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Context: Plyometric training promotes a highly effective neuromuscular stimulus to improve running performance. Jumping rope (JR) involves mainly foot muscles and joints, due to the quick rebounds, and it might be considered a type of plyometric training for improving power and stiffness, some of the key factors for endurance-running performance. Purpose: To determine the effectiveness of JR during the warm-up routine of amateur endurance runners on jumping performance, reactivity, arch stiffness, and 3-km time-trial performance. Methods: Athletes were randomly assigned to an experimental (n = 51) or control (n = 45) group. Those from the control group were asked to maintain their training routines, while athletes from the experimental group had to modify their warm-up routines, including JR (2-4 sessions/wk, with a total time of 10-20 min/wk) for 10 weeks. Physical tests were performed before (pretest) and after (posttest) the intervention period and included jumping performance (countermovement-jump, squat-jump, and drop-jump tests), foot-arch stiffness, and 3-km time-trial performance. Reactive strength index (RSI) was calculated from a 30-cm drop jump. Results: The 2 × 2 analysis of variance showed significant pre-post differences in all dependent variables (P < .001) for the experimental group. No significant changes were reported in the control group (all P ≥ .05). Pearson correlation analysis revealed a significant relationship between Δ3-km time trial and ΔRSI (r = -.481; P < .001) and ΔStiffness (r = -.336; P < .01). The linear-regression analysis showed that Δ3-km time trial was associated with ΔRSI and ΔStiffness (R2 = .394; P < .001). Conclusions: Compared with a control warm-up routine prior to endurance-running training, 10 weeks (2-4 times/wk) of JR training, in place of 5 minutes of regular warm-up activities, was effective in improving 3-km time-trial performance, jumping ability, RSI, and arch stiffness in amateur endurance runners. Improvements in RSI and arch stiffness were associated with improvements in 3-km time-trial performance.
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Jump-Rope Training: Improved 3-km Time-Trial Performance
in Endurance Runners via Enhanced Lower-Limb Reactivity
and Foot-Arch Stiffness
Felipe García-Pinillos, Carlos Lago-Fuentes, Pedro A. Latorre-Román, Antonio Pantoja-Vallejo,
and Rodrigo Ramirez-Campillo
Context:Plyometric training promotes a highly effectiveneuromuscular stimulus to improve running performance.Jumping rope
(JR) involves mainly foot muscles and joints, due to the quick rebounds, and it might be considered a type of plyometric training
for improving power and stiffness, some of the key factors for endurance-running performance. Purpose:To determine the
effectiveness of JR during the warm-up routine of amateur endurance runners on jumping performance, reactivity, arch stiffness,
and 3-km time-trial performance. Methods:Athletes were randomly assigned to an experimental (n =51) or control (n =45) group.
Those from the control group were asked to maintain their training routines, while athletes from the experimental group had to
modify their warm-up routines, including JR (24 sessions/wk, with a total time of 1020 min/wk) for 10 weeks. Physical tests
were performed before (pretest) and after (posttest) the intervention period and included jumping performance (countermovement-
jump, squat-jump, and drop-jump tests), foot-arch stiffness, and 3-km time-trial performance. Reactive strength index (RSI) was
calculated from a 30-cm drop jump. Results:The 2 ×2 analysis of variance showed signicant prepost differences in all
dependent variables (P<.001) for the experimental group. No signicant changes were reported in the control group (all P.05).
Pearson correlation analysis revealed a signicant relationship between Δ3-km time trial and ΔRSI (r=.481; P<.001) and
ΔStiffness (r=.336; P<.01). The linear-regression analysis showed that Δ3-km time trial was associated with ΔRSI and
ΔStiffness (R
2
=.394; P<.001). Conclusions:Compared with a control warm-up routine prior to endurance-running training,
10 weeks (24 times/wk) of JR training, in place of 5 minutes of regular warm-up activities, was effective in improving 3-km
time-trial performance, jumping ability, RSI, and arch stiffness in amateur endurance runners. Improvements in RSI and arch
stiffness were associated with improvements in 3-km time-trial performance.
Keywords:rope jumping, running, plyometric exercises, resistance training, stretch reex
The importance of resistance training (RT) for endurance
runners has been extensively demonstrated in the last decade.
1
This has 2 main goals: maximizing athletic performance (eg,
running economy [RE] or velocity at VO
2
max [vVO
2
max]) and
minimizing the risk of injury.
2
Specically, RT focused on neural
adaptations has been shown as one of the most efcient strategies
for improving sport performance in athletes.
3
The benets of RT
include improvements also in RE (from 3.0% to 8.1%) through
different mechanisms, such as changes in mechanical efciency,
muscle coordination, or motor recruitment patterns.
1,4
Finally,
these adaptations affect positively to athletic performance, with
some previous studies
46
reporting improvements in 3- to 5-km
runs after a protocolized RT program. However, endurance runners
still doubt about the advantages of RT
4
and still think more is
betterby accumulating greater running volumes per week.
7
Some
reasons for not including RT in their trainings might be the fear of
interference effects, the lack of knowledge, time, equipment and
facilities, or enjoyment.
4
One of the most frequently studied types of RT in endurance
runners is plyometric training (PT), with or without external loads.
4
This type of training promotes a highly effective neuromuscular
stimulus. Whereas a traditional heavy RT program induces neural
and hypertrophic adaptations, leading to a dilution of the mito-
chondrial volume density, PT may lead preferentially to adapta-
tions like increased rate of activation of motor units
8,9
with the
advantage of requiring reduced physical space, time, and equip-
ment to complete the training sessions.
7
Furthermore, it produces
improvements in running performance and RE.
4
For instance,
Berryman et al
3
compared PT with dynamic weight training in
runners, showing that the former induced a higher efciency in the
energy cost of running. This can be explained because of improve-
ments in motor unit recruitment and synchronization after PT.
4
However, these PT protocols have shown some limitations such
as not related with running technique (box jumps), an elevated
volume (ie, 2000 jumps in 6 wk), low number of participants, poor
description of PT protocols, among others.
10
That is, PT can be a
good type of training for endurance runners compared with other
traditional RT, but coaches should be cautious about the afore-
mentioned considerations.
Jumping rope (JR) is a consecutive jump exercise with turning
the rope, involving mainly foot muscles and joints, due to the quick
rebounds.
11
Therefore, JR might be considered a type of PT for
improving power and stiffness, some of the key factors for
García-Pinillos is with the Dept of Physical Education, Sports and Recreation,
University of La Frontera, Temuco, Chile. Lago-Fuentes is with the Faculty of
Education and Sport Sciences, University of Vigo, Pontevedra, Spain, and the
Faculty of Health Sciences, European University of the Atlantic, Santander, Spain.
Latorre-Román is with the Dept of Corporal Expression, and Pantoja-Vallejo, the
Dept of Pedagogy, University of Jaén, Jaén, Spain. Ramirez-Campillo is with the
Laboratory of Human Performance, Quality of Life and Wellness Research Group,
Dept of Physical Activity Sciences, University of Los Lagos, Osorno, Chile.
Ramirez-Campillo (r.ramirez@ulagos.cl) is corresponding author.
1
International Journal of Sports Physiology and Performance, (Ahead of Print)
https://doi.org/10.1123/ijspp.2019-0529
© 2020 Human Kinetics, Inc. ORIGINAL INVESTIGATION
endurance running performance.
4
Furthermore, the rope enables to
combine PT with running technique (eg, skipping, dynamic rope
jumping, unilateral jumps),
12
reducing the time to achieve both
goals, with a high level of adherence and enjoyment
13
that can be
used during warm-ups. Therefore, it seems that, compared with
other types of PT as box or hurdle jumps, JR can improve the
athletic performance on endurance runners with low-cost invest-
ments and time efciency.
However, there are few research reports that focus on the
effects of including JR in the warm-up routines of training ses-
sions.
7,11
For instance, besides the positive effects of PT on
endurance runners,
1,4,14
more than 70% of amateur endurance
runners included only continuous run during warm-ups, using
low-intensity running as the most common strategy.
7
Related to
this, running exposure has been strongly correlated with overuse
injuries in endurance runners.
15
Taking this context into account,
low-time cost strategies to improve stiffness and performance have
the potential to be included during warm-ups.
To the authorsknowledge, there are no studies focused
on analyzing the effects of a PT warm-up protocol on amateur
endurance runners. Furthermore, no previous studies exist about
including low-cost strategies to improve athletic performance in
endurance runners. For these reasons, the aim of this study is to
determine the effectiveness of incorporating JR during the warm-
up routine of amateur endurance runners on jumping performance,
reactivity, arch stiffness, and 3-km time-trial performance.
Methods
Subjects
A total of 96 amateur endurance runners (51 males and 45 females;
age range: 1840 y) successfully completed the study (Table 1).
Participants met the following inclusion criteria: (1) should be 18
years and older; (2) able to run 10 km in less than 50 minutes;
(3) recreationally trained (35 running sessions per week); (4) not
to be involved in any RT program, including PT; and (5) have not
suffered from any injury within the last 6 months before data
collection. Initially, 105 participants who fullled the inclusion
criteria were selected to participate in this study. To be included in
the nal analyses, each participant needed to complete the training
program and attend prepost assessments. Related to these strict
requirements, 9 participants were excluded from data analysis
(N =96; Figure 1). Participants were randomly assigned to the
experimental group (EG; n =51, women =24) or the control group
(CG; n =45, women =21). A research assistant who was not
involved in the data collection, using random numbers generated
in Microsoft Excel 2016, conducted randomization independently.
After receiving detailed information on the objectives and proce-
dures of the study, each participant signed an informed consent
form, which complied with the ethical standards of the latest
version of the World Medical Associations Declaration of
Helsinki (2013); it was made clear that the participants were
free to leave the study if they were unt. The University of Jaéns
Ethics Committee approved the study.
Design
The study was conducted between January and April 2019. Using a
between-group design (EG and CG), 96 athletes were assessed.
Testing was completed at week 0 (pre) and at week 11 (post) to
monitor changes over the course of a 10-week training program.
Thus, physical tests were performed before (pretest) and after
(posttest) the 10-week intervention period.
Athletes from the CG were asked to maintain their training
routines, whereas athletes from the EG modied their warm-up
routines, but maintained their running routines (see Table 2for
more information about training background of both EG and CG).
Training
Athletes from the EG included JR during their warm-up routines
(ie, just after the running-based exercises in the warm-up, 24
sessions per week, with a total time of 1020 min/wk) for 10
weeks. Since athletes replaced 5 minutes of their habitual warm-
up routines with JR drills, 2 to 4 times per week, the current JR
training was easily incorporated into the regular training sche-
dules of the participants. Before starting the training program
(week 0), the EG participants were instructed with technical key
points about JR. These included (1) rope rotation should be gener-
ated by the wrists with minimal movement of the elbows and
shoulders, (2) jump height should be maximized and ground contact
time should be minimized, and (3) landing should be softened on the
forefoot and with the knees slightly exed. More details about the
10-week JR training program can be checked in Table 3.The
participants from the CG maintained their training plans, whereas
the athletes from EG just changed the content of the warm-up
routines, with no other changes in their training program.
Methodology
The athletes were instructed to refrain from intense exercise
(ie, score of 15 in the rating of perceived exertion scale of
620) 2 days preceding testing (weeks 0 and 11, pretest and
posttest, respectively). Testing sessions were conducted 3 to 4
days before starting the intervention and 3 to 4 days after nishing
it (pretest and posttest, respectively). They were not allowed to eat
during the hour preceding the test or to consume coffee or other
products containing caffeine during the preceding 3 hours. Pre-
testing and posttesting were conducted at the same time of the day
to avoid the inuence of the circadian rhythm and under similar
environmental conditions (20°C24°C).
Either at pretest or posttest, athletes were tested individually, and
participation involved the execution of 3-km time trial on an outdoor
400-m synthetic track. The elapsed time (in seconds) for the 3-km
running was registered for the subsequent analysis. The only instruc-
tion given to participants was to nishtheraceasfastastheycould.
Before starting the running trial, body height (in centimeters)
and body mass (in kilograms) were determined using a precision
stadiometer and mechanical scale (Seca 222 and 634, respectively;
Seca Corp, Hamburg, Germany). All measurements were taken
with the participants wearing underwear. Also, the arch height and
the arch stiffness of the right foot were assessed. Arch height
Table 1 Descriptive Characteristics of the Participants
Variable EG (n =51) CG (n =45) P
a
Age, y 27.2 (8.6) 26.1 (6.3) .467
Height, m 1.72 (0.1) 1.71 (0.1) .790
Body mass, kg 66.0 (10.4) 65.7 (9.1) .852
BMI, kg/m
2
22.3 (2.0) 21.9 (2.2) .472
Abbreviations: BMI, body mass index; CG, control group; EG, experimental
group. Note: Data are presented as mean (SD).
a
Chi-square test was conducted.
(Ahead of Print)
2García-Pinillos et al
was dened as the height of the dorsum of the foot normalized to
truncated foot length. Truncated foot length was dened as the length
of the foot from the heel cup (most posterior portion of the calcaneus)
to the center of the medial joint space of the rst metatarsal
phalangeal joint.
16
Arch stiffness, a measure of the amount of
deformation per unit of load, was dened as the change in arch
height index (AHI) due to the increase in load between sitting and
standing conditions. Measurements were taken by a single
Figure 1 CONSORT diagram of the full recruitment and randomization process.
Table 2 Characteristics of the Training Plans of the Participants During 2 Periods
a
Variable EG (n =51) CG (n =45) P
10 wk before intervention
Number of running sessions per week 4.0 (0.7) 4.1 (0.4) .772
Running volume,
b
km/wk 41.3 (5.1) 42.4 (6.9) .373
Running volume,
b
h/wk 4.6 (1.3) 4.7 (1.3) .801
10 wk of intervention
Number of running sessions per week 4.2 (0.6) 4.4 (0.5) .690
Running volume,
b
km/wk 42.1 (6.5) 40.5 (5.6) .493
Running volume,
b
h/wk 4.8 (1.1) 4.5 (1.2) .352
Abbreviations: CG, control group; EG, experimental group.
a
Two periods: (1) 10 weeks before starting the intervention and (2) 10 weeks of intervention.
b
Warm-up and cooldown
routines are included.
Table 3 Jump-Rope Training Program
Weeks
Sessions
per week
Time per
session, min
Work:rest
ratio, s
Cadence,
rpm Type
Total weekly
time, min
12 2 5 30:30 100120 Bilateral 10
34 3 5 30:30 100120 Bilateral 15
56 3 5 30:30 120140 Unilateralalternating 15
78 4 5 30:30 120140 Unilateralalternating 20
910 4 5 40:20 12014 Unilateralalternating 20
(Ahead of Print)
Jump-Rope Training in Endurance Runners 3
investigator using the AHI Measurement System.
16
Butler et al
16
reported high intrarater and interrater reliability. Participants were
asked to sit in a height-adjustable chair. Then, the chair was adjusted
to keep knees and hips under a 90° alignment and with slight contact
between plantar foot surface and the measurement platform. A
specially designed platform for undertaking this measurement was
used.
17
The dorsum of the foot at 50% of total foot length was
measured with a digital caliper. The total foot length was considered
from the most posterior aspect of the calcaneus xed at a heel cup to
the most distal aspect of the longest toe. It was repeated in a bipedal
stance position assuming body weight. Both feet were xed in the
heel cups positioned 15 cm apart. The dorsal arch height difference
was calculated as the difference between dorsal arch in bipedal
standing and in sitting position, known as sit-to-stand difference,
whereas the AHI was calculated as follows
18
:
AHI =Dorsum height=Truncated foot length (1)
Based on a previous study,
19
the arch stiffness was calculated by
assuming a 40% change in load between seating and standing
conditions (that value of change reected the difference between
half the body weight and the weight of the foot +shank) as follows:
Arch stiffness =ð0.40 ×Body massÞ=ðAHI ½seated
AHI ½standingÞ (2)
The average of 3 repeated measurements was computed and used for
subsequent analysis. The static foot posture and foot mobility
measures have reported moderate to good intrarater reliability (in-
traclass correlation coefcient =.81.99) and moderate to good
interrater reliability (intraclass correlation coefcient =.58.99),
respectively.
17,18
After anthropometric and foot measurements, at both pretest
and posttest, the participants performed a standardized warm-up
(ie, mobility, continuous low-intensity running, jumping, and
sprinting bouts) and a battery of jumping tests (squat jump [SJ],
countermovement jump [CMJ], and 30-cm drop jumps [DJ30]).
The participants were unexperienced athletes in terms of plyomet-
ric drills and jumping test. To make sure the execution was correct,
2 familiarization sessions were carried out during the previous
week before testing. The SJ, CMJ, and DJ30 tests were recorded
using the OptoGait system (Microgate, Bolzano, Italy), which has
been previously used in a similar study.
20
This device measures the
contact time on the oor and the ight time using photoelectric
cells. Flight time was used to calculate the height of the rise using
the bodys center of gravity. Athletes performed 2 trials of every
test, with a 15-second recovery period between them, with the best
trial being used for the statistical analysis. As described by a
previous study,
21
during SJ, participants were instructed to adopt
aexed knee position (approximately 90°) during 3 seconds before
jumping, whereas during CMJ, no restriction was imposed over the
knee angle achieved before jumping. Jumping tests were executed
with arms akimbo. Takeoff and landing were standardized to full
knee and ankle extension on the same spot. The participants were
instructed to maximize jump height. For the DJ30, participants
were instructed to maximize jump height and minimize ground
contact time after dropping down from a 30-cm drop box.
22
Reactive strength index (RSI) was calculated as follows:
RSI =Flight time ðmsÞ=Contact time ðmsÞ(3)
Statistical Analysis
Data are presented as group mean values (SDs). After data normality
assumption was veried with the Levene test, analyses of variance
were used to detect differences between study groups in all variables
at pretest and posttest. Measures of dependent variables were
analyzed in separate 2 (groups) ×2 (time [pre, post]) analyses of
variance with repeated measures on time, with Bonferroni-adjusted
α. The magnitude of the differences between values was also
interpreted using the Cohen deffect size (ES) (between-group
differences). ESs are reported as follows: trivial (<0.2), small
(0.20.49), medium (0.50.79), and large (0.8). A Pearson corre-
lation analysis was conducted between changes (Δ; eg, 3-km time
trial at pretest minus 3-km time trial at posttest) experienced in
athletic performance, RSI, and stiffness. Finally, a simple linear
regression analysis was used to determine the association between
the improvement in the 3-km test (dependent variable: Δ3-km time
trial) and the improvements in RSI and arch stiffness (independent
variables: ΔRSI and ΔStiffness) during the intervention. Data anal-
ysis was performed using the SPSS software (version 21; SPSS Inc,
Chicago, IL). Signicance levels were set at α=5%.
Results
No signicant between-group differences (P.05) were found in
age, anthropometric characteristics, and sex distribution at baseline
(before training intervention; Table 1). Table 2presents the char-
acteristics of training plans of athletes from both CG and EG before
starting the 10-week intervention period and during that period, and
no signicant between-group differences were found (all Ps.05).
The effects of the intervention on dependent variables are
displayed in Table 4. The main group ×time effect revealed signi-
cant differences in all variables (P<.001). The post hoc analysis
showed signicant differences in all variables (all Ps<.001, small
ES [arch stiffness, SJ, and 3-km time trial] and moderate ES [CMJ,
DJ30 cm, and RSI]) for the EG, whereas no signicant changes
were reported in the CG (all Ps.05, trivial ES).
A Pearson correlation analysis revealed signicant relation-
ship between Δ3-km time trial and ΔRSI (r=.481; P<.001) and
ΔStiffness (r=.336; P<.01). The linear regression analysis
showed that Δ3-km time trial was associated with ΔRSI and
ΔStiffness (R
2
=.394; P<.001).
Discussion
The aim of this study was to determine the effectiveness of a 10-
week JR training program, incorporated into the warm-up routines
of amateur endurance runners, on jumping performance, reactivity,
arch stiffness, and 3-km time-trial performance. The main ndings
indicate that JR training was effective for the improvement of
jumping performance, reactivity, arch stiffness, and 3-km time-trial
performance. Although previous studies incorporated JR training
as a strategy to improve the physical tness of athletes,
11,23
to our
knowledge, this is the rst study to analyze the effects of a JR
training approach in endurance runners. Moreover, the current JR
training approach incorporated an ecological-valid (practical)
approach. In this sense, athletes replaced 5 minutes of their habitual
warm-up routines with JR drills. In addition, the replacement was
applied only 2 to 4 times per week. Therefore, the current JR
training approach was easily incorporated into the regular training
schedules of the participants.
(Ahead of Print)
4García-Pinillos et al
One of the main ndings from the current intervention was the
signicantly greater improvement of 3-km time-trial performance
in the JR training group (3%, ES =0.4) compared with the CG
(1.5%, ES =0.1). Such improvement has been previously reported
in endurance runners, from different tness levels, after PT inter-
ventions
1
and may be related to adaptations in several physiologi-
cal and biomechanical determinants of endurance running
performance,
24
with the most relevant being probably RE.
1
In
fact, improvements in RE have been associated with increased RSI
and stiffness,
1,14
which is in line with the results obtained in the
current study (ie, Δ3-km time trial was signicantly associated with
ΔRSI and ΔStiffness). Although improvements in neuromuscular
factors presumably mediated the improvement in the 3-km time-
trial performance, the high jumping frequency involved in the
current JR training intervention may have also induced an impor-
tant cardioventilatory stimulation (eg, 90% of VO
2
max),
25
with a
potential positive impact on vVO
2
max.
26
Future studies may
elucidate if high-frequency JR training, such as the one applied
in this intervention, may contribute to improvements in cardio-
ventilatory parameters (eg, VO
2
max, VO
2
peak, or vVO
2
max).
The relationship between jumping performance and running
endurance performance has been previously established.
27
In this
regard, an important nding in the current study was the greater
increase of explosive strength performance requiring slow stretch-
shortening cycle (SSC) action (ie, CMJ) and fast SSC action
(ie, DJ30) in the JR training group compared with the CG.
Improved reactivity (ie, DJ30) may be related to increased neural
drive to the agonist muscles, improved intermuscular coordination,
changes in muscle size and/or architecture, changes in single-ber
mechanics, among others.
5
Such improvements may reduce the
time the athletes foot spends in contact with the ground during
running,
5
favorably affecting performance during running endur-
ance events.
Another nding from this study was the signicantly greater
improvement of arch stiffness in the JR training group (7.8%)
compared with the CG (0.1%). Such improvement is similar to the
one previously reported for endurance runners after PT.
6
Improve-
ments in stiffness at the muscle ber level may occur mainly on
fast-twitch bers.
28
It may be possible that endurance runners, who
usually have a relatively more developed slow-twitch ber pheno-
type,
24
had greater ceiling for improvements in their fast-twitch
bers.
29
Although improvements in stiffness have been observed in
previous PT studies, including endurance runners,
6
others have
found mixed ndings
28
or not such an improvement.
28,30
Part of the
disagreement among studies might be related with the assessment
technique and the structures assessed. Whereas the current work
evaluated arch stiffness, dened as the change in AHI due to the
increase in load between sitting and standing conditions, Spurrs
et al
6
obtained musculotendinous stiffness of the lower limb
through the oscillation technique by performing an isometric
contraction on an instrumented seated calf raise machine. Likewise,
Fouré et al
28
focused on passive stiffness of the gastrocnemii
dened as the slope of the lengthtension relationship for the
common range of gastrocnemii length. In this regard, current
results suggest that the assessment of arch stiffness may be a
sensitive measurement technique for stiffness changes in endur-
ance runners.
It seems logical that those improvements in jumping ability
and arch stiffness are linked to improvements in reactivity (ie, RSI
in the current work). Previous studies have revealed a strong
association between those parameters and running perfor-
mance.
31,32
Current results demonstrated that the JR training group
improved the RSI (13%) when compared with the CG. This index
denotes that per each unit of time the foot is on the ground, greater
jump height (ight time) is achieved, an indirect marker of greater
rate of force development. Additionally, the linear regression
analysis showed that Δ3-km time trial was associated with ΔRSI
and ΔStiffness (R
2
=.394; P<.001), which reinforces the associa-
tion between lower body stiffness and reactivity with athletic
performance in endurance runners.
Of note, the improvements in jumping performance in the JR
training group were achieved after an intervention with a focus
on jump repetitions with short contact time. In this context, it is
tempting to speculate that the time the athletes foot spends in
contact with the ground during jumps can modulate training-related
adaptations in endurance runners. However, this should be tested in
future studies comparing interventions with different contact times
during the jumps.
Table 4 Effects of a 10-Week Jump-Rope Training Program on Arch Stiffness, Jumping, and 3-km Time-Trial
Performance of Amateur Endurance Runners
Variable Groups
Pretest,
mean (SD)
Posttest,
mean (SD)
Post pre
(Δ,%)
P
(group ×time)
Bonferroni post
hoc P(Cohen d)
Arch stiffness
(body mass/AHI units)
EG (n =49) 925.5 (388.7) 997.95 (373.17) 72.4 (7.8) <.001 <.001 (0.23)
CG (n =45) 947.7 (418.8) 949.01 (427.31) 1.33 (0.1) .944 (0.01)
CMJ, cm EG (n =47) 28.59 (5.79) 31.59 (6.01) 3.0 (10.5) <.001 <.001 (0.52)
CG (n =44) 29.46 (7.15) 29.30 (7.07) 0.2 (0.5) .165 (0.01)
Squat jump, cm EG (n =47) 23.72 (3.90) 25.08 (3.76) 1.4 (5.7) <.001 <.001 (0.41)
CG (n =44) 24.75 (5.70) 24.66 (4.35) 0.1 (0.4) .525 (0.02)
DJ30, cm EG (n =47) 25.40 (3.47) 26.84 (3.18) 1.4 (5.7) <.001 <.001 (0.54)
CG (n =44) 26.65 (4.96) 26.76 (4.58) 0.1 (0.4) .193 (0.02)
RSI, ms/ms EG (n =47) 1.92 (0.45) 2.17 (0.42) 0.3 (13.0) <.001 <.001 (0.62)
CG (n =44) 1.91 (0.41) 1.92 (0.41) 0.01 (0.5) .280 (0.03)
3-km time trial, s EG (n =44) 774.6 (79.5) 751.7 (65.8) 22.9 (3.0) <.001 <.001 (0.44)
CG (n =42) 762.1 (87.5) 750.8 (83.6) 11.3 (1.5) .136 (0.12)
Abbreviations: AHI, arch height index; CMJ, countermovement jump; DJ30, 30-cm drop jumps; RSI, reactive strength index.
(Ahead of Print)
Jump-Rope Training in Endurance Runners 5
Practical Applications
The replacement of 5 minutes of regular warm-up routines, 2 to
4 times per week, with JR training drills might be an effective and
safe resource to incorporate into the training schedule of amateur
endurance runners as a time-efcient strategy to improve several
proxies associated with endurance running performance, such as
jumping, RSI, stiffness and, mostly, 3-km time trial. Moreover,
JR training drills are probably related to lower mechanical stress
than other plyometric exercises like drop jumps performed from
high heights. This may help to preservethe musculoskeletal
system from excessive loading, especially before habitual running
sessions.
Conclusions
When compared with a control warm-up routine previous to
endurance running, 10 weeks (24 times per week) of JR training,
in replacement of 5 minutes of regular warm-up activities, was
effective in improving 3-km time-trial performance, jumping
ability involving concentric (SJ), slow SSC (CMJ), fast SSC
(DJ30), RSI, and arch stiffness in amateur endurance runners.
Moreover, improvements in RSI and arch stiffness were associated
with improvements in 3-km time-trial performance.
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Jump-Rope Training in Endurance Runners 7
... The role played by the foot is essential in running since it is the ultimate part of the body in contact with the ground. It has been suggested that stronger foot muscles lead to a stiffer longitudinal arch [8] which is associated with increased running performance [9]. ...
... Therefore, as heightened arch stiffness has been associated with better distance running performance [9], the role of the LLS and SSC related to the use of elastic energy [3,4], as well as the relationship of both Kvert and Kleg with running performance [3,37] [9] in habitually shod runners. The similarity of the results between the present study and the two aforementioned studies relies on the same methods to evaluate arch stiffness and the very similar individual characteristics of the participants. ...
... Therefore, as heightened arch stiffness has been associated with better distance running performance [9], the role of the LLS and SSC related to the use of elastic energy [3,4], as well as the relationship of both Kvert and Kleg with running performance [3,37] [9] in habitually shod runners. The similarity of the results between the present study and the two aforementioned studies relies on the same methods to evaluate arch stiffness and the very similar individual characteristics of the participants. ...
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... produce and transmit high amounts of muscular force to the ground (running) [49] rather than improved ability to recover between sprints (e.g., aerobic fitness) [22]. Enhanced aerobic fitness, such as Yo-Yo test distance [98,103,104] and time-trial running performance [47,105,106], were observed after PJT. Nonetheless, such physical performance improvements were probably more directly associated with neuro-mechanical factors [68,107,108] than with increased VO2max [109][110][111]. ...
... Using a jumping interval training approach in amateur endurance runners, meaningful improvements in VO2 peak (9.1%; ES = 1.28) and neuromechanical outcomes (i.e., jump height; rate of torque development) occurred [46]. Similar findings were recently reported after a jump rope-based intervention involving endurance runners [106]. Such PJT approaches, although not intensity-dominant, involve a high volume of jumps. ...
... Of note, improvements in RSA after PJT typically occurred after high (e.g., 1284-1600) [52][53][54] compared to low (e.g., 564-722) [50,51] total number of jump repetitions. Pending confirmatory research, PJT interventions including drills with high jumping frequency (i.e., one jump every 0.6 s) [116] and short inter-set resting intervals (e.g., 15-30 s) might serve the purpose of concomitant improvements in neuro-mechanical and cardiorespiratory functions [46,47,106]. Such an effect may potentially translate to greater PJTinduced improvements in RSA. ...
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... Reliability and validity of its measurement in adolescents through the maximum hopping test has been proven [40] and has recently been recommended for development as part of the strength training of athletes, especially in women [41]. In addition, the increase in reactive strength index has been linked to performance improvements in middle-distance running [42]. ...
... Although the influence of neuromuscular factors on performance in endurance athletes seems clear [5,28,29,35,42], current findings suggest that combined training of neuromuscular performance and endurance does not produce changes in step length and frequency during running at the constant submaximal speed [62]. Roche-Seruendo et al. [43] also measured the neuromuscular performance of amateur adult runners by jumping capacity, finding a lack of influence of the neuromuscular performance on spatiotemporal adaptations produced during the increase in running speed. ...
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... Concurrent development in agility, coordination, balance, and reaction can be achieved by means of variations in rope swing, skipping drills, movement directions, and stepping rhythms (Orhan, 2013;Partavi, 2013;Eler and Acar, 2018;Yang et al., 2020). In addition, the quick stretch-shortening cycle contractions during repetitive jumps indicate the characteristics of plyometric training which has been proved effective in improving speed and jump performance (Miyaguchi et al., 2014;García-Pinillos et al., 2020). It is worth noting the limited effects of jump rope exercise on flexibility. ...
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... Similarly, recreationally endurance runners showed no improvement in jump performance, rate of force development or running velocity at VO2max (Taipale et al., 2010). Conversely, significant improvements in jumping, sprinting and time-trial performance have also been reported (Andrade et al., 2018;García-Pinillos, Lago-Fuentes, Latorre-Román, Pantoja-Vallejo, & Ramirez-Campillo, 2020;Ramirez-Campillo et al., 2014) with such contrasting findings possibly related to factors such as loading characteristics of JT interventions (e.g., duration, intensity, frequency) and participants' characteristics (e.g., initial fitness level, previous strength training experience) (Ramirez-Campillo, Alvarez, Garcia-Hermoso, et al., 2018; Ramirez-Campillo, . One additional limitation in studies exploring the effects of JT interventions is their overall small sample size. ...
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... Stiffness has been proposed as the key mechanical parameter for the spring-mass model [11,12]. It represents the capacity of the lower extremity as a whole to alleviate the excessive forces produced during the running stance phase [13,14]. When decreased stiffness is present, the system becomes too compliant, which might cause both overuse and overload of the structures involved in the force attenuation phase. ...
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... There are some limitations to the current study so our results should be interpreted with caution. Just two studies (64,65) in this meta-analysis were conducted in female participants meaning the results' applicability to that population is undermined, particularly as these studies included mixed male/female samples. Also, because stiffness is measured and represented in studies in a number of different ways, it is not yet possible to conclude if the positive increases we report can be attributed to changes in muscle activity, mechanical properties of the MTU or a combination of both. ...
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Objectives: To examine the effects of plyometric jump training (PJT) on lower limb stiffness. Methods: Systematic searches were conducted in PubMed, Web of Science, and SCOPUS. Studies included healthy males and females who undertook a plyometric jump training programme, isolated from any other training type. Results: There was a small effect size (ES) of PJT on lower limb stiffness (0.33 [0.07, 0.60], Z = 2.47, p = 0.01). Untrained individuals exhibited a larger ES (0.46 [0.08, 0.84], p = 0.02) than trained (0.15 [-0.23, 0.53], p = 0.45). Those interventions with a greater number of weeks (>7 weeks) had a larger ES (0.47 [0.06, 0.88], p = 0.03) than those with fewer weeks (0.22 [-0.12, 0.55], p = 0.2). Two sessions or fewer per week exhibited a larger ES (0.39 [0.01, 0.77], p = 0.04) than programmes which incorporated more than two sessions (0.20 [-0.10, 0.50], p = 0.18). Fewer than 250 jumps per week (0.50 [0.02, 0.97], p = 0.04) showed a larger ES than 250 to 500 jumps (0.36 [0.00, 0.72], p = 0.05) which, in turn, was larger than the negative ES for more than 500 jumps per week (-0.22 [-1.10, 0.67], p = 0.63). More than 7.5 jumps per set showed a larger effect size (0.55 [0.02, 1.08], p = 0.04) than fewer than 7.5 jumps (0.32 [0.01, 0.62], p = 0.04). Conclusions: PJT enhances lower body stiffness which can be optimised with lower volumes (<250 jumps per week) over a relatively long period of time (>7 weeks).
... Short ground CTs (,0.2 seconds) should be prioritized for plyometric exercises because they resemble competitive endurance running CTs (56,85), promote fast SSC sequences, and enhance musculotendinous stiffness (56,116,140,145). The high intensity of plyometric training is well known among coaches; thus, activities such as jump-rope training exercises could be a good way to scaffold this workload (52). Foot strength training positively affects the muscles involved in the foot core and the longitudinal arch that stiffens the foot when loading, allowing its propulsive lever function during running (130). ...
Article
Researching running spatiotemporal parameters has deepened knowledge of the spring-mass model and its capacity to estimate and predict kinetic and kinematic variables. However , although the impact of lower-limb stiffness on athletic performance seems considerable, recognition of lower-limb stiffness among coaches and practitioners remains sparse. This review highlights factors influencing lower-limb stiffness during running and their relationship to injury prevention and performance. Current knowledge of lower-body stiffness during running is integrated and new scientific scope offered. Because the different variables are correlational, it is strongly recommended not to measure their effects on lower-limb stiffness individually. The spring-mass model behavior when altering variables such as footwear or foot-strike pattern needs cautious examination. Although both stretch-shortening cycle and lower-limb stiffness are key parameters in elastic strain energy storage and release during sport activities, hormonal fluctuations (particularly associated with the menstrual cycle) should draw special attention because they affect musculotendinous stiffness properties and therefore may influence athletic performance and injury prevalence. Introducing lower-limb strength training would improve the characteristics of stiffness in running, contributing to maximized performance and reduced injury risk.
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The major purpose of this study was to examine the effects of a jump rope-based physical activity afterschool program on middle school students’ physical fitness. Sixty students (Mage = 13.37, SD = 0.58; 53.3% female) participated in a 12-week jump rope-based afterschool program (45 min/time, three times/week). Participants were randomly assigned to three groups: (a) freestyle rope skipping (N = 20), traditional jump rope (N = 20), and a control group (N = 20). Physical fitness tests, including muscular strength (standing long jump, right-hand grip, and left-hand grip), flexibility, body composition, and bone mineral density (BMD) were measured in pre- and post-tests. A 2 (time) × 3 (groups) repeated measure multivariate analysis of variance (MANOVA) was performed. The results found significant improvements in muscular strength (standing long jump, right-hand grip, and left-hand grip) in both intervention groups (p < 0.001; ds = 0.2–0.44). Only the freestyle rope skipping group had increased BMD (p < 0.05, d = 0.33). Compared to the traditional jump rope, the freestyle rope skipping group showed significantly higher improvement in flexibility (p < 0.05, d = 0.83). These findings suggest that the jump rope-based afterschool program with freestyle rope skipping would be more effective than traditional jump rope to promote physical fitness performance among adolescents.
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Context: Drop jumps and high-intensity interval running are relevant training methods to improve explosiveness and endurance performance, respectively. Combined training effects might, however, be achieved by performing interval drop jumping. Purpose: To determine the acute effects of interval drop jumping on oxygen uptake (V̇O2)-index of cardioventilatory/oxidative stimulation level, and peripheral fatigue-a limiting factor of explosiveness. Methods: Thirteen participants performed three 11-min interval-training sessions during which they ran 15 s at 120% of the velocity that elicited maximal V̇O2 (V̇O2-MAX) (ITRUN) or drop-jumped at 7 (ITDJ7) or 9 (ITDJ9) jumps per 15 s, interspersed with 15 s of passive recovery. V̇O2 and the time spent above 90% of V̇O2-MAX (TV̇O2-MAX) were collected. Peripheral fatigue was quantified via preexercise to postexercise changes in evoked potentiated quadriceps twitch (ΔQT). Power output was estimated during ITDJs using optical sensors. Results: All participants reached 90% of V̇O2-MAX or higher during ITRUN and ITDJ9, but only 11 did during ITDJ7. TV̇O2-MAX was not different between ITRUN and ITDJ9 (145±76 vs 141 ± 151 s; P = .92) but was reduced during ITDJ7 (28 ± 26 s; P = .002). Mean ΔQT in ITDJ9 and ITDJ7 were not different (-17% ± 9% vs -14% ± 8%; P = .73) and greater than in ITRUN (-8% ± 7%; P = .001). No alteration in power output was found during ITDJs (37±10 W.kg-1). Conclusion: Interval drop jumping at a high work rate stimulated the cardioventilatory and oxidative systems to the same extent as interval running, while the exercise-induced increase in fatigue did not compromise drop-jump performance. Interval drop jumping might be a relevant strategy to get concomitant improvements in endurance and explosive performance.
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