MASS (Monthly Applications in Strength Sport) - Volume 5 - Issue 04

122 Pages·2021·10.577 MB·English

by  Greg Nuckols, Eric Trexler, Eric Helms, Mike Zourdos

VOLUME 5, ISSUE 4 APRIL 2021
M A S S
MONTHLY APPLICATIONS IN
STRENGTH SPORT
ERIC HELMS | GREG NUCKOLS | MICHAEL ZOURDOS | ERIC TREXLER
The Reviewers
Eric Helms
Eric Helms is a coach, athlete, author, and educator. He is a coach for drug-free strength and physique
competitors at all levels as a part of team 3D Muscle Journey where he is also the Chief Science
Officer. Eric regularly publishes peer-reviewed articles in exercise science and nutrition journals on
physique and strength sport, in addition to contributing to the 3DMJ blog. He’s taught undergraduate-
and graduate-level nutrition and exercise science and speaks internationally at academic and
commercial conferences. He has a B.S. in fitness and wellness, an M.S. in exercise science, a second
Master’s in sports nutrition, a Ph.D. in strength and conditioning, and is a research fellow for the Sports
Performance Research Institute New Zealand at Auckland University of Technology. Eric earned pro
status as a natural bodybuilder with the PNBA in 2011 and competes in numerous strength sports.
Greg Nuckols
Greg Nuckols has over a decade of experience under the bar and a B.S. in exercise and sports
science. Greg earned his M.A. in exercise and sport science from the University of North Carolina
at Chapel Hill. He’s held three all-time world records in powerlifting in the 220lb and 242lb classes.
He’s trained hundreds of athletes and regular folks, both online and in-person. He’s written for many
of the major magazines and websites in the fitness industry, including Men’s Health, Men’s Fitness,
Muscle & Fitness, Bodybuilding.com, T-Nation, and Schwarzenegger.com. Furthermore, he’s had the
opportunity to work with and learn from numerous record holders, champion athletes, and collegiate
and professional strength and conditioning coaches through his previous job as Chief Content
Director for Juggernaut Training Systems and current full-time work on StrongerByScience.com.
Michael C. Zourdos
Michael (Mike) C. Zourdos, Ph.D., CSCS, has specializations in strength and conditioning and skeletal
muscle physiology.  He earned his Ph.D. in exercise physiology from The Florida State University (FSU)
in 2012 under the guidance of Dr. Jeong-Su Kim. Prior to attending FSU, Mike received his B.S. in
exercise science from Marietta College and M.S. in applied health physiology from Salisbury University.
Mike served as the head powerlifting coach of FSU’s 2011 and 2012 state championship teams. He
also competes as a powerlifter in the USAPL, and among his best competition lifts is a 230kg (507lbs)
raw squat at a body weight of 76kg. Mike owns the company Training Revolution, LLC., where he has
coached more than 100 lifters, including a USAPL open division national champion.
Eric Trexler
Eric Trexler is a pro natural bodybuilder and a sports nutrition researcher. Eric has a PhD in Human
Movement Science from UNC Chapel Hill, and has published dozens of peer-reviewed research
papers on various exercise and nutrition strategies for getting bigger, stronger, and leaner. In
addition, Eric has several years of University-level teaching experience, and has been involved in
coaching since 2009. Eric is the Director of Education at Stronger By Science.
Table of Contents
6 B Y G R E G N U C K O L S
Is the “Sticking Region” of the Squat Actually the Weakest
Part of the Lift?
It’s natural to assume the sticking region of the squat is the biomechanically weakest
point in the lift. It’s the hardest part of the range of motion to get through when
you’re attempting a 1RM or taking a set to failure, after all. This article explores why
that intuitive idea may not actually be correct.
20 B Y M I C H A E L C . Z O U R D O S
You Should Probably Be Stretching
Twenty years ago, everyone decided that stretching before lifting was a bad idea, and
that’s generally true. However, this advice caused lifters to avoid stretching at all times.
This article reviews a new study on chronic stretching and its potential benefits.
35 B Y E R I C H E L M S
Creatine Monohydrate, Tried and True
Every few years new forms of creatine are introduced by the supplement industry
and touted as superior in one way or another to creatine monohydrate. Are the
claims true, or are they marketing ploys to separate your money from your wallet?
46 B Y E R I C T R E X L E R
Ketogenic Diets Still Aren’t Superior for Hypertrophy
In the past few years, we’ve reviewed multiple studies assessing the effects of
ketogenic diets on hypertrophy. This month, a new study in competitive natural
bodybuilders gives us even more information about keto and hypertrophy for highly
trained lifters.
59 B Y G R E G N U C K O L S
How Do Twice-Daily Training Sessions Affect Hypertrophy
and Strength Gains?
Can you improve your strength gains and rate of muscle growth by splitting your
training sessions up into a morning session and an afternoon session? Prior
research is inconclusive. A recent study, however, found that two-a-days may
improve strength gains, but probably not muscle growth.
72 B Y M I C H A E L C . Z O U R D O S
Workload Metrics are What We Thought They Were
There are various metrics to track workload. The reviewed study attempted to
reduce these metrics to one value; however, these metrics gauge different things
and shouldn’t be combined. This article discusses what each metric is attempting to
quantify and how you can use them.
85 B Y E R I C T R E X L E R
Vegan Diets: Not a “Gamechanger” for Hypertrophy, but
a Viable Alternative
Many studies have compared the acute effects of plant versus animal protein
sources on muscle protein synthesis, but fewer have looked at hypertrophy over
time. This month, a new study gives us more direct information about the magnitude
of hypertrophy achieved with vegan versus omnivorous diets.
99 B Y G R E G N U C K O L S
Getting Pinned by Your Squats? Maybe Try Pin Squats
A recent study examined the effects of traditional squats and pin squats on strength
and various measures of athletic performance. In the interpretation section of this
article, I’ll explain why I think pin squats are criminally underrated and underutilized.
113 B Y M I C H A E L C . Z O U R D O S
VIDEO: Neuroprotection Part 2
You can get strong and jacked from lifting weights, but can lifting also improve
cognition and memory? This video examines recent updates regarding
resistance training’s ability to alter biomarkers associated with the protection
of neurons. While more research is needed, there’s reason to be optimistic for
resistance training to benefit long-term cognition.
116 B Y E R I C H E L M S
VIDEO: An Update on Intermittent Energy Restriction
Research on intermittent energy restriction has picked up in the last few years
as there are now multiple new studies on diet breaks in athletes published, with
more to come. How does this research fit in with our previous understanding of
intermittent energy restriction for contest prep in physique athletes? What avenues
of research still need to be explored and what conclusions can we make at this
time? Watch this video to learn more.
Letter From the Reviewers
V
olume 5 of MASS keeps getting better and better, so we are excited to
welcome you to Issue 4.
On the training side, Dr. Zourdos covers a couple of frequently discussed
topics in the training world. In the first article he discusses some common metrics
used to track workload (including a new one), and in the second he covers a new study
on the potential benefits of stretching regularly. In addition, more data have become
available since the last time Dr. Zourdos discussed lifting and neuroprotection, so
this month he has a fantastic video about how to structure your training to facilitate
neuroprotective adaptations to resistance exercise.
One of Greg’s articles takes a close look at a new study examining how splitting your
workout into two sessions (morning and evening) can impact strength and hypertrophy.
He also covers a very practical study comparing training adaptations to pin squats
versus traditional squats, and a third study that set out to explore the factor(s)
contributing to the sticking region of the squat.
Over in the nutrition department, Dr. Trexler covers two very popular diets that both
have a tendency to attract some pretty enthusiastic advocates. One study revisits the
question of whether or not ketogenic diets can support hypertrophy and strength gains
as effectively as higher-carbohydrate approaches. The other study provides some
excellent longitudinal data comparing the effects of vegan and omnivorous diets on
strength and body composition adaptations to resistance training.
In this issue, Dr. Helms discusses a new systematic review about creatine. While
creatine monohydrate is the king of all creatine products, this paper evaluated several
other forms of creatine to see if any of them might have a legitimate claim to the
throne. Finally, a new video by Dr. Helms gives us a fantastic update on some new
research covering intermittent dieting strategies, including both refeeds and diet breaks.
As always, we hope you enjoy this issue of MASS. If you have any questions about the
articles or videos in this month’s issue, or you’d just like to discuss them further, be
sure to post your questions or comments in the MASS Facebook group.
Sincerely,
The MASS Team
Eric Helms, Greg Nuckols, Mike Zourdos, and Eric Trexler
5
Study Reviewed: Is the Occurrence of the Sticking Region in Maximum Smith Machine
Squats the Result of Diminishing Potentiation and Co-Contraction of the Prime Movers
among Recreationally Resistance Trained Males? van den Tillaar et al. (2021)
Is the “Sticking Region” of the Squat
Actually the Weakest Part of the Lift?
BY GREG NUCKOLS
It’s natural to assume the sticking region of the squat is the
biomechanically weakest point in the lift. It’s the hardest part of
the range of motion to get through when you’re attempting a 1RM
or taking a set to failure, after all. This article explores why that
intuitive idea may not actually be correct.
6
KEY POINTS
1. This study looked at force output, joint kinematics, and muscle EMG during 1RM
squats and maximal isometric squats at various depths.
2. During 1RM squats, force output was higher at the bottom of the squat than
through the sticking region. During maximal isometric squats at the same barbell
heights, force output didn’t significantly vary from the bottom of the squat until after
the sticking region. If anything, force output was actually slightly lower at the very
bottom of the squat than through the sticking region.
3. This article argues that the very bottom of the squat is the biomechanically weakest
part of the lift, not the sticking region. The presence of muscle potentiation and the
stretch-shortening cycle explain the disconnect.
I
f you’ve ever done a one rep max squat of joint positions for producing force, then
(1RM), or you’ve taken a set of squats it would make sense that force output drops
to failure, I’m sure you’ve noticed the during the sticking region, and the bar decel-
presence of a “sticking region” during the erates. While that’s an intuitive idea, we have
lift. As you start the concentric portion of the to ask if it’s actually correct.
lift, the bar initially accelerates, then slows
The presently reviewed study (1) aimed to
way down as you attempt to grind out the lift,
investigate the factors contributing to the ex-
and finally starts accelerating again once you
istence of the “sticking region” in the squat.
break through the sticking region. The stick-
It examined force output, muscle EMG, and
ing region spans the entire range of motion
joint angles during 1RM Smith machine
where the bar is decelerating.
squats and maximal isometric squats. At the
So, what causes the sticking region to exist?
bottom of the lift, force output and muscle
This is an important question to answer, be-
EMG were greater during 1RM squats than
cause strength through the sticking region
maximal isometric squats performed at the
ultimately constrains the amount of weight
same heights. Furthermore, the pattern of
we’re able to squat. If we know the cause of
force output differed between 1RM squats
the sticking region, we can do a better job of
and isometric squats. As we’d expect, force
figuring out how to build strength through
output dropped during the sticking region
this crucial part of the lift.
of 1RM squats, but it was not lower at the
It may be natural to assume that the sticking depth corresponding with the sticking point
region merely corresponds with the least bio- during isometric squatting compared to the
mechanically favorable part of the range of very lowest position, suggesting that the
motion. If it represents the set of joint posi- sticking region isn’t actually the least bio-
tions that are simply the least favorable mix mechanically favorable part of the range of
7
motion. Rather, force output at the very bot-
Subjects and Methods
tom of 1RM squats is actually elevated due
to potentiation of muscle activation and the Subjects
stretch-shortening cycle, as a result of the ec-
12 recreationally trained males participated
centric phase. However, the very bottom of
in this study. They all had at least three years
the lift is actually the least biomechanically
of strength training experience. The average
favorable position, in all likelihood.
squat 1RM for the cohort was about 125% of
body mass (106kg at 83.5kg).
Purpose and Hypotheses
Experimental Design
Purpose
This was a straightforward study, with one fa-
The purpose of this study was to compare the
miliarization session and one testing session
kinetic, kinematic, and EMG responses be-
for each subject. The familiarization session
tween 1RM Smith machine squats and iso-
seems to have followed the same procedures
metric squats at various barbell heights. The
as the actual testing session (except for the
point of the comparison was to learn more
fact that no data was collected).
about the factor(s) contributing to the stick-
For the testing session, subjects worked up
ing region in the squat.
to a 1RM Smith machine squat. For a rep to
Hypotheses
count, they needed to achieve a depth corre-
The authors hypothesized that force output sponding to a 90° knee angle, but they were
during isometric squats would be lowest at encouraged to squat to legal powerlifting
positions that corresponded to the sticking depth, if possible. The depth achieved during
region during dynamic squatting. They also each subject’s 1RM was noted, and following
“expected differences in force output and 10 minutes of rest, they began isometric test-
muscle activation between maximal squats ing. Isometric testing consisted of perform-
and isometric squats due to potentiation and ing three-second maximal isometric reps at
increased muscle activation due to the de- barbell heights spanning from the bottom po-
scending phase in maximal squats.” Thus, sition of the subjects’ squats to fully upright,
they clearly expected to see greater muscle in 5cm increments. The order of the isometric
activation during 1RM squatting than iso- rep heights was randomized for each subject
metric squatting. Furthermore, the language (in other words, maybe their first test was at
related to force output is imprecise, but since 20cm above full depth, their second test was
they noted that they anticipated “potentia- at 5cm above full depth, their third was 30cm
tion” as a result of the eccentric phase during above full depth, etc., rather than testing full
dynamic squatting, we can surmise that they depth first, followed by 5cm above full depth,
expected force output at the bottom of 1RM then 10cm above full depth, then 15cm above
squats to be greater than force output at simi- full depth, etc.), and they rested for five min-
lar depth during isometric squatting. utes between isometric tests.
8
All testing was performed on a force plate, region (V ; this was defined as the start
max1
joint and bar kinematics were assessed via a of the sticking region), the point of minimal
camera system and reflective markers places concentric velocity (V ; this was defined as
min
on the subjects’ joints and the bar, and elec- the end of the sticking region), and the point
trodes were placed on the subjects’ vastus of maximal barbell velocity after the sticking
medialis, vastus lateralis, rectus femoris, lat- region (V ).
max2
eral gastrocnemius, gluteus maximus, semi-
tendinosus, biceps femoris, soleus, and spinal Findings
erectors in order to assess muscle EMG.
Kinetic and kinematic variables reported
The EMG signals were normalized to the
during the 1RM attempt can be seen in Table
highest EMG amplitude attained during any
1. When reading the table, the joint angles re-
of the isometric contractions for each muscle
ported are the actual angles made by the joint
within each subject. This normalization pro- (so, for example, a 60° hip angle means 120°
cedure is adequate for being able to compare of hip flexion is taking place, while a 130°
between the dynamic and isometric reps, but hip angle means 50° of hip flexion is taking
it doesn’t allow us to compare relative mus- place). The total vertical displacement during
cle activation between muscles. the 1RM attempts was 0.486 ± 0.072m (that
will be relevant in the next section).
As with the bench press study I reviewed
from this same research group last month The pattern of force output during 1RM at-
(2), kinetic and kinematic data related to tempts differed from the pattern of force out-
the sticking region were of particular inter- put during maximal isometric squats (Figure
est. Variables were analyzed and reported at 1). Force output near full depth was lower for
the start of the concentric (V ), at the point isometric squats than dynamic squats (0-15 cm
0
of peak barbell velocity prior to the sticking above full depth), while force output near the
9
top of the lift was higher for isometric squats ly, EMG amplitudes for the hip extensors
(35+ cm above full depth). Furthermore, force tended to be higher during dynamic squatting
output dipped between 0cm and 5cm above than isometric squatting through most of the
full depth during the 1RM attempts, whereas range of motion, and didn’t majorly drop off
it was nominally (non-significantly) higher at during dynamic squatting until the subjects
5cm above full depth than at 0cm above full were approaching lockout.
depth during isometric squats.
It’s worth noting that joint kinematics differed
The EMG outcomes can be seen in Figure 2. a bit between dynamic and isometric squat-
For most muscles through most of the range of ting. Most notably, the ankle angle was basi-
motion, EMG amplitudes were higher during cally the same at all depths during isometric
1RM squatting than isometric squatting. The squatting, whereas it increased with increasing
figure shows the individual patterns for each barbell height (less dorsiflexion was present)
muscle, but the most important thing to note is during dynamic squatting. However, I don’t
that EMG amplitudes of the quads were way think this difference is all that meaningful, es-
higher during 1RM squatting than isometric pecially through the most important part of the
squatting near the bottom of the lift, and then range of motion (from the bottom of the squat
drop off considerably during 1RM squatting until the end of the sticking region). The ankle
as the concentric progresses, such that quad angle was ~70° at all depths during isometric
EMG was comparable between dynamic and squatting; during dynamic squatting, it was
isometric squatting at depths above the end of 67° at the bottom of the squat, and 73.7° at the
the sticking region (V ; >10cm). Converse- end of the sticking region.
min
10