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Eccentric cycling does not improve cycling performance in amateur cyclists

Authors:
  • The Norwegian School of Sport Sciences, Oslo, Norway

Abstract

Eccentric cycling training induces muscle hypertrophy and increases joint power output in non-athletes. Moreover, eccentric cycling can be considered a movement-specific type of strength training for cyclists, but it is hitherto unknown if eccentric cycling training can improve cycling performance in trained cyclists. Twenty-three male amateur cyclists were randomized to an eccentric or a concentric cycling training group. The eccentric cycling was performed at a low cadence (~40 revolution per minute) and the intensity was controlled by perceived effort (12–17 on the Borgs scale) during 2 min intervals (repeated 5–8 times). The cadence and perceived effort of the concentric group matched those of the eccentric group. Additionally, after the eccentric or concentric cycling, both groups performed traditionally aerobic intervals with freely chosen cadence in the same session (4–5 x 4–15 min). The participants trained twice a week for 10 weeks. Maximal oxygen uptake (VO2max), maximal aerobic power output (Wmax), lactate threshold, isokinetic strength, muscle thickness, pedaling characteristics and cycling performance (6- and 30-sec sprints and a 20-min time trial test) were assessed before and after the intervention period. Inferences about the true value of the effects were evaluated using probabilistic magnitude-based inferences. Eccentric cycling induced muscle hypertrophy (2.3 ± 2.5% more than concentric) and augmented eccentric strength (8.8 ± 5.9% more than concentric), but these small magnitude effects seemed not to transfer into improvements in the physiological assessments or cycling performance. On the contrary, the eccentric training appeared to have limiting or detrimental effects on cycling performance, measured as Wmax and a 20-min time trial. In conclusion, eccentric cycling training did not improve cycling performance in amateur cyclists. Further research is required to ascertain whether the present findings reflect an actual lack of efficacy, negative effects or a delayed response to eccentric cycling training.
RESEARCH ARTICLE
Eccentric cycling does not improve cycling
performance in amateur cyclists
Gøran PaulsenID
1
*, Hedda Ø. Eidsheim
2
, Christian Helland
1
, Olivier Seynnes
3
, Paul
A. Solberg
4
, Bent R. Rønnestad
2
1The Norwegian Olympic and Paralympic Committee and Confederation of Sport, Oslo, Norway, 2Inland
Norway University of Applied Sciences, Department of Sport Sciences, Lillehammer, Norway, 3Norwegian
School of Sport Sciences, Department of Physical Performance, Oslo, Norway, 4The Norwegian Olympic
and Paralympic Committee and Confederation of Sport, Region East, Fredrikstad, Norway
*goran.paulsen@olympiatoppen.no
Abstract
Eccentric cycling training induces muscle hypertrophy and increases joint power output in
non-athletes. Moreover, eccentric cycling can be considered a movement-specific type of
strength training for cyclists, but it is hitherto unknown if eccentric cycling training can
improve cycling performance in trained cyclists. Twenty-three male amateur cyclists were
randomized to an eccentric or a concentric cycling training group. The eccentric cycling was
performed at a low cadence (~40 revolution per minute) and the intensity was controlled by
perceived effort (12–17 on the Borgs scale) during 2 min intervals (repeated 5–8 times). The
cadence and perceived effort of the concentric group matched those of the eccentric group.
Additionally, after the eccentric or concentric cycling, both groups performed traditionally
aerobic intervals with freely chosen cadence in the same session (4–5 x 4–15 min). The par-
ticipants trained twice a week for 10 weeks. Maximal oxygen uptake (VO
2max
), maximal aer-
obic power output (W
max
), lactate threshold, isokinetic strength, muscle thickness, pedaling
characteristics and cycling performance (6- and 30-sec sprints and a 20-min time trial test)
were assessed before and after the intervention period. Inferences about the true value of
the effects were evaluated using probabilistic magnitude-based inferences. Eccentric
cycling induced muscle hypertrophy (2.3 ±2.5% more than concentric) and augmented
eccentric strength (8.8 ±5.9% more than concentric), but these small magnitude effects
seemed not to transfer into improvements in the physiological assessments or cycling per-
formance. On the contrary, the eccentric training appeared to have limiting or detrimental
effects on cycling performance, measured as W
max
and a 20-min time trial. In conclusion,
eccentric cycling training did not improve cycling performance in amateur cyclists. Further
research is required to ascertain whether the present findings reflect an actual lack of effi-
cacy, negative effects or a delayed response to eccentric cycling training.
Introduction
A cyclist’s capacity to release energy and the ability to transfer this energy to pedaling the bike
are major performance determinants for cycling. Road cycling performance is primarily
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 1 / 15
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OPEN ACCESS
Citation: Paulsen G, Eidsheim HØ, Helland C,
Seynnes O, Solberg PA, Rønnestad BR (2019)
Eccentric cycling does not improve cycling
performance in amateur cyclists. PLoS ONE 14(1):
e0208452. https://doi.org/10.1371/journal.
pone.0208452
Editor: Alessandro Moura Zagatto, Sao Paulo State
University - UNESP, BRAZIL
Received: July 11, 2018
Accepted: November 7, 2018
Published: January 2, 2019
Copyright: ©2019 Paulsen et al. This is an open
access article distributed under the terms of the
Creative Commons Attribution License, which
permits unrestricted use, distribution, and
reproduction in any medium, provided the original
author and source are credited.
Data Availability Statement: All relevant data are
within the paper and its Supporting Information
files.
Funding: The authors received no specific funding
for this work.
Competing interests: The authors have declared
that no competing interests exist.
limited by aerobic energy capacity, but strength (anaerobic) training has been shown to be a
valuable supplementary to the traditional endurance training for cyclists [1,2]. Rønnestad et al
[3] showed that 12 weeks of strength training improved cycling economy during long-dura-
tion submaximal cycling and increased the mean power output in a final 5 min with maximal
effort. Other studies support these findings [4], but the beneficial effects of strength training is
not unequivocal [1]. Interestingly, Vikmoen et al [4] found a strong relationship between mus-
cle hypertrophy of the quadriceps muscle and improvements in cycling performance after 11
weeks of strength training (40 min time trial). Moreover, in addition to hypertrophy, the con-
version of type IIx to type IIa muscle fibers were also associated with performance improve-
ments [4,5]. Consequently, we could hypothesize that lack of response to strength training in
cyclists could be due to a lack of hypertrophy and/or fiber type conversion. It seems reasonable
to envision that strength training not always results in muscle morphological adaptations in
cyclists, as the strength training is conducted along with large volume of aerobic endurance
training [2]. This is consistent with previous reports suggesting that concurrent endurance
training may mitigate the effects of resistance training via inhibition of anabolic pathways [6].
We should, however, recognized that strength training induces neural effects, e.g., increased
rate of force development (RFD) through increased motoneuron firing frequency [1] and that
these neural effects may contribute to better cycling performance independent of muscle
hypertrophy [2].
Assuming that strength training-induced hypertrophy and fiber type conversion (IIx to IIa)
contribute to improve cycling performance (e.g.: [4]), we can deduce that exercises that acti-
vate the IIx motor units (i.e., all motor units) are imperative for cyclists. To this end, the high
loading imposed during eccentric exercise has proven effective in inducing muscle hypertro-
phy and strength, and to initiate type IIx to type IIa conversion [7,8,9,10].
Eccentric cycling was initially introduced as a way to investigate the physiology of concentric
and eccentric muscle work [11], and as a model for exercise-induced muscle damage [12]. In
recent years, eccentric cycling has been applied to increase knee-extensor strength and hyper-
trophy in different populations, and to facilitate recovery from injuries, such as anterior cruciate
ligament ruptures [9]. Furthermore, Leong et al [13] observed improved maximal concentric
cycling power and increased thickness of vastus lateralis and rectus femoris after only 8 weeks
of eccentric cycling (5–10.5 min per session) in young, healthy participants (non-athletes). Sur-
prisingly, few studies have included athletes, but Gross et al [14] reported that eccentric cycling
(20 min, 3 sessions per week) induced muscle hypertrophy and improved counter-movement
jump height in junior alpine skiers. As far as we know, no study has tested the effectiveness of
eccentric cycling to improve cycling performance in road cyclists. Furthermore, previous stud-
ies have conducted the eccentric cycling on a recumbent bike, while we herein utilized an ordi-
nary bike allowing a more cycling-specific positioning during the exercise.
The principle of specificity has long been documented in relation to the operating range of
joints and is believed to be linked to both neural and morphological adaptations [15]. Since
conventional cycling requires pure concentric work, the neural adaptations stemming from
eccentric cycling is expected to have limited transfer into improved cycling performance
[8,16]. However, the specificity of eccentric exercise (lengthening muscle actions at higher
force levels) could induce distinct architectural changes of advantage for cycling power output.
Based on observations from studies on other forms of eccentric training [17,18], greater
regional muscle hypertrophy and longer fascicle length could be expected from eccentric
cycling training.
Consequently, the purpose of the present study was to compare the effects of specific eccen-
tric cycling with regular concentric cycling–with the same perceived effort and cadence–on
cycling performance and physiological determinants of cycling performance in trained,
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 2 / 15
amateur road cyclists. We hypothesized that eccentric cycling would work as a specific form of
strength training and thereby increase knee-extensor thickness (hypertrophy), resulting in
improved cycling performance at both short- (anaerobic) and long-duration (aerobic) tests.
Methods
Design
The present study was a randomized controlled trial. The participants were randomly allocated
to an eccentric cycling group (ECC) or a concentric cycling group (CON). The CON group
performed conventional concentric cycling, with the same low cadence and rate of perceived
exertion (RPE) as the ECC group (Table 1). In addition to the low cadence eccentric and con-
centric training, all participants performed traditional aerobic interval training on the same
days (Table 1). The participants underwent a 10-week period of supervised training (17 ses-
sions). Performance and physiological tests were conducted within one week before and after
the intervention period. The pre-tests were preceded by a test-familiarization session.
Participants
The participants were 23 male amateur cyclists (33 ±12 years and 77 ±7 kg), with a mean
training volume of 10 ±5 hours per week in the year prior to the study. Within the last 3
months prior to the study, 1.0 ±1.7 hours per week of strength training had been conducted,
and none of the athletes did systematic sprint cycling training (e.g., <30 sec all-out intervals).
Based on the criteria presented by De Pauw et al [19], our cyclist could be defined as trained
(level 3 or 4 of 5). All cyclists completed the study.
The study was performed according to the ethical standards established by the Helsinki
Declaration of 1975 and was approved by the local ethical committee of the Department of
Sports Science, Inland Norway University of Applied Sciences, Lillehammer; and The Norwe-
gian Data Protection Authority. All participants signed an informed consent form.
Cycling tests
All the cycling tests were performed with a Lode Excalibur Sport cycle ergometer (Lode, Gro-
ningen, The Netherlands), and conducted in standardized environmental conditions: 16˚-18˚
Table 1. Overview of the intervention period.
Week ECC/CON RPE (Borgs scale) Aerobic intervals
1st session
Aerobe intervals
2nd session
RPE (Borgs scale)
1 Familiarization to tests and pre-testing
25x2 min12 4x12 min (83–87% HR
max
) 4x15 min (83–87% HR
max
)15–16
35x2 min 13 4x12 min (83–87% HR
max
) 4x15 min (83–87% HR
max
) 15–16
46x2 min 13 4x12 min (83–87% HR
max
) 4x15 min (83–87% HR
max
) 15–16
56x2 min 14 5x8 min (88–92% HR
max
) 4x10 min (88–92% HR
max
) 16
67x2 min 15–16 5x8 min (88–92% HR
max
) 4x10 min (88–92% HR
max
) 16–17
78x2 min 15–16 5x8 min (88–92% HR
max
) 4x10 min (88–92% HR
max
) 16–17
88x2 min 16–17 5x4 min (93–98% HR
max
) 5x6 min (93–98% HR
max
) 17
97x2 min 16–17 5x4 min (93–98% HR
max
) 5x6 min (93–98% HR
max
) 17–18
10 6x2 min 16–17 5x4 min (93–98% HR
max
) 17–18
11 Post-testing
2 min rest periods between all intervals.
CON: Concentric cycling; ECC: Eccentric cycling; HR
max
: Maximal heart rate; RPE: Rate of perceived exertion.
https://doi.org/10.1371/journal.pone.0208452.t001
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 3 / 15
and 30–40% humidity. The participants were asked to refrain from caffeine and nicotine 4
hours prior to testing and avoid high intensity physical activity the day before testing. Food
intake was individually standardized on the test days. The performance and physiological tests
were conducted over two days. A blood lactate profile protocol, VO
2max
, and a 20-min time
trial were performed during the first day, while the sprint tests were performed along with the
isokinetic strength tests on the second day. Twenty minutes of rest was given between the
VO
2max
and the 20-min time trial test, while 10 min was given between other tests.
Blood lactate profiling, cycling economy and VO
2max
.With freely chosen cadence, the
lactate profile test started at 125 W for 5 min. Thereafter, the load was increased by 50 W every
5 min until reaching a capillary blood lactate concentration ([La
-
]
b
) of 3.0 mmolL
-1
. The load
was then increase by 25 W until a [La
-
]
b
of 4.0 mmolL
-1
was reached (Biosen C-line Clinic,
EKF Diagnostics, GmbH, Barleben, Germany). The lactate threshold was determined as the
power output at 4 mmolL
-1
[La
-
]
b
, calculated from the relationship between [La
-
]
b
and power
output using linear regression between the nearest [La
-
]
b
below and above 4 mmolL
-1
. Cycling
economy (Wml O
2-1
) was calculated from the average oxygen consumption between 3 and
4.5 min of the two first submaximal stages (125 W and 175 W).
The VO
2max
test was initiated with 1 min of cycling at a power output corresponding to 3
Wkg
–1
(rounded down to the nearest 50 W). Power output was subsequently increased by 25
W every minute until exhaustion. VO
2max
was determined by the average of the two highest
VO
2
measurements (30 sec periods), and maximal aerobic power output (W
max
) was calcu-
lated as the mean power output of the last minute of the test.
Pedal force measurements. The torque generated at the crank axle was measured every
2˚ by strain gauges developed and bonded on to the crank arm by the Lode cycle ergometer
manufacturer. Peak torque, angle of peak torque, and minimum torque were averaged from
both legs. Peak torque was calculated as the mean of the highest propulsive torque during the
down-stroke phase, while minimum torque was calculated as the mean of the highest resistive
torque during the upstroke phase. Crank angles were referenced to 0˚ at the top dead center
and 180˚ at the bottom dead center; zero adjustment calibration in Lode software was per-
formed prior to every test (Lode Ergometry Manager 9.3.1.0). The crank torque data was
recorded as the average from 1.5 to 4.5 min during the 5-min period closest to 4 mmolL
-1
lac-
tate during the blood lactate profile test (273 ±23 W for the ECC group and 239 ±42 W for
the CON group). At the post-test, individual crank torque measurements were performed at
the same power output and using the same cadence as during the pre-test.
20-min time trial. In the 20-min time trial test, the participants aimed for a highest possi-
ble mean power output (Lode Excalibur Sport cycle ergometer). The cadence was freely cho-
sen, and the participants controlled the power output during the whole test by using an
electronic control unit that governed the electromagnetic brake on the drive wheel of the cycle
ergometer (hyperbolic mode). [La
-
]
b
was measured every 5 min. The amount of water or sports
drink consumed were noted during the pre-test and replicated during the post-test.
Sprints cycling tests. A 10-min cycle specific warm-up, including two submaximal sprints
and 1-min rest, were performed before the 6-sec and 30-sec (Wingate) sprint tests (Lode Excal-
ibur Sport cycle ergometer). The 6-sec test was performed with maximal effort from a standstill
(2 attempts; 2 min rest; the best attempt was used for statistical analysis). The 30-sec all-out
Wingate test started while pedaling at 60 revolution per minute (RPM) without braking resis-
tance. Then, following a 3-sec countdown, braking resistance was applied to the flywheel and
remained constant throughout the test. Braking resistance was set to 0.75 Nmkg
-1
body mass
on both the 6-sec and 30-sec tests. The cadence was sampled at 5 Hz and matching power out-
put values were calculated (Lode Ergometry Manager 9.3.1.0). The mean power output was
presented as the average power output sustained during the 6-sec and 30-sec tests. The cyclists
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 4 / 15
remained seated throughout the tests and strong verbal encouragement was provided. The
participants were instructed to pedal as fast as possible from the start and not to conserve
energy for the last part of the test (to avoid pacing during the Wingate test).
Isokinetic strength tests
Seated with 85˚ in the hips and upper body and thighs stabilized by belts and Velcro bands, the
participants were subjected to isokinetic knee-extensor strength tests of their dominant leg
(HUMAC NORM, Computer Sports Medicine Inc, Massachusetts, USA). Preceded by 5
warm-up contractions for each velocity, maximal concentric and eccentric strength was tested
at 60˚sec
-1
. The highest torque of three consecutive attempts at each velocity was used in fur-
ther statistical analysis. Maximal knee-extensor isometric torque was assessed at 60˚ for 5 secs
(2 attempts; the highest value used for statistical analysis). One minute and 30 secs of rest was
given between tests and warm-ups, respectively.
Muscle thickness
The ultrasound assessment was always conducted before any other tests and with a minimum
of 24 hours rest from the last training session.
Muscle thickness of m. vastus lateralis (VL) and m. rectus femoris (RF) were measured
from ultrasound scans (HL9.0/60/128Z-2, Telemed Ltd Lithuania, Echo Wave II, Italy,
Milano). Images were obtained at the mid-distance between the greater trochanter and the
femoral condyle. Scanning sites were recorded on acetate paper for subsequent measurements.
However, great care was taken to match pre- and post-intervention scanning sites by adjusting
the probe orientation to display similar landmarks (e.g. connective tissue and blood vessels).
All images were analyzed in a blinded fashion by the same investigator using ImageJ (Wayne
Rasband, National Institutes of Health, Bethesda, MD). The distance between the superficial
and deeper aponeuroses was measured at three different sites in the middle third of the width
of the field of view. An average of these measurements was used as muscle thickness.
Ultrasound measurements of muscle architecture have consistently been shown to be valid
[20]. The reliability of repeated measurements using the present method has been estimated as
acceptable, with coefficient of variation of 2.0% [21].
Training
Eccentric cycling or concentric cycling. Each session started with a 10-min warm-up at
low intensity (120–160 W). Table 1 provides an outline of the eccentric and concentric train-
ing, which started 2 x 2 min and progressed to 8 x 2 min. Inter-interval rests were always 2
min. The participants in the ECC group performed their training on a Cyclus2 Eccentric
Trainer (RBM elektronik-automation GmbH, Leipzig, Germany), while those in the CON
group used a Body Bike Classic (BODY BIKE international A/S, Frederikshavn, Denmark).
Rate of perceived exertion (Borgs scale 6–20) was used to target intensity during eccentric and
concentric cycling (Table 1). Both the ECC and the CON group cycled at a cadence of 40
RPM. The eccentric ergometer displayed the cadence, while the CON group followed the beat
of a metronome. Consequently, intensity was individually adjusted with the resistance. Mean
force (N), power (W) and heart rate were recorded during the eccentric cycling, while only
heart rate was recorded from the concentric cycling.
Aerobic intervals. The last part of the training session was equal for all the participants
and started with 10 min progressive warm-up to prepare for aerobic intervals (Table 1). Dur-
ing these aerobic intervals, most participants used their own bike on CompuTrainers (Racer-
Mate Inc, Seattle, Washington, USA) with cadence and power output registration, while the
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 5 / 15
remaining cyclists completed the aerobic intervals on a Body Bike Classic. At the end of each
session, the participants received a 29 g protein bar (“Big100 bar”, Proteinfabrikken, Stokke,
Norway) for recovery purposes.
Tapering. The last organized training session and the post-testing were separated by 5
days. In this period, the participants were instructed to perform a step taper by decreasing
their individual training volume by 50 percent [22], and to perform a training session of 5 x 2
min aerobic intervals at 93–98% of maximal heart rate and 17–18 on the Borgs scale, two days
before post-testing. The purpose with the taper was to allow for recovery and final adaptations
before the post-tests [23]
Statistics
The data were analyzed in a spreadsheet designed for a controlled trial that allows for adjust-
ment of two predictor variables [24]. In all analyses, the differences in changes between groups
were adjusted for baseline level to correct for the regression to the mean effect (those with a
high score at the pre-test tends to get weaker and those with a low score at the pre-test tends to
get better). In addition, the spreadsheet allows for including an additional explanatory variable,
and we included changes in VO
2max
and hypertrophy as possible mediators explaining the dif-
ferences between training groups. All data were log-transformed and differences between
groups are reported as percent with its associated 90% confidence interval (CI).
Effects were evaluated using the clinical magnitude-based inferences (MBI; [25]), a method
particularly recommended for small samples. The magnitude of a difference in mean between
groups was assessed by standardization, i.e., the mean change divided by baseline standard
deviations (SD) of all subjects. The resulting standardized effect was evaluated as following:
<0.2, trivial; 0.2–0.6, small; 0.6–1.2, moderate; >1.2, large [25].
To make clinical inferences about true values of effects in the population studied, the effects
were expressed as probabilities of harm or benefit in relation to the smallest substantial effect
(0.2 SD; [25]). The ratio of wanting to use the experimental training corresponds to the case of
an effect that is almost certainly not harmful (<0.5% risk of harm) and possibly beneficial
(>25% chance of benefit). This corresponds to an odds ratio of 66 which is according to
[24,25] enough to warrant to use the treatment. The effect is shown as the difference or change
with the greatest probability, and the probability is shown qualitatively using the following
scale: 25–75%, possibly; 75–95%, likely; 95–99.5%, very likely; >99.5%, most likely [25].
Pearson´s correlations between the change in the possible mediators (delta hypertrophy
and VO
2max
) and performance tests were performed among all subjects. According to [25] a
correlation <0.1 is considered trivial, 0.1–0.3 small, 0.3–0.5 moderate and >0.5 large, and
their inferences were evaluated using the same scale as described for effects above.
Results
Eccentric cycling was based on the perceived effort (Table 1), which resulted in a resistance
during each 2-min interval of 400 ±80 N (290 ±60 W) during the three first sessions and
700 ±90 N (520 ±70 W) during the last three sessions. The heart rate was 115 ±15 beats per
minute (BPM) and 130 ±15 BPM during the first and last three sessions, respectively. For the
CON group, the heart rate was 140 ±20 BPM during the three first sessions and 150 ±15 BPM
during the last three sessions.
Table 2 shows the mean and SD of all variables in the two groups at baseline. We did not
investigate the difference between groups at baseline, because all analyses included baseline as
a covariate (controlling for possible differences). Baseline values together with delta changes
within each group are presented in S1 Table.
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 6 / 15
Table 3 presents the percent difference in mean changes between CON and ECC. The left
column shows the effects of the ECC compared to CON when only adjusting for baseline. In
general, the differences between groups were trivial or small. There was a small likely beneficial
effect of ECC on eccentric strength compared to CON (isokinetic eccentric force/work/
power). Moreover, there was a small possibly clear effect on change in hypertrophy in ECC.
For the performance tests, the effects of ECC were overall negative small or trivial, with clear
negative effects on the 20-min time trial, W
max
and average pedaling peak torque and angle.
The middle column (Table 3) shows the difference in means when adjusting for baseline
and change in VO
2max
, meaning that the delta VO
2max
between groups is held constant
(adjusted to zero). This approach showed overall similar results as adjusting for baseline, but
Table 2. Descriptive statistics for the main variables in each group at baseline.
ECC
Mean ±SD
(n = 12)
CON
Mean ±SD
(n = 11)
Muscle thickness
Vastus lateralis (VL; mm) 2.7 ±0.4 2.6 ±0.3
Rectus femoris (RF; mm) 2.0 ±0.3 1.8 ±0.2
Mean of RF and VL (mm) 2.3 ±0.3 2.2 ±0.2
Strength
Eccentric peak torque at 60˚s
-1
(Nm) 241 ±43 265 ±52
Eccentric work at 60˚s
-1
(J) 317 ±72 317 ±66
Eccentric power at 60˚s
-1
(W) 150 ±28 160 ±28
Eccentric angle at peak torque at 60˚s
-1
(˚) 79.8 ±11.8 72.9 ±11.4
Concentric peak torque at 60˚s
-1
(Nm) 221 ±37 229 ±33
Concentric work at 60˚s
-1
(J) 278 ±51 280 ±60
Concentric power at 60˚s
-1
(W) 146 ±25 154 ±23
Concentric angle at peak torque (˚) 63.4 ±8.1 64.1 ±7.1
Isometric peak torque at 60˚ (Nm) 242 ±41 263 ±38
Performance tests
6-sec sprint mean power (W) 1276 ±102 1251 ±84
30-sec sprint mean power (W) 776 ±62 761 ±52
20-min time trial (W) 268 ±32 260 ±42
20-min time trial (Wkg
-1
) 3.6 ±0.6 3.4 ±0.7
20-min time trial average lactate (mmolL
-1
) 8.5 ±1.7 6.6 ±1.5
Endurance determinants
VO
2max
(ml) 4668 ±616 4796 ±518
VO
2max
(mlkg
-1
) 62.1 ±10.1 62.0 ±9.4
W
max
(W) 406 ±54 383 ±36
4 mmolL
-1
lactate threshold (Wkg
-1
) 3.3 ±0.7 3.0 ±0.8
Cycling economy (Wml
-1
) 16.3 ±0.9 16.9 ±0.8
Pedaling characteristics
Pedaling peak torque (N) 69.5 ±7.2 69.5 ±9.8
Pedaling efficiency (%) 86.4 ±3.1 80.6 ±8.1
Pedaling average angle (˚) 90.2 ±5.6 90.3 ±5.2
Pedaling min torque (N) -9.5 ±1.3 -12.8 ±3.9
Pedaling cadence (RPM) 94.4 ±5.6 91.0 ±4.8
Training volume last 12 weeks (hours per week) 10 ±4 8 ±4
CON: Concentric cycling; ECC: Eccentric cycling; RPM: Revolutions per minute.
https://doi.org/10.1371/journal.pone.0208452.t002
Eccentric cycling for amateur cyclists
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Table 3. Percent difference in changes between groups with magnitude-based inferences when adjusted to baseline, adjusted to baseline and change in VO
2max
, or
adjusted to baseline and change in muscle volume.
Diff ECC-CON adjusted for baseline Diff ECC-CON adj for baseline and
delta VO
2max
Diff ECC-CON adj for baseline
and delta hypertrophy
Mean diff ±90% CI Inference Mean diff ±90% CI Inference Mean diff ±
90% CI
Inference
Muscle thickness
Vastus lateralis (VL; mm) 2.6 ±5.2 small
unclear
4.8 ±6.7 small
unclear
Rectus femoris (RF; mm) 2.6 ±3.8 small
unclear
5.5 ±6.1 small
unclear
Mean of RF and VL (mm) 2.3 ±2.5 small4.3 ±3.4 small
Strength
Eccentric peak torque at 60˚s
-1
(Nm) 8.8 ±5.9 small 11.6 ±9.4 small12.6 ±9.9 small
Eccentric work at 60˚s
-1
(J) 5.4 ±7.1 small
unclear
7.7 ±10.5 small
unclear
16.9 ±8.9 mod
Eccentric power at 60˚s
-1
(W) 8.2˚10.2 small
unclear
9.2 ±13.5 small
unclear
35.8 ±13.6 large
Eccentric angle at peak torque at 60˚s
-1
(˚) -2.7 ±6.8 triv
+
-0.4 ±11.2 triv
unclear
-8.7 ±12.0 small
++
Concentric peak torque at 60˚s
-1
(Nm) -3.1 ±6.2 triv
+
-3.8 ±9.5 small
+
-9.0 ±7.5 small
++
Concentric work at 60˚s
-1
(J) -2.5 ±5.9 triv
+
-4.5 ±7.3 small
+
-5.8 ±8.5 small
+
Concentric power at 60˚s
-1
(W) -1.9 ±5.8 triv
+
-2.8 ±7.7 triv
+
-5.3 ±9.1 small
+
Concentric angle at peak torque (˚) -0.7 ±5.6 triv
+
5.4 ±7.1 small
unclear
0.2 ±8.4 triv
unclear
Isometric peak torque at 60˚ (Nm) 3.2 ±8.9 triv
unclear
13.4 ±12.6 mod
unclear
8.1 ±15.0 small
unclear
Performance tests
6-sec sprint mean power (W) 0.9 ±5.0 triv
unclear
0.9 ±6.1 triv
unclear
3.6 ±8.5 small
unclear
30-sec sprint mean power (W) -0.6 ±2.5 triv
+
1.9 ±3.8 small
unclear
-0.3 ±3.1 triv
0
20-min time trial (W) -3.5 ±3.8 small
+
-3.2 ±6.4 small
+
-4.2 ±4.6 small
+
20-min time trial (Wkg
-1
) -2.3 ±3.9 triv
00
-2.5 ±6.7 triv
+
-3.2 ±4.8 triv
+
20-min time trial average lactate (mmolL
-1
) 3.3 ±22.1 triv
unclear
-7.8 ±26.2 small
+
-1.0 ±24.3 triv
unclear
Endurance determinants
VO
2max
(ml) -1.6 ±2.9 triv
+
-0.7 ±3.8 triv
0
VO
2max
(mlkg
-1
) 0.0 ±3.2 triv
00
2.8 ±4.1 triv
unclear
W
max
(W) -3.0 ±2.9 small
+
-1.7 ±3.3 triv
+
4 mmolL
-1
lactate threshold (Wkg
-1
) -0.9 ±5.0 triv
00
-0.3 ±8.9 triv
0
0.7 ±5.3 triv
00
Cycling economy (Wml
-1
) 0.3 ±3.8 triv
unclear
0.1 ±5.1 triv
unclear
-0.9 ±5.1 triv
+
Pedaling characteristics
Pedaling peak torque (N) -5.9 ±8.2 small
++
2.9 ±12.4 small
unclear
-6.7 ±9.5 small
++
Pedaling efficiency (%) -1.1 ±3.5 triv
+
0.6 ±4.6 triv
unclear
-0.7 ±3.7 triv
+
Pedaling average angle (˚) -2.7 ±3.4 small
++
-1.7 ±5.2 small
+
-1.8 ±4.5 small
+
Pedaling min torque (N) 1.1 ±18.7 triv
unclear
-7.7 ±25.6 small
+
-3.4 ±18.0 triv
+
Pedaling cadence (RPM) 0.4 ±3.9 triv
unclear
-4.2 ±4.9 mod
++
-0.8 ±4.5 triv
+
Magnitude thresholds (for mean change divided by baseline SD of the total sample): <0.20, trivial; 0.20–0.59, small; 0.60–1.19, moderate; >1.20, large.
Asterisks indicate effects clear at the 5% level and likelihood that the true effect is substantial or trivial, as follows
possible
likely
very likely
most likely.
+
possibly harmful
++
likely harmful.
0
possibly trivial
00
likely trivial.
CI: Confidence intervals; CON: Concentric cycling; ECC: Eccentric cycling; RPM: Revolutions per minute.
https://doi.org/10.1371/journal.pone.0208452.t003
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 8 / 15
concentric strength (peak torque and work), average blood lactate during 20-min time trial,
pedaling minimum torque and pedaling RPM became small and clearly negative for ECC.
The right column (Table 3) shows the effect of ECC (compared to CON) when adjusted for
baseline and hypertrophy (mean of VL and RF). The differences in the performance tests were
still negative and trivial or small (20-min all-out W, possibly harmful). If anything, the differ-
ences between ECC and CON on the performance tests became larger when controlling for
the change in hypertrophy indicating that the effect of hypertrophy on cycling performance
was negative for the ECC group.
The effects of change in the possible mediators, VO
2max
and hypertrophy, on the differences
between the two groups are given in Table 4. Generally, the effects of the mechanisms were
trivial or small and unclear. However, for change in VO
2max
there were some clear negative
effects of VL muscle thickness, 30-sec sprint mean power, pedaling peak torque, pedaling
mechanical efficiency, concentric angle of peak torque and isometric peak torque, indicating
that the increases in VO
2max
in ECC negatively influenced these outcomes compared to CON.
For hypertrophy, there were some clear negative effects on 6-sec sprint mean power, eccen-
tric work and power indicating that increased hypertrophy had negative effects in ECC com-
pared to CON (Table 4)
Including all participants (n = 23), there were large clear correlations between change in
hypertrophy (RF+VL) and change in W
max
(0.62, most likely positive) and change in Wkg
-1
at
4 mmolL
-1
[La
-
]
b
(0.56, very likely positive), and a moderate correlation to average Wkg
-1
during the 20-min time trial out (0.48, very likely positive).
Discussion
In the present study, we hypothesized that low cadence eccentric cycling would induce more
muscle hypertrophy in the knee-extensors than perceived effort-matched low cadence concen-
tric cycling, and that this muscle hypertrophy would translate into improved cycling perfor-
mances in amateur cyclists. The main findings were 1) eccentric cycling induced hypertrophy
of vastus lateralis and rectus femoris, 2) eccentric cycling resulted in improved isokinetic
eccentric strength, which did not transfer to isokinetic concentric strength nor to cycling
sprint performance, 3) eccentric cycling changed the pedaling characteristics by an earlier and
lower peak torque during the pedaling stroke, and 4) eccentric cycling demonstrated possible
unfavorable effects on W
max
and the 20-min time trial performance.
Eccentric cycling and hypertrophy
Eccentric exercise has for years been advocated for inducing hypertrophy and strength
[9,26,27], and eccentric cycling appear a viable mode of exercise for this purpose [10,28,29]. In
the present study, we noted increased thickness of vastus lateralis and rectus femoris. However,
the hypertrophy was (with unclear to likely likelihood) of small magnitude compared to other
studies investigating resistance exercise in general (~3% in the present study vs. 6–9% as sum-
marized by Wernbom et al [30]). Rønnestad et al [31] reported a quadriceps hypertrophy
translating into 0.05% increase in cross-sectional area (CSA) per day in well-trained cyclist,
which is close to 0.04% in muscle thickness in the present study (assuming changes in thick-
ness and CSA are comparable [30,32,33]). However, when comparing our results to pure
eccentric training regimes, our observations are within the range (0.03–0.09%) of observations
summarized by Wernbom et al [30]. Intriguingly, Leong et al [13] reported a very large muscle
hypertrophy of vastus lateralis and rectus femoris (13 and 24%, respectively) after only 8 weeks
of eccentric cycling (i.e., 0.2–0.4% increase per day). This discrepancy may be ascribed to the
untrained status of the participants recruited by Leong et al, in contrast to the trained cyclists
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 9 / 15
of the present study. In fact, our participants appeared to have larger muscle thickness of vastus
lateralis at baseline than the participants in the study of Leong et al (~27 vs. ~20 mm, respec-
tively); and therefore attenuated hypertrophy could be expected [15]. Years with road cycling
may indeed induce muscle hypertrophy per se [34].
Table 4. Percent effect of change in VO
2max
and change in hypertrophy (mediators) on the difference between groups.
Effect of delta
VO
2max
Effect of delta hypertrophy
Mean diff ±90% CI Inference Mean diff ±90% CI Inference
Muscle thickness
Vastus lateralis (VL; mm) -1.4 ±4.2 triv
+
Rectus femoris (RF; mm) -2.7 ±3.7 small
+
Mean of RF and VL (mm) -1.6 ±2.0 triv
+
Strength
Eccentric peak torque at 60˚s
-1
(Nm) -2.5 ±5.9 triv
+
-1.8 ±4.8 triv
00
Eccentric work at 60˚s
-1
(J) -1.9 ±6.4 triv
0
-7.2 ±4.5 small
++
Eccentric power at 60˚s
-1
(W) -0.5 ±8.0 triv
0
-13.6 ±5.1 mod
+++
Eccentric angle at peak torque at 60˚s
-1
(˚) -2.3 ±8.1 triv
+
4.7 ±7.6 small
unclear
Concentric peak torque at 60˚s
-1
(Nm) 0.2 ±6.8 triv
0
5.8 ±5.6 small
Concentric work at 60˚s
-1
(J) 1.8 ±4.9 triv
00
3.1 ±5.5 triv
unclear
Concentric power at 60˚s
-1
(W) 0.4 ±5.2 triv
00
3.1 ±5.9 triv
unclear
Concentric angle at peak torque (˚) -5.1 ±4.1 small
++
-1.4 ±5.0 triv
+
Isometric peak torque at 60˚ (Nm) -9.0 ±7.1 small
++
-3.4 ±7.8 triv
+
Performance tests
6-sec sprint mean power (W) 0.8 ±3.7 triv
unclear
-2.5 ±4.8 small
+
30-sec sprint mean power (W) -1.5 ±2.3 small
+
-1.3 ±3.1 triv
+
20-min time trial (W) -0.4 ±5.2 triv
0
-1.0 ±2.4 triv
00
20-min time trial (Wkg
-1
) 0.2 ±5.9 triv
0
-1.1 ±2.8 triv
00
20-min time trial average lactate (mmolL
-1
) 11.3 ±20.6 small
unclear
8.3 ±13.2 small
+
Endurance determinants
VO
2max
(ml) -1.4 ±2.1 triv
00
VO
2max
(mlkg
-1
) -2.5 ±2.4 triv
+
W
max
(W) -2.3 ±1.8 triv
+
4 mmolL
-1
lactate threshold (Wkg
-1
) -0.6 ±6.8 triv
00
-4.5 ±3.2 triv
+
Cycling economy (Wml
-1
) 0.2 ±3.0 triv
unclear
1.1 ±2.3 triv
unclear
Pedaling characteristics
Pedaling peak torque (N) -8.2 ±7.5 mod
++
-0.3 ±4.9 triv
0
Pedaling efficiency (%) -1.8 ±3.2 small
+
-0.6 ±1.6 triv
00
Pedaling average angle (˚) -1.1 ±3.7 triv
+
-0.6 ±2.3 triv
+
Pedaling min torque (N) 9.4 ±22.4 small
unclaer
5.7 ±8.1 triv
unclear
Pedaling cadence (RPM) 3.9 ±3.2 mod
unclear
0.9 ±1.9 triv
unclear
Magnitude thresholds (for mean change divided by baseline SD of the total sample): <0.20, trivial; 0.20–0.59, small; 0.60–1.19, moderate; >1.20, large.
Asterisks indicate effects clear at the 5% level and likelihood that the true effect is substantial or trivial, as follows
likely.
+
possibly harmful
++
likely harmful
+++
very likely harmful.
0
possibly trivial
00
likely trivial.
CI: Confidence intervals; CON: Concentric cycling; ECC: Eccentric cycling; RPM: Revolutions per minute.
https://doi.org/10.1371/journal.pone.0208452.t004
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 10 / 15
The reasons for modest effects on muscle thickness in our cyclists after eccentric cycling are
not possible to ascertain with the design and methods applied, but some likely culprits are
worth mentioning. First, the eccentric exercise was conducted on an ordinary bike, which
meant that the athlete had to use considerable upper body force to maintain a seated cycling
position during exercise. In contrast, when using a recumbent bike set-up, typically used for
eccentric cycling (see: [13,14,35]), the stabilization gained from back support makes it easier to
generate eccentric force against the pedals. In other words, the muscle hypertrophy in the pres-
ent study was possibly limited by a suboptimal loading stimulus. Moreover, eccentric exercise
sessions were immediately followed by an aerobic cycling session. During concurrent training,
it is well established that aerobic exercise can hinder the hypertrophy response to resistance
exercise, especially when aerobic and resistance exercises are conducted with little rest in-
between, as in the present study [6,36]. Interestingly, the statistical analyses with changes in
VO
2max
as a mediator revealed that VO
2max
increased on the expense of vastus lateralis muscle
thickness, pedaling peak torque and mechanical efficacy. We combined the training modes in
order to fit the intervention into the participants training regimes; however, better results
could probably have been achieved by separating the eccentric training from the aerobic
endurance training, and/or applying a block periodization approach [37].
Eccentric cycling and cycling performance
According to our hypothesis, we observed hypertrophy after eccentric cycling, but no
benefits was observed in the cycling tests. It is possible that the hypertrophy response was
too small to result in performance enhancements. Vikmoen et al [4] observed a ~7% CSA
quadriceps enlargement (vs. ~3% in the present study) and strong correlation with 40 min
performance test (mean watts; r = 0.7). Interestingly, when groups were pooled, changes
in hypertrophy showed moderate to large correlations to changes in W
max
, Wkg
-1
at 4
mmolL
-1
[La
-
]
b
, and average Wkg
-1
during the 20-min time trial, indicating that hypertro-
phy is a mechanism behind the improved cycling performance. It is tempting to speculate
whether the eccentric training induced very contraction-specific effects, which somehow
blunted or held back the participants ability to utilize the increased muscle mass in conven-
tional cycling tests. In agreement with this suggestion, previous studies have resulted in no
or only small improvements in concentric strength/power after 4–8 weeks (2–3 sessions per
week) of eccentric cycling [13,35,38]. Leong et al [13] reported robust hypertrophy, but saw
only minor transfer to concentric cycling power output one week after the eccentric cycling.
Intriguingly, Leong et al [13] reported signs of a delayed response with a larger increase in
concentric cycling power 8 weeks after the training intervention. A delayed effect could be
related to prolonged muscle remodeling/adaptation process [13,39], and/or time needed to
“calibrate” the neuromuscular system to the gained muscle mass. Unfortunately, we were not
able to test our cyclists at a later time point (e.g., 2–4 weeks) after the intervention, so we can
only hypothesize about a delayed positive effect of eccentric cycling. Of note, we did reduce
the training volume in the two lasts weeks and included a 5-day tapering period after the last
eccentric training session.
Specificity of training and possible detrimental effects on performance
The specificity of strength improvements is well-documented [15], and our result confirm an
isolated improvement in eccentric strength and power to eccentric training (e.g., [8,16].
Applying changes in muscle thickness as a statistical mediator showed that hypertrophy
appeared to limit the improvements in eccentric strength while facilitate concentric strength.
This suggests that the eccentric strength increase was brought about via neural adaptions.
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 11 / 15
Surprisingly, the eccentric training appeared to induce some limiting and even detrimental
effects on both isolated concentric strength/power tests, as well as for the W
max
and the
20-min time trial performances. The adverse effects on the cycling tests may be related to the
fact that the eccentric training affected pedaling characteristics, i.e., an earlier and lower peak
torque during the pedaling stroke, compared to the concentric group. The group difference in
changes of mechanical efficiency was trivial, but also this variable tipped in disfavor for the
eccentric training. Confusingly, earlier pedaling peak torque have been observed after tradi-
tional strength training and was positively associated with improved 40-min cycling perfor-
mance [39]. Thus, our observations indicate that the changes in peak torque angle per se have
limited effect on performance, at least when peak torque is reduced.
Related to high mechanical forces and low metabolic challenges, eccentric exercise may
preferentially stimulate type II fibers hypertrophy and in some cases even increase IIx expres-
sion [40]. These adaptations could prove counter-productive for aerobic endurance and may
explain why we did not find any beneficial effects of tests taxing the aerobic systems. On the
other hand, if the eccentric cycling did stimulate type II fibers to grow concomitant with
increased IIx fiber type expression, it could be argued that we should have seen improvements
in the cycling sprint tests, which we did not. However, a more dominating fiber type II pool
may have shifted the optimal cadence for peak power to the right [41], and thus masked true
changes in sprint peak power as we tested our cyclists with a single (and similar) load before
and after the intervention period.
Study limitations
The present study lasted for merely 10 weeks and, as previously mentioned, the low to moder-
ate eccentric forces and concurrent training may have restricted the hypertrophy we aimed
for. Moreover, we compared eccentric cycling training to concentric cycling training, which
means the control group performed more aerobic endurance training than the intervention
group. We did not measure oxygen uptake during the eccentric cycling training, but we know
from extensive previous work that the cardiovascular load during eccentric cycling is low, even
at very high workloads [11,26,42]. Thus, the lower aerobic endurance training load in the
intervention group could explain some of the apparently adverse effects of the eccentric
cycling. Finally, our results must be interpreted with caution due to the small sample size and
many inferences. Some effects were substantial (small), but unclear, indicating that a larger
sample size was needed.
Practical applications and further research
Despite some weaknesses, our study questions the use of eccentric cycling in cyclists as we
observed likelihood of adverse effects in cycling performance; which is in contrast to tradi-
tional strength training [2]. However, as eccentric cycling seems to have many potential bene-
fits used in both clinical and sport settings [9], it is important to further investigate this mode
of training for each specific population. Concerning cyclists, it would be very interesting to
test the effects of eccentric cycling in adjunction with traditional strength training exercises,
such as leg press and squats, and/or conventional sprint cycling exercise (e.g., 5–30 sec all-out
intervals). In this context, it seems reasonable to suggest that the benefits of the hypertrophic
stimulus and specific joint movements would give a better transfer to cycling performance.
Conclusion
Herein we compared low cadence eccentric cycling to perceived effort-matched low cadence
concentric cycling training for 10 weeks. The eccentric cycling increased eccentric strength
Eccentric cycling for amateur cyclists
PLOS ONE | https://doi.org/10.1371/journal.pone.0208452 January 2, 2019 12 / 15
and induced hypertrophy–even when conducted in concurrence with conventional aerobic
endurance training–in trained amateur cyclists. Still, the eccentric cycling did not improve any
physiological measurements or cycling performance tests, encompassing short sprints and a
20-min time trial test. On the contrary, eccentric cycling may partly prevent improvements in
cycling performance, unlike concentric cycling training. Nonetheless, the present observations
were obtained immediately after the training intervention and future studies should ascertain
that positive effects were not missed because of delayed adaptations.
Supporting information
S1 Table. Baseline values and changes (delta) within each group.
(DOCX)
Acknowledgments
We thank Hanne B. Eriksen, Maria Moen, Mari M. Dagslet, Merete Nybru, Kristian S. Anker-
sen, Håkon Thomassen and Aleksander Warming for great work during data sampling. Fur-
ther, the authors wish to thank Proteinfabrikken A/S for providing the project with protein
chocolate bars.
Author Contributions
Conceptualization: Gøran Paulsen, Bent R. Rønnestad.
Formal analysis: Paul A. Solberg.
Investigation: Gøran Paulsen, Hedda Ø. Eidsheim, Christian Helland.
Methodology: Olivier Seynnes, Bent R. Rønnestad.
Project administration: Bent R. Rønnestad.
Supervision: Gøran Paulsen, Olivier Seynnes, Bent R. Rønnestad.
Writing – original draft: Gøran Paulsen, Hedda Ø. Eidsheim.
Writing – review & editing: Gøran Paulsen, Hedda Ø. Eidsheim, Christian Helland, Olivier
Seynnes, Paul A. Solberg, Bent R. Rønnestad.
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... Response: Thank you very much for your suggestion. The text was modified as suggested (Page 13; Lines [14][15][16][17][18][19]. ...
... However, evidence indicates that eccentric cycling training does not improve cycling performance in amateur cyclists, 15 and there is limited evidence regarding the mechanisms of acute physiological and chronic adaptive responses to eccentric cycling, although there is evidence showing especial benefits from improvements in aerobic power/capacity, exercise tolerance, strength and muscle mass in clinical populations. 16 Therefore, the aim of this study was to assess the workload level effects on the timing of lower-limb muscles' concentric and eccentric actions, assessed by surface electromyography (EMG) and lower-limb kinematics analysis. ...
... Indeed, eccentric cycling training may improve muscle force by using cycling motion14 if eccentric contractions are pronounced at high workload levels. However, evidence indicates that eccentric cycling training does not improve cycling performance in amateur cyclists,15 and there is limited evidence regarding the mechanisms of acute physiological and chronic adaptive responses to eccentric cycling, although there is evidence ...
Article
Background: The mechanical energy required to drive the cranks during cycling depends on concentric and eccentric muscle actions. However, no study to date provided clear evidence on how workload levels affect concentric and eccentric muscle actions during cycling. Therefore, the aim of this study was to investigate the workload effects on the timing of lower limb concentric and eccentric muscle actions, and on joint power production. Methods: Twenty-one cyclists participated in the study. At the first session, maximal power output (POMAX) and power output at the first (POVT1) and second (POVT2) ventilatory thresholds were determined during an incremental cycling test. At the second session, cyclists performed three trials (2-min/each) in the workloads determined from their POMAX, POVT1 and POVT2, acquiring data of lower limb muscle activation, pedal forces and kinematics. Concentric and eccentric timings were computed from muscles' activations and muscle-tendon unit excursions along with hip, knee and ankle joints' power production. Results: Longer rectus femoris eccentric activation (62%), vastus medialis concentric (66%) and eccentric activation (26%) and biceps femoris concentric (29%) and eccentric (133%) activation at POMAX were observed compared to POVT1. Longer positive (12%) and shorter negative (12%) power were observed at the knee joint for POMAX compared to POVT1. Conclusions: We conclude that, to sustain higher workload levels, cyclists improved the timing of power transmission from the hip to the knee joint via rectus femoris eccentric, vastus medialis concentric and eccentric and biceps femoris concentric and eccentric contractions.
... At similar mechanical power output, ECC cycling elicits lower oxygen consumption (VO2) [8,9] and reduced ventilator [10] and cardio-circulatory responses [11]. Studies like Moysi et al. [12] and Vogt M. and Hoppeler [13] tried to establish the positive effect of ECC on improving cycling performance but, on the other hand, research such as Paulsen et al. [14] encouraged the controversy over the resultant effectiveness of ECC. ...
... Pol. J. Sport Tourism 2020, 27(1), [14][15][16][17][18][19][20] activation, neural activation and faster force generation [17]. PLYO improves power through increased neural drive, changes in muscle coordination, changes in the muscle tendon complex and changes in muscle size and architecture [17]. ...
... In the case of the present study, the concurrent training protocol was intended to improve the hydration status [TBW (~1%) and ICW (~1%)], glycogen content (~3%), muscular strength including back and grip strength (~6-11%), trunk flexibility (~5%), leg explosive strength (~7%), aerobic/ Pol. J. Sport Tourism 2020, 27(1), [14][15][16][17][18][19][20] endurance capacity (~5%), absolute and relative anaerobic power output (~9%), acceleration (~7%) and agility (~2%) of junior track cyclists. ...
Article
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Introduction. Some certain well-established training protocols exist for developing physical and physiological demands of a track cyclist. But still there is controversy on the effectiveness of combined training protocols. The present study was aimed to investigate the effects of 4-week concurrent eccentric cycling and plyometric training on cycling performance of male cyclists at the pre-competitive phase. Material and methods. A paired study design was applied to 15 young (15.04 ± 1.01 yrs) Indian male track cyclists to assess the effects of proposed concurrent training protocol on body composition and various physical fitness parameters. Results. Hydration status [TBW (~1%) and ICW (~1%)], glycogen content (~3%), muscular strength (~6-11%), trunk flexibility (~5%), anaerobic power output (~9%), endurance capacity (~5%), acceleration (~7%), leg explosive strength (~7%) and agility (~2%) were found to be improved significantly after the 4-week concurrent training protocol. Conclusions. The concurrent intervening physical training protocol was intended to increase muscular hypertrophy, peripheral factor gradient, glycolytic and oxidative enzyme capacity with proper neuromuscular coordination which may ultimately help the cyclists to pedal at a faster rate with higher muscular power output even for longer time.
... To date, it is widely accepted that high forces can be produced with low metabolic cost during eccentric actions (Abbott et al. 1952;Hody et al. 2019). The great mechanical stress imposed over the muscle-tendinous tissue during ECC CYC has been proven as an excellent stimulus for locomotor muscles hypertrophy and strengthening in healthy (Elmer et al. 2012;Gross et al. 2010;LaStayo et al. 1999LaStayo et al. , 2000Leong et al. 2014;Paulsen et al. 2019) and clinical populations (Bourbeau et al. 2020;Dibble et al. 2006;MacMillan et al. 2017;Nickel et al. 2020;Steiner et al. 2004). ...
... Additionally, knee extensor strength increased only in the ECC CYC group during concentric (16%), eccentric (21%), and isometric (28%) maximal voluntary contractions (Julian et al. 2019). More recently, Paulsen et al. (2019) showed that 10 weeks of ECC CYC training led to increases in muscle thickness of the vastus lateralis and rectus femoris muscles of amateur road cyclists. They also reported that ECC CYC training protocol resulted in improvements in isokinetic eccentric strength whereas isokinetic concentric strength did not change (Paulsen et al. 2019). ...
... More recently, Paulsen et al. (2019) showed that 10 weeks of ECC CYC training led to increases in muscle thickness of the vastus lateralis and rectus femoris muscles of amateur road cyclists. They also reported that ECC CYC training protocol resulted in improvements in isokinetic eccentric strength whereas isokinetic concentric strength did not change (Paulsen et al. 2019). ...
Article
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Purpose There is a profound gap in the understanding of the eccentric cycling intensity continuum, which prevents accurate exercise prescription based on desired physiological responses. This may underestimate the applicability of eccentric cycling for different training purposes. Thus, we aimed to summarize recent research findings and screen for possible new approaches in the prescription and investigation of eccentric cycling. Method A search for the most relevant and state-of-the-art literature on eccentric cycling was conducted on the PubMed database. Literature from reference lists was also included when relevant. Results Transversal studies present comparisons between physiological responses to eccentric and concentric cycling, performed at the same absolute power output or metabolic load. Longitudinal studies evaluate responses to eccentric cycling training by comparing them with concentric cycling and resistance training outcomes. Only one study investigated maximal eccentric cycling capacity and there are no investigations on physiological thresholds and/or exercise intensity domains during eccentric cycling. No study investigated different protocols of eccentric cycling training and the chronic effects of different load configurations. Conclusion Describing physiological responses to eccentric cycling based on its maximal exercise capacity may be a better way to understand it. The available evidence indicates that clinical populations may benefit from improvements in aerobic power/capacity, exercise tolerance, strength and muscle mass, while healthy and trained individuals may require different eccentric cycling training approaches to benefit from similar improvements. There is limited evidence regarding the mechanisms of acute physiological and chronic adaptive responses to eccentric cycling.
... Previous ECC cycling studies have shown significant neuromuscular and musculoskeletal improvements among clinical populations (Dibble et al., 2006(Dibble et al., , 2009Gerber et al., 2007;Elmer et al., 2010;Chasland et al., Frontiers in Physiology | www.frontiersin.org 2 November 2021 | Volume 12 | Article 756805 2017; MacMillan et al., 2017;Lewis et al., 2018). Additional studies have also investigated whether ECC cycling-induced lower limb strength adaptations translate into improved exercise performance including cycling power outputs and squat and countermovement jump height (Gross et al., 2010;Leong et al., 2014;Paulsen et al., 2019). Eccentric contractions involve the active lengthening of a muscle when an applied force exceeds the force produced by the muscle (Lindstedt et al., 2001;Vogt and Hoppeler, 2014). ...
... However, a single electric motor was used to operate a chain drive system, as opposed to the dual-sided electric servo motors, with regenerative braking capacity, used in the current ergometer. Indeed, most studies have used semirecumbent ECC cycle ergometers fitted with a single electric motor and chain drive system that rotate the cranks and pedals backward, without controlling how participants apply force during an ECC pedal cycle (Elmer and Martin, 2013;Leong et al., 2014;Paulsen et al., 2019). It may be that muscle activation patterns are completely in line with what would be regarded as purely ECC, when using chain-driven ECC cycle ergometers. ...
Article
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Eccentric (ECC) cycling is used in rehabilitation and sports conditioning settings. We present the construction and mode of operation of a custom-built semi-recumbent ECC cycle designed to limit the production of lower limb muscle activity to the phase of the pedal cycle known to produce ECC contractions. A commercially available semi-recumbent frame and seat (Monarch, 837E Semi-recumbent Bike, Sweden) were used to assemble the ergometer. An electrical drive train system was constructed using individual direct drive servo motors. To avoid active muscle activation occurring during the non-ECC pedaling phase of cycling, a ‘trip’ mechanism was integrated into the drivetrain system using a servo-driven regenerative braking mechanism based on the monitoring of the voltage produced over and above a predetermined threshold produced by the motors. The servo-drive internal (DC bus) voltage is recorded and internally monitored during opposing (OPP) and non-opposing (N-OPP) phases of the pedal cycle. To demonstrate that the cycle functions as desired and stops or ‘trips’ when it is supposed to, we present average (of 5 trials) muscle activation patterns of the principal lower limb muscles for regular ECC pedal cycles in comparison to one pedal cycle during which the muscles activated outside the desired phase of the cycle for a sample participant. This semi-recumbent ECC cycle ergometer has the capacity to limit the occurrence of muscle contraction only to the ECC phase of cycling. It can be used to target that mode of muscle contraction more precisely in rehabilitation or training studies
... However, while the benefits of submaximal ECC cycling exercise for clinical populations are well-understood, any potential benefits among healthy and athletic populations are as yet unconvincing (Paulsen et al., 2019). It has been recently suggested that prescribing semi-recumbent ECC cycling intensity based on CON-derived measures likely results in an underestimation of workload and potentially limits the efficacy of ECC-induced adaptations in healthy populations (Coratella et al., 2019). ...
... This indicates that the PETP requires minimal learning and can therefore be easily applied by researchers and practitioners who use semi-recumbent ECC cycling in clinical or laboratory settings and have access to an easily modifiable isokinetic dynamometer. Taking into account the well-documented differences when comparing CON and ECC exercise, including cycling (Herzog, 2014;Clos et al., 2019), previous studies using CON methods to determine ECC cycling workloads may have underestimated specific intensities needed to induce training adaptations that would translate into improved performance outcomes, particularly in healthy populations (Paulsen et al., 2019). Future studies should investigate the validity of using the PETP test to prescribe semi-recumbent ECC cycling workloads, ranging from low to high intensities. ...
Article
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Semi-recumbent eccentric (ECC) cycling is increasingly used in studies of exercise with healthy and clinical populations. However, workloads are generally prescribed using measures obtained during regular, concentric cycling. Therefore, the purpose of the study was to quantify the reliability of measures derived from a protocol that elicited peak ECC torque produced by the lower limb in a semi-recumbent position. Experiments were carried out on a dynamometer in a seated, semi-recumbent position identical to that of a custom-built eccentric cycle, a modified Monark recumbent cycle. Thirty healthy participants completed two testing sessions. Each session comprised three series of six-repetitions of a peak ECC torque protocol (PETP) on an isokinetic dynamometer. Absolute and relative reliability of peak torque, power, angle of peak torque and work (recorded for each repetition) was determined using coefficient of variation (CV) and intraclass correlation coefficients (ICC), respectively. Ratings of perceived exertion (RPE), muscle soreness and perceived effort (PE) were recorded pre-, immediately post and 1-min post each PETP. The protocol showed absolute reliability values <15% for mean peak (CV = 10.6-12.1) torque, power (CV = 10.4-12.3), angle of peak torque (CV = 1.2-1.4) and work (CV = 9.7-12.1). Moderate to high between-test relative reliability is reported for mean and highest torque (ICC = 0.84-0.95; ICC = 0.88-0.98), power (ICC = 0.84-0.94; ICC = 0.89-0.98) and work (ICC = 0.84-0.93; ICC = 0.88-0.98), respectively. Within-session peak torque, peak power and peak work showed high relative reliability for mean (ICC = 0.92-0.95) and highest (ICC = 0.92-0.97) values. Overall, the PETP test provides a reliable way of determining peak ECC torque specific to semi-recumbent ECC cycling that may be used to prescribe workloads for this form of exercise.
... At an equivalent metabolic cost or oxygen consumption (VO 2 ), ECC can be performed at much higher power levels, resulting in enhancement of muscular size, strength, and oxidative properties [1,[4][5][6]. However, it appears that ECC cycling offers no benefit for peak aerobic training over CON methods [5,7]. Therefore, this modality is particularly suited for rehabilitation purposes in patients with cardiovascular or pulmonary disease who are unable to mount sufficient muscular pedaling force due to inherent limitations. ...
Article
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Eccentric cycling (ECC) has attracted attention as a method to improve muscle strength and aerobic fitness in populations unable to tolerate conventional methods. However, agreement on exercise prescription targets have been problematic. The current report is an initial exploration of a potentially useful tool, a nonlinear heart rate (HR) variability (HRV) index based on the short-term scaling exponent alpha1 of detrended fluctuation analysis (DFA a1), which has been previously shown to correspond to exercise intensity. Eleven male volunteers performed 45 min of concentric (CON) cycling and ECC separated by 1 month. Work rates were matched for HR (~50% of the maximal HR) during the first 5 min and remained stable thereafter. HRV, HR, oxygen consumption (VO 2), and cycling power were monitored and evaluated at elapsed times of 10 (T10) and 45 (T45) minutes duration. HR significantly increased between ECC T10 and ECC T45 (p = 0.003, d = 1.485), while DFA a1 significantly decreased (p = 0.004, d = 1.087). During CON, HR significantly increased (p < 0.001 d = 1.570) without significant DFA a1 change (p = 0.48, d = 0.22). Significantly higher HR was observed at T45 in ECC than in CON (p = 0.047, d = 1.059). A session of unaccustomed ECC lead to decreased values of DFA a1 at T45 in comparison to that seen with CON at similar VO 2. ECC lead to altered autonomic nervous system balance as reflected by the loss of correlation properties compared to CON.
Article
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Aim: Muscle thickness (MT) measured by ultrasound has been used to estimate cross-sectional area (measured by CT and MRI) at a single time-point. We tested whether MT could be used as a valid marker of MRI determined muscle anatomical cross-sectional area (ACSA) and volume changes following resistance training (RT). Methods: Nine healthy, young, male volunteers (24±2 y.o., BMI 24.1±2.8 kg/m(2) ) had vastus lateralis (VL) muscle volume (VOL) and ACSA mid (at 50% of femur length, FL) assessed by MRI, and VL MT measured by ultrasound at 50% FL. Measurements were taken at baseline and after 12 weeks of isokinetic RT. Differences between baseline and post-training were assessed by Student's paired t-test. The relationships between MRI and ultrasound measurements were tested by Pearson's correlation. Results: After RT, MT increased by 7.5±6.1% (p<0.001), ACSAmid by 5.2±5% (p<0.001) and VOL by 5.0±6.9% (p<0.05) (values: means±S.D.). Positive correlations were found, at baseline and 12 weeks, between MT and ACSAmid (r=0.82, p<0.001 and r=0.73, p<0.001, respectively), and between MT and VOL (r=0.76, p < 0.001 and r=0.73, p < 0.001, respectively). The % change in MT with training was correlated with % change in ACSAmid (r=0.69, p = 0.01), but not % change in VOL (r= 0.33, p>0.05). Conclusions: These data support evidence that MT is a reliable index of muscle ACSAmid and VOL at a single time-point. MT changes following RT are associated with parallel changes in muscle ACSAmid but not with the changes in VOL, highlighting the impact of RT on regional hypertrophy. This article is protected by copyright. All rights reserved.
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The purpose of this study was to investigate the effects of adding heavy strength training to female duathletes' normal endurance training on both cycling and running performance. Nineteen well-trained female duathletes (VO2max cycling: 54 ± 3 ml∙kg−1∙min−1, VO2max running: 53 ± 3 ml∙kg−1∙min−1) were randomly assigned to either normal endurance training (E, n = 8) or normal endurance training combined with strength training (E+S, n = 11). The strength training consisted of four lower body exercises [3 × 4-10 repetition maximum (RM)] twice a week for 11 weeks. Running and cycling performance were assessed using 5-min all-out tests, performed immediately after prolonged periods of submaximal work (3 h cycling or 1.5 h running). E+S increased 1RM in half squat (45 ± 22%) and lean mass in the legs (3.1 ± 4.0%) more than E. Performance during the 5-min all-out test increased in both cycling (7.0 ± 4.5%) and running (4.7 ± 6.0%) in E+S, whereas no changes occurred in E. The changes in running performance were different between groups. E+S reduced oxygen consumption and heart rate during the final 2 h of prolonged cycling, whereas no changes occurred in E. No changes occurred during the prolonged running in any group. Adding strength training to normal endurance training in well-trained female duathletes improved both running and cycling performance when tested immediately after prolonged submaximal work.
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Despite early and ongoing debate among athletes, coaches, and sport scientists, it is likely that resistance training for endurance cyclists can be tolerated, promotes desired adaptations that support training, and can directly improve performance. Lower-body heavy strength training performed in addition to endurance-cycling training can improve both short- And long-term endurance performance. Strength-maintenance training is essential to retain strength gains during the competition season. Competitive female cyclists with greater lower-body lean mass (LBLM) tend to have ~4-9% higher maximum mean power per kg LBLM over 1 s to 10 min. Such relationships enable optimal body composition to be modeled. Resistance training off the bike may be particularly useful for modifying LBLM, whereas more cycling-specific training strategies like eccentric cycling and single-leg cycling with a counterweight have not been thoughtfully investigated in well-trained cyclists. Potential mechanisms for improved endurance include postponed activation of less efficient type II muscle fibers, conversion of type IIX fibers into more fatigueresistant IIa fibers, and increased muscle mass and rate of force development.
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The purpose of this study was to investigate the effect of adding heavy strength training to well-trained female cyclists' normal endurance training on cycling performance. Nineteen female cyclists were randomly assigned to 11 weeks of either normal endurance training combined with heavy strength training (E+S, n = 11) or to normal endurance training only (E, n = 8). E+S increased one repetition maximum in one-legged leg press and quadriceps muscle cross-sectional area (CSA) more than E (P < 0.05), and improved mean power output in a 40-min all-out trial, fractional utilization of VO2 max and cycling economy (P < 0.05). The proportion of type IIAX-IIX muscle fibers in m. vastus lateralis was reduced in E+S with a concomitant increase in type IIA fibers (P < 0.05). No changes occurred in E. The individual changes in performance during the 40-min all-out trial was correlated with both change in IIAX-IIX fiber proportion (r = -0.63) and change in muscle CSA (r = 0.73). In conclusion, adding heavy strength training improved cycling performance, increased fractional utilization of VO2 max , and improved cycling economy. The main mechanisms behind these improvements seemed to be increased quadriceps muscle CSA and fiber type shifts from type IIAX-IIX toward type IIA. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.
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The purpose was to investigate the effect of 25 weeks heavy strength training in young elite cyclists. Nine cyclists performed endurance training and heavy strength training (ES) while seven cyclists performed endurance training only (E). ES, but not E, resulted in increases in isometric half squat performance, lean lower body mass, peak power output during Wingate test, peak aerobic power output (Wmax), power output at 4 mmol L−1 [la−], mean power output during 40-min all-out trial, and earlier occurrence of peak torque during the pedal stroke (P < 0.05). ES achieved superior improvements in Wmax and mean power output during 40-min all-out trial compared with E (P < 0.05). The improvement in 40-min all-out performance was associated with the change toward achieving peak torque earlier in the pedal stroke (r = 0.66, P < 0.01). Neither of the groups displayed alterations in VO2max or cycling economy. In conclusion, heavy strength training leads to improved cycling performance in elite cyclists as evidenced by a superior effect size of ES training vs E training on relative improvements in power output at 4 mmol L−1 [la−], peak power output during 30-s Wingate test, Wmax, and mean power output during 40-min all-out trial.
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The aim of the current review is to discuss applications and mechanism of eccentric exercise in training regimes of competitive sports. Eccentric muscle work is important in most sports. Eccentric muscle contractions enhance the performance during the concentric phase of stretch shortening cycles, which is important in disciplines like sprinting, jumping, throwing and running. Muscles activated during lengthening movements can also function as shock absorbers, to decelerate during landings tasks or to precisely deal with high external loading in sports like alpine skiing. Of the few studies available on trained subjects reveal that eccentric training can further enhance maximal muscle strength and power. It can further optimize muscle length for maximal tension development at a greater degree of extension, and has potential to improve muscle coordination during eccentric tasks. In skeletal muscles, these functional adaptations are based on increases in muscle mass, fascicles length, number of sarcomeres and cross sectional area of type II fibers. Identified modalities for eccentric loading in athletic populations involve classical isotonic exercises, accentuated jumping exercises, eccentric overloading exercises and eccentric cycle ergometry. We conclude that eccentric exercise offers a promising training modality to enhance performance and to prevent injuries in athletes. However, further research is necessary to better understand how the neuromuscular system adapts to eccentric loading in athletes.
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Specificity is a core principle of exercise training to promote the desired adaptations for maximising athletic performance. The principle of specificity of adaptation is underpinned by the volume, intensity, frequency and mode of contractile activity and is most evident when contrasting the divergent phenotypes that result after undertaking either prolonged endurance or resistance training. The molecular profiles that generate the adaptive response to different exercise modes have undergone intense scientific scrutiny. Given divergent exercise induces similar signalling and gene expression profiles in skeletal muscle of untrained or recreationally active individuals, what is currently unclear is how the specificity of the molecular response is modified by prior training history. The time-course of adaptation and when ‘phenotype specificity’ takes place has important implications for exercise prescription. This context is essential when attempting to concomitantly develop resistance to fatigue (through endurance-based exercise) and increased muscle mass (through resistance-based exercise), typically termed ‘concurrent training.’ Chronic training studies provide robust evidence that endurance exercise can attenuate muscle hypertrophy and strength but the mechanistic underpinning of this ‘interference’ effect with concurrent training is unknown. Moreover, despite the potential for several key regulators of muscle metabolism to explain an incompatibility in adaptation between endurance and resistance exercise, it now seems likely that multiple integrated, rather than isolated, effectors or processes generate the interference effect. Here we review studies of the molecular responses in skeletal muscle and evidence for the interference effect with concurrent training within the context of the specificity of training adaptation. This article is protected by copyright. All rights reserved
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Over the last 30+ years, it has become axiomatic that performing aerobic exercise within the same training program as resistance exercise (termed concurrent exercise training) interferes with the hypertrophic adaptations associated with resistance exercise training. However, a close examination of the literature reveals that the interference effect of concurrent exercise training on muscle growth in humans is not as compelling as previously thought. Moreover, recent studies show that, under certain conditions, concurrent exercise may augment resistance exercise-induced hypertrophy in healthy human skeletal muscle. The purpose of this article is to outline the contrary evidence for an acute and chronic interference effect of concurrent exercise on skeletal muscle growth in humans and provide practical literature-based recommendations for maximizing hypertrophy when training concurrently.
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Fast acceleration is an important performance factor in handball. In addition to traditional sprint training (TST), resisted sprint training (RST) is a method often used to improve acceleration. However, studies on RST show conflicting results, and underlying mechanisms are not studied. To compare the effects of RST, by sled towing, against traditional sprint training on sprint performance and muscle architecture. Participants (n=18) were assigned to either RST or TST and completed two training sessions of RST or TST per week (10 weeks), in addition to their normal team training. Sprint-tests (10-m and 30-m) and measurements of muscle architecture were performed pre- and post-training. Beneficial effects were found in the 30-m sprint test (mean; ±90% CL) for both groups (TST=-0.31; ±0.19 s, RST=-0.16; ±0.13 s), with unclear differences between the groups. Only TST had a beneficial effect on 10-m time (-0.04; ±0.04 s), with a likely difference between the two groups (85 %, ES= 0.60). Both groups had a decrease in pennation angle (-6.0; ±3.3% for TST and -2.8; ±2.0% for RST), which had a nearly perfect correlation with percentage change in 10-m sprint performance (r=0.92). A small increase in fascicle length (5.3; ±3.9% and 4.0; ±2.1% for TST and RST, respectively) was found, with unclear differences between groups. TST appears to be more effective than RST in enhancing 10-m sprint time. Both groups showed similar effects in 30-m sprint time. A similar, yet small, effect of sprint training on muscle architecture was observed in both groups.