Systematic Review and Meta-Analysis of Linear and Undulating Periodized Resistance Training Programs on Muscular Strength

Abstract

Periodization is known to improve training adaptations but the most effective periodization approach for muscular strength development for a wide variety of populations is yet to be determined. This systematic review and meta-analysis examined all studies directly comparing linear and undulating periodized resistance training programs to determine and compare their effects on muscular strength. A systematic search of the MEDLINE, SCOPUS, and SPORTDiscus databases revealed 17 studies satisfying the inclusion criteria. There were a total of 510 participants in the included studies. Sixteen studies reported significant increases in strength for both periodization approaches. Five studies reported significant differences in improvements between groups. The meta-analyses determined there were no differences in the effectiveness of linear versus undulating periodization on upper or lower body strength. The short-term nature of studies and the previous training history of participants were identified as potential confounding factors in the interpretation of findings. The results suggest that novelty or training variety are important for stimulating further strength development. Few studies have examined the effect of periodization approaches in adolescent, or athletic populations.

Full text

SYSTEMATIC REVIEW AND META-ANALYSIS OF LINEAR
AND UNDULATING PERIODIZED RESISTANCE TRAINING
PROGRAMS ON MUSCULAR STRENGTH
SIMON K. HARRIES,
1,2
DAVID R. LUBANS,
2,3
AND ROBIN CALLISTER
1,2
1
School of Biomedical Sciences and Pharmacy, Faculty of Health, University of Newcastle, Callaghan, New South Wales,
Australia;
2
Priority Research Centre in Physical Activity and Nutrition, University of Newcastle, New South Wales, Australia;
and
3
School of Education, Faculty of Education and Arts, University of Newcastle, New South Wales, Australia
ABSTRACT
Harries, SK, Lubans, DR, and Callister, R. Systematic
review and meta-analysis of linear and undulating perio-
dized resistance training programs on muscular strength.
J Strength Cond Res 29(4): 1113–1125, 2015—Periodiza-
tion is known to improve training adaptations but the most
effective periodization approach for muscular strength
development for a wide variety of populations is yet to be
determined. This systematic review and meta-analysis
examined all studies directly comparing linear and undulat-
ing periodized resistance training programs to determine
and compare their effects on muscular strength. A system-
atic search of the MEDLINE, SCOPUS, and SPORTDiscus
databases revealed 17 studies satisfying the inclusion cri-
teria. There were a total of 510 participants in the included
studies. Sixteen studies reported significant increases in
strength for both periodization approaches. Five studies
reported significant differences in improvements between
groups. The meta-analyses determined that there were no
differences in the effectiveness of linear vs. undulating peri-
odization on upper-body or lower-body strength. The short-
term nature of studies and the previous training history of
participants were identified as potential confounding fac-
tors in the interpretation of findings. The results suggest
that novelty or training variety are important for stimulating
further strength development. Few studies have examined
the effect of periodization approaches in adolescent or
athletic populations.
KEY WORDS periodization, fitness, daily undulating, weekly
undulating, performance
INTRODUCTION
Resistance training (RT) is a specialized form of
conditioning using a range of resistive loads and
a variety of training modalities designed to
enhance health, fitness, and sports performance
(9). Participation in RT results in numerous performance-
and health-related benefits in adolescent and adult popula-
tions (9,22,33). These benefits include improvements in
athletic performance, musculoskeletal health, muscular
strength, power and endurance, motor performance includ-
ing jumping ability, balance and coordination, and cardio-
vascular and metabolic health (9,11,14,22,33,38,40). The
American College of Sports Medicine (ACSM) recommends
the use of periodized RT programs based on evidence that
such programs are more effective than nonperiodized pro-
grams (33). Periodization is the systematic planning and
structuring of training variables (intensity, volume, fre-
quency, and rest) throughout designated training timeframes
aimed at maximizing performance gains and minimizing the
potential for overtraining or decrements in performance
(3,5,16,25–27,29,32,35,36).
There is debate regarding the terminology used to
describe periodized programs (13,19,31) and the most effec-
tive manipulation of key training variables to improve neu-
romuscular performance for a wide variety of populations is
yet to be determined (5,28,32,35,36). Two of the most com-
monly referred to periodization models in the literature are
linear periodization (LP) and undulating periodization (UP).
Linear periodization has been described as involving the
breakdown of the training year into weekly (microcycle),
monthly (block or mesocycle), and multi-monthly (cycle
or macrocycle) periods. A key characteristic of LP is an
initial high volume and low intensity of training with gradual
increases in intensity and decreases in volume within and
across training periods (3,5,15–17,20,25–27,33,35–37). Undu-
lating periodization has been described as more frequent,
daily, weekly, or biweekly variation of intensity and volume
and generally uses repetition maximum zones to prescribe
exercise intensity (5,16,17,20,26,28,29,32,33,35–37). Undulat-
ing periodization is commonly identified as daily undulating
Address correspondence to Simon K. Harries, Simon.Harries@uon.
edu.au.
29(4)/1113–1125
Journal of Strength and Conditioning Research
Ó2015 National Strength and Conditioning Association
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1113
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

periodization (DUP) or weekly undulating periodization
(WUP) depending on whether volume and intensity of RT
is manipulated on a daily or weekly basis. It has been pro-
posed that these nonlinear manipulations of volume and
intensity, providing more frequent changes in stimuli and
periods of recovery, are more conducive to strength gains
(3,5,16,26,27,32,35,36).
A number of studies have compared the effects of LP RT
programs with UP or nonlinear periodized programs. The aims
of this review were to (a) systematically identify and examine all
studies directly comparing linear and undulating periodized RT
programs and to synthesize the results, (b) quantitatively
compare linear and undulating periodized RT programs’ effects
on muscular strength using meta-analysis, (c) evaluate the risk
of bias in previous studies and provide recommendations to
improve the quality of future studies, and (d) review the study
populations in which the comparisons of these resistance train-
ing programs have been investigated.
METHODS
Experimental Approach to the Problem
The conduct and reporting of this review was guided by the
Preferred Reporting Items for Systematic reviews and Meta-
Analyses (PRISMA) statement (23). A comprehensive
search of the MEDLINE, SCOPUS, and SPORTDiscus da-
tabases was conducted on April 27, 2012. A librarian assisted
in the development of unique search strategies for the differ-
ent databases. No year restriction was placed on the search.
Titles and abstracts of identified articles were checked for
relevance in the first stage of screening. In the second stage,
full-text articles were retrieved and considered for inclusion.
Finally, the reference lists of included articles were screened
for additional articles. The search was updated to the July 28,
2014, during the revision process.
Studies were assessed for eligibility based on the following
inclusion criteria: (a) participants were from a nonclinical
population, (b) study compared the use of a linear RT
program (LP) with an undulating periodized RT program
(UP) (free weights, bodyweight resistance [including plyo-
metrics], elastic tubing, machine weights, isokinetic devices),
(c) study involved a randomized controlled trial (RCT) or
quasi-experimental design, (d) study included a quantitative
assessment of muscular strength, and (e) study was pub-
lished in English. Conference abstracts, dissertations, theses,
and articles published in non–peer-reviewed journals were
not included. No restriction was placed on participant age or
training experience.
Studies had to meet the following additional criteria to be
included in the meta-analysis: (a) assessed muscular strength
by a bench press, squat, or leg press repetition maximum
test; and (b) data were reported as means and SDs for the
linear and undulating periodized groups at post-test. Sepa-
rate meta-analyses were conducted for studies that assessed
bench press, squat, or leg press. Authors were contacted in
attempts to obtain further details when required.
Statistical Analyses
Meta-analyses have been strongly emphasized for their
utility to provide a quantitative summary of treatment effects
and their use as a tool to bridge the gap between the science
and practice of exercise prescription (30). All meta-analyses
were performed in RevMan (6). The meta-analyses sought to
determine the effect of the periodization approaches on
upper- and lower-body muscular strength. Muscular strength
was considered a continuous data variable; therefore, the
mean difference (MD) with 95% confidence intervals were
used to determine effect measures. The inverse-variance ran-
dom effects model was used for the meta-analysis procedure
because of studies being performed with varied populations
and methods. The x
2
and the I
2
-Index tests were used to
examine statistical heterogeneity. A previous meta-analysis
provided the following guide for the interpretation of hetero-
geneity based on the I
2
-Index: 0–40% might not be important,
30–60% may represent moderate heterogeneity, 50–90%
may represent substantial heterogeneity, and 75–100% con-
siderable heterogeneity (8,14).
Studies were assessed for “risk of bias” using criteria adap-
ted from the Consolidated Standards of Reporting Trials
(CONSORT) statement by 2 authors independently, and
in the case of disagreement, further discussion was under-
taken to achieve consensus. A “risk of bias” score for each
study was completed on an 8-point scale by assigning a value
of 0 (absent or inadequately described) or 1 (explicitly
described and present) to each methodological item listed
in Table 1. Studies that scored 0–2 were regarded as having
a high risk of bias, studies that scored 3–5 were classified as
having a medium risk of bias, and those that scored 6–8 were
classified as having a low risk of bias.
RESULTS
The flow of studies through the review process is reported in
Figure 1. Twenty-five full-text articles were assessed; 17 met
the inclusion criteria (Table 2), and 17 were included in the
meta-analyses. Twelve studies compared the effectiveness of
LP and DUP RT programs (7,12,15–17,20,26,27,29,32,35,36).
Three studies compared LP and WUP RT programs (1,3,39).
One study compared LP, WUP, and DUP programs (5), and
1 study compared an LP program with a program incorpo-
rating both WUP and DUP (37).
There were a total of 510 participants in the included
studies. Twelve of these studies assessed males only, 3
studies females only and 2 studies assessed both males and
females. The average age of participants was 24 years (SD:
5), with a range of 19–39 years. One study did not report
participant age. Resistance training experience was reported
in all studies. Seven studies were conducted in untrained
participants (,1 year RT experience), whereas participants
in 10 studies were identified as trained ($1 year RT experi-
ence). No studies were conducted in advanced resistance
trained participants (.5 years RT experience). Participants
in 10 studies were identified as recreational trainers, in 1
Linear and Undulating Periodization on Strength
1114
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

TABLE 1. Risk of bias assessment.*
Study
(i) Were the
groups
comparable at
baseline on key
characteristics?
(ii) Did the study
randomize
participants? And was
the randomization
procedure adequately
described and carried
out?
(iii) Did the study
report a power
calculation and was
the study adequately
powered to detect
intervention effects?
(iv) Were the
assessors
blinded to
treatment
allocation at
baseline and
posttest?
(v) Did at least
80% of
participants
complete
follow-up
assessments?
(vi) Did the
study
analyses
account for
potential
differences at
baseline?
(vii) Did the
study
report 95%
confidence
intervals?
(viii) Did the
study
equate
volume and
intensity
between
groups? Total
Baker et al. (3) 1 0 0 0 0 1 0 1 3
Rhea et al. (35) 1 0 0 0 1 1 0 1 3
Hoffman et al. (17) 0 0 0 0 0 1 0 0 1
Rhea et al. (36) 1 0 0 0 1 1 0 1 3
Buford et al. (5) 1 0 0 0 1 1 0 1 3
Peterson et al. (29) 0 0 0 0 1 1 0 1 2
Hartmann et al. (15) 0 0 0 0 1 1 0 0 2
Hoffman et al. (16) 0 0 0 0 0 1 0 0 1
Kok et al. (20) 1 0 0 0 1 1 1 1 4
Monteiro et al. (27) 1 0 0 0 1 1 0 1 3
Prestes et al. (32) 1 0 0 0 1 1 0 1 3
Vanni et al. (39) 1 0 0 0 1 1 0 1 3
Miranda et al. (26) 1 0 0 0 1 1 0 1 3
Simao et al. (37) 1 0 0 0 1 1 0 1 3
Apel et al. (1) 1 0 0 0 1 1 0 1 4
de Lima et al. (7) 1 0 0 0 1 1 0 1 4
Franchini et al. (12) 1 0 0 0 0 1 0 1 3
*Yes = 1; no = 0.
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1115
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

study participants were sedentary, 2 studies were conducted
in American football athletes, 1 study was conducted with
Judo athletes, and participants in 2 studies were tactical ser-
vice operators (firefighters or military personnel).
The mean duration of RT programs was 12.6 64.1 weeks.
Nine of the studies were of 12-week and 3 studies were of
9-week duration. Mean training frequency was 3.2 60.7
sessions per week. Session duration was not reported in 10
of the 17 studies. Most RT programs (11 studies) used a com-
bination of both multi-joint and single-joint free weight and
machine-based exercises. Five studies consisted of mostly
multi-joint free weight exercises (3,16,17,27,29). One study
used single-joint machine-based exercises only (15).
Maximal strength was assessed in all studies. Sixteen
studies assessed upper-body strength by a repetition maxi-
mum bench press test. Lower-body strength was assessed
using a repetition maximum squat test in 7 studies and a leg
press repetition maximum test in 7 studies. Of the
included studies, 16 reported statistically significant
increases in maximal strength for both LP and UP RT
programs (1,3,5,7,12,15,16,20,26,27,29,32,35–37,39). Twelve
of these studies found no significant difference in maximal
strength gains between LP and UP RT programs
(3,5,7,12,15,16,20,26,29,32,36,39). Three studies found a sig-
nificant difference favoring UP RT programs (27,35,37),
whereas 2 studies found a significant difference favoring
the LP group (1,17).
After the initial risk of bias assessment, there was 96%
agreement between authors and full consensus was achieved
after discussion (Table 1). There was a high risk of bias in 4
studies (23.5%) and a medium risk in 13 (76.5%) studies. No
studies had a low risk of bias. Thirteen studies reported
randomizing participants to groups; however, no study ade-
quately described the randomization process. No studies
Figure 1. Flow of studies.
Linear and Undulating Periodization on Strength
1116
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

TABLE 2. Characteristics of included studies.*
Study
Participants Training programs
Participant numbers,
gender, and mean age
Resistance
training
experience
Study
period
Sessions
per week
Session
duration
Training attendance/
compliance rate
Description of resistance
training program
Baker et al. (3) 33 (M) recreational
participants; NP control
group (n= 9): 19.0 61.1 y;
LP group (n= 8): 20.2 6
1.2 y; WUP group (n= 5):
21.4 65.0 y
Trained 12 wks 3/wk Not
reported
Not reported Nonperiodized vs. LP or WUP;
resistance training on maximal
strength and vertical jump;
majority free weight multi-joint
exercises
Rhea et al. (35) 20 (M) recreational
participants; LP group (n=
10): 21.2 63.1 y; DUP
group (n= 10): 20.2 6
2.4 y
Trained 12 wks 3/wk 40 min Not reported LP vs. DUP resistance training on
1RM strength; periodization of
loading was prescribed for the
leg press and bench press for
each group; additional
exercises identical for each
group
Hoffman et al. (17) 28 (M) freshman American
football participants; LP
group (n= 14): age not
reported; DUP group (n=
14): age not reported
Trained 12 wks 2/wk Not
reported
LP group performed
squat in 83.8 6
15.6% and bench
press in 85.7 6
13.4% of workouts;
DUP group
performed squat in
90.8 69.2% and
bench press in 93.9 6
5.4% of workouts
LP vs. DUP in-season resistance
training on 1RM strength;
majority free weight multi-joint
exercises
Rhea et al. (36) 30 (M) and 30 (F) recreational
participants; LP group (n=
20): 21 62.4 y; reverse LP
group (n= 20): 22 61.6 y;
DUP group (n= 20): 21 6
1.9 y
Trained 15 wks 2/wk Not
reported
Participants required to
attend 28 of the 30
training sessions
LP vs. reverse LP or DUP
resistance training on muscular
endurance; single-joint isolation
exercises
Buford et al. (5) 28 (M) and 10 (F) recreational
participants; LP group (n=
9): 22.67 63.61 y; DUP
group (n= 10): 23.90 6
5.11 y; WUP group (n= 9):
20.11 61.54 y
Untrained 9 wks 3/wk Not
reported
90% attendance
required
LP vs. DUP or WUP resistance
training on 1RM strength;
a mixture of both free weight
and machine-based multi-joint
exercises
(continued on next page)
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1117
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

Peterson et al. (29) 14 (M) firefighter academy
participants; LP group (n=
7): 21.6 y; DUP group (n=
7): 22.1 y
Trained 9 wks 3/wk 60–90 min Participants required to
attend 25 of the 27
training sessions
LP vs. DUP resistance training on
strength and power; majority
free weight multi-joint exercises
but also included plyometric
movements and machine-
based exercises
Hartmann et al. (15) 40 (M) recreational participants;
LP group (n= 13): 24.31 6
3.17 y; DUP group (n= 14):
25.14 63.98 y; non-training
control group (n= 13): 24.77
63.09 y
Trained 14 wks 3/wk Not
reported
Participants required to
attend 39 of the 42
training sessions
LP vs. DUP resistance training on
strength and power in the
bench press; intervention
consisted of training bench
press exercise only
Hoffman et al. (16) 51 (M) American football
players; NP control group
(n= 17): 19.9 61.3 y; LP
group (n= 17): 19.5 61.1
y; DUP group (n= 17): 19.6
60.9 y
Trained 15 wks 4/wk Not
reported
Not reported NP vs. LP or DUP resistance
training on strength and power;
a majority of free weight multi-
joint exercises; also included
a number of single-joint
isolation exercises
Kok et al. (20) 20 (F) recreational participants;
LP group (n=10):19.66
1.6 y; DUP group (n=10):
19.9 62.3 y
Untrained 9 wks 3/wk 60 min 100% compliance for
18 participants; 97%
compliance for 2
participants
LP vs. DUP resistance training on
strength and power; a mixture
of both free weight and
machine-based multi-joint and
single-joint isolation exercises
Monteiro et al. (27) 27 (M) recreational
participants; 19.9 62.3 y;
NP group (n= 9): 26.6 6
2.2 y; LP group (n=9):27.6
62.7 y; DUP group (n=9):
28.1 62.9 y
Trained 12 wks 4/wk Not
reported
Not reported NP vs. LP or DUP resistance
training on maximal strength;
majority free weight multi-joint
exercises
Prestes et al. (32) 40 (M) recreational participants;
LP group (n= 20): 22.3 6
7.5 y; DUP group (n=20):
21.2 69.2 y
Trained 12 wks 4/wk 50 min Ø 98% compliance for
all participants
LP vs. DUP resistance training on
maximal strength; a mixture of
both free weight and machine-
based multi-joint and single-
joint isolation exercises
Vanni et al. (39) 27 (F) recreational participants;
LP group (n=14):39.56
0.60 y; WUP group (n=13):
39.7 60.59 y
Untrained 28 wks 3/wk 70–90 min 2 participants dropped
out of the study; there
was 100%
compliance with
remaining participants
LP vs. WUP resistance training
on muscular and bone
responses in premenopausal
women; a mixture of both free
weight and machine-based
multi-joint and single-joint
isolation exercises
Linear and Undulating Periodization on Strength
1118
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

Miranda et al. (26) 20 (M) recreational
participants; LP group (n=
10): 26 66y;DUPgroup(n
=10):26.565y
Trained 12 wks 4/wk Not
reported
Not reported LP vs. DUP resistance training on
strength; a mixture of both free
weight and machine-based
multi-joint and single-joint
isolation exercises
Simao et al. (37) 30 (M) Brazilian Navy
participants; LP group
(n= 10): 29.8 61.9 y;
WUP/DUP group (n= 11):
30.2 61.1 y; non-training
control group (n= 9): 25.9
63.6 y
Untrained 12 wks 2/wk Not
reported
100% compliance for
all participants
LP vs. WUP/DUP resistance
training on 1RM strength;
a mixture of both free weight
and machine-based multi-joint
and single-joint isolation
exercises
Apel et al. (1) 42 (M) recreationally active
participants; LP (traditional)
group (n= 14): 23 62.8 y;
WUP group (n= 14): 22 6
1.9 y; non-training control
group (n= 14): 22 62.3 y.
Untrained 12 wks 3/wk
weeks
1–2;
4/wk
weeks
3–12
45 min 5 participants dropped
out of the study; there
was 100%
compliance with
remaining participants
LP (traditional) vs. WUP
resistance training on 10RM
strength; a mixture of both free
weight and machine-based
multi-joint and single-joint
isolation exercises
de Lima et al. (7) 28 (F) sedentary participants;
LP group (n= 10): 25.20 6
4.35 y; DUP group (n= 10):
27.40 62.80 y; non-training
control group (n= 8): 23.40
61.29 y
Untrained 12 wks 4/wk Not
reported
Not reported LP vs. DUP resistance training on
1RM strength and maximum
repetitions at 50% 1RM;
a mixture of both free weight
and machine-based multi-joint
and single-joint isolation
exercises
Franchini et al. (12) 13 (M) judo athlete
participants; LP group (n=
6); DUP group (n= 7); age
range of participants: 18–
35 y
Untrained in
regards to
resistance
training;
trained
athletes
8 wks 3/wk Not
reported
7 participants dropped
out of the study; there
was 100%
compliance with
remaining participants
LP vs. DUP resistance training on
1RM strength and strength
endurance and specific judo
tests; a mixture of both free
weight and machine-based
multi-joint and single-joint
isolation exercises
Study
Methods Results
Study
design Outcomes Analysis Results
Effect sizes
reported for
primary
outcomes
Baker et al. (3) QEXP 1RM squat; 1RM bench press; vertical jump ANCOVA Significant improvements in 1RM squat for all
groups (26.1% NP; 27.7% LP; 28.4% WUP);
significant improvements in 1RM bench press for
all groups (12.5% NP; 11.6% LP; 16.4% WUP)
No
(continued on next page)
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1119
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

Rhea et al. (35) QEXP 1RM leg press; 1RM bench press ANOVA with
repeated
measures
Both groups increased strength significantly; 1RM
bench press increased 14.4% for LP group and
28.8% for DUP group; 1RM leg press increased
25.61% for LP group and 55.8% for DUP group;
significantly greater percent gains for DUP
compared with LP group
No
Hoffman et al. (17) QEXP 1RM squat; 1RM bench press ANOVA with
repeated
measures
Significant improvement in 1RM squat for LP but
not for DUP; no significant improvement for either
group in 1RM bench press
No
Rhea et al. (36) QEXP Local muscular endurance test (maximum reps
on leg extension at load of 50% body mass);
1RM leg extension
ANOVA with
repeated
measures
All groups significantly increased muscular
endurance and 1RM strength; muscular
endurance increased 55.9, 54.5, and 72.8% for
LP, DUP, and reverse LP, respectively; no
difference between groups; 1RM strength
increased 9.1, 9.8, and 5.6% for LP, DUP, and
reverse LP groups, respectively; no difference
between groups
Yes
Buford et al. (5) QEXP 1RM leg press; 1RM bench press ANCOVA Significant increases in leg press and bench press
strength for all groups; no significant difference
between groups although DUP resulted in a lower
percentage change in 1RM leg press and bench
press
No
Peterson et al. (29) QEXP 1RM squat; 1RM bench press; vertical jump ANOVA with
repeated
measures
Significant increases in both groups for 1RM squat
and 1RM bench press strength and vertical jump;
greater % change in 1RM squat, 1RM bench
press, and vertical jump for DUP group than LP
No
Hartmann et al. (15) QEXP 1RM bench press ANOVA Significant improvements in 1RM bench press for
LP (14.6 611.0%) and DUP (10.0. 64.5%)
groups; no difference between groups; significant
difference for both experimental groups
compared with control group who achieved no
significant change (1.38 65.84%)
No
Hoffman et al. (16) QEXP 1RM squat; 1RM bench press; vertical jump;
seated medicine ball throw
ANOVA with
repeated
measures
All groups significantly improved 1RM squat and
bench press strength; no difference between
groups; all groups significantly improved vertical
jump performance
No
Kok et al. (20) QEXP 1RM squat; 1RM bench press; loaded squat
jump
ANOVA with
repeated
measures
Significant improvements in 1RM squat for both
groups (34.8%, ES: 1.88 LP; 41.2%, ES: 2.10
DUP); significant improvements in 1RM bench
press for both groups (21.8%, ES: 0.88 LP;
28.3%, ES: 1.05 DUP); increases in jump height
for both LP (28.0%, ES: 1.15) and DUP (21.5%,
ES: 0.96) groups were observed
Yes
Linear and Undulating Periodization on Strength
1120
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

Monteiro et al. (27) QEXP 1RM leg press; 1RM bench press ANOVA Only DUP significantly improved 1RM bench press
strength; significant improvements in 1RM leg
press strength DUP and LP; no improvement in
1RM leg press for NP
No
Prestes et al. (32) QEXP 1RM leg press; 1RM bench press; 1RM
standing arm curl
ANOVA with
repeated
measures
Significant improvements in 1RM leg press
(24.71%, LP; 40.61%, DUP), 1RM bench press
(18.2%, LP; 25.08%, DUP), and 1RM standing
arm curl for both groups (14.15%, LP; 23.53%,
DUP); no significant differences between groups
No
Vanni et al. (39) QEXP 1RM leg press; 1RM bench press Linear mixed
models
Significant improvements in 1RM leg press (48.2 6
6.1% LP; 51.8 68.0% WUP) and 1RM bench
press (27.0 64.7% LP; 45.9 68.4% WUP); no
statistically significant differences between
groups
No
Miranda et al. (26) QEXP 1RM and 8RM leg press; 1RM and 8RM bench
press
ANOVA Significant increase in 1RM leg press (10%, ES:
1.23, LP; 18%, ES: 1.55, DUP); and 1RM bench
press for both groups (15%, ES: 0.75, LP; 16%,
ES: 1.02, DUP); no significant differences
between groups
Yes
Simao et al. (37) RCT 1RM bench press; 1RM lat pull down; 1RM
machine triceps extension; 1RM bicep curl
ANOVA Both training groups increased 1RM lat pull down
(LP ES: 0.77; WUP/DUP ES: 0.56), 1RM bicep
curl (LP ES: 0.83; WUP/DUP ES: 0.98), and
1RM tricep extension (LP ES: 0.81; WUP/
DUPES: 1.53); only WUP/DUP significantly
increased 1RM bench press (ES: 1.74)
Yes
Apel et al. (1) RCT 10RM squat; 10RM bench press; 10RM leg
extension; 10RM lat pull down; 10RM
shoulder press
ANOVA Both training groups significantly increased 10RM
squat (LP 54%; WUP 34%) and bench press (LP
24%; WUP 19%) at 12 wk; but only the LP
(traditional) group showed significant increases in
10RM strength from week 8 to week 12
No
de Lima et al. (7) RCT Leg press 1RM; bench press 1RM; standing
arm curl 1RM; maximum repetitions using
50% of 1RM on leg press, bench press and
standing arm curl
ANOVA Significant increases in 1RM leg press (ES: 2.99,
LP; ES: 1.73, DUP), 1RM bench press (ES: 1.77,
LP; ES: 0.95, DUP), and 1RM arm curl (ES: 1.30,
LP; ES: 1.19, DUP) for both groups; no
significant differences between groups
Yes
Franchini et al. (12) QEXP 1RM squat; 1RM bench press; 1RM row;
maximal isometric handgrip test; standing long
jump; special judo fitness test
ANOVA Significant improvements in 1RM squat, bench
press and row for both groups; significant
improvements in maximal isometric handgrip
strength for both groups; no significant
differences between groups
No
*M = male; F = female; ES = effect size; NP = nonperiodized; LP = linear periodization; WUP = weekly undulating periodization; DUP = daily undulating periodization; 1RM = 1
repetition maximum; ANOVA = analysis of variance.
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1121
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

reported using blinded assessors. No studies reported
a power calculation to determine whether their study was
adequately powered to detect their hypothesized effects. In
addition, effect sizes were reported in only 5 of the included
studies (7,20,26,36,37). Eighty percent of participants com-
pleted follow-up assessments in 13 studies. Analyses in all
studies accounted for potential baseline differences. All but 3
studies equated the volume and intensity between training
groups.
Meta-analyses
Sixteen studies were evaluated in a meta-analysis comparing
1 repetition maximum (1RM) bench press at postinterven-
tion (Figure 2). Overall, the studies were found to be mod-
erately heterogeneous (x
2
= 33.41, df =15[p= 0.004], I
2
=
55%). The meta-analysis showed no clear effect for either LP
or UP (MD = 1.71 [22.05 to 5.47] kg, Z= 0.89 [p,0.37]).
Seven studies were evaluated in a meta-analysis comparing
1RM leg press at postintervention (Figure 2). These studies
had significant heterogeneity (x
2
= 16.55, df =6[p= 0.01],
I
2
= 64%). No clear effect was shown for either LP or UP
(MD = 25.93 [22.48 to 54.35] kg, Z=1.79[p=0.07]).
Seven studies were evaluated in a meta-analysis comparing
1RM squat at postintervention (Figure 2). These studies
were homogenous (x
2
=7.83,df =5[p=0.17],I
2
= 36%).
No effect favoring LP or UP was found (MD = 21.67
[210.88 to 7.54] kg, Z=0.36[p= 0.72]).
DISCUSSION
This review identified 17 studies that directly compared LP
and UP programs. Studies were mostly conducted in young
adult males with limited RT experience. Most studies found
no differences between the 2 periodization models, and this
was supported by the findings of the meta-analyses where no
Figure 2. Meta-analyses of linear and undulating periodization on muscular strength.
Linear and Undulating Periodization on Strength
1122
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

difference was identified for both upper- and lower-body
strength. There is substantial room to improve the quality of
future studies comparing training manipulations to reduce
the risk of bias. There is also a lack of studies investigating
more athletic or highly resistance trained populations as well
as adolescents and over long time frames.
The RT programs evaluated in this review were pre-
dominantly short-term interventions and only 4 studies had
a duration greater than 12 weeks. Two studies found DUP
RT resulted in increased strength in the initial weeks of the
intervention with no increase in strength with LP RT until
later stages of the intervention (27,35). The short-term
nature of these interventions makes it difficult to draw con-
clusions regarding the long-term effectiveness of LP or UP.
Longer-term interventions are needed in order to assess the
purported advantage of greater variation in UP being more
effective at breaking strength plateaus than LP
(5,10,17,20,26,29,35).
The majority of study participants were adult males and
none of the studies investigated the effects of LP and UP in
adolescents. Additionally, supporting evidence for both
forms of periodization is lacking in novice and athletic
populations. Generalized training theories underpin the
rationale for periodized training programs (32,35,36,40).
Selye’s General Adaptation Syndrome states that if a stress
or bout of exercise is experienced by a system, the system
will respond with a temporary decrease in performance
followed by restitution returning to or above the initial level
of physical fitness (2,40). This enhancement of physical
fitness is termed supercompensation (2,40) and is the primary
purpose of all training interventions where an improvement
in physical fitness is sought. If the applied stress remains
at the same magnitude (intensity, volume and frequency)
the system will accommodate to this stress and no further
improvements in physical fitness will occur (2,40). To avoid
this accommodation, training programs must be varied
over time (40).
Previous training history and training status will influence
adaptations to further training interventions, particularly in
respect to muscular strength. Over a 4-week to 2 year period
muscular strength increases of 40, 16, 10, and 2% are
representative of the expected improvements in untrained,
trained, advanced and elite resistance trained individuals,
respectively (21,33). Most participants in this review had
some prior RT experience and were identified by study au-
thors as trained. When planning training interventions it is
important to consider generalized theories of training adap-
tation and in particular the initial level of physical fitness or
physical preparedness of participants. The description of
study participants’ previous training history was poorly re-
ported in most of the included studies. For example, Rhea
et al. (35) indicated that all participants in their 12-week
study reported undertaking RT equivalent to a LP approach
during the 2 years prior to the study but did not describe the
volume or frequency of training. They found a significant
difference favoring DUP for strength improvement only in
the first 6 weeks of the intervention. However, no significant
difference in strength gains between groups was found in the
last 6 weeks of the intervention. Prior experience with LP RT
creates the potential for UP to provide a more novel stimu-
lus. It is reasonable to suggest that the novelty or variation in
stimulus compared to participants’ previous training experi-
ence is of greater importance for eliciting strength improve-
ments and overcoming accommodation than the specific
type of periodization approach employed. There is a need
for authors to clearly describe the training experience of their
participants with different periodization approaches.
The majority of studies included in this review found
significant increases in muscular strength for both periodi-
zation approaches, whereas significant differences between
approaches were rarely found. One possibility is that studies
were underpowered to detect statistically significant differ-
ences. Considering the small sample sizes often involved in
sports science studies, the reporting of effect sizes may be
more practically meaningful in RT interventions (4,18,34).
Only 5 of the studies included in this review reported effect
sizes (7,20,26,36,37). In a previous review, Rhea (34) re-
ported that the effect sizes in RT studies were much larger
than those typically observed in the social/behavioral fields.
He recommended scales for assessing the practical signifi-
cance of effect sizes in RT research based on participant’s
training status (34). This scale highlights the importance for
RT research studies to adequately describe the training his-
tory and background of participants. Comprehensive report-
ing of effect sizes in the scientific literature will enable
strength and conditioning professionals to use theoretical
knowledge and implement practical evidence-based training
programs. Further within group variations in baseline
strength and responsiveness may also influence the capacity
to detect differences between training approaches.
To the authors knowledge this is the first systematic
review and meta-analysis comparing linear and undulating
periodized RT programs. A strength of a systematic review is
that the criteria for inclusion is determined prior to the
search and is designed to minimize reviewer bias in regards
to what is included. This objectivity is strengthened by
adherence to the PRISMA reporting guidelines and
CONSORT statement. A strength of combining a system-
atic search with a meta-analysis is that it allows data from
multiple studies to be combined to determine an outcome.
This is particularly advantageous when studies have small
sample sizes and risk an inability to identify differences
due to lack of statistical power. A number of limitations
should be noted. Firstly, there may be bias in the selection
of studies as abstracts, theses, or studies published in non
peer-reviewed journals were not included. Additionally,
there was considerable heterogeneity between studies
and no study adequately described the randomization of
participants. Therefore, caution should be taken in the
interpretation of the meta-analysis results.
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1123
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

PRACTICAL APPLICATIONS
The results of this systematic review and meta-analysis
reveal that both LP and UP RT programs can increase
maximum strength substantially, but no clear evidence
favoring either periodization approach was found for the
development of upper or lower body strength. The results
suggest that novelty or training variety are important for
stimulating further strength development. When the work
performed is equal, neither periodized approach is necessar-
ily superior and either approach can be used to provide
variety and therefore enhance adaptation. Potentially the
implementation of short training blocks, of 2–6 weeks dura-
tion, using either LP or UP RT within current training re-
gimes may provide an adequate and novel stimulus to
promote further strength increases and overcome plateaus.
Therefore, strength and conditioning professionals are
advised to design periodized training programs taking into
account the RT principle of “variety” to prevent stagnation
and accommodation to a particular training approach. Care-
ful consideration should be given to the previous training
history and current training status of participants.
Further research is needed in adolescent, athletic, and
possibly for rehabilitation (24) populations to investigate the
effects of different periodized approaches to RT. Further-
more, longer-term studies are also needed to determine
and compare the long-term effectiveness of LP and UP RT
on strength development. Researchers are advised to ade-
quately report the previous training history of participants,
stratify assignment to groups on the basis of prior training
experience, or implement standardized pre-intervention
training to reduce the influence of training history on inter-
vention effects.
ACKNOWLEDGMENTS
The authors of this article would like to thank the inves-
tigators who responded to requests to provide additional
information for the meta-analysis. No external funding was
used for this project. The authors have no competing
interests relating to the content of this manuscript. There
were no other contributors to this manuscript.
REFERENCES
1. Apel, JM, Lacey, RM, and Kell, RT. A comparison of traditional and
weekly undulating periodized strength training programs with total
volume and intensity equated. J Strength Cond Res 25: 694–703,
2011.
2. Baechle, T.R. and Earle, R.W., eds. Essentials of Strength Training and
Conditioning/National Strength and Conditioning Association.
Champaign, IL: Human Kinetics, 2008.
3. Baker, D, Wilson, G, and Carlyon, R. Periodization: The effect on
strength of manipulating volume and intensity. J Strength Cond Res
8: 235–242, 1994.
4. Batterham, AM and Hopkins, WG. Making meaningful inferences
about magnitudes. Sportscience 9: 6–13, 2005.
5. Buford, TW, Rossi, SJ, Smith, DB, and Warren, AJ. A comparison of
periodization models during nine weeks with equated volume and
intensity for strength. J Strength Cond Res 21: 1245–1250, 2007.
6. Collaboration TC. Review Manager (RevMan) [Computer
program]. The Nordic Cochrane Centre, The Cochrane
Collaboration, Copenhagen, Denmark, 2011.
7. de Lima, C, Boullosa, DA, Frollini, AB, Donatto, FF, Leite, RD,
Gonelli, PR, Montebello, MI, Prestes, J, and Cesar, MC. Linear and
daily undulating resistance training periodizations have differential
beneficial effects in young sedentary women. Int J Sports Med 33:
723–727, 2012.
8. Deeks, J, Higgins, JPT, and Altman, DG. Analysing data and
undertaking meta-analyses. In: Cochrane Handbook for
Systematic Reviews of Interventions (Version 5.1.0, updated
March 2011). T. Higgins and S. Green, eds. The Cochrane
Collaboration, 2011. Available at: www.cochrane-handbook.org.
9. Faigenbaum, AD, Kraemer, WJ, Blimkie, CJR, Jeffreys, I,
Micheli, LJ, Nitka, M, and Rowland, TW. Youth resistance
training: Updated position statement paper from the national
strength and conditioning association. JStrengthCondRes23:
S60–S79, 2009.
10. Fleck, SJ. Non-linear periodization for general fitness & athletes.
J Hum Kinetics 29A: 41–45, 2011.
11. Folland, JP and Williams, AG. The adaptations to strength training:
Morphological and neurological contributions to increased strength.
Sports Med 37: 145–168, 2007.
12. Franchini, E, Branco, BM, Agostinho, MF, Calmet, M, and
Candau, R. Influence of linear and undulating strength periodization
on physical fitness, physiological and performance responses to
simulate judo matches. J Strength Cond Res 2014. [Epub ahead of
print]. doi: 10.1519/JSC.0000000000000460.
13. Haff, GC. Roundtable discussion: Periodization of training. Part 2.
Strength Cond J 26: 56–70, 2004.
14. Harries, SK, Lubans, DR, and Callister, R. Resistance training to
improve power and sports performance in adolescent athletes: A
systematic review and meta-analysis. J Sci Med Sport 15: 532–540,
2012.
15. Hartmann, H, Bob, A, Wirth, K, and Schmidtbleicher, D. Effects of
different periodization models on rate of force development and
power ability of the upper extremity. J Strength Cond Res 23: 1921–
1932, 2009.
16. Hoffman, JR, Ratamess, NA, Klatt, M, Faigenbaum, AD, Ross, RE,
Tranchina, NM, McCurley, RC, Kang, J, and Kraemer, WJ.
Comparison between different off-season resistance training
programs in division III American college football players. J Strength
Cond Res 23: 11–19, 2009.
17. Hoffman, JR, Wendell, M, Cooper, J, and Kang, J.
Comparison between linear and nonlinear in-season training
programs in freshman football players. J Strength Cond Res 17 :
561–565, 2003.
18. Hopkins, WG, Marshall, SW, Batterham, AM, and Hanin, J.
Progressive statistics for studies in sports medicine and exercise
science. Med Sci Sports Exerc 41: 3–12, 2009.
19. Issurin, VB. New horizons for the methodology and physiology of
training periodization. Sports Med 40: 189–206, 2010.
20. Kok, LY, Hamer, PW, and Bishop, DJ. Enhancing muscular qualities
in untrained women: Linear versus undulating periodization. Med
Sci Sports Exerc 41: 1797–1807, 2009.
21. Kraemer, WJ, Adams, K, Cafarelli, E, Dudley, GA, Dooly, C,
Feigenbaum, MS, Fleck, SJ, Franklin, B, Fry, AC, Hoffman, JR,
Newton, RU, Potteiger, J, Stone, MH, Ratamess, NA, and Triplett-
McBride, T; American College of Sports Medicine. American
College of Sports Medicine position stand. Progression models in
resistance training for healthy adults. Med Sci Sports Exerc 34: 364–
380, 2002.
Linear and Undulating Periodization on Strength
1124
Journal of Strength and Conditioning Research
the
TM
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.

22. Kraemer, WJ and Ratamess, NA. Fundamentals of resistance
training: Progression and exercise prescription. Med Sci Sports Exerc
36: 674–688, 2004.
23. Liberati, A, Altman, D, Tetzlaff, J, Mulrow, C, and Gotzche, P.
The PRISMA statement for reporting systematic reviews and
meta-analyses of studies that evaluate health care interventions:
Explanation and elaboration. PLoS Med 6: 1–28, 2009.
24. Lorenz, DS, Reiman, MP, and Walker, JC. Periodization: Current
review and suggested implementation for athletic rehabilitation.
Sports Health 2: 509–518, 2010.
25. Mann, JB, Thyfault, JP, Ivey, PA, and Sayers, SP. The effect of
autoregulatory progressive resistance exercise vs. linear
periodization on strength improvement in college athletes.
J Strength Cond Res 24: 1718–1723, 2010.
26. Miranda, F, Sima
˜o, R, Rhea, M, Bunker, D, Prestes, J, Leite, RD,
Miranda, H, De Salles, BF, and Novaes, J. Effects of linear vs. daily
undulatory periodized resistance training on maximal and
submaximal strength gains. J Strength Cond Res 25: 1824–1830, 2011.
27. Monteiro, AG, Aoki, MS, Evangelista, AL, Alveno, DA,
Monteiro, GA, Picarro Ida, C, and Ugrinowitsch, C. Nonlinear
periodization maximizes strength gains in split resistance training
routines. J Strength Cond Res 23: 1321–1326, 2009.
28. Painter, KB, Haff, GG, Ramsey, MW, McBride, J, Triplett, T,
Sands, WA, Lamont, HS, Stone, ME, and Stone, MH. Strength
gains: Block versus daily undulating periodization weight training
among track and field athletes. Int J Sports Physiol Perform 7: 161–
169, 2012.
29. Peterson, MD, Dodd, DJ, Alvar, BA, Rhea, MR, and Favre, M.
Undulation training for development of hierarchical fitness and
improved firefighter job performance. J Strength Cond Res 22: 1683–
1695, 2008.
30. Peterson, MD, Rhea, MR, and Alvar, BA. Applications of the dose-
response for muscular strength development: A review of meta-
analytic efficacy and reliability for designing training prescription.
J Strength Cond Res 19: 950–958, 2005.
31. Plisk, SS and Stone, MH. Periodization strategies. Strength Cond J 25:
19–37, 2003.
32. Prestes, J, Frollini, AB, de Lima, C, Donatto, FF, Foschini, D, de
Cassia Marqueti, R, Figueira, A Jr, and Fleck, SJ. Comparison
between linear and daily undulating periodized resistance
training to increase strength. J Strength Cond Res 23: 2437–2442,
2009.
33. Ratamess, NA, Alvar, BA, Evetoch, TK, Housh, TJ, Kibler, WB,
Kraemer, WJ, and Triplett, NT. American College of Sports
Medicine: Progression models in resistance training for healthy
adults: Position stand. Med Sci Sports Exerc 41: 687–708, 2009.
34. Rhea, M. Determining the magnitude of treatment effects in
strength training research through the use of the effect size.
J Strength Cond Res 18: 918–920, 2004.
35. Rhea, MR, Ball, SD, Phillips, WT, and Burkett, LN. A comparison
of linear and daily undulating periodized programs with equated
volume and intensity for strength. J Strength Cond Res 16: 250–255,
2002.
36. Rhea, MR, Phillips, WT, Burkett, LN, Stone, WJ, Ball, SD,
Alvar, BA, and Thomas, AB. A comparison of linear and daily
undulating periodized programs with equated volume and
intensity for local muscular endurance. JStrengthCondRes17 :
82–87, 2003.
37. Simao, R, Spineti, J, Freitas De Salles, B, Matta, T, Fernandes, L,
Fleck, SJ, Rhea, MR, and Strom-Olsen, HE. Comparison between
nonlinear and linear periodized resistance training: Hypertrophic
and strength effects. J Strength Cond Res 26: 1389–1395, 2012.
38. Smith, CJ, Callister, R, and Lubans, DR. A systematic review of
strength and conditioning programmes designed to improve fitness
characteristics in golfers. J Sports Sci 29: 933, 2011.
39. Vanni, AC, Meyer, F, Da Veiga, AD, and Zanardo, VP. Comparison
of the effects of two resistance training regimens on muscular and
bone responses in premenopausal women. Osteoporos Int 21: 1537–
1544, 2010.
40. Zatsiorsky, VM and Kraemer, WJ. Science and Practice of Strength
Training. Champaign, IL: Human Kinetics, 2006.
Journal of Strength and Conditioning Research
the
TM
|
www.nsca.com
VOLUME 29 | NUMBER 4 | APRIL 2015 | 1125
Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.