Influence of resisted sled-push training on the sprint force-velocity profile of male high school athletes

Abstract

Sled pushing is a commonly used form of resisted sprint training, however little empirical evidence exists, especially in youth populations. The aim of this study was to assess the effectiveness of unresisted and resisted sled pushing across multiple loads. Fifty high school athletes were assigned to an unresisted (n=12), or 3 resisted groups; light (n=14), moderate (n=13) and heavy (n=11) resistance that caused a 25, 50 and 75% velocity decrement in maximum sprint speed, respectively. All participants performed two sled push training sessions twice weekly for 8 weeks. Before and after the training intervention, the participants performed a series of jump, strength and sprint testing to assess athletic performance. Split times between 5 – 20 m improved significantly across all resisted groups (all p<0.05, d = 0.34 – 1.16) but did not improve significantly with unresisted sprinting. For all resisted groups gains were greatest over the first 5 m (d = 0.67‐0.84) and then diminished over each subsequent 5 m split (d = 0.08‐0.57). The magnitude of gains in split times was greatest within the heavy group. Small but non‐significant within group effects were found in pre to post force‐velocity profiles. There was a main effect of time but no interaction effects as all groups increased force and power, although the greatest increases were observed with the heavy load (d = 0.50‐0.51). The results of this study suggest that resisted sled pushing with any load was superior to unresisted sprint training, and that heavy loads may elicit the greatest gains in sprint performance over short distances.

Full text

Scand J Med Sci Sports. 2019;00:1–8. wileyonlinelibrary.com/journal/sms
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© 2019 John Wiley & Sons A/S.
Published by John Wiley & Sons Ltd
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INTRODUCTION
Sprint speed and its development throughout maturation
is a crucial characteristic of athletic performance in team
sport competition.1 Various training methods and modali-
ties exist to develop and enhance speed capability in young
athletes.2 Coaches have employed both non–sprint-specific
and sprint-specific training methods with varying responses
in young athletes.3-5 Sprint-specific training can be defined
as training that is specific to the movement patterns and di-
rection of sprinting,6 whereas non–sprint-specific training
typically includes different forms of resistance, plyomet-
rics, and combined training primarily in a vertical plane of
motion. Sprint-specific training has largely proven more ef-
fective than non–sprint-specific training, with the greatest ef-
fects generally observed over shorter distance acceleration.7,8
One such method of sprint-specific training is to push or pull
a resistive load in a horizontal plane of motion known as re-
sisted sled training. Resisted sled training has been shown
to be more effective in the acceleration phase compared to
the max velocity phase of sprinting.9 Despite widespread use
by practitioners, both sled pulling and sled pushing have not
Received: 29 June 2019
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Revised: 30 September 2019
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Accepted: 6 November 2019
DOI: 10.1111/sms.13600
ORIGINAL ARTICLE
Influence of resisted sled-push training on the sprint force-
velocity profile of male high school athletes
Micheál J.Cahill1,2
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Jon L.Oliver2,3
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John B.Cronin2
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Kenneth P.Clark4
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Matt R.Cross2,5
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Rhodri S.Lloyd2,3,6
1Athlete Training and Health, Plano, TX,
USA
2Sports Performance Research Institute
New Zealand, Auckland University of
Technology, Auckland, New Zealand
3Youth Physical Development Centre,
Cardiff Metropolitan University, Cardiff,
UK
4West Chester University, West Chester,
PA, USA
5Laboratoire Interuniversitaire de Biologie
de la Motricité, University Savoie Mont
Blanc, Chambéry, France
6Centre for Sport Science and Human
Performance, Waikato Institute of
Technology, Hamilton, New Zealand
Correspondence
Micheál J. Cahill, Athlete Training and
Health, 6010 W Spring Creek Pkwy, Plano,
TX 75024, USA.
Email: mcahill@athleteth.com
Sled pushing is a commonly used form of resisted sprint training; however, little
empirical evidence exists, especially in youth populations. The aim of this study was
to assess the effectiveness of unresisted and resisted sled pushing across multiple
loads. Fifty high school athletes were assigned to an unresisted (n=12), or 3 resisted
groups; light (n=14), moderate (n=13), and heavy (n=11) resistance that caused
a 25%, 50%, and 75% velocity decrement in maximum sprint speed, respectively. All
participants performed two sled-push training sessions twice weekly for 8weeks.
Before and after the training intervention, the participants performed a series of jump,
strength, and sprint testing to assess athletic performance. Split times between 5 and
20m improved significantly across all resisted groups (all P<.05, d=0.34-1.16) but
did not improve significantly with unresisted sprinting. For all resisted groups, gains
were greatest over the first 5m (d=0.67-0.84) and then diminished over each sub-
sequent 5m split (d=0.08-0.57). The magnitude of gains in split times was greatest
within the heavy group. Small but non-significant within-group effects were found in
pre to post force-velocity profiles. There was a main effect of time but no interaction
effects as all groups increased force and power, although the greatest increases were
observed with the heavy load (d=0.50-0.51). The results of this study suggest that
resisted sled pushing with any load was superior to unresisted sprint training and that
heavy loads may elicit the greatest gains in sprint performance over short distances.
KEYWORDS
acceleration, horizontal resistance training, resisted sprinting

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received much research attention, with the latter much less
researched.10
Anecdotally, sled pushing is a common training method
utilized by coaches in team sport settings such as rugby
and football. While research using the method is relatively
uncommon, sled pushing has been examined in relation to
post-activation potentiation and blood lactate response in
adults in which relatively heavy loading parameters were
used.11,12 A recent study by Cahill et al13 examined the reli-
ability and variability within sled pushing concluding that
loads can be reliably prescribed to young athletes, with the
caveat that the loading response is highly individualized.
However, there is a paucity of longitudinal research exam-
ining the effectiveness of sled pushing in improving sprint
performance. Although sled pushing is viewed as a similar
method to sled pulling, many differences exist (eg, size,
shape, friction, and anterior positional orientation of the
sled) which likely result in unique kinematic and kinetic
changes.10 Only one study exists on resisted sled pushing
in young athletes and although it found the prescription of
load reliable for post-peak height velocity (PHV) athletes;
a greater degree of between-participant variability in load
was found in sled pushing in comparison with sled pulling
when reported as the percentage of body mass (%BM) re-
quired to cause a given decrement in velocity.6 The most
notable difference between push and pull conditions is the
use of the arms to directly apply force onto the sled device
and overcome momentum during the initial first step of the
sprint is unique to sled pushing. Therefore, sled pushing
should be viewed as a unique and specialized form of hori-
zontal resistance training.13
Given the horizonal nature of resisted sled pushing,
the same limitations exist as observed in sled pulling with
regard to prescription of load as a set %BM in adult and
youth populations.6,13-15 The high degree of variability
of sled load tolerance in young athletes could be due to a
combination of maturation, training history, and strength.13
An alternative method of sled loading is to prescribe load
based on the decrement in maximal sprint velocity (Vdec)
with increases in load.14 This method uses the known lin-
ear relationships between force and velocity and load and
velocity, which have been shown to exist for sled pulling6,16
and more recently, sled pushing.13 Cahill et al13 suggested
light, moderate, and heavy loading parameters at sled push-
ing loads corresponding to 25%, 50%, and 75% Vdec to
represent speed-strength, power, and strength-speed zones,
respectively, but further research is needed to confirm the
effectiveness of training within these zones. Categorizing
sled pushing as a horizontal strength training exercise
might suggest that training would be most effective at
heavier loads, particularly with young athletes where there
is a large potential to develop force production.17 Resisted
sled-push training at different loads may have differential
transference effects to the force-velocity and velocity-dis-
tance relationships during unresisted sprinting.
There is currently a paucity of research that has directly
compared responses to sled-push training at a range of loads
from across the force-velocity spectrum, and no research with
young athletes. Therefore, the aim of the present study was to
assess the effectiveness of unresisted and resisted sled-push
training at light, moderate, and heavy loads in high school
athletes. The authors hypothesize that training at heavier
loads in young athletes will lead to greater gains in horizon-
tal force production and velocity over the initial period of a
sprint.
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METHODS
2.1
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Participants
Fifty male high school athletes (16.6±0.8years; height,
1.75 ± 7.1 cm; weight, 74.3 ± 11.5 kg; and Vmax;
8.31± 0.58 m/s PHV; 2.3 ± 0.8 years) from two sports
(rugby and lacrosse) were recruited to participate in this
study during the off-season. All participants biological ma-
turity was established as post-PHV using a non-invasive
method of calculating the age at PHV.18 All participants
had a minimum of one-year resistance training experience,
although athletes were familiar with resisted sprinting,
they had never performed a cumulative structured block of
resisted sprint training. All participants were healthy and
injury-free at the time of testing. Any athletes who were
rehabilitating a previous lower body injury within the last
6months were excluded from the study. Written consent
was obtained from a parent/guardian and assent from each
subject before participation. Experimental procedures were
approved by West Chester University Institutional Ethics
Committee.
2.2
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Test protocols
2.2.1
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Load-velocity profiling and
prescription
All participants were familiarized with the equipment
and testing procedures 1week prior to data collection by
performing two maximal effort repetitions at loads cor-
responding to light, moderate, and heavy. Load-velocity
profiling and prescription of loads was conducted using
unresisted and resisted trials as described by Cahill et al.13
A radar device (Model; Stalker ATS II, Applied Concepts,
Dallas, TX, USA) was positioned 10 m directly behind
the starting position to determine the maximum velocity
(Vmax) of both unresisted and resisted trials. The range of

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selected loads at increments of 20% was based on pilot test-
ing that reduced an athletes velocity by values above and
below 50% of unresisted Vmax.
2.2.2
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Pre- and post-intervention testing
Jump testing
Jump testing consisted of both horizontal and vertical jump
measures. Both protocols have been shown to be reliable in
assessing jump performance in youth populations.19,20 During
the standing long jump, participants were asked to stand on
the start line and jump horizontally as far as possible and
then to hold their landing position. A tape measure was then
used to measure jump distance from the start line to the rear-
most heel of the foot upon landing. The countermovement
jump used a self-selected depth in which participants were
instructed to jump vertically as high as possible and to keep
their legs extended while in the air. Jump height was calcu-
lated from flight time using an optical measurement system
(Optojump, Microgate, Italy). The best of two attempts was
recorded for both jump tests.
Strength testing
Lower limb strength was measured using a linear position
transducer (Gym aware, Kinetic, Australia) to estimate the
one maximum-repetition (1RM) of a deadlift exercise utiliz-
ing a velocity-based protocol provided by the manufacturer.
This device has been shown to be valid and reliable method
of determining a 1RM across commonly practiced resistance
training exercises.21 Participants performed a minimum of
three, one-repetition lifts at maximum speed at incremen-
tal loads of 20% BM until their speed dropped to less than
0.5meters per second (m/s). All athletes rested between 4
and 6minutes between repetitions. Pilot testing was used to
determine a starting baseline weight of each participant.
Sprint testing
Acceleration sprint testing was assessed using a radar gun,
with the set up as per the load-velocity testing except that it
took place indoors in a controlled environment over 22m.
Each participant performed two trials with the fasted time
recorded. The same software provided by the radar device
manufacturer used during load-velocity testing was used
to collect raw velocity data during each sprint, which was
subsequently fitted with an exponential function with its
maximal velocity (Vmax) extracted. Instantaneous velocity
was derived to calculate net horizontal force and maximum
power (Pmax). Each linear force-velocity relationship was
then extrapolated to calculate theoretical maximum horizon-
tal force (F0). This method has been shown to be a reliable
field method to assess force-velocity profiles during over-
ground sprinting.22 Sprint force-velocity profiles were then
TABLE 1 Sets, reps and weekly total distances for unresisted, speed-strength, power or strength-speed groups
Week
Unresisted Light Moderate Heavy
Rest per
rep (min)Reps p/w
Distance
per rep (m)
Total
distance
p/w Reps p/w
Distance
per rep (m)
Total
distance
p/w Reps p/w
Distance
per rep (m)
Total
distance
p/w Reps p/w
Distance
per rep (m)
Total
distance
p/w
1 6 30 360 6 22.5 270 6 15 180 6 7.5 90 3
2 7 30 420 7 22.5 315 7 15 210 7 7.5 105 3
3 8 30 640 8 22.5 360 8 15 240 8 7.5 120 3
4 6 30 360 6 22.5 270 6 15 180 6 7.5 90 3
5 7 30 420 7 22.5 315 7 15 210 7 7.5 105 3
6 8 30 480 8 22.5 360 8 15 240 8 7.5 120 3
7 9 30 540 9 22.5 405 9 15 270 9 7.5 135 3
8 7 30 420 7 22.5 315 7 15 210 7 7.5 105 3
Abbreviations: p/w, per week; m, meters; min, minute.

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TABLE 2 Means±SD for all measured variables pre- to post-intervention in young athletes completing 8weeks of either unresisted, light, moderate or heavy resisted sprint training

Unresisted
ES
Light
ES
Moderate
ES
Heavy
ESPre Post Pre Post Pre Post Pre Post
VJ (cm) 41.8±6.8 41.8±5.0 0.00 41.4±5.5 43.0±6.3 0.30 43.5±6.55 42.4±5.8 0.17 42.9±5.7 44.2±6.0 0.21
SLJ (cm)a213±24 215±22 0.10 212±25 222±23 0.10 221±24 225±22 0.08 222±19 228±17 0.34
Hex Bar DL (kg) 134±26 137±25 0.11 151±22 155±29 0.10 149±36 152±31 0.08 141±24 143±24 0.07
0-5m (s)a1.62±0.13 1.57±0.10 0.40 1.66±0.09 1.60±0.13* 0.67 1.58±0.08 1.52±0.10* 0.74 1.58±0.07 1.52±0.07* 0.84
0-10m (s)a2.41±0.16 2.37±0.14 0.28 2.47±0.12 2.39±0.15* 0.60 2.38±0.15 2.31±0.13* 0.47 2.39±0.09 2.30±0.08** 1.05
0-15m (s)a3.11±0.19 3.08±0.17 0.18 3.20±0.17 3.11±0.19** 0.54 3.09±0.20 3.01±0.16* 0.42 3.09±0.09 2.99±0.09** 1.16
0-20m (s)a3.77±0.21 3.75±0.21 0.09 3.88±0.21 3.79±0.23* 0.47 3.76±0.23 3.68±0.19* 0.34 3.76±0.10 3.65±0.09** 1.03
5-10m (s) 0.80±0.05 0.80±0.05 0.13 0.81±0.04 0.80±0.05 0.38 0.81±0.07 0.80±0.05 0.15 0.82±0.05 0.79±0.03* 0.57
10-15m (s) 0.70±0.04 0.71±0.03 0.32 0.73±0.05 0.71±0.04 0.34 0.71±0.06 0.70±0.04 0.24 0.70±0.03 0.69±0.02 0.32
15-20m (s) 0.66±0.03 0.68±0.04 0.43 0.68±0.05 0.68±0.04 0.08 0.67±0.04 0.67±0.03 0.06 0.67±0.04 0.66±0.02 0.24
F0 (N/kg)a5.9±1.3 6.2±1.1 0.26 5.4±1.0 5.8±1.7 0.37 5.9±0.8 6.2±0.8 0.39 5.7±1.0 6.3±0.9 0.50
Vmax (m/s)a8.50±0.58 8.24±0.57 0.46 8.10±0.91 8.14±0.70 0.04 8.35±0.76 8.16±0.47 0.25 8.31±0.61 8.24±0.40 0.11
Pmax (w/kg)a12.9±2.7 13.2±2.5 0.12 11.5±2.9 12.3±4.0 0.27 12.6±2.0 13.1±1.8 0.19 12.2±2.0 13.3±1.8 0.51
Abbreviations: CT, contact time; F, maximal theoretical force; FT, flight time; Pmax, maximal theoretical power; SLJ, standing long jump; VJ, vertical jump; Vmax, maximal theoretical velocity.
aSignificant main effect of time (P<.05).
*Significant within-group difference pre- to post-intervention (P<.05).
**Significant within-group difference pre- to post-intervention (P<.01).

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CAHILL et AL.
constructed using custom-made LabVIEW software. All pre-
and post-intervention tests were preceded by a minimum of
72hours to ensure athletes were not fatigued prior to testing.
Pre-testing was also preceded by a familiarization period of
2 weeks low-intensity resistance training and familiariza-
tion of sled pushing. Post-training was preceded by a 1-week
taper to ensure no overreaching occurred.
2.2.3
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Training intervention
Participants were initially matched by speed and randomly
allocated between four training groups: one unresisted and
three resisted groups. A compliance threshold of 85% (14/16
training sessions) was set to be included in the study, leading
to slightly uneven group sizes; unresisted n=12, light=15,
moderate n=14, and heavy n=12, with loads correspond-
ing to a Vdec of 0%, 25%, 50%, and 75% of Vmax, respec-
tively. The training intervention consisted of two resisted
sprint sessions immediately followed by a strength session
in the weight room plus two sport practice sessions on sepa-
rate days per week. All athletes were asked to abstain from
high-intensity activity for the 24 hours prior to each sled-
push training session. Both resisted sprint and strength train-
ing protocols followed a linear periodization model, which
involved a standard 3:1 mesocycle arrangement (ie, 3weeks
of increasing intensity followed by 1week of reduced work-
load) being completed for two consecutive 4-week meso-
cycles. Sport practice training load could not be controlled
due to differentiating demands between lacrosse and rugby.
However, sprint-specific training and strength training load
was controlled across all participants. All groups preformed
identical strength training programs consisting of compound
multi-joint exercises for repetitions ranging between 5 and
10. Specific sets and repetitions for resisted sprinting are pro-
vided in Table 1.
The sled load and sprint distance remained constant for
each subject throughout the training intervention. Total work
was equated for all resisted groups to that of the unresisted
control group by reducing the distance per rep by the same
percentage Vdec caused by sled loading. This resulted in
sprint distances of 22.5, 15, and 7.5m for the training groups
loaded to cause a Vdec of 25%, 50%, and 75%, and meant that
sprint efforts lasted approximately the same duration across
participants in all training groups. All participants had 3min-
utes rest between maximal sprint efforts.
Prior to each training session, all participants performed a
standardized 10-minute dynamic warm-up, inclusive of sub-
maximal repetitions of sprinting and dynamic mobilization
and activation exercises targeting the main muscle groups
of the upper and lower extremities. Upon completion of the
warm-up, all athletes performed sprint training specific to
their training group.
2.3
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Statistical analysis
Descriptive statistics (mean±SD) and effect size statistics
are reported for all dependent variables of jump and sprint-
ing performance. Levene's test was used to ensure the data
met the criteria for normality and homogeneity of variance.
A 4 × 2 (group × time) repeated-measured ANOVA with
Bonferroni post hoc comparisons was used to determine
the within- and between-group effects for each dependent
variable as well as examining interaction effects. An alpha
level of P<.05 was used to indicate statistical significance.
Effect sizes (Cohen's d) were used to quantify the magnitude
of the performance change in each group, with values of
0.00<0.20, 0.20<0.60, 0.60<1.20, and ≥1.20 represent-
ing the qualitative thresholds for trivial, small, moderate, and
large effects, respectively.23
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RESULTS
Means±SD and magnitude of within-group changes for all
variables, in all conditions pre- and post-intervention, are
shown in Table 2. For all variables, there were no signifi-
cant differences between groups at baseline (P>.05). Table
2 shows that there were main effects of time for 0-5, 0-10,
0-15, and 0-20m splits (P<.05), all force-velocity variables
(P<.05), and the standing long jump (P<.05). There are
clear trends for different responses across the groups when
assessing the within-group changes. In terms of the jumps
and lower body strength, there were no significant changes
observed with effect sizes ranging between trivial to small
(d=0.00-0.34).
All resisted interventions demonstrated significant with-
in-group improvements for 0-5, 0-10, 0-15, and 0-20m sprint
times (P < .05). Across 5, 10, 15, and 20 m sprint times,
there is a clear trend of an increasing effect as load increases;
unresisted sprinting resulted in trivial to small improvements
(d= 0.09-0.40), light (d = 0.47-0.67), and moderate load-
ing elicited small to moderate improvements (d=0.34-0.74)
and heavy loading led to moderate improvements (d=0.84-
1.16). The heavy group was the only group to significantly
improve 5-10m. No significant improvement occurred in any
group from 10 to 15m or 15 to 20m. For all resisted groups,
improvements in split times beyond the initial 5m accelera-
tion phase diminished (see Table 2).
With regards to force-velocity profiling across four in-
tervention groups, Vmax, F0 and Pmax all showed main
effects between pre- and post-test. There were small but
non-significant within-group differences, approaching
significance for the heavy group for both F0 and Pmax
(P < .07). Within-group comparisons demonstrated triv-
ial to small effect size changes (d= 0.12-0.51) with the
heavy group resulting in the greatest magnitude of change.

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CAHILL et AL.
An illustration of the change in velocity over distance and
force-velocity profile from pre- and post-training in each
group can be observed in Figure 1.
4
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DISCUSSION
The aim of the study was to assess the effectiveness of un-
resisted and resisted sled-push training at multiple loads re-
flective of speed-strength, power, and strength-speed zones
of training. The main findings of the present study were
that resisted sprinting was more effective than unresisted
sprinting in improving short-distance sprint performance,
and that heavy loads seem to provide the greater benefits
of increasing acceleration, force, and power. It seems that
young athletes respond to resisted sled pushing across a
range of loads. However, resisted sled pushing at heavier
loads in a strength-speed training zone may elicit enhanced
acceleration performance in comparison with lighter or un-
resisted loads.
Sled-push training being categorized as a sprint-spe-
cific horizontal strength training exercise provided minimal
transfer to both vertical and horizontal jump performance
and lower body strength. The non-significant and trivial to
small magnitude of change within groups supports previous
research that training is movement specific.24 A small ef-
fect size change was observed in the heavy group during the
standing long jump and the light group during the vertical
jump. Due to the reduced sprint distances as load increased
within each intervention group, the lightest resisted group
and heaviest resisted would have spent more time applying
force vertically and horizontally, respectively.25
The availability of research on resisted sled push-train-
ing in comparison with resisted sled pull training reinforces
the need for more intervention studies to determine the ef-
fectiveness of sled pushing as a sprint-specific method of
training. However, given the lack of empirical evidence
in sled pushing, similarities do exist with sled pulling in
favoring heavier loading over lighter loading to enhance
targeted areas of sprint performance, particularly during
the initial acceleration phase of young athletes.26 It is im-
portant to note; however, the loads previously studied and
categorized as “heavy” (20%BM) within a youth popula-
tion would still be considered light in comparison with the
loads used in this study.26 All resisted sprint groups had
small to moderate significant within-group improvements
in sprint times. The magnitude of effect was greatest over
the initial 5 m and increased with greater loading. This
indicates that resisted sprinting affected the first step and
initial acceleration phase, particularly in the heavy group.
Decreases in split times beyond the initial 5m were pri-
marily a result of the improvement within the acceleration
phase. However, the heavy group was the only group to
significantly improve between the 5 and 10m split, sug-
gesting sled pushing at heavy loads may have additional
benefits outside the initial acceleration phase, providing
the necessary force dominant stimulus to elicit the desired
training response in young athletes. However, more re-
search is needed examining the acute kinetics and kinemat-
ics of sled pushing to quantify the mechanical determinants
of these changes.
There were significant main effects of time on the
force-velocity profiles but no significant changes at a group
level. However, small changes that approached significance
(P<.07) in F0 and Pmax were observed in the heavy group
(d=0.50-0.51) and illustrate that the adaptations occurring
from resisted loads are specific to the imposed demands,
with heavier loads appearing to favor horizontal force pro-
duction during the early acceleration phase (0-10m). The
fact Vmax decreased for most groups also supports the
notion of training specificity, with most groups working
against resistance and below maximal speed. The lack of
any improvement in Vmax in the unresisted group may re-
flect the fact that sprinting is a habitual activity in young
athletes and that the training program did not provide a
stimulus to elicit performance improvements. The findings
may also be specific to the population studied. Previous
meta-analyses have shown that with traditional resistance
training young athletes respond most to work at higher
intensities and that post-pubertal athletes make greater
strength gains than pre-pubertal populations following re-
sistance training.27,28 If sled pushing is considered a spe-
cialized form of horizontal resistance training, then heavy
loads, representing a high-intensity of work, may be par-
ticularly useful for young athletes who are post-PHV to in-
crease their sprint force, power, and velocity.
5
|
PERSPECTIVE
The aim of the present study was to assess the effective-
ness of unresisted and resisted sled-push training at light,
moderate, and heavy loads in high school athletes. All
resisted groups made significant, positive improvements,
suggesting a range of loads can be effective in improv-
ing the sprint performance of young athletes. However,
there was a clear trend for greater and more consistent
improvements in sprinting force, power, and performance
over short distances when training with heavier sled loads.
Cumulatively, the results of this study show that post-PHV
males within limited training exposure to resisted sprint-
ing may reap the greatest gains in acceleration performance
with a heavier external resistance which is representative
of a strength-speed training zone. Given the constant desire
to individualize training, future research should examine
whether greater gains in performance can be achieved if

|
7
CAHILL et AL.
FIGURE 1 Pre- to post-changes in velocity-distance and force-velocity profiles after an 8-week sled-push training intervention at unresisted,
light, moderate, and heavy load
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0510 15 20 25
Velocity (m/s)
Distance (m)
Pre
Post
Light
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0510 15 20 25
Velocity (m/s)
Distance (m)
Pre
Post
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0510 15 20 25
Velocity (m/s)
Distance (m)
Pre
Post
Moderate
0.00
1.00
2.00
3.00
4.00
5.00
6.00
7.00
8.00
9.00
0510 15 20 25
Velocity (m/s)
Distance (m)
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Pre
Post
Heavy
0
1
2
3
4
5
6
7
0123456789
Force (n/kg)
Velocity (m/s)
Heavy
0
1
2
3
4
5
6
7
0123456789
Force (n/kg)
Velocity (m/s)
Moderate
0
1
2
3
4
5
6
7
0123456789
Force (n/kg)
Velocity (m/s)
Light
0
1
2
3
4
5
6
7
0123456789
Force (n/kg)
Velocity (m/s)
Unresisted Unresisted

8
|
CAHILL et AL.
resisted push-load is prescribed based on individual weak-
nesses in the force-velocity profile.
ORCID
Micheál J. Cahill https://orcid.
org/0000-0001-8010-2901
Jon L. Oliver https://orcid.org/0000-0001-7425-3148
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How to cite this article: Cahill MJ, Oliver JL, Cronin
JB, Clark KP, Cross MR, Lloyd RS. Influence of
resisted sled-push training on the sprint force-velocity
profile of male high school athletes. Scand J Med Sci
Sports. 2019;00:1–8. https ://doi.org/10.1111/
sms.13600