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Training Strategies to Improve Muscle Power:
Is Olympic-style Weightlifting Relevant?
CHRISTIAN HELLAND
1
, EIRIK HOLE
1
, ERIK IVERSEN
1
, MONICA CHARLOTTE OLSSON
2
,
OLIVIER SEYNNES
3
, PAUL ANDRE SOLBERG
4
, and GØRAN PAULSEN
1,3
1
The Norwegia n Olympic and Paralympic Committee and Confederation of Sports, Oslo, NORWAY;
2
Biological and
Environmental Systems Laboratory, Halmstad University, Halmstad, SWEDEN;
3
Norwegian School of Sport Sciences,
Oslo, NORWAY; and
4
Defense Institute, Norwegian School of Sport Sciences, Oslo, NORWAY
ABSTRACT
HELLAND, C., E. HOLE, E. IVERSEN, M. C. OLSSON, O. SEYNNES, P. A. SOLBERG, and G. PAULSEN. Training Strategies to
Improve Muscle Power: Is Olympic-style Weightlifting Relevant? Med. Sci. Sports Exerc., Vol. 49, No. 4, pp. 736–745, 2017. Intro-
duction: This efficacy study investigated the effects of 1) Olympic-style weightlifting (OWL), 2) motorized strength and power training
(MSPT), and 3) free weight strength and power training (FSPT) on muscle power. Methods: Thirty-nine young athletes (20 T3 yr; ice
hockey, volleyball, and badminton) were randomized into the three training groups. All groups participated in two to three sessions per
week for 8 wk. The MSPT and FSPT groups trained using squats (two legs and single leg) with high force and high power, whereas the
OWL group trained using clean and snatch exercises. MSPT was conducted as slow-speed isokinetic strength training and isotonic power
training with augmented eccentric load, controlled by a computerized robotic engine system. FSPT used free weights. The training
volume (sum of repetitions kg) was similar between all three groups. Vertical jumping capabilities were assessed by countermovement
jump (CMJ), squat jump (SJ), drop jump (DJ), and loaded CMJ (10–80 kg). Sprinting capacity was assessed in a 30-m sprint. Secondary
variables were squat one-repetition maximum (1RM), body composition, quadriceps thickness, and architecture. Results: OWL resulted
in trivial improvements and inferior gains compared with FSPT and MSPT for CMJ, SJ, DJ, and 1RM. MSPT demonstrated small but
robust effects on SJ, DJ, loaded CMJ, and 1RM (3%–13%). MSPT was superior to FSPT in improving 30-m sprint performance. FSPT
and MSPT, but not OWL, demonstrated increased thickness in the vastus lateralis and rectus femoris (4%–7%). Conclusions: MSPT
was time-efficient and equally or more effective than FSPT training in improving vertical jumping and sprinting performance. OWL was
generally ineffective and inferior to the two other interventions. Key Words: ATHLETES, POWER TRAINING, STRENGTH TRAINING,
JUMP PERFORMANCE, SPRINT RUNNING, MUSCLE ARCHITECTURE
Olympic-style weightlifting (OWL) includes the snatch
and the clean and jerk. In both lifting techniques, high
performance necessitates not only great strength,
butalsohighpower(workperunittime[W]).Indeed,high
power outputs and rate of force development have been
reported during these lifts (13,25,27). Moreover, high-level
weightlifters exhibit impressive generic power abilities
in the lower extremities, for example, countermovement
jump (CMJ) heights are higher than those for power lifters
and equivalent to high-level track and field sprinters
(8,29). Consequently, OWL and similar strength exer-
cises (‘‘weightlifting derivatives’’) are often advocated for a
range of athletes to improve lower-body muscle power (14,41).
However, although cross-sectional studies have documented a
positive association between OWL performance and lower-
body muscle power, there have been few experimental train-
ing studies conducted to establish cause and effect (15).
Hoffman et al. (18) compared OWL with heavy, slow-
velocity powerlifting in college American football players.
No statistical significant improvements in vertical jump and
sprint performance were found during the training period
with either training protocol (four sessions per week; 15 wk).
However, there was a group difference in the changes in vertical
jump height, favoring the OWL group. Tricoli et al. (42)
reported clear improvements in vertical jump performance in
physically active college students who trained using OWL for
8 wk (three sessions per week). In Tricoli et al."sstudy,OWL
was more effective than plyometrics in improving squat jump
(SJ) and CMJ heights, but not sprint performance. Channell
and Barfield (9) found no statistical difference in vertical
jump improvements between adolescent males (~16 yr of age)
training with either OWL or traditional strength training (i.e.,
squats and deadlifts; three sessions per week for 8 wk).
However, based on the effect sizes (ES), Channell and
Barfield (9) claimed that OWL might provide a modest
advantage over traditional strength training. In a study by
Arabatzi and Kellis (4), OWL resulted in robust increases
Address for correspondence: GLran Paulsen, Ph.D., The Norwegian Olympic
and Paralympic Committee and Confederation of Sport, Pb 4004 Ullevål
stadion, 0806 Oslo, Norway; E-mail: goran.paulsen@olympiatoppen.no.
Submitted for publication March 2016.
Accepted for publication October 2016.
0195-9131/17/4904-0736/0
MEDICINE & SCIENCE IN SPORTS & EXERCISE
Ò
Copyright Ó2016 by the American College of Sports Medicine
DOI: 10.1249/MSS.0000000000001145
736
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Copyright © 2017 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
in vertical jumping abilities after 8 wk of training in
recreationally trained students. OWL was found superior to
traditional strength training (leg extension, half-squats, and
leg press). Finally, Chaouachi et al. (10) recruited boys age
10 to 12 yr and reported that two sessions per week of
OWL over 12 wk was superior to traditional strength training
(squats and lunges) in improving isolated knee-extensor
power (300-Is
j1
) and balance, but not for improving
jumping and sprinting capabilities.
In summary, few studies have investigated the training ef-
fects of OWL (and derivative exercises) for improving jumping
and sprinting properties, and the results of these studies are
ambiguous. Only one study involved athletes (18), and only
two of the studies controlled for training volume (4,10). Thus,
in contrast to what has been advocated in reviews primarily
based on cross-sectional studies and power measurements
during lifting (14,41), limited longitudinal experimental evi-
dence supports OWL as being superior to other strength, and
power training exercises for improving lower-body muscle
power in athletes.
Isokinetic Squat Exercises
In essence, strength training is about challenging the ability
to generate maximal force (or joint torque). Unlike traditional
isotonic resistance exercises (free weights), isokinetic resis-
tance exercises have the advantage that maximal force can be
exerted throughout the range of motion (ROM) (34). Numerous
investigators have examined isokinetic exercises and training,
but longitudinal experiments typically involved only single
joint movements (33). Isolated, single joint exercises may,
however, have very limited performance value for athletes.
Isokinetic multijoint exercises should have much greater po-
tential to transfer to sport performance, but only a few studies
have investigated this hypothesis (45). Four decades ago, Pipes
and Wilmore (34) investigated isokinetic leg press and bench
press devices that allowed maximal force generation in full
ROM. Compared with traditional isotonic strength training, the
isokinetic training induced superior improvements in sprint,
jumping, and throwing performance in adult men (nonathletes).
Intriguingly, the isokinetic training was purely concentric (no
eccentric phase). More recently, multijoint isokinetic strength
training (concentric and eccentric) was investigated and re-
portedly improved performance in functional tests, although no
comparisons were made against traditional strength training
(only a nonexercising control group [32,35,38]).
The squat exercise—commonly considered more func-
tional than the leg press—is the cornerstone of the strength
training regimes of many athletes. Isokinetic squat devices
have been developed and described (28,45), but to the best
of our knowledge, no previous studies have investigated the
effects of isokinetic squat resistance training on strength and
power in athletes. Therefore, a goal of the present study was
to investigate the effects of isokinetic squat exercise training
in comparison to OWL and free weight strength and power
training (FSPT).
Eccentric Exercise Training
Muscle force may be higher during eccentric than con-
centric contractions (3). High-force eccentric contractions
therefore have a larger potential for stimulating muscle cells
via mechanosensitive pathways (23,26). In line with this,
researchers have concluded that eccentric exercise is superior
to concentric exercise regimes in promoting muscle growth
and strength (11,21,37,43,44). Notably, eccentric training will
primarily induce augmented eccentric strength, and the
transfer to concentric strength seems more variable (37).
Furthermore, few studies have investigated the effects of
eccentric training in athletes. Vikne et al. (43) recruited a
mix of recreationally trained individuals and elite athletes
engaged in power sports, such as track and field and
powerlifting. They demonstrated more hypertrophy in the
exercised musculus biceps brachii muscle after eccentric
training compared with concentric training over a 12-wk
study, but one repetition maximum (1RM) and maximal
concentric velocity at submaximal loads increased equally in
both groups. In power-sports athletes (e.g., track and field),
Friedmann-Bette et al. (12) compared eccentric overload
training, that is, maximal eccentric and concentric loads, with
traditional isotonic training in a one-legged knee-extension
exercise. The results were equivocal, but type IIX fiber
hypertrophy and improved vertical jump performance were
observed in the eccentric overload group only. These results
are intriguing, but isolated knee-extension is an open-chain
exercise that may have limited transfer to multijoint jumping
and sprinting abilities. In a recent study, Papadopoulos et al.
(32) used an isokinetic, eccentric bilateral leg press exercise
and reported robust effects on drop jump (DJ) performance.
However, this study was conducted on untrained students
with no active control groups, which raises questions about
the effectiveness of this intervention in athletes when com-
pared with other forms of resistance exercise training. To the
best of our knowledge, no previous study has investigated the
effects of SJ training with computer-controlled augmented
eccentric loading in athletes.
Purpose. The purpose of the present study was to exam-
ine training strategies for improving lower-body muscle
power in the form of vertical jumping and sprinting abilities.
We designed and tested three intervention strategies in well-
trained young athletes: 1) OWL, 2) motorized strength and
power training (MSPT), that is, isokinetic resistance exercise
combined with augmented eccentric load power training,
and 3) FSPT.
METHODS
Recruitment and Inclusion
Badminton, volleyball, and hockey players were recruited
from a Norwegian High School for elite sports. In addition,
we recruited volleyball players (G30 yr of age) from teams
competing at the two highest levels in Norway. All partici-
pants confirmed that they had regularly performed strength
OLYMPIC-STYLE WEIGHTLIFTING AND MUSCLE POWER Medicine & Science in Sports & Exercise
d
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and power training during the last 2 yr (Q1 session per
week), and all had some experience with OWL. Typically,
the athletes based their strength and power training on exer-
cises, such as squats, jump squats, deadlifts, Bulgarian split
squats, step-ups, lunges, power cleans, and hang cleans. None
of the athletes had experience with isokinetic exercise training
or augmented eccentric load exercises.
Fifty-two athletes provided written informed consent to
participate in this randomized controlled study. The National
Regional Committee for Research Ethics approved the pro-
ject. Before the intervention period started, six participants
declined to participate due to scheduling problems. During
the intervention period, seven participants dropped out: two
due to injury during the intervention period (lower back pain
and partial rupture of the musculus rectus femoris muscle),
two had difficulties attending at the scheduled times, two
moved, and finally, one refused to participate because he
was randomized into an unsatisfactory group. Thus, 39 par-
ticipants (10 women and 29 men) completed the intervention
(20 T3 yr; 182 T10 cm; 78 T12 kg).
Experimental Procedure
The participants were familiar with maximal vertical
jumping, strength, and sprint testing before commencing the
study. All performance tests were conducted twice before and
once after the intervention period. Two pretests were conducted
to allow for familiarization to the tests. Before the tests,
participants rested for a minimum of 24 h. All tests were
performed after a standardized warm-up of 5 min submaximal
cycling (100–150 W), followed by three to five submaximal
CMJ. Two to three submaximal 40-m runs were conducted
before the 30-m sprint test. Body composition, muscle thick-
ness, and muscle architecture were assessed in the fasted state
between 7 and 10 AM on test days.
After the pretests, the participants were randomly allo-
cated into three groups: OWL (n= 13, four women and nine
men), MSPT (n= 13, three women and 10 men), and FSPT
(n= 13, three women and 10 men). The athletes continued
their regular off-season training, but were instructed not to
conduct any strength and power training apart from the in-
tervention programs. Because of the complexity of the ath-
letes"training programs, we did not quantify their total
training loads. To counteract possible group allocation bias,
the group randomization process was stratified by sex, sport,
and CMJ (jump height).
Before the first training session, all participants took part
in two separate lifting-technique courses (of 1–2 h each).
The intention was primarily to ensure that the participants
had proper and similar lifting-technique skills. Second, we
aimed to identify individual flaws and weaknesses in the
participants"lifting techniques and provide feedback on how
to improve. The coaches who supervised the familiarization
training continued to provide technique supervision and cor-
rection during the intervention period.
Intervention Programs
The participants underwent an 8-wk, progressive training
program, involving 21 sessions (Table 1). During the first 3 wk,
participants completed two similar strength and power training
sessions per week. Thereafter, the training frequency increased
to three sessions per week, including two combined strength
and power training sessions, and one power training session.
The training programs were designed to ensure equal
training volumes between groups: sum of repetitions load
on bar (kg). To achieve an equal training volume, the OWL
group was assigned to perform the highest number of repe-
titions per session, whereas the MSPT group did the least
(due to the higher force per repetition in this technique).
Interset and interexercise rest periods were always 3 min.
For the training sessions that combined strength and power
training (Table 1), the mean durations were approximately
25, 35, and 45 min for the MSPT, FSPT, and OWL sessions,
respectively. The loads in the MSPT group were calculated
from the mean concentric force generated in each repetition,
which were recorded and digitally stored (1080 Quantum
synchro; 1080 Motion AB, Stockholm, Sweden).
Generally, the training programs combined heavy lifts
(strength) with lighter load power training (Table 1). All
training exercises were conducted with the intention to move
as fast as possible in the concentric phase, irrespective of load.
The OWL group applied the heaviest loads possible without
compromising adequate lifting techniques (repetition maxi-
mum [RM]). The FSPT group applied RM loads during the
heavy strength training. The MSPT group conducted isokinetic
squats with maximal effort in each repetition. For the MSPT
and FSPT groups, the power-training loads were reduced from
60% to 40% to 20% of squat 1RM during the training period
(20%, 15%, and 10% for the single leg exercises; Table 1).
In the first 3 wk, the heavy load strength training exercises
were followed by power training exercises in the MSPT and
FSPT groups, whereas in weeks 4–8, the sessions started
with power training exercise (loaded CMJ; Table 1). After
the initial 3 wk, a low volume power session was added and
conducted on every third training day (Table 1). For the
OWL group, we chose power cleans, hang cleans and hang
snatches, because these exercises are conducted with rela-
tively low loads and high velocity movements (Table 1). In
contrast to the other groups, the OWL group participants
were motivated to increase the loads in these ‘‘power
sessions’’ during the training intervention (applying the
heaviest loads possible in all sessions). The rationale for this
was based on the observations of McBride et al. (27) that
reported the highest power in the jump squat at low loads
(only body weight), whereas the opposite was the case for
power cleans; the highest power was reached at the heaviest
load (90% of 1RM).
Olympic-style weightlifting. OWL included full cleans
with front squat, hang cleans, power jerk behind the neck, full
snatches, and hang snatches (Table 1). The exercises and
combinations were based on best practice at the Norwegian
http://www.acsm-msse.org738 Official Journal of the American College of Sports Medicine
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Olympic Training Center (Oslo, Norway). The idea was to
combine exercises with a focus on different ROM. For ex-
ample, the clean with front squat ensures large knee and hip
ROM and allows for quite heavy weights, whereas the power
jerk behind the neck, in contrast, involves a small ROM and a
very rapid movement. The snatch, hang snatch, and hang
clean were considered to be exercises that lay in between the
previously mentioned exercises in terms of ROM and loads.
Motorized strength and power training. Acomput-
erized robotic engine system (1080 Quantum synchro; 1080
Motion AB, Stockholm, Sweden) controlled the load for the
MSPT group. The robotic engine was attached to a custom-
made Smith machine.
The strength training was conducted as isokinetic squat
training. The concentric velocity was set to 0.2–0.4 mIs
j1
,
starting with 0.4 mIs
j1
and progressing to 0.3 mIs
j1
, and
finally, 0.2 mIs
j1
during the intervention period (Table 1).
The participants were instructed to switch from eccentric to
concentric phases with maximal effort and keep on pushing
maximally until they reached the upright position. The ec-
centric phase was always isotonic, with a velocity of less than
1.0 mIs
j1
. The participants were instructed to lower the bar in
a slow, controlled manner (~0.4–0.5 mIs
j1
). The eccentric
load was individually adjusted to match the concentric force
generated; that is, if the mean concentric force for the
full ROM was 1000 N, the constant eccentric load was set to
1000 N. The participants received feedback on their perfor-
mance after each set via graphs displaying the mean con-
centric force (N) for each repetition and the whole set.
Power training was conducted as CMJ with external loads
(countermovement to half squat depth). The loads were iso-
tonic and set to 20%–60% of the participant"s squat 1RM
(10%–20% for single leg CMJ; see Table 1). The eccentric
load was 20%–40% higher than the concentric load (in-
creasing from 20% to 30% and finally 40%; see Table 1). The
robotic engine system seamlessly switched off the eccentric
overload when the eccentric velocity reached G0.2 mIs
j1
.
This allowed for continuous jumping in the five repetitions
per set. The participants received feedback on their perfor-
mance after each set via graphs displaying the mean con-
centric power (W) for each repetition and the whole set.
Free weight strength and power training. The
FSPT was designed to be as simple as possible and was
identical to the MSPT group, except for the use of freeweights
TABLE 1. Overview of the three training interventions: OWL, MSPT, and FSPT.
OWL MSPT FSPT
Sessions 1–6 Sessions 1–6 Sessions 1–6
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Clean with front squat 4 5 RM Squat 0.4 mIs
j1
25 Squat 3 5RM
Hang clean 3 5 RM Single leg squat 0.4 mIs
j1
225 Single leg squat 2 25RM
Snatch 2 5 RM CMJ 60% of 1RM + 120% ecc. 2 5 CMJ 60% of 1RM 2 5
Power jerk behind the neck 3 5 RM Single leg CMJ 20% of 1RM + 120% ecc. 2 25 Single leg CMJ 20% of 1RM 2 25
Sessions 7, 9, 10, 12, 13, and 15 Sessions 7, 9, 10, 12, 13, and 15 Sessions 7, 9, 10, 12, 13, and 15
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Snatch 4 4 RM CMJ 40% of 1RM + 130% ecc. 3 5 CMJ 40% of 1RM 3 5
Hang clean 4 4 RM Single leg CMJ 15% of 1RM + 130% ecc. 2 25 Single leg CMJ 15% of 1RM 2 25
Clean with front squat 4 5 RM Squat 0.3 mIs
j1
35 Squat 5 4RM
Power jerk behind the neck 4 4 RM Single leg squat 0.3 mIs
j1
225 Single leg squat 2 35RM
Sessions 8, 11, and 14 (power only) Sessions 8, 11, and 14 (power only) Sessions 8, 11, and 14 (power only)
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Power clean 5 3 RM CMJ 40% of 1RM + 130% ecc. 3 5 CMJ 40% of 1RM 3 5
Hang clean 3 3 RM Single leg squat 15% of 1RM + 130% ecc. 2 35 Single leg CMJ 15% of 1RM 2 35
Hang snatch 3 3RM
Sessions 16, 18, and 19 Sessions 16, 18, and 19 Sessions 16, 18, and 19
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Snatch 5 3 RM CMJ 20% of 1RM + 140% ecc. 4 5 CMJ 20% of 1RM 4 5
Hang clean 5 3 RM Single leg CMJ 10% of 1RM + 140% ecc. 2 25 Single leg CMJ 10% of 1RM 2 25
Clean with front squat 4 5 RM Squat 0.2 mIs
j1
45 Squat 6 3RM
Power jerk behind the neck 4 3 RM Single leg squat 0.2 mIs
j1
225 Single leg squat 2 35RM
Session 17 (power only) Session 17 (power only) Session 17 (power only)
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Power clean 5 3 RM CMJ 20% of 1RM + 140% ecc. 4 5 CMJ 20% of 1RM 4 5
Hang clean 3 3 RM Single leg CMJ 10% of 1RM + 140% ecc. 2 35 Single leg CMJ 10% of 1RM 2 35
Hang snatch 3 3RM
Session 20 (power only) Session 20 (power only) Session 20 (power only)
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Power clean 5 3 RM CMJ 20% of 1RM + 140% ecc. 2 5 CMJ 20% of 1RM 3 5
Hang clean 3 3 RM Single leg squat 10% of 1RM + 140% ecc. 2 15 Single leg CMJ at 10% of 1RM 2 25
Hang snatch 3 3RM
Session 21 Session 21 Session 21
Warm-up. (40%, 60%, 80% of training load) 3 5 Warm-up. (increasing effort during the set) 1 10 Warm-up. (40%, 60%, 80% of training load) 3 5
Snatch 3 3 RM CMJ 20% of 1RM + 140% ecc. 2 5 CMJ 20% of 1RM 2 5
Hang clean 3 3 RM Single leg CMJ 10% of 1RM + 140% ecc. 2 15 Single leg CMJ 10% of 1RM 2 25
Clean with front squat 3 5 RM Squat 0.2 mIs
j1
25 Squat 3 3RM
Power jerk behind the neck 3 3 RM Single leg squat 0.2 mIs
j1
215 Single leg squat 2 25RM
The MSPT group trained isokinetic squats and the speed of the concentric phase is given in meter per second. For the MSPT and FSPT groups, CMJ loads (including single leg squats)
are given as percentage of 1RM in the bilateral squat. For the MSPT group, the CMJ were conducted with augmented eccentric loads given as percentage of the concentric loads (i.e.,
120% ecc could mean a 50-kg concentric load and a 60-kg eccentric load).
ecc, eccentric load.
OLYMPIC-STYLE WEIGHTLIFTING AND MUSCLE POWER Medicine & Science in Sports & Exercise
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Copyright © 2017 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
(isotonic) instead of a Smith machine (Table 1). We chose
free weights because most high-level athletes generally
favor this over the Smith machine.
Tests
Jump performance. Participants performed SJ, CMJ,
and DJ on a force platform with arms akimbo (sampling rate,
2000 Hz; AMTI OR6-5-1; AMTI, Watertown, MA). For
SJ, participants were instructed to squat until their knee
joint angle reached 80-–90-(verified by a goniometer during
warm-ups). The hips were flexed to 70-–80-(180-in upright
position). Approximately 1 s after reaching this position, the
investigator gave the signal to perform a maximal vertical
jump. SJ attempts flawed by an initial counter movement
(more than 5% below body weight) were discarded. CMJ
were performed from an upright position to a self-
determined depth, followed by an immediate maximal ver-
tical jump. DJ were performed from a 40-cm-high box, with
the same instructions as for CMJ. In each case, the mean of
the two highest jumps of three to six attempts was used for
further analysis.
Sprint performance. We assessed sprint performance
on an indoor rubberized track (Mondo, Conshohocken, PA)
with an electronic timing system (Biomekanikk, Oslo, Norway).
As a timing trigger, a single-beamed timing gate was placed
0.6 m after the start line (0.5 m above ground level). Dual-
beamed timing gates were placed every 5 m along the 30-m
sprint distance. A stand-still start was used, one foot in front
of the other; and the participants accelerated as fast as possible.
Haugen et al. (16,17) have previously reported coefficients
of variation (CV) in the range of 0.9%–1.6% with this
system setup and procedure.
Vertical jump power. A linear encoder was used to
assess vertical power during loaded CMJ (Musclelab Linear
Encoder; Ergotest Innovation, Porsgrunn, Norway). The en-
coder"s string was mounted to the bar, and the device mea-
sured the vertical displacement (d) and velocity (v)duringthe
concentric phase of the jump (200 Hz sampling rate; 0.019 mm
resolution). The power output(P) was estimated on the system
mass (m), that is, 90% of body mass and the external mass
(v=d/t; acceleration [a]=v/t,force[F]=mg + ma;P=
Fv). A concentric force–velocity relationship was established
and peak power could be estimated (best fit polynomial;
software from Ergotest Innovation). With the instruction to
jump as high as possible, the participants completed three
CMJateachloadwith~5sbetweeneachjumpand2min
between sets. Participants performed the first set without
external load (body weight and a plastic stick [~300 g]), and
then the female and male participants increased the load by
10 and 20 kg, respectively. The women progressed to 60 kg
and the men to 80 kg, or until the lifting technique was
judged inadequate by the test leader. The attempt with
highest peak power from each load was used for further
analysis.
Squat. For measurements of 1RM in parallel squat, we
used a Smith machine (Multipower, Technogym, Cecena FC,
Italy). The first 1RM attempt was conducted after two warm-
up lifts at ~85% and one repetition at ~92.5% of expected
1RM. Warm-up sets and attempts were separated by 3 min of
rest. If the 1RM attempt was successful, the load was in-
creased by 2.5%–5% until the test leader predicted failure on
the next attempt. To ensure the same squat depth from
pretesting to posttesting, we measured the distance from the
floor to the bar. The distance was marked with a pen,
providing visual feedback for the test leader.
Lean mass measurements and ultrasound mea-
surements . Body composition was assessed using a narrow
angle fan beam Lunar iDXA scan (DXA; GE Healthcare,
Madison, WI). The iDXA was calibrated daily according to the
manufacturer"s guidelines. The iDXA machine automatically
chose scanning mode, with all athletes scanned in the standard
mode. The images were analyzed with enCORE software
(version 14.10.022; GE-Healthcare). The software automati-
cally defined the different body segments: arms, trunk, and
legs. However, all scans were manually controlled and adjusted
to ensure optimal pretraining and posttraining comparisons.
Muscle thickness and architecture of musculus vastus
lateralis and muscle thickness of musculus rectus femoris
in the dominant leg were assessed using B-mode ultraso-
nography (probe size of 4.5 cm and 8–17 MHz scanning
frequency; GE Logiq 9, GE Healthcare, Little Chalfont,
UK). The scans were obtained at 50% of the femur length
(1). Two to three images were captured at each position.
The position of the probe was marked on the skin (hy-
drophobic pen) and subsequently marked on a soft trans-
parent plastic sheet superimposed on the thigh. Landmarks,
such as moles and scars, were also marked on the plastic
sheets for relocation of the scanned areas during posttraining
measurements. Both longitudinal and cross sectional images
were obtained from musculus vastus lateralis, whereas only
transverse images were obtained from musculus rectus
femoris. Transverse images were used for assessing muscle
thickness, whereas longitudinal images were used for
assessing pennation angle and fascicle length. ImageJ
software was used for image analyses (Wayne Rasband,
National Institutes of Health, Bethesda, MD), where muscle
thickness was measured at three different sites on the
transverse image and an average of these measurements was
used for further calculations. Pennation angle was measured
three times at the same site on the longitudinal image and an
average was used for further calculations. Fascicle length
was calculated from the following equation: fascicle length =
thickness/sin(pennation angle). The thickness value was
the average of three measurements at three sites on the
longitudinal image. For both transverse and longitudinal
images, the preimages and postimages were analyzed at
the same time, and great care was taken to match the
thickness and angle measurements sites on the preimages and
postimages. The assessor was blinded for the participants"
group affiliations.
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Nutrition
To ensure adequate energy and protein intake, a high-
protein bar was ingested after eachtrainingsession(20gpro-
tein, 31 g carbohydrates, and5gfat;Yt,Tine,Oslo,Norway).
Statistical Analysis
A priori power calculations with a SD of 5% suggested 15
participants were needed in each group to detect a difference
of 5% with 80% power (GraphPad StatMate version 2.00;
GraphPad Software, CA). We ended up with 13 athletes in each
group, which gave us 80% power to detect a difference of 6%
between groups with a standard deviation of 5% (e.g., CMJ).
For all performance tests the means of the two pretests
were used as baselines for further calculations. Based on the
two pretests, CV and intraclass correlation (ICC) were calcu-
lated for each test (19). The linear mixed model procedure in
SPSS Statistics (version 21; IBM Corp. Armonk, NY) was
used to analyze the changes and differences in the means
while adjusting for the effects of covariates in the three
groups: baseline level, bodyweight, and training volume. A
more detailed description of the procedures used can be found
elsewhere (40). Changes within groups are reported as % TSD.
The magnitudes of within-group changes and between-group
differences were assessed as ES (mean change or difference
divided by baseline SD of all subjects), and evaluated with a
modification of Cohen"s scale that aligns with the ES used for
biserial correlations: G0.2, trivial; 0.2–0.6, small; 0.6–1.2,
moderate; 91.2, large (20). Inferences were based on the
assumption of the normality of sampling distribution of the
differences. To make inferences about true values of effects
in the population studied, we used nonclinical magnitude-
based inference rather than null-hypothesis significance
testing (20). Magnitudes were evaluated mechanistically: if
the confidence interval overlapped substantial positive and
negative values (0.2 and j0.2), the effect was deemed
unclear. 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 (***);
999.5%, most likely (20).
RESULTS
Adequate reliability was established for all performance
tests. Loaded CMJ, DJ, and SJ had the highest CV of
5%–10%, and lowest ICC of 0.92–0.96, whereas 1RM
squat, CMJ, and 30-m sprint had the lowest CV, 1%–5%; and
highest ICC, 0.96–0.98. Moreover, there were no performance
improvements from pre 1 to pre 2 for any tests (all partici-
pants pooled).
No group differences were detected before the interven-
tion period (Table 2). The total training volume (sum of
repetitions load [kg]) during the intervention period was
similar between the groups (Table 2).
Except for SJ with heavy loads (40 kg for women and 80 kg
for men) 8 wk of OWL did not affect vertical jumping or
sprinting performance (Table 3). Body composition was
unaltered, and no clear architectural changes were dem-
onstrated in musculus rectus femoris and musculus vastus
lateralis.
MSPT demonstrated overall small but clear changes in
both vertical jumping and sprinting performance (Table 3).
Total lean mass and bone mass increased significantly
(PG0.05), but the changes in whole body composition
were trivial after 8 wk of MSPT. However, the thickness of
musculus rectus femoris and musculus vastus lateralis in-
creased. A small increase in fascicle angle in musculus
vastus lateralis was detected, although fascicle length was
unaltered.
FSPT induced generally small but clear changes in 1RM
squat and vertical jump performance. Performance in the
30-m sprint, however, did not improve after 8-wk FSPT
training (Table 3). There were no clear changes in body
composition, but muscle thickness of musculus vastus
lateralis and musculus rectus femoris increased slightly.
TABLE 2. Simple statistics for the main variables in each group at baseline.
All (N= 39) OWL (n= 13) FSPT (n= 13) MSPT (n=13)
Mean TSD Mean TSD Mean TSD Mean TSD
1 RM squat (kg) 112 T25 109 T28 116 T27 111 T23
CMJ (cm) 37.4 T6.8 35.8 T8.8 39.3 T5.2 37.0 T6.1
SJ (cm) 35.0 T6.4 33.7 T8.2 36.6 T5.6 34.6 T5.1
DJ 40 (cm) 36.8 T6.9 35.4 T8.5 38.7 T5.9 36.4 T6.3
Peak power (W) 1847 T388 1786 T490 1946 T362 1809 T301
Power 40/80 kg (W) 1618 T365 1571 T449 1736 T321 1547 T309
30 m sprint (s) 4.29 T0.26 4.38 T0.37 4.19 T0.17 4.32 T0.19
20–30 m flying (s) 1.27 T0.09 1.30 T0.13 1.24 T0.06 1.28 T0.06
Bodyweight (kg) 78 T12 76 T15 80 T12 78 T11
Lean body mass (kg) 60.3 T11.0 58.8 T14.0 62.1 T10.4 59.9 T8.5
Fat mass (kg) 13.4 T3.9 13.2 T3.8 13.4 T2.7 13.6 T5.1
Musculus vastus lateralis fascicle angle (-) 21.3 T2.9 21.2 T3.1 21.5 T3.4 21.2 T2.4
Musculus vastus lateralis fascicle length (mm) 74.6 T10.0 73.9 T10.8 77.4 T9.5 72.8 T9.9
Musculus vastus lateralis thickness (mm) 26.8 T3.8 26.1 T4.5 28.0 T3.8 26.4 T3.0
Musculus rectus femoris thickness (mm) 16.6 T3.1 15.3 T3.8 17.3 T2.6 17.4 T2.6
Total training volume (kg) 58,084 T13,080 59,876 T18,595 55,674 T9067 58,700 T10,178
OLYMPIC-STYLE WEIGHTLIFTING AND MUSCLE POWER Medicine & Science in Sports & Exercise
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Changes in musculus vastus lateralis architecture, fascicle
angle, and length were trivial (Table 3).
The group comparisons showed that the FSPT group had
small, but clear improvements in 1RM strength (ES = 0.32 T
0.22), SJ height (ES = 0.22 T0.27), CMJ height (ES = 0.22 T
0.25) and loaded CMJ peak power (ES = 0.23 T0.35)
compared with the OWL group. The OWL group showed
improved 30-m sprint performance (ES = 0.20 T0.25)
compared with the FSPT group, mainly due to a decrease in
the FSPT group. The MSPT intervention was superior to
OWL in increasing 1RM strength (ES = 0.40 T0.22), SJ
height (ES = 0.26 T0.27), loaded jump power (40/80 kg; ES =
0.28 T0.31), DJ height (ES = 0.33 T0.31), 20–30 m flying
sprint performance (ES = 0.30 T0.25), fascicle angle (ES =
0.25 T0.40), and musculus vastus lateralis thickness (ES =
0.24 T0.22). MSPT was also more effective than FSPT in
increasing DJ height (ES = 0.26 T0.33), 30-m sprint
performance (ES = 0.34 T0.24), and fascicle angle (ES =
0.26 T0.41).
DISCUSSION
In the present study, we observed that OWL was statisti-
cally inferior to FSPT in improving SJ and CMJ height, peak
power during loaded CMJ, and 1RM squat. In contrast,
MSPT, that is, isokinetic strength training combined with
augmented eccentric load power training, induced generally
small but robust effects on CMJ and SJ height, DJ rebound
height, and sprint running, as well as loaded CMJ power and
1RM squat. MSPT was superior to FSPT in improving DJ
rebound height and 30-m sprint times.
Our participants were encouraged to have a fast, ‘‘explo-
sive’’ concentric phase in each lift, and all sessions included
supervised training with technical feedback. Despite this,
we observed that OWL training resulted in smaller im-
provements in jumping and sprinting performances than
expected based on previous publications (9,10,14,18,41,42).
We included several derivatives of OWL exercises, and the
training volume and frequency seemed appropriate (two to
three sessions per week). The intervention period was short
(8 wk), but still relevant for athletes with limited prepara-
tory periods, and of similar duration to the study of Channell
and Barfield (9), in which OWL training did improve vertical
jumping abilities. To illustrate the specific effects of the OWL
training, our athletes improved their 1RM hang clean by
29% T11% (PG0.001; estimated from training loads [31]);
in line with the observations of others (42). This indicates
that the problem may lie in the transfer from OWL techniques
to jumping and sprinting movements.
Although studies have shown high lower-body power
outputs during OWL (13,25,27), there are often large dif-
ferences between skilled weightlifters and athletes engaged
in other sports that use OWL as part of their training. Inap-
propriate lifting techniques would probably reduce or abolish
the transfer to other abilities, such as jumping and sprinting.
Intriguingly, the OWL training induced larger gains of lean
mass in the arms than the lower body (3.3% vs j0.4%, PG
0.05; trivial effects). These results indicate that upper-body
muscles were highly active during the OWL training, thereby
alleviating the load on the lower-body muscles. Indeed, the
ability to transfer forces between joints via biarticular muscles
implies the possibility of reducing the work of the lower limb
muscles in OWL.
OWL is kinematically different from both vertical jumping
(25) and sprinting (unilateral movement). Thus, the transfer
from OWL training to jump and sprint performance is not
TABLE 3. Percent changes across groups and magnitude-based inferences for the changes when adjusted to baseline mean, bodyweight and total training volume.
OWL (n= 13) FSPT (n= 13) MSPT (n=13)
Mean Change TSD Inference Mean Change TSD Inference Mean Change TSD Inference
Performance tests (% change from baseline)
1RM squat 3.4 T7.9 trivial j11.4 T4.0 smallj***
a
13.4 T4.3 sm/modj***
a
CMJ 0.8 T6.2 trivial j5.0 T4.5 smallj**
a
3.3 T.6.0 trivial j
SJ 1.2 T7.7 trivial j5.4 T2.5 smallj**
a
6.2 T5.3 small j**
a
DJ 40 j0.4 T6.7 trivial ,1.0 T6.9 trivialj6.1 T7.7 small j**
a,b
Peak power 2.6 T5.2 trivial j8.1 T10.9 small j**
a
6.1 T2.8 small j**
Power 40/80 kg 5.9 T8.1 small j** 10.1 T8.7 small j*** 12.6 T9.4 sm/mod j***
a
30 m sprint j0.5 T1.8 trivial j
b
0.7 T1.3 trivial ,j1.3 T1.7 smallj**
b
20–30 m flying 0.5 T2.0 trivial ,j0.2 T2.5 trivial ,j1.5 T2.0 small j**
a
Body composition (% change from baseline)
Bodyweight 0.3 T2.2 trivial j0.5 T2.8 trivial j0.5 T2.2 trivial j
Lean mass (total) 0.7 T2.2 trivial j1.2 T2.9 trivial j2.0 T3.5 trivial j
Lean mass legs j0.4 T2.7 trivial j1.3 T2.6 trivial j2.2 T3.2 trivial j
Lean mass arms 3.3 T3.8 trivial j0.1 T4.3 trivial j2.1 T4.5 trivial j
Fat mass j1.3 T5.8 trivial ,j3.3 T10.9 trivial ,j0.6 T12.5 trivial ,
Bone mass 0.3 T1.1 trivial j0.8 T0.7 trivial j0.8 T0.9 trivial j
Musculus vastus lateralis fascicle angle 2.2 T5.7 trivial j2.0 T5.6 trivial j5.4 T6.9 small j**
a,b
Musculus vastus lateralis fascicle length 0.2 T7.1 trivial j1.7 T6.7 trivial jj0.4 T5.9 trivial ,
Musculus vastus lateralis thickness 2.8 T4.0 trivial j3.8 T4.8 small j** 6.1 T3.3 small j***
a
Musculus rectus femoris thickness 2.8 T9.1 trivial j5.4 T7.7 small j** 6.6 T6.5 small j**
Magnitude thresholds (for mean change divided by baseline SD of the total sample): G0.20, trivial; 0.20–0.59, small; 0.60–1.19, moderate; 91.20, large.
Asterisksindicate effects clearat the 5% level and likelihoodthat the true effect issubstantial or trivial,as follows: *possible,**likely, ***very likely, ****most likely. **issignificant at PG0.05.
Differences between groups are marked with numbers:
a
Different from OWL.
b
Different from FSPT.
c
Different from MSPT.
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obvious. Nevertheless, OWL might be more advantageous for
improving hip extension moments in joint positions more
relevant for sprinting than vertical jumping. Interestingly, the
improvement in 30-m sprint was trivial for OWL, but still
superior to free weight strength training, due to a slight
decrease in performance in the latter group.
Another possibility for limited improvements from OWL
is low eccentric muscle force production, because eccentric
muscle actions are possibly more potent in increasing muscle
mass than concentric contractions (37). In OWL, the bar must
be dropped to the hips or directly to the floor, and the eccentric
stimulus for the lower leg muscles is consequently negligible.
In addition to myofiber hypertrophy, eccentric contraction–
induced neuraland tendon adaptations could plausibly explain
the group differences in jumping and sprinting improvements.
In accordance with our results, Hoffman et al. (18) found
no significant improvements in either vertical jumping or
sprinting after 15 wk of OWL training. In contrast to other
previous studies (4,9,10,18,42), but similar to the present
study, Hoffman et al. recruited well-trained athletes. How-
ever, the authors concluded that OWL training was superior
to powerlifting training, mostly because the powerlifting
group surprisingly showed reductions in their vertical jump
height. It seems fair to say that the efficacy of OWL training
in athletes warrants further research.
In the present study, we included OWL exercises only,
similar to Chaouahi et al. (10). Other previous investigations
have included a mix of exercises, such as squats, lunges
and leg press exercises, in addition to the OWL exercises
(4,9,18,42). The inclusion of other exercises makes it im-
possible to conclude that OWL per se induced the observable
training effects.
In accordance with the present study, some previous studies
equalized or controlled for training volume when comparing
OWL with traditional strength and power training (4,10), but
not all did so (9,18). Without equal training volume, one
cannot exclude the possibility of a dose–response effect, and
direct comparisons are not readily possible.
The motorized strength and power training, using a ro-
botic engine training device, allowed for maximal effort and
force generation through the whole ROM during the slow,
isokinetic squat exercises, and augmented eccentric loading
during the power training exercises. MSPT induced similar
improvements in 1RM squat as did FSPT, but did lead to
larger progressions in DJ performance (vertical rebound
jump height) and sprint running ability (and was clearly
better than OWL). The muscle thickness of musculus rectus
femoris and musculus vastus lateralis consistently increased
in both the MSPT and FSPT groups, but fascicle angle in-
creased only in the MSPT group. Previous studies have
shown that various resistance training modalities induce
contrasting changes in fascicle angle (6,36). Training regimes
involving concentric contractions typically yield a higher
angle of pennation with no consistent change in fascicular
length, whereas the opposite findings are observed with ec-
centric contractions. With equal training volumes across
groups, the higher concentric force generation during isokinetic
squats seems to have driven these adaptations.
In contrast to hypertrophic strength training (1,22), power
training has been accompanied by no change or a decrease in
fascicle angle and an increase in fascicle length (2,7,24). The
participants in the present study conducted both heavy strength
and power training. Since the fascicle angle increased and fas-
cicle length trivially decreased in the MSPT group, we suggest
that the concentric, high-force contractions were the domi-
nating stimulus for the architectural changes. Arguably, hy-
pertrophy was achieved in this group via sarcomerogenesis in
parallel, rather than in series. However, fascicle length was
calculated using simple trigonometric extrapolation tech-
niques in the present study. Advanced techniques enabling
direct measurements may have been more sensitive to
changes in this parameter.
The MSPT group performed power training with an aug-
mented eccentric load (120%–140% of the concentric load).
The idea was that this would give a stronger stimulus to the
neuromuscular system(30). This was, apparently, not the case
for the SJ or the CMJ abilities. On the other hand, the MSPT
group did experience superior improvements in the DJ test.
Intriguingly, a DJ will cause a high eccentric load, quite
similar to the augmented eccentric load during the loaded
CMJ training. Consequently, the augmented eccentric load
training appears to have transferred effectively to DJ per-
formance. In support of our findings, strategies (e.g., use of
rubber bands) to augment eccentric loading during plyomet-
rics are used in practice by athletes (30,39).
This study has several potential limitations. First, one
could argue that it is atypical to train using purely OWL
exercises, and their effects could be optimized when com-
bined with traditional strength and power training; similar
studies have successfully added squats and leg press exer-
cises to an OWL program (5,9,10,42). However, we chose
the present design to isolate the effects of OWL. Second, the
motorized training included slow velocity, isokinetic squat
training and augmented eccentric load jump squat training.
The relative contribution of these training modes in terms of
performance enhancements cannot be inferred from the
present results. Future experiments should investigate these
training modes separately. Third, the motorized squat train-
ing was an unaccustomed exercise modality for all partici-
pants, and we therefore cannot exclude the possibility that
some of the performance gains were due to this being a
novel stimulus and/or the enhanced feedback on perfor-
mance. Finally, we calculated the total training volume
simply by summarizing the products of the load on the bar
and the number of repetitions for each set. This approach
may not be optimal when comparing training programs with
different exercises, including ballistic exercises (such as OWL).
PRACTICAL APPLICATION
In the present study, we demonstrated that using computer-
controlled robotic engines for strength and power training was
OLYMPIC-STYLE WEIGHTLIFTING AND MUSCLE POWER Medicine & Science in Sports & Exercise
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a time-efficient approach to increase vertical jumping and
sprinting performance in athletes. Traditional FSPT seemed
also effective in improving vertical jumping height, whereas
OWL appeared less effective as a sole training mode. If any-
thing, OWL appeared more favorable in improving sprinting
than vertical jumping performance. OWL may work well for
certain athletes, but adequate lifting technique is probably an
important prerequisite. Moreover, for athletes with already
high maximal strength, OWL might be more relevant for im-
proving lower-body muscle power and speed than for weaker
athletes. It could also be important to combine OWL exercises
with exercises focusing on eccentric muscle actions (i.e., DJ).
For young ‘‘power athletes,’’ such as those recruited in the
present study (ice hockey, volleyball, and badminton players),
we recommend a base of simple heavy strength and power
training exercises (e.g., squats) that includes a controlled ec-
centric phase, to favor muscle growth and maximal force gains.
CONCLUSIONS
MSPT was more time-efficient while being equally as ef-
fective or superior to FSPT in improving both vertical jumping
and sprinting performance. Hence, isokinetic strength training
combined with eccentric augmented load power training
emerges as an attractive training approach for a wide range of
athletes. In contrast, OWL appeared generally ineffective and
inferior to traditional FSPT in developing vertical jumping
performance in athletes.
We would like to thank Magnus Midttun, Yngve Apneseth, Lene
Puntervold, Charlotte Krohn, Vebjørn Vingsand, Line Rønningen,
Marte Mo Anderssen, Jon Aase, Sindre Madsgaard and Annbjørg
Engeseth for supervising the athletes during the training sessions,
and all the athletes for their hard work.
The authors declare no conflicts of interest. This study is not
funded. The results of the present study do not constitute endorsement
by the American College of Sports Medicine.
REFERENCES
1. Aagaard P, Andersen JL, Dyhre-Poulsen P, et al. A mechanism for
increased contractile strength of human pennate muscle in response
to strength training: changes in muscle architecture. J Physiol.
2001;534(Pt. 2):613–23.
2. Alegre LM, Jime
´nez F, Gonzalo-Orden JM, Martin-Acero R, Aguado X.
Effects of dynamic resistance training on fascicle length and iso-
metric strength. JSportsSci. 2006;24(5):501–8.
3. Amiridis IG, Martin A, Morlon B, et al. Co-activation and tension-
regulating phenomena during isokinetic knee extension in seden-
tary and highly skilled humans. Eur J Appl Physiol Occup Physiol.
1996;73(1–2):149–56.
4. Arabatzi F, Kellis E. Olympic weightlifting training causes dif-
ferent knee muscle-coactivation adaptations compared with tradi-
tional weight training. J Strength Cond Res. 2012;26(8):2192–201.
5. Arabatzi F, Kellis E, Sae
`z-Saez De Villarreal E. Vertical jump
biomechanics after plyometric, weight lifting, and combined
(weight lifting + plyometric) training. J Strength Cond Res. 2010;
24(9):2440–8.
6. Blazevich AJ, Cannavan D, Coleman DR, Horne S. Influence of
concentric and eccentric resistance training on architectural adap-
tation in human quadriceps muscles. J Appl Physiol (1985). 2007;
103(5):1565–75.
7. Blazevich AJ, Gill ND, Bronks R, Newton RU. Training-specific
muscle architecture adaptation after 5-wk training in athletes. Med
Sci Sports Exerc. 2003;35(12):2013–22.
8. Carlock JM, Smith SL, Hartman MJ, et al. The relationship be-
tween vertical jump power estimates and weightlifting ability: a
field-test approach. J Strength Cond Res. 2004;18(3):534–9.
9. Channell BT, Barfield JP. Effect of Olympic and traditional resis-
tance training on vertical jump improvement in high school
boys. J Strength Cond Res. 2008;22(5):1522–7.
10. Chaouachi A, Hammami R, Kaabi S, Chamari K, Drinkwater EJ,
Behm DG. Olympic weightlifting and plyometric training with
children provides similar or greater performance improvements
than traditional resistance training. J Strength Cond Res. 2014;
28(6):1483–96.
11. English KL, Loehr JA, Lee SM, Smith SM. Early-phase muscu-
loskeletal adaptations to different levels of eccentric resistance
after 8 weeks of lower body training. Eur J Appl Physiol. 2014;
114(11):2263–80.
12. Friedmann-Bette B, Bauer T, Kinscherf R, et al. Effects of strength
training with eccentric overload on muscle adaptation in male ath-
letes. Eur J Appl Physiol. 2010;108(4):821–36.
13. Garhammer J. Power production by Olympic weightlifters. Med
Sci Sports Exerc. 1980;12(1):54–60.
14. Garhammer J, Takano B. Training for weightlifting. In: Komi PV,
editor. Strength and Power in Sports. 2nd ed. Blackwell Science
Ltd; 2003. p. 502–15.
15. Hackett D, Davies T, Soomro N, Halaki M. Olympic weightlifting
training improves vertical jump height in sportspeople: a systematic
review with meta-analysis. Br J Sports Med. 2016;50(14):865–72.
16. Haugen T, Tonnessen E, Seiler S. Correction factors for photocell
sprint timing with flying start. Int J Sports Physiol Perform.
2015;10(8):1055–7.
17. Haugen TA, Tonnessen E, Svendsen IS, Seiler S. Sprint time dif-
ferences between single- and dual-beam timing systems. J Strength
Cond Res. 2014;28(8):2376–9.
18. Hoffman JR, Cooper J, Wendell M, Kang J. Comparison of
Olympic vs. traditional power lifting training programs in football
players. J Strength Cond Res. 2004;18(1):129–35.
19. Hopkins WG. Spreadsheets for analysis of validity and reliability.
Sport Science. 2015;19:36–42.
20. Hopkins WG, Marshall SW, Batterham AM, Hanin J. Progressive
statistics for studies in sports medicine and exercise science. Med
Sci Sports Exerc. 2009;41(1):3–13.
21. Isner-Horobeti ME, Dufour SP, Vautravers P, Geny B, Coudeyre
E, Richard R. Eccentric exercise training: modalities, applications
and perspectives. Sports Med. 2013;43(6):483–512.
22. Kawakami Y, Abe T, Fukunaga T. Muscle-fiber pennation angles
are greater in hypertrophied than in normal muscles. J Appl Physiol
(1985). 1993;74(6):2740–4.
23. Lueders TN, Zou K, Huntsman HD, et al. The >7A1-integrin ac-
celerates fiber hypertrophy and myogenesis following a single bout
of eccentric exercise. Am J Physiol Cell Physiol. 2011;301(4):
C938–46.
24. Luteberget LS, Raastad T, Seynnes O, Spencer M. Effect of tra-
ditional and resisted sprint training in highly trained female team
handball players. Int J Sports Physiol Perform. 2015;10(5):642–7.
25. MacKenzie SJ, Lavers RJ, Wallace BB. A biomechanical compari-
son of the vertical jump, power clean, and jump squat. JSportsSci.
2014;32(16):1576–85.
26. Martineau LC, Gardiner PF. Insight into skeletal muscle
mechanotransduction: MAPK activation is quantitatively related to
tension. J Appl Physiol (1985). 2001;91(2):693–702.
27. McBride JM, Haines TL, Kirby TJ. Effect of loading on peak
power of the bar, body, and system during power cleans, squats, and
jump squats. JSportsSci. 2011;29(11):1215–21.
http://www.acsm-msse.org744 Official Journal of the American College of Sports Medicine
APPLIED SCIENCES
Copyright © 2017 by the American College of Sports Medicine. Unauthorized reproduction of this article is prohibited.
28. McBride JM, Skinner JW, Schafer PC, Haines TL, Kirby TJ.
Comparison of kinetic variables and muscle activity during a squat
vs. a box squat. J Strength Cond Res. 2010;24(12):3195–9.
29. McBride JM, Triplett-McBride T, Davie A, Newton RU. A
comparison of strength and power characteristics between power
lifters, olympic lifters, and sprinters. J Strength Cond Res. 1999;
13(1):58–66.
30. Moore CA, Schilling BK. Theory and application of agumented
eccentric loading. Strength and Conditioning Journal. 2006;27(5):
20–7.
31. Morales J, Sobonya S. Use of submaximal repetition tests for
predicting 1-RM strength in class athletes. J Strength Cond Res.
1996;10(3):186–9.
32. Papadopoulos C, Theodosiou K, Bogdanis GC, et al. Multiarticular
isokinetic high-load eccentric training induces large increases in
eccentric and concentric strength and jumping performance.
JStrengthCondRes. 2014;28(9):2680–8.
33. Pereira MI, Gomes PS. Movement velocity in resistance training.
Sports Med. 2003;33(6):427–38.
34. Pipes TV, Wilmore JH. Isokinetic vs isotonic strength training in
adult men. Med Sci Sports. 1975;7(4):262–74.
35. Ratamess NA, Beller NA, Gonzalez AM, et al. The effects of
multiple-joint isokinetic resistance training on maximal isokinetic
and dynamic muscle strength and local muscular endurance.
J Sports Sci Med. 2016;15(1):34–40.
36. Reeves ND, Maganaris CN, Longo S, Narici MV. Differential
adaptations to eccentric versus conventional resistance training in
older humans. Exp Physiol. 2009;94(7):825–33.
37. Roig M, O"Brien K, Kirk G, et al. The effects of eccentric versus
concentric resistance training on muscle strength and mass in healthy
adults: a systematic review with meta-analysis. Br J Sports Med.
2008;43:556–68.
38. Sharp RL, Troup JP, Costill DL. Relationship between power and
sprint freestyle swimming. Med Sci Sports Exerc. 1982;14(1):53–6.
39. Sheppard J, Hobson S, Barker M, et al. The effect of training with
accentuated eccentric load counter-movement jumps on strength
and power characteristics of high-performance volleyball players.
Int J Sports Sci Coach. 2008;3(3):355–63.
40. Solberg PA, Hopkins WG, Ommundsen Y, Halvari H. Effects of three
training types on vitality among older adults: a self-determination
theory perspective. Psychol Sport Exerc. 2012;13:407–17.
41. Suchomel TJ, Comfort P, Stone MH. Weightlifting pulling de-
rivatives: rationale for implementation and application. Sports
Med. 2015;45(6):823–39.
42. Tricoli V, Lamas L, Carnevale R, Ugrinowitsch C. Short-term ef-
fects on lower-body functional power development: weightlifting vs.
vertical jump training programs. JStrengthCondRes.2005;
19(2):433–7.
43. Vikne H, Refsnes PE, Ekmark M, Medbo JI, Gundersen V,
Gundersen K. Muscular performance after concentric and eccen-
tric exercise in trained men. Med Sci Sports Exerc. 2006;
38(10):1770–81.
44. Vogt M, Hoppeler HH. Eccentric exercise: mechanisms and effects
when used as training regime or training adjunct. J Appl Physiol
(1985). 2014;116(11):1446–54.
45. Wilson GJ, Walshe AD, Fisher MR. The development of an
isokinetic squat device: reliability and relationship to functional
performance. Eur J Appl Physiol Occup Physiol. 1997;75(5):
455–61.
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