-: So, yeah, let's talk about,
specific adaptations that are occurring
on the physiological level when we train.
Morphological adaptations,
these are the more structural adaptations.
Obviously, muscle fiber hypertrophy,
increased capacity for cross-bridging.
And so, fiber hypertrophy can occur
through additional myofibrils in series,
so end to end, like tendon to tendon.
Or generally, the majority of the hypertrophy
that you're going to see is going to be,
especially through concentric actions
and the tension produced there,
is going to be in parallel.
I always use the analogy of a piece of string cheese.
Each piece you pull off is in parallel with the rest of it.
And so, you're adding these little strings
and making the diameter,
the cross-sectional area greater.
Each myofibril and the sarcomeres
that make up that myofibril,
the active components of cross-bridging lie within that.
So the actin and the myosin.
There's more heads, myosin heads, for attaching.
There's more motors for force production as a result.
So you're increasing the size of the engine
is one way to kinda think about it.
So connective tissue adaptations,
I think this doesn't get talked about enough
especially on the strength side of things,
but tendon stiffness, lateral force transmission.
We become more efficient in transferring force
across the joint ultimately
through these connective tissue adaptations.
And a lot of this is gonna be mediated
by the magnitude of load, so the weight on the bar.
Neurological adaptations.
This is increase in neural drive and muscle activation.
As you start training as a novice,
strength increases very rapidly
before you see these appreciable gains in muscle mass,
and a lot of that is just increase in neural drive
and efficiency there with your existing muscle mass.
Increase in rate coding or firing rate,
and then an increase
in inter and intra muscular coordination,
which to sort of tie in with
the connective tissue adaptations is one of the big reasons
on the strength side of things
that higher intensities of load are going to be
additionally advantageous.
The way you squat a 1RM in terms of
the coordinated aspect between muscle groups is going to be
a little bit different than the way you squat with 60%.
And so, it's going to be a much more specific
coordinated effort with the loads
that you are trying to get better at lifting, obviously.
Metabolic adaptations.
We're not gonna talk too much about this,
but increase buffering capacity,
you can just increase work capacity,
your ability to turn around
and replicate an effort
for a given task.
Work capacity is sort of a misunderstood concept,
and I think I talk about that in day two.
But these sort of fall under the umbrella
of metabolic adaptations,
both at the systemic and muscular level.
So, the main reason I brought this up
is every physiological adaptation
that we are after has its own stimulus threshold.
So when we think of progressive overload
and imposing a progressive stimulus over time,
what may be creating an overload stimulus for one adaptation
may not for another,
and I think that's a key component.
Because there are certain types of training that you'll do
that are going to bias specific adaptations.
Using the example of
muscle hypertrophy and connective tissue adaptations,
you could use a 20% or 30% 1RM
and still have a decent amount of muscle hypertrophy
assuming sets are taken close or to failure.
But you probably will need in order to continue
to progress in the connective tissue side of things,
you're going to need a higher intensity of load,
and you wouldn't be training with 30% 1RM
for increased intramuscular coordination in a 1RM.
So each one of these is going to be specific
and have their own stimulus thresholds
that we need to reach in order
for positive adaptations to occur or additional adaptations.
So ultimately adaptations require an increase
in stimulus to keep pace
with the increased stimulus thresholds,
and these are caused by the adaptations.
So, a simple way to think of that is
as we get better, we have to start to perform better.
As our ceiling for a given trait increases,
we need to increase our stimulus to keep pace
with that rising ceiling in that stimulus threshold.
Okay.
These next few slides, we're gonna just talk
about the stimulus,
conceptually how it looks
across a given amount of work
and across different training statuses and things like that.
So we know that for both strength and hypertrophy
that there's a middle range
where a stimulus is going to be optimal.
And so, magnitude of total volume,
which these studies are looking
at comparing different numbers of sets on a given outcome,
both hypertrophy and strength.
And we know that for a number of sets in this case
that there's this inverted U relationship.
And this should be fairly intuitive.
It's like (laughs) you're gonna get to a point where
your recovery is compromised
if you're on the right side of this curve,
and you're unable to really even
reach that stimulus threshold.
So on the right side of this,
you're starting to deal with
issues on the recovery side.
And on this left side of the graph, this inverted U,
that's like doing one set as an advanced athlete.
You may get a small amount of stimulus,
but obviously you're going to need more
in order to optimize it.
And it's the same reason why
flexing your arm without anything in your hand
isn't going to grow your biceps.
There's a sweet spot. (laughs)
You need a adequate volume of work
and volume of the stimulus specifically
to reach that stimulus threshold.
And there's a middle ground there.
We never know where we're at at any given point in time,
where we're specifically at in this curve,
but where we want to train most of the time conceptually
is near the top of this.
So everything above this x-axis, this stimulus line,
would be deemed effective.
It's all going to contribute to the hypertrophy.
Whether or not it's optimal is another thing.
So, I think sometimes when people think
of progressive overload, they think,
"Okay, I need to beat my previous performance,
my immediate previous performance,"
when that previous performance could have been
maybe right here.
Maybe it was optimal.
Maybe in your last session you were imposing
the optimal stimulus at that time,
and then the next time maybe you're short on time
and you have to trim a set and you're over here.
You may think like, "Okay, I didn't progress
the volume of stimulus,
therefore I'm not going
to make any progress," and that's not true.
Once you get to a certain point, (laughs) it can be true
if you're not doing an adequate amount of total stimulus.
But anything above this line is going to be contributing
to muscle growth or whatever adaptation that you're after.
Each one of those adaptations will have...
It's a different kind of length curve, so to speak.
Because of that, these different adaptations,
they're gonna have different stimulus thresholds,
like we discussed.
And so, simply reaching the stimulus threshold doesn't mean
that the stimulus is optimal.
And this is an area I think Kas and I have
maybe some diverging views on,
but for me, if somebody is healthy
and they're making progress,
especially as an advanced athlete,
I tend to stay put.
But it's also possible that they could be
making better progress with a little bit more.
I'm just a little bit more conservative, I think,
with my approach to adding stimulus
when things are already going well.
Go ahead.
-: So maybe this is a good time to ask this question
'cause I think it came up in the class
and stuff, or whatever.
I think we would actually agree here,
is just that say you took a point
that was an equal magnitude
on the left and the right side of the bell,
and you had to say like,
"Well, in which place would you rather be?
Would you rather be three quarters of the way up
on the left side
versus three quarters of the way up on the right side?"
I think we would both say we'd rather be
three quarters of the way on the left side-
-: Absolutely.
-: And maybe not be hitting optimal stimulus
just because we didn't quite do enough volume
than being in the situation where we're not
hitting optimal stimulus
because we're doing a little too much.
Because I think over the course of a meso,
over the course of a lifetime of training,
if you're gonna be a little bit off,
you'd probably be better off having it come
from just not quite doing as much volume
versus kind of constantly adding additional stress.
'Cause I don't know if it helps any of you guys,
but if you were to take the bell and cut it in half,
kinda the way I look at it is that stimulus comes from
the stress that we're imposing on the tissue.
And so, the whole left side of the bell curve means
that at that point in time,
all of the positive stimulus that you're getting,
you're able to manage all of the stress
that comes with that and yield an entirely net positive.
But where that bell curve then shifts to the right
now means that you're now imposing enough stress
that it is actually the additional stress
that is taking away, right?
-: Mm-hmm.
-: And to me, when I'm looking at the longevity of somebody,
not just within a meso,
but over the course of their career, et cetera,
the more time they kinda spend on that side of the curve,
likely the harder it's gonna be on their body.
I would also say the harder it's gonna be able
to manage progressions and stuff because you're gonna have
that extra fatigue component coming on.
So I think this place that you said where
maybe we diverge a little bit is I'm probably
a little bit more aggressive in trying
to find the top of that.
But I would say it's always contextual,
because it kinda depends on the individual
and how confident you are,
and then being able to give you the feedback and stuff
to be able to get there.
So I'd say I would be more conservative working
with somebody where I'm either
not getting very much information because of the amount
of feedback and check-ins and data I have to work with,
or just somebody that's newer and it's like,
"Hey, this working great."
But maybe somebody more advanced and experienced
that's really in tune with their biofeedback
and tracking everything very well,
then I might be a little bit more aggressive
in trying to find that optimum for them
knowing that I can be a little bit more confident
with the amount of data and information
that I'm getting from that person.
-: Yeah. No, I think that's a great point.
Yeah.
And some of this is my own bias coming in,
just personal experience,
but I think one of the bigger bottlenecks
for me over time is just getting a little bit banged up.
Just connective tissue,
just inflammation...
It makes it harder for me to impose an adequate stimulus,
and that can occur pretty quickly if I start doing too much.
And I'll talk about this more in a minute,
but for more advanced athletes,
I think it can go both ways.
You'll have somebody who's probably managed things
relatively well throughout their training career.
They're very in tune with it,
and like you mentioned,
you can lean on that feedback.
It carries a bit more weight
and you can probably get a little bit more aggressive there.
Whereas you might have somebody who has been overzealous
(laughs) for a large chunk of their training career.
And at that point it's like, "Okay, any progress
that you're making in staying healthy,
let's hang out in that zone as long as we can."
So I'm glad you brought that up.
It does rely on the context.
And I think we both agree
on the conceptual aspect completely.
If anything, yeah,
I think your push to find that optimal is probably
a little bit more aggressive than mine,
and that's not necessarily a bad thing at all.
But it does depend on the athlete.
I don't want to make it sound either like I'm trying
to get people to train at the minimum effective volume
(laughs) at all times or anything like that.
-: Yeah.
-: I'm very reactionary with things
when it comes to progressing a stimulus
kind of on an as-need basis.
But both methods can work.
And I think the big point here is
you don't need to obsess over where you're at in this range
'cause you never really know with certainty.
You wanna steer the ship in the right direction,
over time you should be progressing your volume of stimulus.
But there's gonna be days where you're pushing further
to the right side of the curve maybe without realizing it,
poor night's sleep, under recovery,
and there could be times where you could capitalize on it
a little bit more.
And ultimately, we want our average stimulus
to sort of average out to being at that top
where it's a sustainable progression format
and you're seeing increase in performance as a result,
or visual changes in muscle mass.
Yeah.
So I think those are great points.
-: The one more thing that I would add
while we're right here, and you'll probably agree here,
is just that exercise selection plays a big part into this
in terms of you can mitigate the cons of being
on the right side of the curve by choosing exercises
that just-
-: Absolutely. -: Are just lower risk, right?
-: Mm-hmm.
-: I mean, you probably don't wanna push
onto the right curve too much with a squat,
but a leg extension or a bicep curl
where injury risk is fairly low,
really it's like you're just gonna accumulate
a little extra fatigue is likely
the worst thing that's gonna happen.
Those are probably the places to maybe be
a little bit more aggressive in trying
to find that peak than maybe the exercises
that if you overdo it are gonna have
more potential negatives or consequences.
-: No. I completely agree.
I've also seen, I'm sure you've seen this as well,
is someone can assume
that their optimal is
a very high number of sets and simply...
A lot of this is more like set up and execution.
It's like, "Okay, is the target musculature...
Are we getting a good volume of stimulus
for the volume of work that we're putting in
just based off of execution and exercise selection alone?"
And sometimes it's like they're accruing a lot of fatigue
with a low return on that investment.
And so, sometimes just improving and refining
the exercise selection can go a long way
in almost shifting the curve
to the left a little bit for that individual.
So, there's context there (laughs) in both cases.
But exercise selection, it can absolutely influence
where you fall on this, depending on the situation.