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Abstract and Figures

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.
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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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CAHILL et AL.
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.
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Test protocols
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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.
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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.
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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
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8
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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
REFERENCES
1. Köklü Y, Alemdaroğlu U, Özkan A, Koz M, Ersöz G. The relation-
ship between sprint ability, agility and vertical jump performance
in young soccer players. Sci Sport. 2015;30:e1-e5.
2. Rumpf MC, Cronin JB, Pinder SD, Oliver J, Hughes M. Effect of
different training methods on running sprint times in male youth.
Pediatr Exerc Sci. 2012;24:170-186.
3. Moran J, Sandercock G, Rumpf MC, Parry DA. Variation in re-
sponses to sprint training in male youth athletes: a meta-analysis.
Int J Sports Med. 2017;38(1):1-11.
4. Lloyd RS, Radnor JM, De Ste CM, Cronin JB, Oliver JL. Changes
in sprint and jump performances after traditional, plyometric, and
combined resistance training in male youth pre- and post-peak
height velocity. J Strength Cond Res. 2016;30(5):1239-1247.
5. Rumpf MC, Cronin JB, Mohamad IN, Mohamad S, Oliver JL,
Hughes MG. The effect of resisted sprint training on maxi-
mum sprint kinetics and kinematics in youth. Eur J Sport Sci.
2015;15(5):374-381.
6. Cahill MJ, Oliver JL, Cronin JB, Clark KP, Cross MR, Lloyd RS.
Sled-pull load-velocity profiling and implications for sprint train-
ing prescription in young male athletes. Sports. 2019;7(5):119.
7. Rumpf MC, Lockie RG, Cronin JB, Jalilvand F. Effect of different
sprint training methods on sprint performance over various dis-
tances: a brief review. J Strength Cond Res. 2016;30(6):1767-1785.
8. Petrakos G, Morin JB, Egan B. Resisted sled sprint training to
improve sprint performances: a systematic review. Sports Med.
2016;46(3):381-400.
9. Alcaraz PE, Carlos-Vivas J, Oponjuru BO, Martinez-Rodriguez
A. The effectiveness of Resisted Sled Training (RST) for sprint
performance: a systematic review and meta-analysis. Sports Med.
2018;48(9):2143-2165.
10. Cahill M, Cronin JB, Oliver JL, Clark K, Cross MR, Lloyd RS.
Sled pushing and pulling to enhance speed capability. Strength
Cond J. 2019;41(4):94-104.
11. Seitz LB, Mina MA, Haff GG. A sled push stimulus poten-
tiates subsequent 20-m sprint performance. J Sci Med Sport.
2017;20(8):781-785.
12. Waller M, Robinson T, Holman D, Gersick M. The effects of re-
peated push sled sprints on blood lactate, heart rate recovery and
sprint times. J Sport Res. 2016;3(1):1-9.
13. Cahill MJ, Oliver JL, Cronin JB, Clark KP, Cross MR, Lloyd RS.
Sled-push load-velocity profiling and implications for sprint train-
ing prescription in young male athletes. J Strength Cond Res. 2019.
In press.
14. Cross MR, Lahti J, Brown SR, et al. Training at maximal power in re-
sisted sprinting: optimal load determination methodology and pilot
results in team sport athletes. PLoS ONE. 2018;13(4):e0195477.
15. Rumpf MC, Cronin JB, Mohamad IN, Mohamad S, Oliver J,
Hughes M. Acute effects of sled towing on sprint time in male youth
of different maturity status. Pediatr Exerc Sci. 2014;26:71-75.
16. Cross MR, Samozino P, Brown SR, Morin JB. A comparison be-
tween the force-velocity relationships of unloaded and sled-resisted
sprinting: single vs. multiple trial methods. Eur J Appl Physiol.
2018;118(3):563-571.
17. Keiner M, Sander A, Wirth K, Hartmann H, Yaghobi D.
Correlations between maximal strength tests at different squat
depths and sprint performance in adolescent soccer players. Amer J
Sports Sci. 2014;2(6):1-7.
18. Mirwald RL, Baxter-Jones ADG, Bailey DA, Beunene GP. An
assessment of maturity from anthropometric measures. Med Sci
Sports Exerc. 2002;34(4):689-694.
19. Lloyd RS, Oliver JL, Huges MG, Williams CA. Reliability and va-
lidity of field-based measures of leg stiffness and reactive strength
index in youths. J Sport Sci. 2009;27(14):1565-1573.
20. Fernandez-Santos JR, Ruiz JR, Cohen DD, Gonzalez-Montesinos
JL, Castro-Piñero J. Reliability and validity of tests to assess
lower-body muscular power in children. J Strength Cond Res.
2015;29(8):2277-2285.
21. Dorrell H, Moore J, Smith MF, Gee T. Validity and reliability of a
linear positional transducer across commonly practised resistance
training exercises. J Sport Sci. 2018;37:1-7.
22. Samozino P, Rabita G, Dorel S, et al. A simple method for measur-
ing power, force, velocity properties, and mechanical effectiveness
in sprint running. Scand J Med Sci Sports. 2016;26(6):648-658.
23. Hopkins WG, Marshall SW, Batterham AM, Hanin J. Progressive
statistics for studies in sports medicine and exercise science. Med
Sci Sports Exerc. 2009;41(1):3-13.
24. Maulder P, Cronin J. Horizontal and vertical jump assessment:
Reliability, symmetry, discriminative and predictive ability. Phys
Ther Sport. 2005;6(2):74-82.
25. Brughelli M, Cronin J, Chaouachi A. Effects of running veloc-
ity on running kinetics and kinematics. J Strength Cond Res.
2011;25(4):933-939.
26. Bachero-Mena B, González-Badillo JJ. Effects of resisted sprint
training on acceleration with three different loads account-
ing for 5, 12.5, and 20% of body mass. J Strength Cond Res.
2014;28(10):2954-2960.
27. Lesinski M, Prieske O, Granacher U. Effects and dose-response re-
lationships of resistance training on physical performance in youth
athletes: a systematic review and meta-analysis. Br J Sports Med.
2016;50(13):781-795.
28. Behringer M, Vom Heede A, Yue Z, Mester J. Effects of resistance
training in children and adolescents: a meta-analysis. Pediatrics.
2010;126(5):e1199-1210.
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
... Sprint performance is considered a foundation for youth physical development [7] and is a fundamental physical component necessary for all athletes [8][9][10][11] and is subsequently highly regarded by coaches and practitioners. This is highlighted by the inclusion of sprint assessments in a multitude of physical performance testing batteries aimed to profile athletes' physical capacities [9,[12][13][14][15][16][17], assess the efficacy of training programs [18][19][20][21][22], or identify and select talented junior athletes [3,[23][24][25][26]. The failure to fully develop sprint performance during adolescence may restrict future sporting opportunities as an adult, since superior sprint performance can distinguish between different competitive standards [9,10,27,28], and is associated with talent identification, and team selection [23,25,26,29,30]. ...
... Understanding the most effective modes for developing sprint acceleration in youth athletes can be challenging for practitioners involved in team sports such as AF [18,19,21,74,80]. Modes of training used to improve sprint performance can be classified according to task specificity and include sprint specific and non-sprint specific methods [81][82][83]. ...
... Like sprint specific primary training methods, secondary training methods overload the sprint movement pattern through increasing (assisted sprinting) or decreasing (resisted sprinting) the movement speed [81,83]. These sprint specific secondary training methods stimulate morphological and neuromuscular adaptations that can improve sprint acceleration performance through allowing the athlete to generate greater GRF's and improve mechanical effectiveness [18,19,21,[94][95][96]. ...
Thesis
Full-text available
This thesis is based on a series of publications that were conducted with the aim of improving the assessment and development of sprint performance in junior AF players. Specifically, the objectives of the thesis were to examine the underlying FVP characteristics of maximum sprint performance through cross-sectional analysis across competition levels, maturation status, and draft outcome. Additionally, a longitudinal analysis explored the natural development of sprint performance and the influence of biological maturation. Finally, a longitudinal training intervention examined the effect of a sprint-specific training mesocycle on sprint performance and FVP characteristics. The specific aims of the thesis were to: 1. To establish the diagnostic ability of sprint times and sprint kinetic and kinematic characteristics in junior AF players. 2. Cross-sectionally explore the differences in sprint performance and sprint kinetics and kinematics in junior AF players through competition levels within the AFL player development pathway. 3. Longitudinally examine the natural development and influence of biological maturation on sprint performance and sprint kinetics and kinematics in junior AF players. 4. To assess the effectiveness of a sprint-specific training mesocycle on sprint performance and sprint kinetics and kinematics in junior AF players.
... In terms of the intermuscular (specific) perspective, training that relates to the hamstring muscles function during dynamic tasks (such as sprinting) may be interesting. Dynamic training modalities could include horizontally oriented exercises, such as basic acceleration sprints or resisted sprint training, which support the development of the horizontal force component of the GRF vector in sprint based team sports (Morin et al., 2017;Cahill et al., 2020;Lahti, Huuhka, et al., 2020;Mendiguchia, Conceição, et al., 2020). ...
... Interventions with heavy loads have shown mixed results, possibly to some degree due to different methodology. Four studies showed positive effects on early sprint performance (Kawamori et al., 2014;Bachero-Mena & González-Badillo, 2014;Morin et al., 2017;Cahill et al., 2020), another showed split time improvements between 10-30-m, while instead a lighter load group improved also at 0-20-m (Pareja-Blanco, Asián-Clemente & SáezdeVillarreal, 2019), and one study showed trivial to small effects on performance from both heavy and light resisted sprinting . Evident methodological differences include large differences in what is considered heavy (range ∼20%-50% velocity decrement), not standardizing each subjects load to a specific velocity decrement (using the less accurate % of BM method) (Petrakos, Morin & Egan, 2016), using 1 vs. 2 training sessions per week, initial level and amount of familiarization of subjects, and timing between training completion and post-testing and associated tapering (Morin et al., 2020). ...
Thesis
Full-text available
Despite efforts to intervene, hamstring muscle injuries (HMI) continue to be one of the largest epidemiological burdens in professional football. The injury mechanism takes place dominantly during sprinting, but also other scenarios have been observed, such as overstretching actions, jumps, and change of directions. The main biomechanical roles of the hamstring muscles are functioning as an accelerator of center-of-mass (i.e., contributing to horizontal force production), and stabilizing the pelvis and knee joint. Multiple extrinsic and intrinsic risk factors have been identified, portraying the multifactorial nature of the HMI. Furthermore, these risk factors can vary substantially between players, portraying the importance of individualized approaches. However, there is a lack of multifactorial and individualized approaches assessed for validity in literature. Thus, the overarching aim of this doctoral thesis was to explore if a specific multifactorial and individualized approach can improve upon the ongoing HMI risk reduction protocols, and thus, further reduce the HMI risk in professional football players. This was done following the Team-sport Injury Prevention model (TIP model), where the target is to evaluate the current injury burden, identify possible solutions, and intervene. The thesis comprised of three themes within professional football, I) evaluating and identifying HMI risk (completed via assessing the current epidemiological HMI situation and the association between HMI injuries and a novel hamstring screening protocol), II) improving horizontal force capacity (completed via testing if maximal theoretical horizontal force (F0) can be improved via heavy resisted sprint training), and III) developing and conducting a multifactorial and individualized training for HMI risk reduction (completed via introducing and conducting a training intervention). The conclusions from theme I were that the HMI burden continues to be high (14.1 days absent per 1000 hours of football exposure), no tests from the screening protocol were associated with an increased HMI risk when including all injuries from the season (n = 17, p > 0.05), and that lower F0 was significantly associated with increased HMI risk when including injuries between test rounds one and two (~90 days, n =14, hazard ratio: 4.02 (CI95% 1.08 to 15.0), p = 0.04). For theme II, the players initial pre-season level of F0 was significantly associated with adaptation potential after 11 weeks of heavy resisted sprint training during the pre-season (r = -0.59, p < 0.05). The heavy resisted sprint load leading to a ~50% velocity loss induced the largest improvements in sprint mechanical output and sprint performance variables. For theme III, no intervention results could be presented within this document due to the Covid-19 pandemic leading to the intervention being postponed. However, a protocol paper was published, describing in detail the intervention approach that will be used outside the scope of the thesis. In future studies, larger sample size studies are needed to support the development of more advanced HMI risk reduction models. Such models may allow practitioners to identify risk on an individual level instead of a group level. Furthermore, constant development of more specific, reliable, and accessible risk assessment tests should be promoted that can be frequently tested throughout the football season. Finally, based on the results of theme II, individualization of a specific training stimulus should be promoted in team settings.
... From these, sled towing and pushing, along with resisted-parachute sprinting, are the most widely used in sports such as football, rugby and soccer. However, the scientific evidence regarding sled-pushing and resisted-parachute sprinting is limited in comparison to sled towing [18][19][20][21][22], particularly for variables such as muscle activation. ...
... In this regard, in the present study, K vert decreased significantly with increasing loads. Nevertheless, caution is necessary when comparing sled-pushing and sled pulling since, despite both being effective RST exercises, they may offer different training stimuli [18]. Another aspect worth noting is that the significant reduction in A angle , K angle and H angle herein could lead to an increased energy cost of the movement pattern as a result of a decline in the amount of stored and reused elastic energy [36]. ...
Article
Full-text available
This study's aim was to analyze muscle activation and kinematics of sled-pushing and resisted-parachute sprinting with three load conditions on an instrumentalized SKILLRUN ® tread-mill. Nine male amateur rugby union players (21.3 ± 4.3 years, 75.8 ± 10.2 kg, 176.6 ± 8.8 cm) performed a sled-push session consisting of three 15-m repetitions at 20%, 55% and 90% body mas and another resisted-parachute session using three different parachute sizes (XS, XL and 3XL). Sprinting kinematics and muscle activity of three lower-limb muscles (biceps femoris (BF), vastus lateralis (VL) and gastrocnemius medialis (GM)) were measured. A repeated-measures analysis of variance (RM-ANOVA) showed that higher loads during the sled-push increased (VL) (p ≤ 0.001) and (GM) (p ≤ 0.001) but not (BF) (p = 0.278) activity. Furthermore, it caused significant changes in sprinting kinematics, stiffness and joint angles. Resisted-parachute sprinting did not change kinematics or muscle activation, despite producing a significant overload (i.e., speed loss). In conclusion, increased sled-push loading caused disruptions in sprinting technique and altered lower-limb muscle activation patterns as opposed to the resisted-parachute. These findings might help practitioners determine the more adequate resisted sprint exercise and load according to the training objective (e.g., power production or speed performance).
... sled pulling and pushing) loading parameters that target particular horizontal force, velocity and power adaptations Cahill et al., 2020a;Carlos-Vivas et al., 2019;Cross, Brughelli, Samozino, Brown, et al., 2017;Cross et al., 2018;Macadam et al., 2017Macadam et al., , 2018. Furthermore, as an important next step, a large amount of research has investigated the efficacy of different resistance training interventions (sprintspecific, non sprint-specific and combined) on improving maximal horizontal sprint acceleration and the underlying kinetic and kinematic determinants (Alcaraz et al., 2014;Cahill et al., 2020b;Carlos-Vivas et al., 2020;Cross et al., 2018;Lahti, Huuhka, et al., 2020;Lahti, Jiménez-Reyes, et al., 2020;Mendiguchia et al., 2015Mendiguchia et al., , 2020Morin et al., 2017Morin et al., , 2020Rakovic et al., 2018). Finally, advanced sprint acceleration diagnostics have also been used in team sport settings to monitor seasonal changes in sprint acceleration force-velocity profile , identify the influence of neuromuscular fatigue on sprint acceleration performance (Edouard et al., 2018;Jiménez-Reyes, Cross, et al., 2019;Marrier et al., 2017;Nagahara et al., 2016) and to assess a player's return-to-sport following injury (Mendiguchia et al., 2014(Mendiguchia et al., , 2016. ...
Thesis
Full-text available
Horizontal accelerations and decelerations are crucial components underpinning the many fast changes of speed and direction that are performed in team sports competitive match play. Extensive research has been conducted into the assessment of horizontal acceleration and the underpinning neuromuscular performance determinants, leading to evidence-informed guidelines on how to best develop specific components of a team sport players horizontal acceleration capabilities. Unlike horizontal acceleration, little scientific research has been conducted into how to assess horizontal deceleration, meaning the neuromuscular performance determinants underpinning horizontal deceleration are largely based on anecdotal opinion or qualitative observations. Therefore, the overall purpose of this thesis was to investigate the neuromuscular determinants of maximal horizontal deceleration ability in team sport players. Furthermore, since there are no recognised procedures on how to assess maximal horizontal deceleration ability, an important and novel aim of this thesis was to develop a test capable of obtaining reliable and sensitive data on a team sport player’s maximal horizontal deceleration ability. In part one of this thesis (chapter three) a systematic review and meta-analysis identified that high-intensity (< -2.5 m.s-2) decelerations were more frequently performed than equivalently intense accelerations (> 2.5 m.s-2) in most elite team sports competitive match play, signifying the importance of developing maximal horizontal deceleration ability in team sport players. In chapter four, a new test of maximal horizontal deceleration ability (named the acceleration-deceleration ability test – ADA test), measured using radar technology, identified a number of kinematic and kinetic variables that had good intra- and inter-day reliability and were sensitive to detecting small-to-moderate changes in maximal horizontal deceleration ability. The ADA test was used in chapters five to seven to examine associations with isokinetic eccentric and concentric knee strength capacities and countermovement and drop jump kinetic and kinematic variables, respectively. Using the neuromuscular and biomechanical determinants identified to be important for horizontal deceleration ability within this thesis, in addition to other contemporary research findings, the final part of this thesis developed an evidence-based framework that could be used by practitioners to help inform decisions on training solutions for improving horizontal deceleration ability – named the dynamic braking performance framework.
... When assessing different periodised models, linear and daily undulating methods provide similar benefits ( Harries et al., 2018). Additionally, the use of heavy sled training ( i.e., loads ~133% of body mass) can provide substantial improvements in 0-20 m sprint performance ( effect size: 0.87; Cahill et al., 2020). Finally, lower body exercise selection may also influence sprint and CoD performance outcomes. ...
Chapter
Youth rugby players are often organised into (bi)annual-age groups to create equal competition and development opportunities for all players. However, the variability in kinanthropometry (i.e., the size, shape, proportion, composition and maturation) that exists between players of a similar chronological age can affect injury risk, physical performance, and talent identification. This chapter aims to review the research on the kinanthropometry of youth rugby players and presents a range of practical implications for coaches, sport scientists and practitioners working with young rugby players to consider in relation to kinanthropometry and grouping strategies within youth rugby development programmes. These practical implications include understanding and assessing growth and maturity, considerations for training and competition, talent identification and development strategies, and stakeholder communication.
... Still, the performance improvement was not fast compared with the experimental group. 6 It can be seen that compound training plays an irreplaceable role in enhancing the explosive power of the lower limbs of athletes. ...
Article
Full-text available
Introduction The explosion force is the neuromuscular system's capacity to overcome resistance with the highest possible contraction speed. It is the result of a kinetic combination between power and speed. The effect of outdoor resistance training is used in several athletics areas to improve the explosive power of the lower limbs. However, there are still few studies focused on basketball athletes. Objective Verify the effect of outdoor resistance training on the explosive power of the lower limbs of basketball players. Methods The article uses mathematical statistics and randomized controlled trials by analytical comparison to explore the influence of compound training methods on basketball players’ lower explosive limb power. Results There was no performance gain in the control group at 30 days. Was an improved ability in the experimental group jumping after high-intensity composite training. Conclusion Compound training plays a crucial role in improving lower limb explosive power in college basketball players. Evidence Level II; Therapeutic Studies - Investigating the result. Keywords: Exercise; Sports; Athletes; Lower Limb
... One of the most frequently used sprint training modalities is resisted sprints in which a load is pushed or pulled in a horizontal plane of motion (18). Studies have shown that resisted sprints may improve both acute physical outputs and efficiency of physical outputs to a greater degree than sprinting with no external load (35,83,99,100,103,116). ...
... Furthermore, athletes who perform fast sprint starts have a psychological advantage over their competitors, which can be significant in many races [10,11]. Given that sprinting performance, especially the sprint start, is a critical skill that underpins performance in many sports, there is a large amount of scientific literature on sprint training, such as plyometric intervention programs [12], resisted sled training [13,14], and lower-limb wearable resistance training [15]. ...
Article
Full-text available
Sprinting is often seen in a variety of sports. Focusing one’s attention externally before sprinting has been demonstrated to boost sprint performance. The present study aimed to systematically review previous findings on the impact of external focus (EF), in comparison to internal focus (IF), on sprint performance. A literature search was conducted in five electronic databases (APA PsycINFO, PubMed, Scopus, SPORTDiscus, and Web of Science). A random-effects model was used to pool Hedge’s g with 95% confidence intervals (CIs). The meta-analysis included six studies with a total of 10 effect sizes and 166 participants. In general, the EF condition outperformed the IF condition in sprint performance (g = 0.279, 95% CI [0.088, 0.470], p = 0.004). The subgroup analysis, which should be viewed with caution, suggested that the benefits associated with the EF strategy were significant in low-skill sprinters (g = 0.337, 95% CI [0.032, 0.642], p = 0.030) but not significant in high-skill sprinters (g = 0.246, 95% CI [−0.042, 0.533], p = 0.094), although no significant difference was seen between these subgroups (p = 0.670). The reported gain in sprint performance due to attentional focus has practical implications for coaches and athletes, as making tiny adjustments in verbal instructions can lead to significant behavioral effects of great importance in competitive sports.
... The research conducted by Cahill et al., (2020), who after 7 weeks of sprint training with sled dragging, used different loads with 5 % of body weight (low load), 12.5 % of body weight (medium load) and 20 % of body weight (high load). It was obtained as a result that only in the group that mobilized high load improved sprint times in the distance of 20 m, 30 m and 40 m. 30 m. and 40 m. ...
Preprint
Full-text available
El entrenamiento individualizado de carreras específicas con medios resistidos es una importante herramienta para la mejora de la velocidad. En virtud a la demanda de esta capacidad para el buen desempeño de los jugadores de béisbol, se re conoce como objetivo del presente estudio diseñar un entrenamiento de sprin t mediante el uso de trineo y paracaídas. Se planifica un cuasiexperimento, con dos grupos: control y experimental y en dos momentos: pre y postest. La etapa experimental se desarro lla durante la pretemporada, conformada por una muestra de diez sujetos con 20.84 años de edad y 79.82 kg. de peso promedio. Se emplearon como métodos teóricos el analíticosintético, inductivodeductivo, históricológico, sistémicoestructuralcomo empíricos el análisis de contenido, la observación, la medición. Para la medición de la velocidad lineal, las variables analizadas son el funcional y test máxima del trineo y de squat de 60 yardas y los test . Los resultados alcanzados indicaron mejoras de fuerza significativas en el grupo experimental en los tres test realizados, con % de incrementos iguales a 3.48, 7.25 y 7.46 % respectivamente. Además, se obtiene que existe una elevada correlación entre la fuerza máxima del trineo y la de squat con respecto al peso de rendimiento al esfuerzo de los atletas, con coeficientes de Pearson iguales a 63.6 % y 62.9 % respectivamente y para un 95 % de confianza. Se demuestra que el entrenamiento resistido nos proporciona información clave en la fase de velocidad máxima para la mejora del rendimiento de sprint en el béisbol.
... La investigación realizada por Cahill et al., (2020), quienes después de 7 semanas de entrenamiento de sprint con arrastre de trineo, utilizaron diferentes cargas con el 5 % del peso corporal (carga baja), 12.5 % del peso corporal (carga media) y el 20 % del peso corporal (carga alta). Se obtuvo como resultado que solo en el grupo que movilizaba carga alta mejoraba los tiempos de sprint en la distancia de 20 m., 30 m. y 40 m. ...
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Aims In the current study we investigated the effects of resisted sprint training on sprinting performance and underlying mechanical parameters (force-velocity-power profile) based on two different training protocols: (i) loads that represented maximum power output (Lopt) and a 50% decrease in maximum unresisted sprinting velocity and (ii) lighter loads that represented a 10% decrease in maximum unresisted sprinting velocity, as drawn from previous research (L10). Methods Soccer [n = 15 male] and rugby [n = 21; 9 male and 12 female] club-level athletes were individually assessed for horizontal force-velocity and load-velocity profiles using a battery of resisted sprints, sled or robotic resistance respectively. Athletes then performed a 12-session resisted (10 × 20-m; and pre- post-profiling) sprint training intervention following the L10 or Lopt protocol. Results Both L10 and Lopt training protocols had minor effects on sprinting performance (average of -1.4 to -2.3% split-times respectively), and provided trivial, small and unclear changes in mechanical sprinting parameters. Unexpectedly, Lopt impacted velocity dominant variables to a greater degree than L10 (trivial benefit in maximum velocity; small increase in slope of the force-velocity relationship), while L10 improved force and power dominant metrics (trivial benefit in maximal power; small benefit in maximal effectiveness of ground force orientation). Conclusions Both resisted-sprint training protocols were likely to improve performance after a short training intervention in already sprint trained athletes. However, widely varied individualised results indicated that adaptations may be dependent on pre-training force-velocity characteristics.
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The trainability of youths and the existence of periods of accelerated adaptation to training have become key subjects of debate in exercise science. The purpose of this meta-analysis was to characterise youth athletes' adaptability to sprint training across PRE-, MID-, and POST-peak height velocity (PHV) groups. Effect sizes were calculated as a measure of straight-line sprinting performance with studies qualifying based on the following criteria: (a) healthy male athletes who were engaged in organised sports; (b) groups of participants with a mean age between 10 and 18 years; (c) sprint training intervention duration between 4 and 16 weeks. Standardised mean differences showed sprint training to be moderately effective (Effect size=1.01, 95% confidence interval: 0.43-1.59) with adaptive responses being of large and moderate magnitude in the POST- (ES=1.39; 0.32-2.46) and MID- (ES=1.15; 0.40-1.9) PHV groups respectively. A negative effect size was found in the PRE group (ES=-0.18; -1.35-0.99). Youth training practitioners should prescribe sprint training modalities based on biological maturation status. Twice weekly training sessions should comprise up to 16 sprints of around 20 m with a work-to-rest ratio of 1:25 or greater than 90 s.