabilitation from injury, like I said, or the athletic performance further down the line.

Concentric Contractions

And then finally, the concentric contractions, essentially most actions that we perform within sport that actually create the performance? Are concentric movements.

Great…eccentric contractions are the things that allow us to control our body position, they’re the things that keep us safe, that are things that allow stability, but typically the “glory moments” for an athlete when lifting heavy or even for any method of athletic performance (e.g. for that elderly individuals having to get up off the couch) –

The glory is in the lift itself.

So if you can get that individual to be able to train the concentric contraction and progress the load through that, I don’t really need to convince you as to why that is important.

The final thing that we need to discuss is, are you loading the muscle or are you loading the movements?

OK, so we’re going to be really quick talk on this before we talk about the programming side of things – but essentially, you’ve got to understand the technique in both areas will govern the amount of stress that is placed through the body.

That bears repeating. So I’m going to say again.

The technique that you use, governs the amount and the direction of the stress that is applied to the body systems.

And I know that sounds incredibly obvious, but if you’ve not got that in mind, you might be getting the individual to perform a pattern moving away from A to B, but not actually putting the stress where it needs to be.

So to use an example – I work with a couple of strongman athletes who deadlift in a way that doesn’t necessarily recruit their hamstrings in the most efficient manner possible.

If I’m wanting to implement the deadlift as a method of strengthening their hamstrings, particularly with a significant amount of load, in a manner that is specific to the sport – I’m not getting the actual desired outcome of progressing the load with that individual – in which case I wouldn’t load the exercise any more until that is taken care of.

So again, moving away from A to B is different from how you actually apply that line of force through the tissue.

We’ve got all this information – we know about different types of resistance – we know about the strength curves within the movement – we know about the different contractile modes – how progressing the load through each of them can differ.

Programming

How do we program it?

1. % 1RM

Well, the obvious very traditional method is a %1RM.

That’s where you take a one rep max – the heaviest weight that you can lift one repetition or it could be a three rep max and then you estimate it there – and then that is your reliable measure of what that individual baseline strength is.

Then you can progress from there and you can create calculations based off a load that is lifted from that point.

Now, this is a very reliable method, but you have to very much be what I like to call the “average athlete” In that sense.

All of these equations that you tend to see e.g. the NSCA say that five reps need to be done with 80%, let’s say, that’s backed by a huge amount of empirical data, and it’s an incredibly valuable resource to have…

But when you’re programming, you have to be aware of all the things that we just talked about and the fact that each of those factors will influence whether or not that percentage is applicable to that number of repetitions or even that individual.

Personal Example…

To use myself as an example, to shine a little bit of empathy on it, I’m pretty skilled at higher loads within the one to three rep range when lifting heavy…but my strength rapidly drops off once I get past about five reps with the most movements.

Limitations

Whereas it might say on certain guidelines that that should be 80 percent of my max, I wouldn’t be able to do 80 percent of my max for five – but that doesn’t necessarily stop my one rep max from being higher, even though if I was to calculate it, it would say that it was lower than it was.

On top of that, the percentage 1RM isn’t really applicable for people that exist on the polar end of those spectrums when lifting heavy.

Really higher level strength athletes or high level athletes in general and then also individuals that are elderly and/or rehabbing from injury, where their tissue tolerance is too low to be able to go right to that extent of the higher end of loading.

Keeping that in mind – where would we go from there?

2. MVC

Well, if we were to use isometric loading – we can use a percentage of maximum voluntary contraction (MVC) – something you’ll see within the literature quite often – And this is literally an estimation of 100% MVC being your one rep max, and you do exactly the same thing from there. So you would program saying, well, 70% MVC, you should be able to hold that for 10 seconds.

With that in mind, even though the tissue tolerance might be a little bit lower and it might not be safe from a skill acquisition standpoint, it’s still relatively safe for them to do a percentage of MVC because it’s something subjective to them.

They can’t physically work harder than their tissues will necessarily allow them to.

And it’s just tends to be a bit of a safer alternative.

With that in mind – we can go on to the final two areas.

3. Rate of Perceived Exertion (RPE)

Which would be an RPE, which I’m a huge fan of – where we’re saying on a scale of one to 10, how hard you think you worked 10 being the absolute limit. 8 being not so bad, 1 being incredibly easy.

That’s actually birthed this notion of reps in reserve (RIR) training as well, which is to do with proximity to failure, which we’ll talk about a later date – but an RPE is a very, very valid method of prescribing intensity for an individual.

All the psychological factors that we talk about as an issue for reliability, which they are an issue from a programming standpoint, at the end of the day, they are the psychological factors that limit an individual’s output anyway.

So it’s circular logic to say that we need to remove the idea of psychology, of having an influence on someone’s output – what they can judge on it…

…Yet that is the thing that limits what output they have in a lift.

So, yes, it’s not the most reliable metric in the world, but it tends to be safer for those individuals – that exist on polar ends of the spectrum because, they won’t allow themselves to go to that level where the tissue tolerance might not necessarily be high enough.

4. Coaches Eye

And then the last thing is it coaches eye.

This is down to you as a practitioner. And we’re going to wrap it up on this but over time – you will develop the experience to see and to understand what load is going through certain tissues.

It seems far fetched if you are new to the industry, but it will become something that you can learn.

You can see when individuals have another 10 kilograms on the bar and they will be able to lift it or not.

So they are the different methods in which you can program it.

Summary

• Differences between the line of force and the load that is lifted, typically comes in the form of the type of resistance that you would be looking to use, whether it’s fixed fluid or body weight.
• You’ve then got to be appreciate the different strength curves and how that has an influence on tissue tolerance; understanding how strength curves can influence the whole rehab process when you’re looking at progressing load.
• How the different contractile types can also allow you to progress load in different ways, depending upon the individual and the context of the goal.

…And then all the different programming parameters.

So I know that was a huge, huge episode, a lot a lot bigger than the last ones that we’ve typically done. I hope you enjoyed it. I hope you took a lot of information from it.

The main thing I’ll say, guys and girls, please get in touch if you have any questions, OK? You don’t understand how excited I get when I talk about these topics and how much of a mission I’m on to be able to bridge that gap and create that network between people.

So any questions that you have, any topics that you disagree with within this discussion or,  if you have an interesting point that you want to make, we might even get you on the next episode. So that’s the goal of these prelim episodes.

As Always, Stay Strong and I’ll see you on the next one.

Reference List

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