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Systematic Review and
Meta-Analysis on the
Effect of Contrast
Training on Vertical Jump
Performance
Jeffrey Pagaduan, MS, CSCS,
1
Brad J. Schoenfeld, PhD, CSCS*D, CSPS*D, NSCA-CPT-D, FNSCA,
2
and Haris Pojski
c, PhD
3,4
1
College of Health and Medicine, School of Health Sciences, University of Tasmania - Newnham, Tasmania, Australia;
2
Department of Health Sciences, CUNY Lehman College, Bronx, New York;
3
Department of Sports Science, Linnaeus
University, Kalmar, Sweden; and
4
The Swedish Winter Sports Research Centre, Mid Sweden University, O
¨stersund, Sweden
Supplemental digital content is available for this article. Direct URL citations appear in the printed text and are provided
in the HTML and PDF versions of this article on the journal’s Web site (http://journals.lww.com/nsca-scj).
ABSTRACT
THE PURPOSE OF THIS ARTICLE
WAS TO PERFORM A SYSTEMATIC
REVIEW AND META-ANALYSIS ON
THE EFFECT OF CONTRAST
TRAINING (CT) ON VERTICAL JUMP
PERFORMANCE. THIRTEEN OF 83
STUDIES WERE INCLUDED FOR
SYSTEMATIC REVIEW, WHEREAS
10 STUDIES WERE USED FOR
META-ANALYSIS. META-ANALYSIS
REVEALED GREATER COUNTER-
MOVEMENT JUMP (CMJ) GAINS IN
CT THAN IN RESISTANCE TRAIN-
ING (RT) (EFFECT SIZE [ES] 51.30;
CONFIDENCE INTERVAL [CI] 5
0.31–2.30). SIMILARLY, CT DIS-
PLAYED HIGHER CMJ THAN CON-
TROL (ES 51.46; CI 50.46–2.46).
IN CONCLUSION, CT SHOWED
GREATER IMPROVEMENT IN CMJ
COMPARED WITH RT AND CON.
FOR A VIDEO ABSTRACT OF THIS
ARTICLE, SEE VIDEO, SUPPLE-
MENTAL DIGITAL CONTENT 1,
HTTP://LINKS.LWW.COM/SCJ/
A247.
INTRODUCTION
The ability to generate power
plays a vital role in sport success
(6,28). Power is defined as the
capacity of the neuromuscular system
to generate maximal force in the short-
est period or at high velocity (12). Ver-
tical jump (VJ) is a common task in
sports performance that is dependent
on lower-body power. Strength and
conditioning practitioners in sports
with jumping tasks consider VJ as
one of the critical parameters in mon-
itoring strength and conditioning train-
ing adaptations. In the past decade,
complex training has received notable
attention as a training scheme to
improve power (5,9,17,18,38). Complex
training combines heavy resistance and
plyometric/ballistic/speed training in
one training session in an effort to
enhance the force-velocity continuum
characteristics of an individual. The
heavy resistance training (RT) in com-
plex training addresses the force curve
component by increasing muscle force
output, whereas the high-velocity
training targets the velocity curve by
producing force at high speeds or over
a short period (5,12,30). The neuro-
physiological mechanism in complex
training has been attributed to postac-
tivation potentiation, which refers to
an improvement in muscle kinetics
from enhanced muscle phosphoryla-
tion through calcium sensitivity and
h-reflex activity (24,33,34). One com-
plex training variation is contrast train-
ing (CT), which is performed by
alternating a set of resistance exercise
with a set of plyometrics or speed drill
(4,14,30). This variation has been pro-
posed to promote an acute ergogenic
Address correspondence to Mr. Jeffrey Paga-
duan, jcpagaduan@gmail.com.
KEY WORDS:
contrast training; complex training;
vertical jump; combined training;
plyometric training; resistance training
Copyright ÓNational Strength and Conditioning Association Strength and Conditioning Journal | www.nsca-scj.com 63
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
effect and enhance subsequent perfor-
mance in power-oriented tasks (9,14).
Given the increasing interest in CT as
a means to enhance performance, it is
important to gain consensus on the lit-
erature on the topic to determine its
efficacy and develop evidence-based
recommendations on its use. To date,
no systematic review or meta-analysis
has been conducted to accomplish this
task. Thus, the purpose of this article
was to conduct a systematic review
and meta-analysis on the effect of CT
on VJ performance.
METHODS
The Preferred Reporting Items for Sys-
tematic Reviews and Meta-Analyses
statement was used to perform a litera-
ture search in Google Scholar,
SPORTDiscus, World of Science,
SpringerLink, and PubMed from all
time points until January 30, 2018.
The following search terms and Boo-
leans were used: (complex training)
OR (contrast training) OR (combined
weight training and plyometrics) OR
(combined strength training and plyo-
metrics) OR (combined resistance
training and plyometrics) AND (verti-
cal jump or jump performance). In
addition, manual searches from rele-
vant journals and reference lists from
articles were conducted. To be
included in the meta-analysis, studies
had to meet the following criteria: (a)
randomized trials peer-reviewed in
English; (b) complex training interven-
tion comparing any RT or plyometric
training (PLYO) or control (CON),
wherein complex training involves
a set of RT followed by a set of high-
velocity exercise/plyometrics; (c)
included countermovement jump
(CMJ) as a dependent variable; and,
(d) training intervention performed at
least twice a week with a duration of
$4 weeks.
A single investigator (J.P.) initially as-
sessed the eligibility of the studies for
inclusion. In the first stage of screen-
ing, titles and abstracts of identified
articles were checked for relevance.
Reference lists of included articles
were also checked for possible
inclusion. In the second stage, full-
text articles of potential studies were
retrieved and assessed individually.
Each study was evaluated for 4 times
separated by 7 days to reduce selec-
tion bias. Studies that were deemed
eligible were coded based on the fol-
lowing variables: author/s, partici-
pant information, description of
exercise/s and activity, intensity of
exercise/s, training frequency, study
duration, CMJ test protocol, and
study result. A second investigator
(H.P.) independently checked the
data extraction. After coding of data,
both investigators rated the included
studies for “risk of bias” using an 8-
point scale from Consolidated Stand-
ards of Reporting Trials (CONSORT)
statement. The instrument uses
a binary scale with each item scored
as either 0 (absently or inadequately
described) or 1 (explicitly described
and present). A study with a score of
0–2 is regarded as having a high risk
of bias, 3–5 as having a medium risk
of bias, and 6–8 considered as having
a low risk of bias. A consensus was
reached for any disagreement pre-
sented in data extraction and CON-
SORT output.
Meta-analysis was conducted using
a free software program (RevMan ver
5.3; The Nordic Cochrane Centre, Co-
penhagen, Denmark). The meta-
analysis aimed to examine CMJ height,
considered as continuous variable,
between: CT versus RT; CT versus
PLYO; and CT versus CON. The stan-
dard mean difference (mean CMJ dif-
ference from CT and comparison
group/pooled SD), also known as
effect size (ES), was used to compare
CMJ differences between groups
(10,39,41). ES was interpreted using
the following classification system: 0.2
—small effect; 0.5—moderate effect; and
0.8—large effect. An inverse-variance
random-effects model was used due
to the heterogeneous study methods
and subject populations. Statistical het-
erogeneity was examined using chi-
squared and I
2
-Index tests (23). An I
2
value greater than 25% is considered to
exhibit low heterogeneity, 50% as
moderate heterogeneity, and 75% as
high heterogeneity.
A subgroup analysis was also con-
ducted to identify potential moderat-
ing variables for any difference in
CMJ between CT and comparison
group. Variables included age ($20
years versus ,20 years) and level of
physical ability (competitive versus
noncompetitive). Training load inten-
sity ($70% repetition maximum
[RM] versus ,70% RM) and study
duration ($6 weeks versus ,6 weeks)
were also included in the subgroup
analysis.
RESULTS
The literature search uncovered 1,067
potential articles and 2 articles identi-
fied from reference lists. Removal of
duplicates (n 5345) left 742 articles.
After screening of title and abstracts, 83
articles underwent a more detailed
evaluation and led to the exclusion of
70 articles. Thirteen studies (1–
3,8,12,16,19,21,25,27,29,36,37) were
ultimately deemed to meet the eligibil-
ity criteria for systematic review. Three
studies from the systematic review
(3,8,29) failed to qualify for meta-
analysis due to missing CMJ data for
prestudy, poststudy, or both. This left
10 studies (1,2,12,16,19,21,25,27,36,37)
for inclusion in the meta-analysis. Flow
diagram of the search process is dis-
played in Figure 1.
Risk of bias of studies based on CON-
SORT is presented in Table 1. Eleven
studies (1,3,8,12,16,19,21,25,29,36,37)
fall within the category of “medium
risk” for bias, whereas 2 studies (2,27)
fall within the “high risk” category.
The total number of participants
involved in the review was 441 (males,
n5408; females, n 533) with ages
ranging from 8 to 30 years. Nine studies
(1,2,8,12,16,19,21,27,36) included an
athlete population, whereas 3 studies
(25,29,37) used an active but nonath-
letic population. Only one study was con-
ducted in an untrained population (3). CT
using pairing (1,3,12,21,29,36,37), triad
(2,8,25) and combinations of both
(16,19,27) were among the CT strategies
identified. A majority of studies
Contrast Training and Vertical Jump
VOLUME 41 | NUMBER 3 | JUNE 2019
64
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
(1–3,8,12,16,19,21,25,27,29,37) were
conducted 2 days a week; only one study
(33) used a frequency of 3 times a week.
Interventions lasted from 4 to 12 weeks.
For identifying CMJ performance, 9
studies used the hands-on-waist CMJ
protocol (1,2,8,16,19,21,25,27,29). In
one study, the Vertec was used to mea-
sure CMJ using the jump and reach pro-
tocol (12) and one study used the chalk
method (37). One study also used a mod-
ified jump and reach protocol without
arm swing (3). Finally, CMJ in one study
was measured using an unloaded bar in
a Smith machine (36). Characteristics of
studies are displayed in Table 2.
In the meta-analysis, 4 studies com-
pared CT with RT (1,12,21,36), one
differentiated CT and PLYO (12), and
6 studies compared CT with CON
(1,16,19,21,27,36). The CON in one
study was reclassified into RT because
participants underwent stability and
light RT (1).
OUTCOMES
Table 3 displays the CMJ output from
CT, RT, PLYO, and CON.
Contrast training versus resistance
training. Five of 10 studies compared
CT with RT (1,12,21,25,36). These
studies were found to have consider-
able heterogeneity at x
2
521.03, df
54, P50.0003, I
2
581%.
Meta-analysis showed an effect favor-
ing CT compared to RT with an ES of
1.30 (0.31–2.30), Z52.56, P50.01.
CMJ from CT showed a 12.7% (95%
confidence interval [CI] 53.11–6.51
cm) increase compared with a 5.90%
(95% CI 50.95–3.72 cm) CMJ
enhancement in RT. Figure 2 depicts
the forest plot comparing CT ver-
sus RT.
Subgroup analysis in CT versus RT
(Table 3) revealed a nonsignificant
CMJ improvement for age (20 years
$versus ,20 years; P50.08) with
CT compared to RT. However, longer
participation in CT showed a signifi-
cantly greater CMJ performance ($6
weeks versus ,6 weeks; ,0.00001)
than in RT.
Contrast training versus control.
Comparison between CT and CON
was analyzed in 6 of 10 studies. These
studies displayed high heterogeneity at
x
2
533.32, df 55, P,0.00001, I
2
5
85%. Meta-analysis showed greater
CMJ improvements in CT compared
to CON with an ES difference of 1.46
(0.46–2.46), Z52.85, P50.004. On
a percentage basis, CT resulted in an
increase in CMJ of 8.6% (95% CI 5
1.17–4.61 cm), whereas CON showed
a decrement in performance of 20.91%
(95% CI 522.38 to 1.13 cm). Figure 3
depicts the forest plot comparing CT
and CON. Subgroup analysis in CT
versus CON (Table 4) showed a non-
significant difference in CMJ between
subjects $20 years and ,20 years, P5
0.44. There was also no significant dif-
ference in CMJ between $70% RM
Figure 1. Flow diagram of search process.
Strength and Conditioning Journal | www.nsca-scj.com 65
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Table 1
CONSORT scores of studies included in the systematic review
Study Were the
groups
comparable at
baseline on key
characteristics?
Did the study
include a true
control group
(randomized
participants—
not
a comparison
group)
Was the
randomization
procedure
adequately
described and
performed?
Did the study
report a power
calculation and
was the study
adequately
powered to
detect
intervention
effects?
Were the
assessors
blinded to
treatment
allocation at
baseline and
posttest?
Did at least 80%
of participants
complete follow-
up assessments?
Did the study
analyses
account for
potential
differences at
baseline?
Did the study
report effect
sizes?
Total
Alvarez et al. (1) 1 0 0 0 0 1 1 1 4
Alves et al. (2) 0 0 0 0 0 1 1 0 2
Arazi et al. (3) 0 0 0 1 0 1 1 1 4
Brito et al. (8) 1 0 0 0 0 1 1 1 4
Dodd and Alvar (12) 0 0 0 0 0 1 1 1 3
Faude et al. (16) 0 0 0 0 0 1 1 1 3
Garcı
´a-Pinillos et al.
(19)
000 101103
Hammami et al. (21) 0 0 0 0 0 1 1 1 3
Jua
´rez et al. (25) 0 0 1 0 0 1 1 0 3
Latorre Roma
´n et al.
(27)
000 001102
MacDonald et al. (29) 0 0 0 0 0 1 1 1 3
Spineti et al. (36) 1 0 0 1 0 1 1 1 5
Stasinaki et al. (37) 1 0 0 0 0 1 1 1 4
Contrast Training and Vertical Jump
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Table 2
Characteristics of studies
Authors Participants Exercises Intensity Frequency Duration Test parameter Result
Alvarez
et al. (1)
Male right-handed
golfers: CT (n 55;
24.2 65.4 y); RT (n 5
5; 23.9 66.7 y)
CT: horizontal bench press; seated row
machine; barbell squats; seated military
press; seated calf extension; triceps cable
pushdown (week 1–6)
335 @ 85% RM 2/7 d 12 wk hands-on-waist
CMJ (cm) on
a jumping mat
(SportJUMP
System; DSD
Inc., Leo
´n,
Spain)
CT .RT
Horizontal bench press + plyo push-ups;
seated row machine + explosive pull-downs;
barbell squats + vertical jumps (VJs) over
hurdles (45 cm); seated barbell military press
+ plyo push-ups; seated calf extension + VJs
over hurdles (45 cm); Triceps cable
pushdown + plyometric push-ups (week 6–
12); day 1 and day 2 exercises of RT
336 @ 70% RM + 3 3
10 reps for the first 5
complexes; last
complex: 3 36@
70% RM + 3 310
reps
Golf training; full round (18 holes)/rest — 5/7 d; 1–2/
7d
12 wk
RT: core training (day 1); light RT using
portable rubber bands, ropes, or resistance
from the trainer (day 2): front deltoid raises,
military press, abdominal crunches, 1- and 2-
arm biceps curls, standing kickbacks, triceps
extensions, overhead triceps extensions,
standing back rows, lunges, squats, glute
kickbacks, bent-over rows, hamstring curls,
and different forearm exercises
2/7 d 12 wk
Golf training; full round (18 holes)/rest — 5/7 d; 1–2/
7d
12 wk
Alves et al.
(2)
Male soccer players: CT
(n 58); CON (n 56)
CT: 1st complex: squat + high skips (5 m) +
sprint (5 m); 2nd complex: standing calf raise
+ VJ + ball headers; 3rd complex: leg
extension + VJ from seated position + depth
jump (60 cm box height) to headers
1st complex: 1 36@
90% RM + 1 31+1
31; 2nd complex: 1
36 @ 90% RM + 1 3
8+133 reps; 3rd
complex: 1 36@
80% RM + 6 reps + 1
33
2/7 d 6 wk Hands-on-waist
CMJ (cm) on
a jumping mat
(Ergojump;
Globus Inc.,
Codogne
´,
Italy)
CT .CON
Regular soccer training — — 6 wk
(continued)
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Table 2
(continued)
CON: regular soccer training — — 6 wk
Arazi et al.
(3)
Healthy untrained
women: CT (n 57;
20.8 60.70 y); RT (n
58; 20.7 61.1 y),
PLYO (n 58; 20.6 6
1.10 y)
CT: half squat + depth jump; knee extension +
multiple jumps; knee flexion + zigzag jumps;
single-leg lunge + lunge jump
Resistance exercises: 3
36 @ 60% RM;
plyometric exercises:
336@ME
2/7 d 6 wk CMJ without arm
swing (Vertec;
Power
Systems;
Knoxville, TN,
USA)
CT 5RT 5
PLYO
RT: half squat; knee extension; knee flexion;
single-leg lunge
336 @ 60% RM 2/7 d 6 wk
PLYO: depth jump; multiple jumps; zigzag
drillls; lunge jump
336 @ ME 2/7 d 6 wk
Brito et al.
(8)
Adult male soccer
players: CT (n 512;
19.9 60.50 y); RT (n
512; 20.3 60.90 y);
PLYO (n 512; 20.0 6
0.60 y); CON (n 521;
20.7 61.00 y)
CT: squat + skip + sprint; calf extension on leg
press device + VJs + ball headers; leg
extension + VJs from seated position +
depth jumps (60 cm box height) to soccer
heading
136 @ 85% RM + 5 m
@ ME + 5 m @ ME; 1
36 @ 90% RM + 1 3
8@ME+133 @ ME;
136 @ 80% RM + 1
36@ME+133to
133 @ ME; %5
incremental load
from 1 RM every 3 wk
2/7 d 9 wk Hands-on-waist
CMJ using
contact mat
(Digitime
1000; Digitest,
Jyva
¨skyla
¨,
Finland)
CT 5RT 5
PLYO
Regular soccer training — — 9 wk
RT: squat; calf extension; leg extension 1 36 @ 85% RM; 1 36
@ 90% RM; 1 36@
80% RM; %5
incremental load
from 1 RM every 3 wk
2/7 d 9 wk
Regular soccer training — —
PLYO: skips + sprint; VJ + ball headers; VJs from
seated position + depth jumps (60 cm box
height) to soccer heading; regular
135 m + 5 m @ ME; 1
38+133 @ ME; 1
33to133@ME
2/7 d 9 wk
Regular soccer training — — 9 wk
Dodd and
Alvar (12)
Male junior college
baseball players (18–
23 y): CT (n 532); RT
(n 531); PLYO (n 5
28)
CT: Squat + box jumps; lunge + depth jumps;
split squat + split squat jump
236 @ 80–90% RM + 2
36 @ 0–30% RM
2/7 days 4 wk Jump and reach
using Vertec
(Power
Systems;
Knoxville, TN,
USA)
CT .RT
Contrast Training and Vertical Jump
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Table 2
(continued)
Baseball-specific skill and cardiovascular
routines
45 min 3/7 d 4 wk
RT: squat, lunge, split squat 4 36 @ 80–90% RM 2/7 d 4 wk CT .PLYO
Baseball specific skill and cardiovascular
routines
45 min 3/7 d 4 wk
PLYO: box jumps, depth jumps; split squat 4 36 @ 0–30% RM 2/7 d 4 wk
Baseball-specific skill and cardiovascular
routines
45 min 3/7 d 4 wk
Faude et al.
(16)
High-level amateur
soccer players: CT (n
58; 23.1 62.7 y);
CON (n 58; 22.6 6
2.4 y)
RT: unilateral loaded half squats + single-leg
hurdle jumps (day 1); combination 2 of the
following exercises (day 2):
434 @ 90% RM + 4 3
5
2/7 d 7 wk Hands-on-waist
CMJ using
force platform
(Kistler type
9286AA,
Winterthur,
Switzerland)
CT .CON
Squats + drop jumps + 5 sprint 3 35 @ 50–60% RM + 3
35+331
Loaded calf raises + straight jumps + header 3 35 @ 50–60% RM + 3
35+331
Lateral half squats + lateral jumps + zigzag
sprints
334/leg @ 50–60% RM
+338+3310
Loaded step-ups + bounding jumps + headers 3 34/leg @ 50–60% RM
+335+333
Technical-tactical training — — 7 wk
CON: technical-tactical training — — 7 wk
Garcı
´a-
Pinillos
et al. (19)
Male young soccer
players: CT (n 517;
15.47 61.28 y); CON
(n 513; 16.38 61.5
y)
CT: isometric half squat + jump from seated
position (week 1–2)
4340 s + 4 36 2/7 d 12 wk Hands-on-waist
CMJ using
accelerometer
(FreePower
Jump
Sensorize;
Biocorp, Rome,
Italy)
CT .CON
(continued)
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Table 2
(continued)
Isometric half squat + single-leg jump,
alternating right and left (week 3–4)
5360 s + 5 36
Isometric half squat + (alternatively) jump from
seated position/single-leg jump, alternating
right and left (week 5–6)
6380 s + 6 36
Isometric half squat + single-leg jump,
alternating right and left + isometric half
squat + jump from seated position (week 7–
8)
4340 s + 4 36+43
40 s + 4 36
Identical to weeks 7–8 (week 9–10) 5 340 s + 5 36+53
40 s + 5 36
Identical to weeks 11–12 (week 11–12) 6 340 s + 6 36+63
40 s + 6 36
Normal soccer training — — 12 wk
CON: normal soccer training — — 12 wk
Hammami
et al. (21)
Male young soccer
players: CT (n 516;
16.0 60.5 y); RT (n 5
16; 16.2 60.6 y);
CON (n 512; 16.8 6
0.2)
CT: squat + CMJ (Week 1–4); 3–5 33–8 @ 70–90%
RM + 3–5 33
2/7 d 8 wk Hands-on-waist
CMJ on a force
platform
(Quattro
Jump, version
1.04; Kistler
Instrument
AG,
Winterthur,
Switzerland)
CT .RT
Squat + CMJ + CMJ to 15-m sprint (week 4–8) 3–5 33–8 @ 70–90%
RM + 3–5 33+331
Soccer training 90 min emphasizing
skill activities at
various intensities,
offensive and
defensive strategies;
25–30 min of con-
tinuous play with
brief interruptions
from the coach
4–5/7 d 8 wk CT .CON
RT: squat 3–5 33–8 @ 70–90% 2/7 d 8 wk
Contrast Training and Vertical Jump
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Table 2
(continued)
Soccer training 90 min emphasizing
skill activities at
various intensities,
offensive and
defensive strategies;
25–30 min of con-
tinuous play with
brief interruptions
from the coach
4–5/7 d 8 wk
CON: soccer training 90 min emphasizing
skill activities at
various intensities,
offensive and
defensive strategies;
25–30 min of con-
tinuous play with
brief interruptions
from the coach
4–5/7 d 8 wk
Jua
´rez et al.
(25)
Active male
undergraduate
students: CT (n 58;
19.1 61.36 y); RT (n
58; 20.0 61.93 y)
CT: week 1–2: back squat + VJ + sprint; week
3–4: back squat
Week 1–2: 2 36 @ 70%
RM + 2 35+23
20 m
2/7 d 4 wk Hands-on-waist
CMJ
(Ergojump
Bosco System,
Barcelona,
Spain)
CT 5RT
Hurdle jump + sprint Week 3–4: 2 36 @ 70%
RM + 2 35+23
20 m
RT: back squat Week 1: 4 38 @ 70%
RM; week 2: 5 36@
75% RM
2/7 d 4 wk
Latorre
Roma
´n
et al. (27)
Male and female
children basketball
athletes: CT (n 530:
m525; f 55); CON
(n 528: m 523; f 5
5)
CT: isometric half squat + depth jumps from
seated position + jump from seated position
(week 1–2)
40 s + 2 310 + 3 310 2/7 d 10 wk Hands-on-waist
CMJ using an
infrared sensor
(OptoGait
system;
Microgate,
Bolzano, Italy)
CT .CON
(continued)
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Table 2
(continued)
Isometric half squat + depth jumps from
seated position + jump from seated position
(week 3–4)
50 s + 3 310 + 4 310
Isometric half squat + depth jumps from
seated position + jump from seated position
(week 5–6)
60 s + 5 310 + 5 310
Isometric half squat + depth jumps from
seated position + jump from seated position
(week 7–8)
70 s + 6 310 + 7 310
Isometric half squat with partner sitting on top
of the thigh + depth jumps from seated
position + jump from seated position (week
9–10)
70 s + 6 310 + 7 310
Basketball training; competitive game — 3/7 d; at
least 1/
7d
10 wk
CON: basketball training; competitive game — 3/7 d; at
least 1/
7d
10 wk
MacDonald
et al. (29)
Recreationally trained
college men: CT (n 5
10; 22.5 63.24 y); RT
(n 513; 22.0 63.66
y); PLYO (n 511; 20.6
63.36 y)
CT: Smith machine squat + lateral jumps;
Romanian deadlift + depth jumps; calf raise
+ box jumps
Week 1–3, day 1: 3 35–
6 @ 75–82% RM + 3
35–6; week 1–3, day
2: 3 35–6 @ 60–67%
RM + 3 34–6; week
3–6, day 1: 3 33–4 @
85–90% RM + 3 33–
5; week 3–6, day 2: 3
33–4 @ 45–55% RM
+333–4
2/7 d 6 wk Hands-on-waist
CMJ on force
platform (AMTI
OR 6-7;
Advanced
Mechanical
Technology
Inc.,
Watertown,
MA)
CT 5RT 5
PLYO
RT: Smith machine squat; Romanian deadlift;
calf raise
Week 1–3, day 1: 3 35–
6 @ 75–82% RM;
week 1–3, day 2: 3 3
5–6 @ 60–67% RM;
week 3–6, day 1: 3 3
3–4 @ 85–90% RM;
week 3–6, day 2: 3 3
3–4 @ 45–55% RM
2/7 d 6 wk
Contrast Training and Vertical Jump
VOLUME 41 | NUMBER 3 | JUNE 2019
72
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
Table 2
(continued)
PLYO: lateral jumps; depth jumps; box jumps Week 1–3, day 1: 3 35–
6; week 1–3, day 2: 3
34–6; week 3–6, day
1: 3 33–5; week 3–6,
day 2: 3 33–4
2/7 d 6 wk
Spineti et al.
(36)
Male soccer players (n
522: 18.4 60.4 y):
CT (n 522); RT (n 5
10)
CT: CMJ + frontal jumps over barrier (box: 40
cm high, 80 cm long); CMJ + single frontal
jumps over barrier (30 cm high, 80 cm long
box);
136 @ 60 PP + 1 310;
136 @ 60 PP + 1 3
10;
3/7 d 12 wk CMJ with
unloaded bar
on Smith
machine using
accelerometer
(Myotest, SA,
Sion,
Switzerland)
CT .RT
CMJ + multiple diagonal cone hops (40 cm
high, 80 cm long box) (day 1)
136 @ 60 PP + 1 310
High pull power + frontal sprint; high pull
power + knee up to frontal sprint; high pull
power + 110 degree-curve zigzag sprints
(day 2)
135RM+1310 m; 1
35RM+135m+1
310 m; 1 35RM+4
35m
CMJ + single jump on the box (50 cm box
height); CMJ + depth jumps (“box onto box”;
50 cm box height); CMJ + depth jumps (50
cm box height) (day 3)
134 @ 100 PP + 1 3
10; 1 34 reps @ 100
PP + 1 310; 1 34
reps @ 100 PP + 1 3
10
Technical skills and tactical training — — 12 wk
RT: squat in Smith machine; deadlift knee
flexion with Olympic bar; stiff legged
deadlift with Olympic bar; knee extension
machine; knee flexion machine; hip
adduction machine (day 1)
2312–15 RM 3/7 d 12 wk
Squat in Smith machine; deadlift knee flexion
with Olympic bar; stiff legged deadlift with
Olympic bar; knee extension machine (day
2)
338–10 RM
Squat in Smith machine; deadlift knee flexion
with Olympic bar; stiff legged deadlift with
Olympic bar (day 3)
434–6 RM
(continued)
Strength and Conditioning Journal | www.nsca-scj.com 73
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
and ,70% RM loading schemes (P5
0.34). No subgroup difference in CT
duration ($6 weeks versus ,6 weeks;
P50.05) was also observed.
DISCUSSION
The purpose of this study was to con-
duct a systematic review and meta-
analysis on the effect of CT, a complex
training strategy that involves com-
pleting a set of resistance exercise fol-
lowed by a set of high-velocity
exercise, on VJ performance. In this
review,CMJwasusedasthelower-
body power parameter when compar-
ing CT with RT/PLYO/CON. Thir-
teen studies were included in the
systematic review with CT interven-
tions administered from healthy
untrained population to elite-level
athletes of various age population.
CT schemes ranged from the tradi-
tional complex pairing method to
triad or a combination of both, con-
ducted twice to thrice a week over
a 4 to 12-week study period. In the
meta-analysis, 10 of 13 studies were
analyzed. An analysis comparing
CMJ output from CT and PLYO was
discarded due to lack of available
studies to qualify for meta-analysis
(12). When comparing CT versus
RT, results showed that CT enhanced
CMJ to a markedly greater extent
compared with RT (ES 51.30; i.e.,
large effect). Similar findings were ex-
hibitedwithCTincomparisonwith
CON (ES 51.46, i.e., large effect).
Superior increases resulting from CT
can be attributed to a postactivation
potentiation–induced phosphoryla-
tion and excitation of h-reflex
(11,15,32,34). This hypothesis is par-
tially supported by Labib (2013), who
showed increased CD34/CD45
immune system stem-cell secretions
after CT (13,26,35). Moreover, evi-
dence shows CT preserves type IIX
muscle fibers, which are responsible
for generating faster contraction
velocities, power, and rate of tension
development than type IIA and type I
fibers (7,22,37). Another possible
explanation for CT-induced enhance-
ment in CMJ performance may be
linked to greater volume in CT than
Table 2
(continued)
Technical skills and tactical training — — 12 wk
Stasinaki
et al. (37)
Moderately trained
physical education
students: CT (n 59);
CON (n 57)
CT: leg press + leg press throw; bench press +
bench press throw; Smith squat + squat
jump + drop jumps (every other training
day)
236 @ 85% RM for
heavy load + 2 38@
30% RM for the 2nd
complex pair
exercise; 3 38 @ 30–
45 cm (drop jumps)
3/7 d 6 wk CMJ using jump
and reach
(chalk
method)
CT .CON
Athletic throwing skills training Light-intensity training
for 2 h
2/7 d 6 wk
CON: athletic throwing skills training Light intensity training
for 2 h
2/7 d 6 wk
CMJ 5countermovement jump; CON 5control; CT 5contrast training; ME 5maximal effort; PLYO 5plyometric training; PP 5peak power; RM 5maximum repetition; RT 5resistance
training.
Contrast Training and Vertical Jump
VOLUME 41 | NUMBER 3 | JUNE 2019
74
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
in other interventions, which may in
turn have produced a greater stimula-
tion of the neuromuscular system (40).
However, it should be noted that
higher training volumes may induce
higher levels of neuromuscular fatiga-
bility than in the other groups (20,39).
This, in turn, may negatively influence
neuromuscular adaptations when
combined with sport train-
ing (9,32,40).
In this study, subgroup analysis was
conducted to determine possible mod-
erators that may have contributed to
the difference in CMJ between CT
and RT. These covariates included
age, training level, loading intensity
for resistance exercise, and duration
of intervention. Both subgroups for
age improved CMJ; however, no differ-
ence in CMJ enhancement was seen
between age groups. It should be noted
that one study in the age subgroup was
not included due to ambiguous age data
(12). Analysis for loading intensity was
not possible in availability of at least two
studies in the ,70% RM group. Engag-
ing in CT for shorter duration (,6
weeks) did not show improvement in
CMJ compared to RT. However, there
was a significant enhancement in CMJ
with $6 weeks of CT compared to RT.
There was a significant difference in
Table 3
Subgroup analysis for CT versus RT
Group
Studies
ES (95% CI) I
2
P
Subgroup difference
No. (reference) P
Population characteristics
Age
$20 y 2 (1,25) 1.14 (0.28 to 1.99) 0 0.009 0.08
,20 y 2 (21,36) 2.19 (1.41 to 2.97) 0 ,0.00001
Level
Competitive 4 (1,12,21,36) 1.37 (0.10 to 2.64) 85 0.03 NA
Noncompetitive 1 (25) 1.11 (0.04 to 2.19) NA 0.04
CT training characteristics
Loading intensity
$70% RM 5 (1,12,21,25,36) 1.30 (0.31 to 2.30) 81 0.01 NA
,70% RM NA NA NA NA
Duration
$6 wk 3 (1,21,36) 1.95 (1.26 to 2.63) 0 ,0.00001 0.02
,6 wk 2 (12,25) 0.49 (20.49 to 1.46) 65 0.33
CI 5confidence interval; CT 5contrast training; ES 5effect size; RM 5repetition maximum; RT 5resistance training.
Figure 2. Forest plot comparing contrast training (CT) with resistance training (RT). CI 5confidence interval.
Strength and Conditioning Journal | www.nsca-scj.com 75
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
CMJ between both CT durations. This
may be linked to reduction of fatigue
induced by CT at the onset of its inter-
vention (13,24,39). No analysis was con-
ducted as to the level of activity due to
the presence of only one study in the
noncompetitive group.
Subgroup analysis was also adminis-
tered in CT versus CON. Analysis
showed that athletes in the ,20-year-
old-group exhibited greater gains in
CMJ compared with athletes in the
$20-year-old group; however, the dif-
ference between subgroups was nonsig-
nificant. The CT loading intensity of
,70% RM showed significant improve-
ment in CMJ than CON. On the other
hand, CT loading intensity of $70%
RM did not post any significant CMJ
enhancement compared to CON.
There was no significant CMJ difference
between both CT loading intensity
schemes. One study subgroup analysis
for loading schemes was not included
due to combining both loading schemes
during the intervention (16). Subgroup
analysis for level of physical activity was
Figure 3. Forest plot comparing contrast training (CT ) with control (CON). CI 5confidence interval.
Table 4
Subgroup analysis for CT versus CON
Group
Studies
ES (95% CI) I
2
P
Subgroup difference
No. (reference) P
Population characteristics
Age
$20 y 2 (16,37) 1.04 (21.38 to 3.46) 88 0.40 0.64
,20 y 4 (2,19,21,27) 1.69 (0.41 to 2.97) 88 0.010
Level
Competitive 5 (2,16,19,21,27) 1.80 (0.68 to 2.92) 85 0.002 NA
Noncompetitive 1 (37) 20.15 (21.14 to 0.84) NA 0.77
CT characteristics
Loading intensity
$70% RM 3 (2,21,37) 1.82 (20.79 to 4.44) 93 0.17 0.34
,70% RM 2 (19,27) 0.79 (0.35 to 1.22) 0 0.0004
Duration
$6 wk 6 (2,16,19,21,27,37) 1.46 (0.46 to 2.46) 85 0.004 NA
,6wk NA NA NA NA
CI 5confidence interval; CT 5contrast training; ES 5effect size; RM 5repetition maximum.
Contrast Training and Vertical Jump
VOLUME 41 | NUMBER 3 | JUNE 2019
76
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
not possible due to lack of available
studies in the non-competitive group.
Similarly, subgroup analysis for duration
was not administered because of non-
availability of at least two studies in ,6
week CT intervention.
There are several limitations to this
meta-analysis that must be considered
when attempting to draw practical infer-
ences. First and foremost, analysis is
based on a fairly small number of studies
on the topic (10 total), and there was
substantial heterogeneity in methodol-
ogy between these studies. In particular,
differences exist in the use of specific ex-
ercises (i.e., high pulls, squats, box jumps,
etc.) as well as the CMJ testing measure
(i.e., hands on waist, Vertec, chalk, etc.).
Thus, although the data do indicate
a positive benefit to CT, the ability to
draw strong inferences is limited. More-
over, the combination of mechanical
stimuli within a CT program may impair
the ability to determine direct causality
(18,40). The review also included CT in
comparison with RT/PLYO/CON
groups only. Future studies including
other complex training and RT (e.g.,
compound training) schemes compar-
ing CT is warranted. Furthermore, only
CMJ was used as the dependent vari-
able; other performance parameters
may produce different outcomes from
CT and provide valuable information
on the parameter-dependent effect of
CT (2,12,27,31). Finally, the findings
are limited to athletes and healthy non-
athletes and cannot necessarily be gen-
eralized to other populations.
In conclusion, transference of CT in VJ
enhancement was superior in compar-
ison with RT and CON. However,
changes in CMJ from the use of CT
compared with PLYO are unclear.
PRACTICAL APPLICATION
Current evidence supports CT having
greater efficacy in improving VJ perfor-
mance when compared with RT and
CON. For sports that include VJ ac-
tions, integration of CT for twice to
thrice a week for more than 6 weeks
into the comprehensive sports training
program can help increase leg power in
athletes. A common CT exercise
scheme for the lower body involves
a multijoint exercise (i.e., squat, leg
press) followed by a VJ activity (i.e.,
CMJ jumps). However, coaches may
use other CT variations by adding other
plyometric/speed exercise(s) after the
VJ task. In addition, a rest interval in
between exercises (2–6 minutes)
should be used to maximize CT results.
Finally, when CT is conducted before
sports training, applying one CT exer-
cise performed for 3–5 sets and 10–
20 minutes of active recovery after CT
would seem to be a sound strategy.
Conflicts of Interest and Source of Funding:
The authors report no conflicts of interest
and no source of funding.
Jeffrey
Pagaduan is
a PhD student at
the College of
Health and Med-
icine, School of
Health Sciences,
University of
Tas m an i a -
Newnham,
Australia.
Brad
Schoenfeld is
an Assistant
Professor in
Exercise Science
and the Director
of the Human
Performance
Laboratory at
CUNY Lehman
College.
Haris Pojski
cis
an Assistant
Professor in
Sports Science at
Linnaeus Uni-
versity, Sweden,
and a researcher
at The Swedish
Winter Sports
Research Centre.
REFERENCES
1. Alvarez M, Sedano S, Cuadrado G, and
Redondo JC. Effects of an 18-week
strength training program on low-handicap
golfers’ performance. J Strength Cond Res
26: 1110–1121, 2012.
2. Alves JMVM, Rebelo AN, Abrantes C, and
Sampaio J. Short-term effects of complex
and contrast training in soccer players’
vertical jump, sprint, and agility abilities.
J Strength Cond Res 24: 936–941, 2010.
3. Arazi A, Asadi A, and Roohi S. Enhancing
muscular performance in women:
Compound versus complex, traditional,
resistance and plyometric training alone.
J Musculoskelet Res 17: 4–9, 2014.
4. Argus CK, Gill ND, Keogh JW, McGuigan
MR, and Hopkins WG. Effects of two
contrast training programs on jump
performance in rugby union players during
a competition phase. Int J Sports Physiol
Perform 7: 68–75, 2012.
5. Baker D and Newton RU. Acute effect on
power output of alternating an agonist and
antagonist muscle exercise during complex
training. J Strength Cond Res 19: 202–
205, 2005.
6. Bloomfield J, Polman R, and O’Donoghue
P. Physical demands of different positions
in FA Premier League soccer. J Sports Sci
Med 6: 63–70, 2007.
7. Bottinelli R, Canepari M, Pellegrino MA, and
Reggiani C. Force-velocity properties of
human skeletal muscle fibres: Myosin heavy
chain isoform and temperature dependence.
J Physiol (Lond) 495(Pt 2): 573–586, 1996.
8. Brito J, Vasconcellos F, Oliveira J, Krustrup
P, and Rebelo A. Short-term performance
effects of three difference low-volume
strength training in college male soccer
players. J Hum Kinet 40: 121–128, 2014.
9. Carter J and Greenwood M. Complex
training re-examined: Review and
recommendations to improve strength and
power. Strength Cond J 36: 11–19, 2014.
10. Cohen J. Statistical Power Analysis for the
Behavioural Sciences. Hillsdale, NJ:
Lawrence Earlbaum Associates, 1988.
11. Docherty D, Robbins D, and Hodgson M.
Complex training revisited: A review of its
current status as a viable training approach.
Strength Cond J 26: 52–57, 2004.
12. Dodd DJ and Alvar BA. Analysis of acute
explosive training modalities to improve lower-
body power in baseball players. JStrength
Cond Res 21: 1177–1182, 2007.
13. Donovan JA and Koretzky GA. CD45 and
the immune response. J Am Soc Nephrol
4: 976–985, 1993.
Strength and Conditioning Journal | www.nsca-scj.com 77
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
14. Ebben WP. Complex training: A brief
review. J Sports Sci Med 1: 42–46, 2002.
15. Ebben WP and Watts PB. A review of
combined weight training and plyometric
training modes: Complex training. Strength
Cond J 20: 18–27, 1998.
16. Faude O, Roth R, Di Giovine D, Zahner L,
and Donath L. Combined strength and
power training in high-level amateur
football during the competitive season: A
randomised-controlled trial. J Sports Sci
31: 1460–1467, 2013.
17. Fleck S and Kontor K. Soviet strength and
conditioning: Complex training. Strength
Cond J 8: 66–68, 1986.
18. Freitas TT, Martinez-Rodriguez A, Calleja-
Gonza
´lez J, and Alcaraz PE. Short-term
adaptations following complex training in
team-sports: A meta-analysis. PLoS One
29: e0180223, 2017.
19. Garcı
´a-Pinillos F, Martı
´nez-Amat A, Hita-
Contreras F, Martı
´nez-Lo
´pez EJ, and
Latorre-Roma
´n PA. Effects of a contrast
training program without external load and
vertical jump, kicking speed, sprint, and
agility of young soccer players. J Strength
Cond Res 28: 2452–2460, 2014.
20. Ha
¨kkinen K. Neuromuscular fatigue and
recovery in male and female athletes during
heavy resistance exercise. Int J Sports Med
14: 53–59, 1993.
21. Hammami M, Negra Y, Shephard RJ, and
Chelly MS. The effect of standard strength
vs. contrast strength training on the
development of sprint, agility, repeated
change of direction, and jump in junior male
soccer players. J Strength Cond Res 31:
901–912, 2017.
22. Harridge SD, Bottinelli R, Canipare M,
Pellegrino MA, Reggiani C, Esbjornsson M,
and Saltin B. Whole-muscle and single-
fibre contractile properties and myosin
heavy chain isoforms in humans. Pflugers
Arch 432: 913–920, 1996.
23. Higgins JP, Thompson SG, Deeks JJ, and
Altman DG. Measuring inconsistency in
meta-analyses. BMJ 327: 557–560, 2003.
24. Hodgson M, Docherty D, and Robbins D.
Post-activation potentiation underlying
physiology and implications for motor
performance. Sports Med 25: 385–395,
2005.
25. Jua
´rez D, Gonza
´lez-Rave
´J, and Navarro F.
Effects of complex vs non complex training
programs on lower body maximum strength
and power. Isokin Ex Sci 17: 233–241,
2009.
26. Labib H. Effect of complex training on
CD34/CD45 stem cells, certain physical
variables and jump shoot performance for
female handball. Sci Mov Health 13: 215–
221, 2013.
27. Latorre Roma
´nPA
´, Villar Macias FJ, and
Garcı
´a-Pinillos F. Effects of a contrast
training programme on jumping, sprinting,
and agility performance of prepubertal
basketball players. J Sports Sci 21: 1–7,
2017.
28. Lorenz DS, Reiman MP, Lehecka BJ, and
Naylor A. What performance
characteristics determine elite versus
nonelite athletes in the same sport? Sports
Health 5: 542–547, 2013.
29. MacDonald CJ, Lamont HS, Garner JC,
and Jackson K. A comparison of the effects
of six weeks of traditional resistance
training, plyometric training, and complex
training on measures of power. J Trainol 2:
13–18, 2013.
30. McEvoy KP and Newton RU. Baseball
throwing speed and base running speed:
The effects of ballistic resistance training.
J Strength Cond Res 12: 216–221, 1998.
31. Mujika I, Santisteban J, and Castagna C. In-
season effect of short-term sprint and
power training programs on elite junior
soccer players. J Strength Cond Res 23:
2581–2587, 2009.
32. Rajamohan G, Kanagasabai P,
Krishnaswamy S, and Balakrishnan A.
Effect of complex and contrast resistance
and plyometric training on selected
strength and power parameters. J Exp Sci
1: 1–12, 2010.
33. Robbins D. Postactivation potentiation
and its practical applicability: A brief
review. J Strength Cond Res 19: 453–
458, 2005.
34. Sale DG. Postactivation potentiation: Role
in human performance. Exerc Sport Sci
Rev 30: 138–143, 2002.
35. Sidney LE, Branch MJ, Dunphy SE, Dua
HS, and Hopkinson A. Concise review:
Evidence for CD34 as a common marker
for diverse progenitors. Stem Cells 32:
1380–1389, 2014.
36. Spineti J, Figueiredo T, Bastos DE Oliveira
V, Assis M, Fernandes DE Oliveira L,
Miranda H, Machado DE Ribeiro Reis VM,
Sima
˜o R, Ribeiro Reis VM, and Sima
˜oR.
Comparison between traditional strength
training and complex contrast training on
repeated sprint ability and muscle
architecture in elite soccer players.
J Sports Med Phys Fitness 56: 1269–
1278, 2016.
37. Stasinaki AN, Gloumis G, Spengos K,
Blazevich AJ, Zaras N, Georgiadis G,
Karampatsos G, and Terzis G. Muscle
strength, power, and morphologic
adaptations after 6 weeks of compound vs.
complex training in healthy men. J Strength
Cond Res 29: 2259–2569, 2015.
38. Verkhoshansky Y and Tatyan V. Speed-
strength preparation of future champions.
Legkaya Atleika 2: 12–13, 1973.
39. Walker S, Ahtiainen JP, and Ha
¨kkinen K.
Acute neuromuscular and hormonal
responses during contrast loading: Effect
of 11 weeks of contrast training. Scand J
Med Sci Sports 20: 226–234, 2010.
40. Wilson JM, Duncan NM, Marin PJ, Brown
LE, Loenneke JP, Wilson SM, Jo E, Lowery
RP, and Ugrinowitsch C. Meta-analysis of
postactivation potentiation and power:
Effects of conditioning activity, volume,
gender, rest periods, and training status.
J Strength Cond Res 27: 854–859, 2013.
41. Zlowodzki M, Poolman RW, Kerkhoffs GM,
Tornetta P III, and Bhandari M; International
Evidence-Based Orthopedic Surgery Working
Group. How to interpret a meta-analysis and
judge its value as a guide for clinical practice.
Acta Orthop 78: 598–709, 2007.
Contrast Training and Vertical Jump
VOLUME 41 | NUMBER 3 | JUNE 2019
78
Copyright © National Strength and Conditioning Association. Unauthorized reproduction of this article is prohibited.
