Activation of the Gluteus Maximus During Performance of the Back Squat, Split Squat, and Barbell Hip Thrust and the Relationship With Maximal Sprinting

Abstract

Williams, MJ, Gibson, N, Sorbie, GG, Ugbolue, UC, Brouner, J, and Easton, C. Activation of the gluteus maximus during performance of the back squat, split squat, and barbell hip thrust and the relationship with maximal sprinting. J Strength Cond Res 35(1): 16-24, 2021-The purpose of this research was to compare muscle activation of the gluteus maximus and ground reaction force between the barbell hip thrust, back squat, and split squat and to determine the relationship between these outcomes and vertical and horizontal forces during maximal sprinting. Twelve, male, team sport athletes (age, 25.0 ± 4.0 years; stature, 184.1 ± 6.0 cm; body mass, 82.2 ± 7.9 kg) performed separate movements of the 3 strength exercises at a load equivalent to their individual 3 repetition maximum. The ground reaction force was measured using force plates and the electromyography (EMG) activity of the upper and lower gluteus maximus and was recorded in each leg and expressed as percentage of the maximum voluntary isometric contraction (MVIC). Subjects then completed a single sprint on a nonmotorized treadmill for the assessment of maximal velocity and horizontal and vertical forces. Although ground reaction force was lower, peak EMG activity in the gluteus maximus was higher in the hip thrust than in the back squat (p = 0.024; 95% confidence interval [CI] = 4-56% MVIC) and split squat (p = 0.016; 95% CI = 6-58% MVIC). Peak sprint velocity correlated with both anterior-posterior horizontal force (r = 0.72) and peak ground reaction force during the barbell hip thrust (r = 0.69) but no other variables. The increased activation of gluteus maximus during the barbell hip thrust and the relationship with maximal running speed suggests that this movement may be optimal for training this muscle group in comparison to the back squat and split squat.

Full text

ACTIVATION OF THE GLUTEUS MAXIMUS DURING
PERFORMANCE OF THE BACK SQUAT,SPLIT SQUAT,
AND BARBELL HIP THRUST AND THE RELATIONSHIP
WITH MAXIMAL SPRINTING
MICHAEL J. WILLIAMS,
1,2
NEIL V. GIBSON,
2
GRAEME G. SORBIE,
1,4
UKADIKE C. UGBOLUE,
1,5
JAMES BROUNER,
3
AND CHRIS EASTON
1
1
Institute for Clinical Exercise & Health Science, University of the West of Scotland, United Kingdom;
2
Oriam, Scotland’s
Sports Performance Centre, Heriot-Watt University, United Kingdom;
3
School of Life Sciences, Pharmacy, and Chemistry,
Kingston University, United Kingdom;
4
School of Social & Health Sciences, Sport and Exercise, Abertay University, United
Kingdom; and
5
Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom
ABSTRACT
Williams, MJ, Gibson, N, Sorbie, GG, Ugbolue, UC, Brouner, J,
and Easton, C. Activation of the gluteus maximus during
performance of the back squat, split squat, and barbell hip
thrust and the relationship with maximal sprinting. J Strength
Cond Res XX(X): 000–000, 2018—The purpose of this
research was to compare muscle activation of the gluteus
maximus and ground reaction force between the barbell hip
thrust, back squat, and split squat and to determine the rela-
tionship between these outcomes and vertical and horizontal
forces during maximal sprinting. Twelve, male, team sport ath-
letes (age, 25.0 64.0 years; stature, 184.1 66.0 cm; body
mass, 82.2 67.9 kg) performed separate movements of the 3
strength exercises at a load equivalent to their individual 3
repetition maximum. The ground reaction force was measured
using force plates and the electromyography (EMG) activity of
the upper and lower gluteus maximus and was recorded in
each leg and expressed as percentage of the maximum volun-
tary isometric contraction (MVIC). Participants then completed
a single sprint on a nonmotorized treadmill for the assessment
of maximal velocity and horizontal and vertical forces. Although
ground reaction force was lower, peak EMG activity in the
gluteus maximus was higher in the hip thrust than in the back
squat (p= 0.024; 95% confidence interval [CI] = 4–56%
MVIC) and split squat (p= 0.016; 95% CI = 6–58% MVIC).
Peak sprint velocity correlated with both anterior-posterior hor-
izontal force (r= 0.72) and peak ground reaction force during
the barbell hip thrust (r= 0.69) but no other variables. The
increased activation of gluteus maximus during the barbell
hip thrust and the relationship with maximal running speed
suggests that this movement may be optimal for training this
muscle group in comparison to the back squat and split squat.
KEY WORDS strength training, bilateral exercises, unilateral
exercises, ground reaction force, electromyography
INTRODUCTION
Axial loaded strength exercises, such as the back
squat, are often regarded as a fundamental com-
ponent of strength programs designed to increase
lower-body strength and power (23,38). Tradi-
tional squatting exercises can be further subdivided into
bilateral and unilateral derivatives, although they seem to
be equally as efficacious for developing power and lower-
body strength (24,36). Nevertheless, these movements do
not always improve sprint speed (15). During maximal
sprinting, ground contact seems to occur with the hips in
a neutral to slightly extended position, with the gluteus mus-
culature shown to be the biggest contributor to hip exten-
sion torque (13,18). This position is not replicated by
traditional squatting exercises, and this lack of movement
specificity between the back squat and sprinting mechanics
may explain conflicting reports within the literature regard-
ing its ability to improve running speed (6,15). Although
exercises that elicit vertical forces initiate the gluteal muscles
(particularly the gluteus maximus) in a hips-flexed position,
activation is reduced when the hips are neutral or slightly
extended (8). If strength and or force production in this
position is a limiting factor when sprinting, the back squat
may not be the most suitable exercise to prescribe.
Conversely, horizontal force production is a key com-
ponent in the optimization of acceleration and maximal
sprint speed (4,5,20,27,33), highlighting the importance of
incorporating exercises that develop horizontal forces in
Address correspondence to Dr. Chris Easton, chris.easton@uws.ac.uk.
00(00)/1–9
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training programs. Indeed, when used in combination with
exercises that promote vertical force production, horizon-
tally orientated exercises have been shown to improve
sprint speed and peak power (2,26). Whether the effect of
exercises that use horizontal force expression can stimulate
improvements in maximal sprint speed without the inclu-
sion of traditional squatting exercises has yet to be eluci-
dated. Recent research, however, has proposed the use of
the barbell hip thrust as an alternative means of training the
posterior chain musculature of the lower body (8,9). This
exercise has been shown to elicit greater gluteus maximus
and hamstring activation when compared with the back
squat in strength-trained females and higher anterior-
posterior horizontal forces (9). The barbell hip thrust al-
lows strength to be developed with the hips in an extended
position and via a horizontal force production, which may
be of greater relevance to sprinting (13) (Figure 1).
Although this approach would appear to contravene the
training philosophy of specificity, it does conform to the
theory of dynamic correspondence; although not identical
to the activity of sprinting, the barbell hip thrust replicates
the muscular patterns, synchronicity, and energy produc-
tion involved during training (35).
Despite recent research (8,9,11) comparing the barbell hip
thrust with other bilateral strength exercises and its relation to
physical parameters, including sprint acceleration and jump
performance, to our knowledge, there are no comparisons
between unilateral strength exercises and the barbell hip thrust.
Furthermore, previous research has not determined whether
there is any relationship between gluteus maximus activity and
force production during strength exercises or maximal sprint-
ing. The primary aim of the present study, therefore, was to
determine the difference between muscle activation and force
production during the bilateral squat, unilateral split squat, and
barbell hip thrust. A secondary objective was to determine the
association of the aforementioned dependent variables with
speed, and horizontal and vertical forces during maximal
sprinting. The experimental hypothesis was that the barbell
hip thrust would elicit higher mean and peak gluteus maximus
activity when compared with the back squat and split squat,
and these variables would be more strongly associated with
parameters of maximal running performance.
METHODS
Experimental Approach to the Problem
In the first part of this experiment, measurements of ground
reaction force and electromyography (EMG) of the gluteus max-
imus were recorded in team sport athletes during 3-repetition
maximum efforts of the barbell hip thrust, bilateral squat, and
unilateral split squat. Data were then analyzed to determine
Figure 1. Diagram annotated to show equipment and positional requirements of the barbell hip thrust (permission given by the participant for photographs to be
included in this publication).
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whether there were any differences between the 3 different
exercises. In the second part of the experiment, participants
completed a single maximal sprint effort on a nonmotorized
treadmill while speed, horizontal force, and vertical force were
measured. Data were then analyzed to assess whether there was
any association between the variables of muscle activation and
force measured during the 3 different strength exercises with
metrics of maximal running performance.
Subjects
Twelve, male, team-sport athletes volunteered to participate
in the study (mean 6SD age, 25.0 64.0 years; stature, 184.1
66.0 cm; body mass, 82.2 67.9 kg) who had 4.0 61.0 years
of strength training experience. Subjects had experience in all
3 exercises; however, they were used to varying degrees by
each individual within their own training regimens. Inclusion
criteria required participants to be aged between 18 and 35
years, have a minimum of 3 years resistance training expe-
rience, and able to safely perform each of the 3 exercises
with external load. All participants provided written
informed consent, and the study was approved by the
School of Science and Sport Ethics Committee at the
University of the West of Scotland.
Figure 2. A) Mean gluteus maximus EMG activation for all 3 exercises expressed as a percentage of the maximum isometric voluntary contraction. Data are
presented as mean 6SD. *Significantly greater than the back squat. ◊Significantly greater than the split squat. B) Peak gluteus maximus EMG activation for all
3 exercises expressed as a percentage of the maximum isometric voluntary contraction. Data are presented as mean 6SD. *significantly greater than the back
squat. ◊Significantly greater than the split squat.
Figure 3. Peak ground reaction force in each leg for all 3 exercises. Data are presented as mean 6SD.†Significantly greater than the hip thrust. ◊Significantly
greater than the split squat.
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Procedures
Assessment of Three Repetition Strength. Participants performed
3-repetition maximum testing on each resistance exercise.
Participants performed a standardized warm-up comprising
dynamic movement patterns designed to target the gluteal
musculature, including external resistance via the use
of minibands. Immediately after the warm-up, participants
completed submaximal loads in each of the 3 exercises to
determine the 3 repetition maximum as advocated by Baechle
and Earle (30). This procedure incorporated 5–10 repetitions
with a light to moderate load, progressing to heavier sets of 3
repetitions, until the 3 repetition maximum was determined.
The order in which the exercises were assessed was random-
ized, and participants were allowed to self-select recovery time
between exercises. The barbell back squat was performed with
feet placed slightly wider than shoulder width apart with the
bar secured across the upper trapezius musculature (30). Sub-
jects descended until the top of the thigh was deemed parallel
to the floor, which was continually cued by the researcher
throughout the lifts. The barbell split squat was performed
with the same bar position but in a split stance, with the for-
ward foot placed flat on the floor and the rear knee slightly
flexed to allow for a heel raised foot position on the trailing leg.
The barbell hip thrust was performed with the subject’s upper
back pressed against a weight bench, with feet placed slightly
wider than shoulder width apart and the bar positioned across
the hips, as advocated by Contreras et al. (8).
Maximal Voluntary Isometric Contraction Assessment. Partici-
pants completed the aforementioned warm-up before per-
forming progressive submaximal lifts until they felt prepared
to perform their 3-repetition maximum lifts as determined
during the initial trial. To prepare the subject for electrode
placement, their skin was shaved using a Bic hand razor and
sterilized with an alcohol swab to reduce electrical imped-
ance (1,34). A pair of Ag-AgCl surface conductive gel elec-
trodes (Blue Sensor; Ambu, Ballerup, Denmark) were then
applied with an interelectrode distance of 2 cm in alignment
with the fiber direction of the gluteus maximus using posi-
tional guidelines described elsewhere (14). Electrodes were
attached to both the upper and the lower segment of the
gluteus maximus on both sides of the body. A line was drawn
between the posterior superior iliac spine and the greater
trochanter; the upper electrode was placed approximately
5 cm above and laterally to the midpoint of this line given
the diagonal direction the muscle fibers course. The lower
electrode was positioned approximately 5 cm below and
medially to the same line. Electrodes were secured to the
skin with tape to avoid movement artifacts (21). Maximum
voluntary isometric contraction (MVIC) testing was then
performed for the gluteus maximus musculature using a stand-
ing glute squeeze technique (3,10). This value was used as
a reference for the normalization of data.
EMG and Force Assessment During Resistance Exercises. On
completion of MVIC testing, participants rested for 4 minutes
Figure 4. Correlation between peak anterior-posterior horizontal force during sprinting and peak sprint velocity.
EMG of the Gluteus Maximus During Strength Exercise
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before completing the barbell hip thrust, unilateral split
squat, and bilateral squat in a randomized order using a basic
counterbalanced design. Participants were instructed to
complete a 3-repetition maximum lift for each exercise
according to loads previously established with 4 minutes
rest between exercises (30). Two fixed and embedded force
plates (AMTI Optima 400600; Advanced Mechanical Tech-
nology, Inc, Boston, MA, USA) were used to measure
ground reaction force at a sampling rate of 1,000 Hz cali-
brated according to the manufacturer’s guidelines. Partici-
pants were instructed to place 1 foot on each of the force
plates for the bilateral squat and barbell hip thrust. For the
split squat, participants were required to position their forward
leg onto the force plate; for the split squat, 3-repetition maxi-
mum lifts were completed on both legs. A portable squat rack
was set up in front of the force plates for the bilateral and
unilateral split squats. The barbell hip thrust was performed
with the upper back supported on a 17-inch-high bench as
indicated in Figure 1. An EMG system (Myon AG 320;
Schwarzenberg, Switzerland) was used to collect raw EMG
signals at 1,000 Hz, which were filtered using Myon proEMG
software (Myon; Schwarzenberg, Switzerland). EMG signals
for all 3 repetitions of each set were filtered using a 10–450
Hz band-pass filter and smoothed using root mean square with
a 50-millisecond window (12). The EMG data are presented as
the mean of the 4 EMG electrode sites for each of the 3 ex-
ercises to allow comparisons between unilateral and bilateral
data. Mean and peak data were normalized to MVIC collected
during the preassessment glute squeeze. Force plate data are
presented as the mean of both legs for each of the 3 exercises to
allow comparisons between unilateral and bilateral data.
Maximal Sprint Assessment. Following the strength assess-
ments, participants rested for 10 minutes before performing
a maximal linear sprint on a Woodway Force nonmotorized
treadmill (Woodway Force 3.0; Woodway USA, Inc, Wau-
kesha, WI, USA). Participants performed 3 submaximal
warm-up sprints to habituate themselves with the treadmill.
After a 5-minute rest, they were instructed to complete
a maximal effort sprint during which maximal horizontal and
vertical forces and velocity were determined.
Statistical Analyses
All statistical analyses were conducted using Statistical
Package for the Social Sciences (SPSS 22.0; IBM, Corp,
Armonk, NY, USA). The distribution of the data was first
assessed using a Shapiro-Wilk test. One-way repeated-
measure analysis of variance (ANOVAs) was used to
compare mean and peak EMG values between strength
exercises. Differences in ground reaction forces were as-
sessed between strength exercises and between legs using
a 2-way repeated-measures ANOVA. Any significant main
effects were further analyzed by applying Bonferroni cor-
rections for pairwise comparisons. Effect sizes (M1 2M2/
Figure 5. Correlation between peak force during the barbell hip thrust and peak sprint velocity.
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SD) were calculated using Cohen’s dvalues and defined as
small (0.20), medium (0.50), and large (0.80) (10). Pearson’s
product-moment correlations were also used to determine
the relationship between peak sprinting velocity and selected
variables. Statistical significance was accepted at p,0.05,
and 95% confidence intervals (95% CIs) are presented with p
values.
RESULTS
Exercise Loads
The 3-repetition maximum exercise loads for the barbell hip
thrust (157 629 kg; 1.9 60.3 3body mass) were higher
than both the back squat (117 639 kg; 1.4 60.3 3body
mass; p= 0.001) and the split squat (68 623 kg; 0.8 60.2 3
body mass; p,0.001). The 3-repetition maximum loads for
the back squat was higher than the split squat (p,0.001).
Mean Activation
The barbell hip thrust displayed higher mean gluteus maxi-
mus activation than both the back squat (d= 1.29; p= 0.005;
95% CI = 10–55% MVIC) and split squat (d= 1.24; p=
0.006; 95% CI = 9–54% MVIC; Figure 2A). There was no
difference in mean gluteus maximus activation between the
squat and split squat (d= 0.05; p= 1; 95% CI = 11–13%
MVIC).
Peak Activation
The barbell hip thrust displayed higher peak gluteus maximus
activation than both the squat (d= 1.08; p= 0.024; 95% CI =
4–56% MVIC) and split squat (d= 1.08; p= 0.016; 95% CI =
6–58% MVIC, Figure 2B). There was no difference in peak
gluteus maximus activation between the squat and split squat
(d= 0.07; p= 1; 95% CI = 15–19% MVIC).
Peak Ground Reaction Force
There were no difference in peak ground reaction force
between left and right legs in any 3 of the strength exercises
(Figure 3) Peak force in the right foot was lower in the
barbell hip thrust compared with the back squat (d= 2.98;
p,0.001; 95% CI = 416–1,012 N) and the split squat (d=
2.24; p,0.001; 95% CI = 412–740 N). Peak force in the left
foot was also lower in the barbell hip thrust compared with
the back squat (d= 2.80; p,0.001; 95% CI = 596–1,130 N)
and the split squat (d= 1.80; p,0.001; 95% CI = 412–740
N). Peak force was higher in the back squat than compared
with the split squat in the left leg (effect size = 0.66; p=
0.019; 95% CI = 45–534 N) but not the right leg (p= 0.18).
Maximal Sprinting
Peak anterior-posterior horizontal force during sprinting
significantly correlated with peak velocity (r= 0.72; p=
0.008), but there was no relationship between peak vertical
force and peak velocity (r= 0.232; p= 0.47). Peak force
during the barbell hip thrust significantly correlated with
peak sprint velocity (r= 0.69; p= 0.014). There was a weak
relationship between maximal sprint velocity and peak force
in both the bilateral squat and the unilateral split squat, but
neither reached statistical significance (r= 0.52, p= 0.086; r
= 0.53, p= 0.076, respectively). Peak gluteus maximus activa-
tion for each exercise did not correlate with peak sprint
speed (all p.0.05) (Figures 4 and 5).
DISCUSSION
The objective of the present study was to compare muscle
activation of the gluteus maximus and ground reaction force
between the barbell hip thrust, back squat, and split squat
and to determine the relationship between these outcomes
and vertical and horizontal forces during maximal sprinting.
In agreement with our experimental hypothesis, the barbell
hip thrust elicited significantly higher mean and peak gluteus
maximus activation than the back squat and the split squat
when performing 3-repetition maximum lifts despite a lower
peak ground reaction force in this movement. These data
support recent research with female athletes that demon-
strated a higher gluteus maximus activation in the barbell
hip thrust compared with the back squat (9). The present
study further extends these findings by demonstrating that
peak sprint velocity significantly correlated with both peak
horizontal sprint force and peak barbell hip thrust force.
The results of the present study align with findings of
Contreras et al. and suggest that greater peak and mean
activation of the gluteus maximus occurs in the barbell hip
thrust compared with the back squat. Recent extensive pilot
studies by Contreras et al. (9) have suggested that the gluteus
maximus elicits peak EMG activation at the shortest muscle
length in hip hyperextension. Several researchers have con-
cluded that peak gluteus maximus activation during the back
squat occurs on the ascendancy from the bottom of the lift in
a hip’s flexed position and that activation increases with load
(40). However, Contreras et al. (9) found that during iso-
metric holds of both the barbell hip thrust (fully extended
position) and back squat (fully flexed position), the former
produced significantly greater mean and peak EMG activa-
tion in the gluteus maximus.
Although there have been numerous studies comparing
unilateral to bilateral strength exercises, to the knowledge of
the authors, this is the first study to compare a unilateral
exercise to the barbell hip thrust. The results showed that
although there were no differences between the 2 squat
movements, the barbell hip thrust elicited significantly
greater gluteus maximus activation than the split squat. The
similarity in gluteus maximus activation between the squat
movements may appear surprising given that peak ground
reaction force and the summated total load across both front
limbs in the semiunilateral split squat was higher than in the
bilateral back squat (1.6 vs. 1.4 3body mass, respectively).
Given that an increased load has been shown to increase
muscle activation (32), it may be presumed that the addi-
tional load during the split squat would have produced high-
er gluteus maximus activation than in the back squat. In this
instance, however, the unilateral strength exercise produced
similar EMG activation of the gluteus maximus. These
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findings are similar to that of Jones et al. (17) who found no
difference in gluteus maximus activity between unilateral and
bilateral exercises despite discrepancies in relative load. Mus-
cle activity was not measured in the support leg in either the
present study or in the previous work (17), which may
explain some of this disparity and highlights the necessity
for further research in this area.
Training with traditional squat movements does not
always lead to an improvement in maximal sprinting speed
(15), although this is often a desired outcome given several
studies have demonstrated enhancements in this ability
(22,36). Given that sprint velocity appears to be more depen-
dent on horizontal force production than on vertical force
production (4,19,31), this is perhaps not surprising. Indeed,
in the present study, horizontal force production signifi-
cantly correlated with maximal sprint velocity. Furthermore,
the data presented here demonstrate that peak barbell hip
thrust ground reaction force significantly correlated with
maximal sprint velocity. Although the vertically oriented
back squat and split squat elicited higher ground reaction
forces than the barbell hip thrust, the correlation between
these values and maximal sprinting speed did not reach sta-
tistical significance. Although speculative, this suggests that
force production during the barbell hip thrust may be asso-
ciated with sprint performance in team sport athletes. Fur-
thermore, horizontal anteroposterior-based exercises, such
as the barbell hip thrust, may be more effective for improving
maximal sprint speed than either squat movement. Indeed,
Contreras et al. (11) reported that a 6-week barbell hip thrust
training intervention led to improved 20-m sprint times with
no improvement in a group completing back squat training.
This presents a compelling case that the orientation of force
application is an important factor in determining maximal
sprint performance. Squats and their derivatives are clearly
staples in the field of strength and conditioning; however,
understanding how movement mechanics accentuate force
development is becoming an important factor in exercise
selection.
Despite a positive relationship between horizontal sprint
force and maximal sprint velocity, gluteus maximus activation
did not correlate with maximal sprint velocity. This perhaps
is not surprising given the findings of Morin et al. (28) that
generation of horizontal force during sprinting was linked
with a better activation of the hamstring muscles just before
ground contact. Because the barbell hip thrust and back
squat both produce significantly greater gluteus maximus acti-
vation when compared with biceps femoris (8), the lack of
correlation between muscle activation and sprint velocity
in this study is perhaps to be expected. On the other hand,
muscle activation during a hamstring-dominant exercise
may be more strongly associated with maximal sprint
performance.
The assessment of sprint performance in this study was
conducted using a nonmotorized treadmill. Although this
treadmill is regarded as a valid and reliable means of
assessing short sprint performance (16), some may question
how closely it replicates sprinting outdoors. For example,
running on a treadmill eliminates air resistance, which is
likely to be meaningful during sprinting exercise (37). Fur-
thermore, given the individual is tethered at the hips and has
to manually move the treadmill belt with their feet, one
could argue that this encourages an inclined position,
decreasing the involvement of the postural musculature.
However, McKenna and Riches (25) demonstrated that in-
dividuals use similar sprinting technique on the nonmotor-
ized treadmill to over ground sprinting. Furthermore, Morin
and Se
`ve (29) reported that individuals performing sprint
accelerations on the nonmotorized treadmill produce similar
physical and technical movements to outdoor sprint
accelerations.
In the present study, only 2 force plates were used, both
positioned beneath the feet during the barbell hip thrust
exercise. However, at the top of the lift, it is likely that a large
portion of the vertical force will be exerted through the
bench itself. As such, we would suggest that in future
research, an additional plate is placed under the bench or
structure supporting the back in order that the ground
reaction forces can be more fully quantified. A further
potential limitation of the present study was the use of
surface EMG to measure muscle activity. The limitations of
this technique have been discussed extensively by De Luca
(12) and include muscle fiber movement, cross talk from
adjacent musculature, and extrinsic factors, such as volume
of subcutaneous fatty tissue, and that electrodes may not
detect all active motor units. Additionally, EMG peaks
may potentially be artifacts given that the EMG signal not
only includes muscle movement information but also noise
components that are unpreventable despite efforts being
made to filter out these unwanted components (12). To
reduce potential cross talk, the surface electrodes were posi-
tioned within the middle of the muscle belly of the gluteus
maximus and applied in parallel arrangement to the muscle
fibers, with a center to center interelectrode distance of 2 cm.
Further to this, the upper and lower gluteus maximus have
been shown to activate uniquely (9). However, because in
the current study data from these musculature were aver-
aged, it has not been possible to determine how the upper
and lower fibers correlate with sprinting independently.
Despite some of the positive findings in the present study
between commonly used strength exercises and sprinting,
the data obtained is mechanistic in nature; therefore, the
author suggests that future training studies are required to
show transference to sprinting and to verify the proposed
theories.
PRACTICAL APPLICATIONS
Given that maximal sprint speed correlated with horizontal
force production but not vertical production, using exercises
that develop force in the horizontal plane may provide
superior transfer to sprint-based performance. Furthermore,
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the present study has demonstrated maximal sprinting speed
to be correlated with peak force production during the
barbell hip thrust but neither of the 2 vertical squat move-
ments. Applied practitioners can incorporate the barbell hip
thrust into their strength programs based on data indicating
that it has the capacity to elicit greater gluteus maximus activ-
ity than both the back squat and split squat and that it is
more likely to lead to a greater increase in horizontal force
production. Based on these data, it is proposed that perform-
ing anteroposterior strength exercises, such as the barbell hip
thrust, and focusing on methods to increase horizontal force
during sprinting may be effective in improving maximal
sprint performance. During maximal sprinting, it appears
toe off at ground contact occurs with the hips in a slightly
hyperextended position, which could be a key component as
to why barbell hip thrust force production is a better indi-
cator of maximal sprint velocity (13,18). This is not to sug-
gest that the barbell hip thrust should be used as
a replacement for more traditional vertical orientated exer-
cises given they have also been shown to improve sprint
performance (23,39).
ACKNOWLEDGMENTS
The results of the present study do not constitute endorse-
ment by the authors or the National Strength and Condi-
tioning Association. This project was partly funded by
Oriam: Scotland’s Sport Performance Centre.
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