Don't be afraid of stretching because people
have really strong feelings, opinions, but also
feelings. They might love stretching. They might...
hate it. There's not enough evidence to say you
must do it. It's definitely going to make you
stronger. Nor is there any evidence to say that
not stretching will make you weaker. So don't
be afraid of it. If you or your athlete want
to stretch, go for it. Hi, Alisa. It's my pleasure
to have you on Evidence Strong Show. If you could
briefly introduce yourself, that would be awesome.
Sure. So I'm a lecturer and a researcher at Auckland
University of Technology. I'm also a powerlifting
coach. athlete and referee. And I like to think
of myself as a strength enthusiast. So, you know,
my life, my hobbies, my work, everything tends
to revolve around strength in some capacity.
That's perfect. That's what we like here on the
show. And we'll be talking today about two studies
you've run with New Zealand powerlifters, one
with females and one with males. We'll talk about
them together because they are a little bit...
similar. And I will let you introduce the study.
So what was the goal of the study? So both of
these studies were a part of my PhD. And the
big question that I had going into my PhD was,
what is the relationship between strength and
flexibility? So, you know, that was fueled by
a lot of the conflicting internet opinions that
I was seeing. Everybody has feelings and opinions
about stretching and flexibility. And that led
me to do a lot of reading and in that reading
I found some evidence that powerlifters maybe
had less range of motion than other people and
I also kind of saw a bit of a link between that
reduced or less range of motion and some injury
risk. evidence, you know, suggesting that the
places where there was less range of motion are
also places where powerlifters were often injured.
And so the aim of these studies was just to get
a snapshot. What is the range of motion in powerlifters,
both female and male? Because there was at that
point no evidence in females whatsoever. And
I wanted to compare it to people who lift weights
also because the previous research had compared
to sedentary individuals. So yeah, to find out
what the range of motion was in powerlifters,
compare that to non -powerlifting resistance
trained people and to see if maybe we could link
range of motion with strength performance. That
sounds amazing. So let's dig in and let's hear
from you how you set up the study. Originally,
this would have been one. massive study with
four groups. And what we've just done is we've
broken it into two. So there are four groups,
two powerlifting groups, and the powerlifting
groups were people with a national qualifying
total. So I had 12 women, 12 men, all of them
had a national New Zealand powerlifting qualifying
total. And then this is where the differences
start. The two groups of resistance trained individuals,
the females just had to say they train. We didn't
do any strength measurements with them. But the
males were actually what we would say is well
-trained, meaning that they could squat one and
a half times their body weight and bench their
body weight. And we actually did 1RM testing
of squat and bench with the men as well. The
differences were strictly because we had trouble
recruiting. I couldn't find enough females to
come in and do the testing as it was. And so
I just kind of took away bits until I could get
enough women to have something. Awesome. So you
had athletes and you had trained individuals
as a comparison groups. And now how did you set
up the testing and what did you measure? So for
the testing, we had the men came in twice. one
of their sessions was 1RM testing, but the females
came in for a single session, and that session
was range of motion. testing. So I used goniometry,
you know, which is the manual kind of measure
of range of motion. So you can get the degrees
of motion at individual joints. But yeah, we
did range of motion with everyone and it was
active range of motion. So they were in charge
of moving their limb through as much range as
they could and hold that position. And then I
just measured them and captured those ranges.
We didn't mention it. So you had 12. females
powerlifters and 12 male powerlifters how did
you match the numbers with their controls yes
so also 12 in each recreationally trained group
and they're all age matched So I had, yeah. All
right. So you measured range of motion, anything
else? You had some results in terms of maximal
strength effort. So how did you go about getting
this data? So the other part that we did with
the male group is we looked at, we got velocity
recordings from submaximal squat and bench repetitions.
So how did you measure the performance then?
Okay. So we did 1RM testing. squat and bench
press. And we used those two lifts and calculated
a Wilkes score, just like a two lift Wilkes score
body weight coefficient. So we also found their
competition data and took their competition data.
And we ran linear regressions with it. So what
is the relationship between range of motion at
each of these joints and the performance of these
men, both in the study with the 1RM data and
then for the powerlifters specifically with their
actual competition data? And what we found was
that there was a relationship between shoulder
extension and hip flexion in male powerlifters
and their performance. Less range of motion,
better performance in those two specific ranges.
All right. Interesting. So it seems that it's
an adaptation to the sport, do you think? Maybe.
I mean, if we look at the kind of global results.
it gets more interesting. Because while we did
find that, we found that men had, male powerlifters
had less range of motion in several ranges compared
to recreationally trained men. And those guys
were, some of them were martial artists, some
of them were weightlifters. You know, they had
a range of sports, but the powerlifters had less
ranges in a variety of movements, we'll say.
Whereas the females, there was no difference.
So female powerlifters had very... similar range
of motion to recreationally trained female which
you know then you have to think well why could
that possibly be and one of the things we thought
well what about level of performance as a whole?
Are stronger people different than weaker people?
Or is it a sex difference? Or is it actually
more about training age, like the duration of
time that you've spent specifically powerlifting?
Because we see all of the time that powerlifters
have less range of motion in a bench press than
someone else might, right? We arch. We do things
like sumo deadlifts. We might hit just squat
depth. So is it actually that kind of specificity
of training that's causing it? And so in the
papers themselves, I stick with men. male versus
males, females versus females. But in my actual
thesis, I looked at male powerlifters compared
to female powerlifters. And the competitive level,
like the Wilkes scores, were actually very similar.
So what was the difference between females and
males? Okay, so between female and male powerlifters,
females did have more range of motion in almost
all of the ranges that were measured, something
like seven. out of 28 of them, they had significantly
more range of motion. And actually what we noticed
there was that looking at the differences between
the females and the males, the strength level
or yeah, the strength level was very similar.
So we looked at the Wilkes scores and they were
not significantly different, but huge difference
was in training age. So the training age of our
male powerlifters was roughly eight. years compared
to four on average for the females interesting
you know in weightlifting when we look at the
data for olympians for example it seems like
females get there faster too they need less years
to to medal the olympics in comparison to men
it can be their competitiveness it can be you
know how competitive the female competition versus
male competition is or it may be physiological
aspects to it females have less muscle mass than
males. So maybe they need less time to develop
this muscle mass that is required to lift the
biggest weights. What do you think is influencing
it in powerlifting? You know, I think it's very
similar. I think with powerlifting, the female
component has been growing a lot recently, but
it's definitely new. You know, the unequipped
version of powerlifting is newer than equipped.
And then the addition of more and more female
athletes is slowly increasing. And you can see
like a dramatic raise in the level of performance.
And so I think it is probably that previously
females didn't have to be quite as strong to
do very well and have those higher scoring lifts.
I mean, that's just speculation, but it makes
a lot of sense. looking at how much the world
records have increased recently. That's interesting.
Do you have any ideas why females have bigger
ranges of motion than males? Any speculations?
So that then comes down to, I think it really
could be training age. I think that the amount
of time spent very specifically trying to be
strong in a small range of motion is probably
what is causing it. I think if we could, you
know, wait four years and then test those female
powerlifters again, we would probably see that
they have less range of motion if they've carried
on with their specific training because the general
range of motion. research also seems to be leaning
in that direction. It started off with there's
differences between men and women. And now the
more recent kind of reviews in that area have
said, actually, we think what you do matters
more than if you're a man or a woman. And so
what you're doing all of the time is going to
determine what your range of motion is. Which
makes a lot of sense. Well, this is huge because
we just assumed, as we measured, that females
have inherently more range of motion. But now
we're looking into, okay, how long they have
been training compared to males. Because if they
are training half the time in a specific range
of motion, reduced range of motion for their
sport, maybe that's what influences that they
have more or less. I guess the other thing that
we looked at was the... stronger compared to
weaker lifters. And that was with the combined
male and female power lifters. And we did see
like a similar, I'll say a trend kind of, because
a couple of ranges were less in the weaker or
were less in the stronger group. So shoulder
extension and knee flexion for people who were
stronger had less of those ranges. So I guess
for me, when I put it all together in my... head
because it is a lot, you know, what I wonder
is if it is actually just that time spent specifically
powerlifting causes a slow kind of reduction
in range of motion. And then is time specifically
powerlifting actually what would predict powerlifting
performance instead of the range of motion, right?
Because with a cross -sectional study, you can't,
there's no cause and effect here. We just know
that there is a relationship. Yeah, that's a
very interesting question. Now, is it bad? If
it is true that powerlifters who train longer
and are stronger as well, they are also less
flexible. Is it a good thing as adaptation we
wanted? Or is it a bit risky? It may increase
injury risk and so on. I mean, impossible to
know at this point. But my thoughts on it are,
I mean, we've seen lately a lot of research.
looking at long -term stretching. So not acute
before training stretching, but long -term independent
of training stretching and how that can actually
increase strength and hypertrophy. So I would
say that it's probably something that happened
just because of the way people trained, but not
that we would want to seek. those lesser ranges
of motion. All right. So should we try to prevent
it? Should athletes be paying attention to keeping
their flexibility as they progress through the
sport? I think it's very important to have enough
range of motion to do your sport. So people think
about powerlifting and they think you don't need
a lot of range of motion. And that can be true,
but you do need very specific ranges. And so,
you know, if you look at the bottom position
of your lifts, your body makes these very specific
shapes. And I think it's important that you can
achieve those. shape without having to compensate
in any way because compensations could potentially
lead to injury risk but outside of that having
more range than is necessary doesn't I can't
see any reason why you would need that. All right,
very interesting. How do you see stretching or
flexibility work fit into this equation? So for
me, when I have athletes who struggle to make
shapes, is how I like to call it, I tend to try
and use their accessories. So something like
even just like a dumbbell chest rest, and I'll
say... Full range, right? Like do not stop that
above your chest. Make sure that you go through
the full range that you can. And then you're
having, you're doing stretching, right? Like
that is a loaded stretch, which is quite effective.
Peck flies, similarly, something like. The hamstring
work that we do anyway, RDLs specifically, seem
to be a great way to do some loaded stretching
and build strength. And interestingly, the one
opposing, I guess, finding with the power lifters
compared to both recreationally trained and sedentary
men is that hamstring... Length seems for hamstring
flexibility, I guess, seems to be greater in
powerlifters. And while we don't know the exact
training of the group, like there's a good chance
that's because RDLs are so valued and deadlifts
in general train the hamstrings in long muscle
lengths. So why not do both at the same time?
Get stronger, maintain, if not increase your
flexibility. Good investment. Yeah. And it's
a huge thing right now. Long length muscle training.
training, great for hypertrophy. So great investment.
I'm convinced. I'm actually considering, should
I add it to my training? Training through, I
mean. Range resistance training is stretching.
Half of us do it anyways. We just don't call
it that. Okay. So let's try to sum it up and
come up with some advice for coaches. So how
they should apply the outcomes of your study
with their athletes. Okay. I think my biggest
takeaway from all of this, you know, the whole
PhD experience in combination with my own experience
was like. Don't be afraid of stretching because
people have really strong feelings, opinions,
but also feelings. They might love stretching.
They might hate it. There's not enough evidence
to say you must do it. It's definitely going
to make you stronger. Nor is there any evidence
to say that not stretching will make you weaker.
But there is plenty of evidence to support. stretching
in some way. So don't be afraid of it. If you
or your athlete want to stretch, go for it. If
someone potentially needs to stretch to achieve
shapes, then do it in a smart way. And if someone
really hates stretching, then hide it, you know?
So some people are going to be really flexible
regardless, and you're not going to have to worry
about it. But some people you might need to be
like, oh, you know what? We're going to do this
long length training, long muscle length training,
because it's really great for hypertrophy. And
really what you're going to get from them is
probably that, but also some increased range
of motion. Sounds good. Sounds good. Okay. Two
last short questions to finish the first one
is what is your favorite lift? You know, it's
the squat right now. I'm a little bit even sad
to say that out loud because I'm a deadlifter
at heart, but I've really long legs and arms.
I'm mostly made of limbs. And so deadlift should
be my lift, but it's squat at the moment. All
right. And last question, where people can find
you if they want to look? up what you're doing
or follow your research or ask a question, where
should they go? Asking questions, probably Instagram
is the best way. If anyone is interested in my
research, I'm on ResearchGate. You can ask to
see publications that way. If someone doesn't
have access, I can happily give them access to
anything that I've done via ResearchGate. I think
that answered it. Thank you so much for today.
It was a pleasure. It was great to chat. Thanks
for having me. No worries.