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Medicina Sportiva
Med Sport 15 (3): 147-162, 2011
DOI: 10.2478/v10036-011-0025-x
Copyright © 2011 Medicina Sportiva
REVIEW ARTICLE
147
EVIDENCEBASED RESISTANCE TRAINING
RECOMMENDATIONS
James Fisher1(A,E,F), James Steele1(E,F), Stewart Bruce-Low1(E,F), Dave Smith2(A,E,F)
1Southampton Solent University, UK
2Manchester Metropolitan University, UK
Abstract
Resistance training produces an array of health benefits, as well as the potential to promote muscular adaptations of
strength, size, power and endurance. The American College of Sports Medicine (ACSM) regularly publish a position stand
making recommendations for optimal achievement of the desired training goals. However, the most recent position stand
(as well as previous ones) has come under heavy criticism for misrepresentation of research, lack of evidence and author
bias. Therefore this paper proposes a set of scientifically rigorous resistance training guidelines, reviewing and summarising
the relevant research for the purpose of proposing more logical, evidence-based training advice.
We recommend that appreciably the same muscular strength and endurance adaptations can be attained by perform-
ing a single set of ~8-12 repetitions to momentary muscular failure, at a repetition duration that maintains muscular tension
throughout the entire range of motion, for most major muscle groups once or twice each week. All resistance types (e.g.
free-weights, resistance machines, bodyweight, etc.) show potential for increases in strength, with no significant difference
between them, although resistance machines appear to pose a lower risk of injury.
There is a lack of evidence to suggest that balance from free weights or use of unstable surfaces shows any transfer-
ence to sporting improvement, and explosive movements are also not recommended as they present a high injury risk and
no greater benefit than slow, controlled weight training. Finally, we consider genetic factors in relation to body type and
growth potential.
Key words: muscular strength, bodybuilding, intensity, genetic
Introduction
It is now widely recognized that resistance training
can be of great value, not only for athletes, but also for
all those interested in optimizing health and longevity.
The health benefits associated with resistance training
include: decreased gastrointestinal transit time (reduc-
ing the risk of colon cancer) [1]; increased resting
metabolic rate [2]; improved glucose metabolism [3];
improved blood-lipid profiles [4, 5]; reduced resting
blood pressure [6, 7]; improved bone mineral density
[8]; pain and discomfort reduction for those suffer-
ing from arthritis [9]; decreased lower back pain [10,
11]; enhanced flexibility [12], and improved maximal
aerobic capacity [13].
For those involved in sport, resistance training can
‘prehabilitate’, i.e. prevent potential injuries through
strengthening joints, muscles, tendons, bones, and
ligaments. Enhancing the attributes associated with
physical performance, e.g., endurance, strength,
power, speed and vertical jump, is possible with ap-
propriate resistance training methods [14].
The American College of Sports Medicine (ACSM)
[15], through their publication Medicine and Science in
Sports and Exercise (MSSE), publish a position stand
with guidelines for the recommended training for
enhancing physiological strength and fitness (both car-
diorespiratory and muscular) in trained and untrained
persons. However, the latest [15], and previous [16,
17] position stands have received heavy criticisms for
misrepresentation of research and essentially research
bias [18, 19].
In recent years evidence-based medicine has be-
come the norm and it is generally accepted that medi-
cal treatment should be based on the best available
medical evidence gained from the scientific method.
However, it appears that in exercise science such a
method is still not wholly applied by those entrusted
to provide guidelines for efficacious resistance train-
ing. Unfortunately, as Carpinelli [19] noted, many of
the recommendations provided in the ACSM posi-
tion stand [15] were bereft of supporting scientific
evidence, and, even more worryingly, many of the
references cited simply did not support the statements
made (see Carpinelli, 2009, for a detailed critique
[19]. Therefore, in the spirit of scientific practice we
have compiled the present piece as evidence-based
recommendations for resistance training. This article
advances some of the previous critical analyses, clarify-
ing some commonly misused terminology, as well as
reviewing areas previously omitted by organizations
such as the ACSM. Therefore, our aims are to con-
sider the evidence and present scientifically-validated
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Fisher J., Steele J., Bruce-Low S., Smith D. / Medicina Sportiva 15 (3): 147-162, 2011
guidelines for resistance training for healthy asymp-
tomatic adults looking to improve muscular strength
and fitness, as well as dispelling myths, discussing
other points of general interest and suggesting areas
for future research. We should clarify that older adults
(undefined by ACSM [15]) and clinical populations are
not considered within the present article and might be
better suited to alternative methods. Specifically, the
following issues will be considered and summarized:
• Intensity,Load&RepetitionRange
• ResistanceTypes
• Repetitionduration
• VolumeofExercise,FrequencyandPeriodization
• GeneticFactorsandTheirImplications
Intensity, Load & Repetition Range
Intensity
One of the most important considerations within
resistance training is that of intensity [20, 21]. How-
ever, as with all terms used in the scientific literature, it
is crucial that the term is defined and operationalized
in a logical and meaningful way. The general use of
the term in the strength training literature, including
the ACSM position stand, is as a reference to the load
used. For example, and typically, Willardson and Bur-
kett [22] and Fry [23] suggest that it is a common term
forpercentageof1repetitionmaximum(%1RM).We
propose that ‘intensity’, in the truest sense, is the level
of effort applied to a given load, defined as the number
of repetitions performed in relation to the number
possible. Of course it is logical that this definition
permits only one accurate measure of intensity, that
of 100%; when the participant can perform no more
repetitions with a given resistance. Based on this, we
can perhaps define ‘momentary muscular failure’ as the
inability to perform any more concentric contractions,
without significant change to posture or repetition
duration, against a given resistance. We accept that
effort of a participant would vary in relation to load
and repetitions; however, these factors do not combine
to constitute an accurate expression of ‘intensity’. In
factthisexpressionof%RMisexactlywhatitisand
nothing more: a training load given as a percentage of
repetition maximum as opposed to a measure of inten-
sity or effort. The problem with such a definition is the
lack of any consideration of how hard the individual
is working during the exercise. The definition incor-
rectly implies that two persons performing the same
numberofrepetitionsatagiven%1RMhaveworked
at an identical relative effort. This is, of course, not
necessarily the case. For example, Hoeger et al. [24,
25]andShimanoetal.[26]reported1RMvaluesand
respectiveRMsforgiven%1RMsformaleandfemale,
trained and untrained participants. Their data show
large variations in the number of repetitions possible
forthe same%1RM between participants.Indeed,
Douris et al. [27] reported that participants with a
higher percentage of type-II muscle fibers were able
to perform fewer repetitions than those with a lower
percentageoftype-IIfibers,with70%1RM.
Theknowledgeofaperson’s1RMatagivenexercise
(without the addition of knowledge of their fiber-type)
does not provide any accurate basis for prediction of
how many repetitions that person can perform at any
given%1RM.Thisisanimportantissuegiventhatso
much emphasis is placed on training intensity in the
strength training literature, which is puzzling given
that the research evidence does not support the view
thattrainingwitharelativelyhigh%of1RMisimpor-
tant for strength development (see Carpinelli, 2008,
for a thorough review of this issue [28]). For instance,
according to the accepted definition of intensity, if
one individual performs an exercise with a weight of
80%of1RM,andperformsoneeasyrepetitionwith
that weight, this person is training more ‘intensely’
than another individual who performs a hard set to
momentarymuscularfailurewith79%oftheir1RM.
Clearly this is nonsensical. Therefore, when intensity
is referred to within this article we are referring to
the percentage of momentary muscular effort being
exerted,not%1RM,andwewould suggest for con-
sistency and accuracy in the literature, other authors
follow suit.
Momentary Muscular Failure
Willardson [29] suggested that training to momen-
tary muscular failure may provide greater stimulation
to the higher threshold fast-twitch motor units, which
are capable of producing the greatest increases in
strength and hypertrophy. Thus, training to momen-
tary muscular failure is theoretically more beneficial
simply because doing so would ensure recruitment
of as many motor units and muscle fibers as possible.
A common misconception is that heavy weights are
required to stimulate muscular growth, but Carpinelli
[28] pointed out that this ‘heavier-is-better’ principle
is simply unsubstantiated by research. The evidence
shows that lower threshold motor units in the form
of type I slow-twitch, or type IIa fast-twitch muscle
fibers are recruited first, and as these motor units are
fatigued so the higher threshold motor units of type IIx
fast-twitch fibers are recruited [28, 29]. The final rep-
etitionofatrueRMsetwouldbeamaximalvoluntary
contraction due to the effort and recruitment required
asaRMmeansnofurtherrepetitionsarepossible[28]
(irrespective of the number of previously completed
repetitions).However,unlessperforminga1RM,this
would not be the maximal force possible, simply the
maximalforce of the fatiguedmuscle. Perhapsthe
most important aspect of this is simply that to activate
all the motor units within a muscle group, and thus
recruit all the available muscle fibers to stimulate them
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toadapttothetraining,itisnotthe%1RMthatisthe
primary factor but rather the requirement to train to
momentary muscular failure [28].
Willardson [29] reviewed this concept and in do-
ing so highlighted one of the main issues; that little
research has directly addressed the concept of train-
ing to momentary muscular failure whilst accurately
controlling for other variables such as load, volume
andfrequency.Giventhatitisessentialtocontrolfor
these factors to produce meaningful data only studies
that have done so have been considered herein.
Rodney et al. [30]reported significantlygreater
gains (41.2% to 19.7%) in dynamic strength when
training to muscular failure compared to submaximal
sets of exercise. Similarly, Schott et al. [31] reported
significantly greater gains in isometric strength when
training to failure compared to stopping the exercise
short of failure (24.9kg to 14.3kg) and Drinkwater et
al. [32] reported significantly greater dynamic strength
gains (9.5% to 5%), and also peak power for a bench
press throw exercise when training to muscular failure
compared to not training to failure (40.8W/10.6% to
25W/6.8%). These studies varied in the number of sets
and number of repetitions completed. From a single
set of 6 repetitions [30] to 4 sets of 6 repetitions [32]
and 4 sets of 30 second isometric muscle action [31]
but each study reported that training to momentary
muscular failure produced significantly better results.
Other studies reported no significant difference
between training to momentary muscular failure and
training submaximally [33, 34]. Izquierdo et al. [34]
measured training 2 x/week for 45-60 minutes over 16
weeks, and Folland et al. [33] considered training leg
extensions 3 x/week over 9 weeks. Notably Folland et
al. [2002] reported no significant difference in strength
increase between a training time of around 7 minutes
(to failure) and 25 minutes (not to failure), suggesting
that the same strength gains could be achieved in ap-
proximately 30% of the time by training to momentary
muscular failure.
The evidence suggests that individuals should be
encouraged to train to momentary muscular failure,
as this appears to maximize muscle fiber recruitment
and, according to most of the research to date, will
maximize gains in strength and power.
RPE
An alternative method of measuring intensity is
thatoftheBorg‘RatingofPerceivedExertion’Scale
(RPE;35)oraderivative.AdaptationsoftheRPEscale
have been used in various size scales considering both
overall (O) and active muscle (AM) effort for different
loads [36–43]. However, it seems logical that training
to momentary muscular failure would elicit a higher
exertion or effort level than training submaximally,
irrespective of load, thus questioning the efficacy of
RPEduring resistancetraining.GearhardtJnr.etal.
[37,38]reported significantlylower RPE valuesfor
participantsperforming15 repetitions at30%1RM
compared to those performing 5 repetitions at 90%
1RM.However,it isquestionable how these efforts
were able to keep the total workload equal between
groups. The earlier section discussing intensity, along
with the aforementioned research by Hoeger et al. [25]
and Shimano et al. [26], suggests that 5 repetitions
at90%of1RMisclosertomaximalpossiblerepeti-
tions (and thus equates to a higher intensity) than 15
repetitionsat30%of1RM.Thisisthemostcommon
methodological flaw in such studies; the apparent as-
sumption that load x repetitions = intensity. This, as
noted earlier, is a fallacy.
In fact, all of these studies are probably report-
ing the same results; perceived exertion increases
the closer a participant trains to his or her maximal
intensity, irrespective of the load used. To accurately
measure a participant’s perceived exertion when
trainingatagiven%1RM,amorelogicalstudydesign
would involve performing repetitions to momentary
muscular failure. The value of such a study would be
todeterminewhetherthereisvariationinRPEbased
around the number of repetitions completed preced-
ingamaximumvoluntarycontraction(MVC),orthe
exercise performed based on the muscle mass involved.
Shimano, et al. [26] considered exactly this and
reported no significant difference comparing 60%,
80%and90% 1RM forbenchpressandbicepscurl
for trained and untrained participants. However the
authorsdidreportasignificantlyhigherRPEfor60%
1RMforthe squat exercise whencomparedto80%
and90%1RM,suggestingthatahigherloaddoesnot
correlate with a greater effort. The authors gave no
explanation for this result; they simply concluded that
when exercises and repetitions are completed to mus-
cular failure, intensity is similar. They concluded that
theuseofanRPEscaleinresistancetrainingmightnot
be beneficial. We concur and reiterate that individuals
should simply be encouraged to train to momentary
muscular failure to maximize results.
Load and Repetition Range
As previously stated by Carpinelli [28] the research
suggests that it is not the load lifted that determines
fiber recruitment, but the fatigue of the lower thresh-
old motor-units resulting in a sequential recruitment
of higher threshold motor units through continued
repetitions. Carpinelli [28] describes the facts and
misconceptions of fiber recruitment, as well as the
heavier-is-better misnomer. As a result we have chosen
not to replicate this work by reviewing the literature
but rather acknowledge Dr. Carpinelli’s efforts by
recommending the reading of his article [28], and
summarizing his conclusions herein.
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Researchhasconsideredrangesfrom2RMthrough
to100-150RM andfoundno significantdifference in
strength improvements between the results [44–48], with
only one exception; Campos et al. [49] reported a signifi-
cantlygreaterimprovementin1RMforthesquatandleg
press exercises for previously untrained male participants
performing3-5RMcomparedto9-11RM,over8weeks
of training. However, the authors reported no significant
difference in change in muscle cross-sectional area, or
muscle fiber-type, and could not provide any rationale
as to why these differences might have occurred.
Interestingly the ACSM position stand [15] claimed
that maximal strength gains are obtained training with
loadsofbetween1-6RM.However,itisapparentfrom
the above data as well as recent comprehensive reviews
of the literature that the research findings to date do not
supporttheACSM’sconclusion[19,50].Giventhatdif-
ferent repetition ranges do not appear to differentially
affect strength gains perhaps other health related ben-
efitsshouldbeconsidered.Researchappearstosuggest
that to increase bone mineral density (BMD) training
loadsneedtobe80%1RMorgreater[51].Vincentand
Braith[51] comparedtrainingat50%1RM(~13reps)
totrainingat80%1RM(~8reps).Whilsttheyreported
almost identical strength gains, the higher load group
produced significantly greater increases in BMD.
We, therefore, reiterate our earlier suggestion [50]
thatamoderaterepetitionrange(~8-12repetitions)may
be best to increase BMD. The lighter weights suggested
herein may produce a lower injury risk than the heavier
weights necessitated by the ACSM’s recommendations.
The loads required under the ACSM’s guidance will
impose greater force on muscles and connective tissues.
However, more research is required to confirm this
hypothesis. There may also be more favourable ranges
depending on the individual’s predominant fiber-type in
therelevantmuscle.Forexample,Jones[52]suggested
that persons dominant in fast twitch muscle fibers might
obtain better results performing fewer repetitions with
a greater resistance, whilst persons dominant in slower
twitch muscle fiber-type might obtain better results
performing a greater number of repetitions and lighter
resistance. Based on this hypothesis Darden [53] offered
a rule of thumb protocol to determine optimal1 repetition
ranges for different exercises and/or persons, claiming
that it is a rough gauge of muscle fiber-type. However, the
usefulness of this method has not been tested empirically
and we therefore suggest that future research should test
these methods and associated hypotheses.
Muscular Endurance
We can consider two definitions of muscular en-
durance as being absolute; the number of repetitions
performed at a given resistance, and relative; the number
ofrepetitionsperformedatagiven%1RM[18,54].For
example,apretraining1RMof100kgmightproduce
10 repetitions at an absolute value of 70kg, which is also
therelativevalueof70%1RM.However,afteratraining
regimewherethe1RMhasimprovedto120kg,apar-
ticipant will almost certainly be capable of greater than
10 repetitions at the absolute value of 70kg, but likely
still only produce a maximum of 10 repetitions at the
relativevalueof70%1RM(now84kg).Thisexample
showsanincreaseinmaximalstrength(1RM)leadingto
an increase in absolute muscular endurance, i.e., an in-
crease in number of repetitions at the fixed submaximal
weight.Researchsupportsthisconcept[55].However,
the research does not support the idea that the same is
true of relative loads, but rather that similar maximal
repetitions are possible [55, 56].
The ACSM [15] stated that when training for muscu-
lar endurance, persons should use light-moderate loads
(40-60%1RM)andperformhighrepetitions(>15)us-
ing short rest periods (<90s). They repeat citations from
their 2002 position stand [57, 54] which were heavily
criticized for conclusions that were not supported by
their data [18]. The only study that appears to support
the ACSM’s position is that of Campos et al. [50] who
reportedsignificantlyhigherrepetitionsat60%1RMfor
3 lower body exercises for participants training at higher
repetitions(20-28RM)comparedtolow(3-5RM),and
moderate(9-11RM).Incontrast,otherstudiesdonot
support the hypothesis that higher repetition schemes
are more effective in increasing muscular endurance.
Anderson and Kearney [57] examined the effects of
3 different training protocols on muscular endurance
(measured by the number of bench press repetitions
participantscouldperformwith27.23kg).Participants
weredividedintolowrepetition(3setsof6-8RM),me-
diumrepetition(2setsof30-40RM)andhighrepetition
(1setof100-150RM)groups,eachtraining3xweek
for 9 weeks. No significant between-group differences
in improvements in muscular endurance were found.
Stone and Coulter [54] examined the effects of 3 train-
ingprotocols(3x6-8 RM,2x15-20 RM, and 1x30-40
RM)onthemuscularenduranceofuntrainedfemales,
each of whom trained 3 x week for 9 weeks. Again,
no significant between-group post-test differences in
muscular endurance were found.
Summary:
• PercentageRMdenotestheloadtrainedwith,rather
than effort or intensity.
• Onlyoneaccuratemeasureofintensityispossible,
that of maximal effort, 100% intensity or repetition
max(RM).
1 The term ‘optimal’ herein is defined as ‘the best attainable or most favourable with regard to maximally enhancing muscular strength, within the context
of current evidence’
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• Researchdoesnotunequivocallysupportthesupe-
riority of a particular repetition range for enhancing
any aspect of muscle function.
• Trainingto maximaleffort, or‘momentarymus-
cular failure’, is necessary to recruit all the possible
motor units and muscle fibers.
Resistance2 Typ e s
A recent review article [58] identifies several types
of resistance. One type is constant resistance, e.g. free
weights (although it is worth noting that whilst the
mass of a dumbbell or barbell remains constant, the
resistance or torque applied to the muscular system
itself varies as lever length changes throughout a range
of movement). Other types described are variable; e.g.
resistance machines (where the resistance is system-
atically varied according to a cam or series of cables,
pulleys or linkage leverage chains), accommodating;
e.g. hydraulics (where resistance is proportional to
force applied), and pneumatic (which compresses air
as the form of resistance). It is beyond the scope of this
article to explore the biomechanical advantages and
disadvantages of resistance types. However as some
authors have claimed that certain types of equipment
are more effective for enhancing strength it is impor-
tant for us to examine the evidence relating to such
claims. For example, the ACSM [15] has argued that
free weights are better than machines for enhancing
strength, whereas others have claimed that variable
resistance machines are more effective [59]. It is
noteworthy that much research has compared one
training method against another but only performed
pre and post-testing on each respective method [e.g.
60, 61]. In this case, without a cross-over testing ele-
ment such a design clearly favours the group training
on the equipment on which they will be tested as they
will be more skilled at using the equipment in question.
Therefore, research following such a design has been
excluded from our consideration.
Manystudies havealso used EMGto interpret
muscle activation or force production, most notably
free weights and resistance machines [62, 63], stable
and unstable surfaces [64] and vibration training [65-
67], each of which are examined herein. However, the
limitationsofattemptingtoaccuratelyuseEMGdata
to interpret activation or muscular force production
include (but are not restricted to): crosstalk (readings
from synergist muscles) depth of active motor units
from surface electrode, amplitude related to motor
units and muscle fiber-types, variable firing rates,
muscle-fiber length, velocity and contraction type [68-
74].Possiblymostproblematicisthefactthat,although
in general there is a positive relationship between
forceproductionandEMGactivity,therelationship
is often not linear, particularly in large muscles such
as the biceps and deltoid, and particularly so at high
muscleactivationlevels[75,76].Therefore,EMGis
very limited in what it can tell us regarding the merits
of different equipment or exercises. With this in mind
andsinceEMGdatagivesnoguidanceastooptimal
trainingbenefits,researchconsideringEMGdatahas
been excluded from this article. However, we explore
findings below from studies providing an unbiased
test of different types of equipment using muscular
performance measures.
Free Weights and Machines
Researchhasreportednosignificantdifferencein
strength gains between groups training on resistance
machines and undertaking free weight exercises
[77-79]. Other research has utilized a leg extension
machine but compared variable to constant resistance
(by switching between a cam and a circular disc),
once again reporting no significant difference in the
strength increases between groups [80]. Despite this
the ACSM [15] suggest that free weights have an ad-
vantage over resistance machines due to purported
greater neural activation. The ACSM [15] cite a single
reference to support their statement which found the
only significant difference to be in the activation of
theanteriorand medial deltoidat60% of1RM be-
tween a free weight and machine bench press exercise.
However,this articleuses EMGto measureactiva-
tion which, as clarified previously, does not permit
conclusions to be made regarding the effectiveness of
the exercise. The authors also reported no significant
difference for other muscle groups or at heavier loads
[81], something the ACSM failed to mention. As such
this recommendation by the ACSM is indicative of a
bias towards free-weight resistance forms, which is not
justified by the scientific evidence.
Interestingly, Schwanbeck et al. [62] found that the
8RMforaSmithmachinesquatwas14-23kgheavier
than for a free weight squat. Whilst further research is
necessary, this could indicate that force production is
diminished where balance is required. That is, where
there is a need for balance the muscle fibers likely fa-
tigue performing the skill of balancing the load rather
than contracting against the resistance.
Hydraulic, Pneumatic and other resistance forms
Researchhasalsocomparedgroupstrainingwith
free-weights and hydraulic equipment and reported no
significant difference between strength improvements
2Resistanceinthiscasecanbestbedescribedas‘force acting against muscular contraction’. In the context of an eccentric contraction where the resistance
might appear to be working with the contraction we believe that due to the desirably controlled nature of the movement, the muscle is still acting to slow
the resistance, and thus acting against it.
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for each group [82]. However, Hunter and Culpepper
[83] reported greater gains in isokinetic leg exten-
sion strength in participants limbs trained with fixed
mass (free-weight) resistance compared to hydraulic
resistance. It is perhaps worth noting that a failure of
hydraulic exercise to provide eccentric resistance [84]
could be a factor inhibiting strength production.
Other studies have considered the use of pneumatic
machines, although many articles have used it as a
method of testing [84, 85] or training [86] without
any direct comparison to other training methods.
Obviously further research is warranted within this
area to be more conclusive regarding its use. Finally,
Dorgo,King andRice [87] reported no significant
difference in muscular strength and muscular endur-
ance improvements between groups training with
free-weights and manual (partner applied) resistance.
Overall, therefore, the extent of the research does not
support one training modality over another, it seems
only to reflect our existing knowledge that a muscle
fiber does not recognize a difference between types of
resistance; it simply contracts, or it does not.
Based on the research presented, choice of resis-
tance type appears a personal preference. However,
we should also consider the health and safety element
associated with resistance training. Kerr, Collins and
Comstock [88] revealed statistics around weight train-
ing related injuries. Their data showed that between
1990 and 2007 of the estimated 970, 801 Emergency
Department visits in the USA associated with weight
training, 90.4% of these were free weight related. In
addition, persons using free weights sustained a greater
proportion of fractures/dislocations (23.6%), com-
pared to machine based resistance (9.7%). Of course
we cannot make assumptions as to what proportion
of people training with free weights or machines these
data represent, or the training experience of those per-
sons suffering injury. However, the statistics would still
suggest that the use of free weights presents a greater
potential risk of injury than machine based resistance.
For persons with a finite time resource it might also
be worth considering the additional time required to
load and unload a barbell, compared to repositioning
a pin in a weight stack, or selecting a resistance from
a dial.
Vibration Training
Due to the growing popularity of vibration train-
ing(VT)orwhole-body vibration(WBV),areview
article such as this would not be complete without the
consideration of such equipment. The theory behind
the efficacy of vibration training is related to the fact
that Force = Mass x Acceleration (where typically mass
would be increased by external resistance requiring
a greater force to be applied). Cardinale and Bosco
[89]suggested thatVT can affect the acceleration
aspect of this equation to between 3.5 and 15g [where
g represents the Earth’s gravitational pull (9.81m.s-2)]
This in turn would increase the force requirement and
muscle-fiber recruitment.
VThasbeenconsideredintheareasofpower[90,
91], and recovery [92] amongst others. However, in the
present article it shall be considered only in relation to
the ability to chronically improve strength. Our litera-
turesearchfoundnoarticlesdirectlycomparingWBV
against resistance training, though many considered
the effectiveness of resistance training with or without
theinclusionofWBV.Ronnestad[93,94]reportedno
significantdifferencesin 1RM improvementsinthe
squat exercise when comparing 5 weeks of training
with or without a vibration platform. Moran et al.
[66]andLuoet al. [95]alsoreportednosignificant
difference in strength improvements when consider-
ing a dynamic bicep curl and leg extensor exercises,
respectively with and without direct vibration. Indeed
a review by Nordlund and Thorstensson [96] reported
no significant differences between groups training
withorwithouttheadditionofWBV.
Roelantsetal.[97]comparedWBVtrainingagainst
a general fitness program that included cardiovascu-
lar and resistance exercise, in untrained females, and
reported no significant difference between groups
in isometric and isokinetic strength improvements.
The authors also reported that neither group made
significant changes to body weight, percentage body
fat, or skin-fold thickness over the 3 x/week, 24 week
program. However, the researchers did not match
training intensity or training volume, limiting the
conclusions that can be drawn from the study.
The research to date appears not to support the
useofVTforimprovingstrengthtoagreaterextent
thanresistancetrainingalone.However,Liebermann
and Issurin [98] reported significantly lower ratings
of perceived exertion with identical absolute values
when a vibration stimulus was applied through the
resistance.OtherliteraturesuggeststhatshouldWBV
be used, vertical vibrating platforms rather than os-
cillating platforms, as well as higher frequencies and
larger amplitudes appear to catalyse more favourable
adaptations [99, 100]. We conclude by suggesting that
while at present the literature suggests that there is
littlebenefittoincorporatingWBVtraining,thereis
significant scope for future research within this area.
As an additional note, whilst no data exists regard-
inginjuries directly associated withWBV training,
Jordanetal[101]providedanoverviewoftheareaand
considered the physiological hazards associated with
exposure to vibration. The authors noted the impor-
tance of pre-screening and suggested that frequencies,
amplitudes and durations should be carefully consid-
ered and managed throughout a training protocol.
WesuggestthatshouldtheuseofWBVtrainingbe
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undertaken it is done with the same caution as other
forms of resistance exercise.
The issue of specificity
In their position stand [15], the ACSM argued that
free weights are preferable to machines for athletes’
strength training because the former can mimic bet-
ter the movement patterns involved in sporting skills.
Surprisingly for such an important claim, the authors
provided no research evidence to substantiate it.
There is no evidence that skill development is aided
by the performance of resistance exercises that bear
some superficial resemblance to skills performed on
the sports field. Skill enhancement is highly specific,
with little correlation between the performances of
different skills, even when they appear very similar.
For example, Drowatzky and Zuccato [102] showed
that the correlations between performances on dif-
ferent (superficially very similar) balance tasks were
extremely low and non-significant. They concluded
that there is no such thing as a general phenomenon
called ‘balance’. Instead, there are many different bal-
ancing skills, and because an individual is good at one
type of balancing task it does not follow that he or she
will be good at a different balancing task.
Not only is the transfer between superficially
similar motor tasks quite low, but the performance of
tasks in training that are similar (but not identical) to
those used in actual performance can lead to negative
transfer and a concomitant decrease in performance
on the criterion task. For example, Mount [103] ex-
amined the effect of learning a dart throwing skill in
two different body positions (sitting on a chair and
reclining on a table). Not only was performance poorer
after switching position compared to remaining in the
same position, but performance after practice in the
alternate position was poorer than after no practice.
Therefore, the often-made claim that free weights
are superior to machines because they improve athletes’
balance, or that Olympic lifting might enhance sport-
ing performance due to the forceful extension of the
hips, knees and ankles [104] is simply not supported
by the motor learning research. The balance involved
in free weight exercises is specific to that task and will
not aid the athlete unless he or she is a competitive
weight lifter, when of course such lifts will need to be
practised. Indeed research has shown that the transfer
effects of weight training at different loads, velocities
and movement patterns are limited [105]. Interestingly,
in spite of this, Brewer [104] suggests “when training to
enhance sports performance....train the movements, not
the muscles”, and attempts to make analogies of move-
ment patterns between Olympic lifts and rugby, cricket,
judo, tennis and javelin (amongst others).
However, Brewer [104] appears to be offering bad
advice as performing exercises that mimic a specific
skill with resistance added may interfere with the
performance of the relevant skill by altering the ath-
lete’s movement pattern. For example, Montoya et al.
[106] found that the use of a heavily weighted baseball
bat for practice actually reduced the velocity of the
swing when using the normally weighted bat. This is
hardly surprising as it is impossible to swing a heavily
weighted bat as fast as a normal bat, and therefore by
slowing the movement down in this manner the athlete
is effectively learning to swing the bat more slowly, and
will change the mechanics of the swing accordingly.
Therefore, movements that mimic the performance of
a sports skill with added resistance should be avoided.
Core Stability and Stable/Unstable Surfaces
Kibler,PressandSciascia[107]and Akuthota et
al. [108], detail core stability exercise principles and
athletic function, and define core stability as “proximal
stability for distal mobility”, i.e., a strong core provides
a solid base for the movement and forces generated by
the limbs. This is supported by literature that shows
significantcontraction (up to 30% MVC)of core
muscles such as the transverse abdominis prior to
limb contraction/movement [109-112]. This supports
the need for core strength and stability in both day to
day activity and for potentially enhancing sporting
performance and injury prevention.
Whilst the use of unstable surfaces to train these
core muscles has been documented [113] it should be
recognized that they are not essential [114]. In fact
Behm and Anderson [115] consider the use of unilat-
eral exercises and cite research that shows greater ac-
tivation of the trunk muscles with unilateral shoulder
and chest press actions [116]. The benefit of unilateral
exercise as opposed to alternating movements is that
the removal of the contralateral dumbbell eliminates
the counter balance effect, requiring the core muscles
to stabilize the torso. A practical example of this might
be the lateral raise performed with one dumbbell;
shoulder abduction shifts the center of mass (poten-
tially outside the base of support depending on weight
and lever length) forcing the opposing obliques, as well
as other core muscles, to contract to retain the upright
position of the torso.
We fear there has been a misunderstanding of the
need for unstable surfaces with the premise of challeng-
ing balance and overloading the neuromuscular system
[117]. It seems that instead of focusing an exercise on
a muscle, many have succumbed to the concept of at-
tempting that movement whilst challenging their bal-
ance. This often results in decreased force production
due to instability [117, 118]. Whilst few studies exist
comparing chronic strength adaptations to training on
stable and unstable surfaces, those that do reported no
significant difference between groups [118]. However,
some studies lack sufficient duration [119] and utilize
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potentially biased testing methods [120]. For example
Kibele and Behm [120] adopted a standing knee ex-
tension as their test of strength, which would clearly
incorporate a degree of core stability to produce force
throughout the contracting limb. More realistically, an
isometric test would accurately measure the force of
the knee extensors without overly recruiting the core
musculature due to seating and restraints [cf. 28].
As stated in the preceding section, balance is a non-
transferable skill [102], and as suggested by Willard-
son [121] “performing resistance exercises on unstable
equipment will make an individual more proficient at
performing resistance exercises on unstable equipment
but may not enhance the performance of sports skills”.
There is no evidence that supports any form of bal-
ance transference between performing exercises on
unstable surfaces to any other movement pattern or
skill,whethersportingorotherwise. Indeed,Leder-
man [122] discusses specificity and transference citing
studies that have failed to show any strength or balance
improvements in training on unstable surfaces, other
than enhanced strength/balance on that exact unstable
surface. We should also consider the aforementioned
study by Schwanbeck et al. [62], and the possibility
that fatigue occurs earlier in a set where muscle fibers
are recruited for balance rather than directed against
the resistance.
Therefore, not only is there no significant differ-
ence in strength increases from training on stable and
unstable surfaces, but there is also no evidence (or even
a coherent theoretical rationale) for suggesting that
weight training on unstable surfaces could enhance
performance of specific sporting skills.
Summary:
• Theevidencedoesnotsupportthesuperiorityof
one particular form of resistance for gaining muscle
strength, power or endurance. Therefore, it appears
that how one trains is much more important than
the equipment used.
• Ultimately,choiceofequipmentshouldbedictated
by personal preference, convenience and one’s at-
titude to risk. However, machines appear to offer a
much lower likelihood of injury than free weights
and are thus preferable from a safety perspective.
• Athletesshould avoidexercisesthat attemptto
mimic the performance of a skill with added resis-
tance as this may detrimentally affect the movement
pattern of the skill resulting in a less efficacious
performance.
• Theuseofresistancetrainingforenhancedfunc-
tion and sporting performance should be based on
muscular strength adaptations, and not neuromus-
cular patterns including balance, which shows no
transference.
Repetition Duration
Another area of interest is that of repetition du-
ration, incorrectly referred to by the ACSM [15] as
velocity. Carpinelli et al. [18] discuss this misapplica-Carpinelli et al. [18] discuss this misapplica-[18] discuss this misapplica-
tion, considering the time for concentric and eccentric
contraction as repetition duration, whereas velocity is
an expression of º/s or radians/s for rotary movement,
or cm/s for linear movement. The ACSM [15] appear
to suggest that shorter repetition durations are more
favourable stating “fast velocities have been shown to
be more effective for enhanced muscular performance
capacities (e.g. number of repetitions performed, work
and power output, and volume)”citingLachanceand
Hortobagyi [123] and Morrissey et al. [124]. In reality
this is simply declaring that a greater number of repeti-
tions can be performed when exercising more quickly,
and is further supported by Sakamoto and Sinclair
[125] with the bench press exercise. However, the
present article, and by our understanding the ACSM’s
position stand [15], are focused on training methods;
that is, what will stimulate physiological enhance-
ments, rather than optimize a one-off performance.
The ACSM [15] continues by recommending that
untrained individuals use slow and moderate rep-
etition durations, and trained individuals include a
continuum from slow to fast repetition durations for
enhancing muscular strength, with no explanation as
to why there might be a need to differ between these
groups. Indeed, the position stand [15] also refers to
Olympic lifting and other ballistic (fast movement) ex-
ercises as beneficial in improving sports performance,
notably vertical jump and sprint times.
However,Johnston[126] considered forcepro-
duction in a case study, reporting little difference in
forces generated or experienced where movement
was performed at repetition durations that main-
tained muscular tension (including 10:10, 5:5, and 2:4
(concentric:eccentric)). Nevertheless, when attempt-
ing to move the load explosively forces increased by as
much as 45% initially but then decreased by 85% for
the majority of the repetition. This is likely due to the
excess force provided to overcome the inertia being so
great that momentum carries the weight through the
restoftherangeofmotion.Johnston[126]suggested
that explosive lifts would likely recruit fewer fibers
due to momentum, and that the diminished recruit-
ment through most of the range of motion would be
less effective for enhancing muscle function. This has
previously been reported by Hay et al. [127] with arm
curl exercises. A study by Tran, Docherty and Behm
[128] considered decrement in force production and
rate of force development, noting significantly larger
decreases following sets of 10 repetitions at a 5:5 rep-
etition duration compared to 10 repetitions at 2:2,
and 5 repetitions at 10:4 repetition durations. This
larger decrease in force production suggests fatigue
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in a larger proportion of muscle fibers, potentially
stimulating greater growth and strength/power gains.
This probably also explains the above-noted findings
that a greater number of repetitions can be performed
using shorter repetition durations: as the required
muscle force and resultant fatigue are lower, suggest-
ing exercises are simply easier than when performed
at longer repetition durations.
Comprehensive reviews of this area of research
have reported that resistance training at shorter repeti-
tion durations produced no greater strength or power
increases than training at longer repetition durations
[18, 129]. The latter study also considered the ap-
plication of Olympic lifting and plyometric exercises
concluding that there is no evidence to suggest that
these techniques can enhance strength and/or sport-
ing performance (including vertical jump and sprint)
to any greater degree than traditional weight training
methods.Also,Bruce-LowandSmith[129]specifically
considered the risk of injury from ballistic exercises,
reporting some disturbing statistics suggesting that ex-
plosive lifting such as that involved in performing the
Olympic lifts can cause injuries to the wrist, shoulder,
elbow and lumbar region. For example, Crockett et
al. [130] reported a case study of an NCAA Division
1 basketball player who having trained on a jumping
machine was side-lined due to a sacral stress fracture.
The authors concluded that this was likely caused by
the very high biomechanical loads placed through the
spine in the course of both the jumping and the landing
motion. Bentley et al. [131] reported ground reaction
forces(GRF)for differentrepetitiondurationsof a
squat exercise, reporting significantly higher values
for shorter repetition duration (1s descent: 1s ascent),
compared to medium (3:1) and longer repetition du-
rations (4:2). They also reported significantly higher
values for medium (3:1) when compared to slow (4:2)
repetition durations. Of course, any ground reaction
forces measured are also being transferred through
the joints of the body placing unnecessary stress on
supportingtissues.Bruce-LowandSmith[129]con-
cluded that, particularly given that one of the key aims
of strength training in athletes is to reduce injury risk,
training modalities involving high impact forces or
short repetition duration have no place in the strength
and conditioning of athletes unless there is a direct
requirement to perform the skill of Olympic lifting.
Summary:
• Exercisesshouldbeperformedatarepetitiondura-
tion that maintains muscular tension throughout
the entire range of motion.
• Olympiclifting,plyometricandballisticexercises
remove tension from the muscle and apply greater
forces through joints and associated tissues causing
a greater potential for injury.
Volume of Exercise, Frequency and Periodization
The primary, on-going debate regarding the re-
quired volume of exercise for strength relates to the
recommended number of sets. The ACSM [15] cited
a meta-analysis [132, 133] suggesting that the largest
effect sizes (ES) for strength increases with athletes
occurred when performing 8 sets per muscle group.
Carpinelli [19] considered this meta-analysis, critiz-
ing the authors for the inclusion of studies that failed
to meet their own criteria. In addition their conclu-
sions were unsupported as there were no significant
differences between the ES of the different training
volumes. In fact, most research to date suggests that
there is no significant difference in strength increases
between performing single or multiple set programs
[51, 134-137). For example, Carpinelli and Otto [134]
found that single sets produced similar results in 33
out of 35 studies they reviewed.
Contrary to this evidence, Krieger [138] published a
meta-analysis concluding that “2-3 sets per exercise are
associated with 46% greater strength gains than 1 set, in
both trained and untrained subjects”. However, Krieger
[138] included a study by Kraemer [139] that had previ-
ously received heavy criticism by Winett [136] due to
methodological inadequacies, as well as articles where
groups had not trained to momentary muscular failure
[140].Readers shouldbe wary of meta-analyses that
attempt to consider an assortment of differing research
and provide a single conclusive statement, as Krieger
[138] appears to have done. Indeed, meta-analyses
within this debate [132, 133, 141, 142] have been criti-
cized for their absence of scientific process [137].
The assertion that multiple sets are superior to single
sets has therefore been made despite the absence of
evidence to support this claim. It should also be noted
that the number of sets recommended by the ACSM
appears arbitrary. One might conclude from observation
of data from the cited meta-analysis that more sets in
fact result in reduced gains until the arbitrary number
8 is reached, as no continuum in effect size is demon-
strated [132, 133]. Carpinelli [19] has commented on
this meta-analysis similarly explaining that the data do
not support a dose-response relationship between num-
ber of sets and strength gains. Indeed, the vast majority
of research studies show that performance of multiple
sets of resistance exercise yield no greater gains than
single sets performed to momentary muscular failure
and therefore are not as time and energy effective. In-
terestingly there seems to be no research that focuses
specifically upon variation in the number of exercises
per muscle group. However, there is certainly major
scope for well-controlled studies examining this area.
Frequency
The ACSM [15] suggested the frequency of train-
ing should be dependent upon volume, intensity, level
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of conditioning, recovery ability, number of muscle
groups trained per workout and exercise selection.
They stated that novice individuals should train the
entire body 2-3 x/week whilst intermediates should
train 3 x/week if total body, or 4 x/week if using a split
routine (they do not clarify a training period or other
definition for transition from novice to intermediate).
In fact a plethora of research, reviewed by Carpinelli
etal. [18] and Smithand Bruce-Low[51] suggests
that there is little or no difference between training 1,
2 or 3 x/week for both trained and untrained persons.
The ACSM [15] cited Hoffman et al. [143] as sug-
gesting American football players train 4-5 x/week,
but they fail to clarify that training groups in this study
were not matched for total weekly volume of sets or
repetitions. In fact the 4 and 5 x/week groups in this
study performed less total weekly training than the 3
and 6 x/week groups, which might suggest that it was
not so much the frequency of training but perhaps
the reduced volume that allowed their physiological
development. The authors failed to consider this in
their interpretation of the results.
The ACSM [15] later commented that advanced
weight lifters and bodybuilders should use high fre-
quency training of 4-6 sessions per week, and that
with the inclusion of split (and double-split) routines,
this might increase to 8-12 training sessions per week
(citing as many as 18 sessions per week for Olympic
weightlifters). However, a study by Hakkinen et al.
[144] which the ACSM [15] used to support the ef-
fectiveness of double-split routines (training twice per
day) only considered acute hormonal response and did
not record or report on chronic strength adaptations.
Their reference for Olympic weightlifters training up
to 18 sessions per week is a book by Zatsiorsky and
Kraemer [145] and as such should be considered an
observation rather than an evidence-based recom-
mendation.
The ACSM [17] have previously received criticism
for high volume recommendations by Carpinelli et
al. [18] who calculated that Hakkinen and Kallinen’s
[146] protocol of 14 sets for each muscle group (gen-
erally divided over two daily sessions, performed 3
x/week), amounted to 21 hours per week (including
recommended rest intervals between sets). Of course
this is both unnecessary and unrealistic for most
individuals especially those with athletic/sporting
commitments, as these 21 hours of weight training will
be in addition to their sports practice and any other
conditioning training they need to do, as well as rest
and recovery. Even if such a high training volume was
optimal, something that the research clearly does not
substantiate, it is completely unrealistic to suggest that
athletes spend such a large amount of time engaged
in only one part of their preparatory activity for their
sport. Such a training volume appears to leave little
time and energy for skill development and other as-
pects of training, even for professional athletes, not to
mention amateurs who may also have a full time job
and/or study commitments and a family to look after,
among other essential daily activities. And what of the
individual who is not a competitive athlete but wishes
to optimize strength and/or muscle mass for cosmetic
and/or health reasons? Such an individual would have
to be extraordinarily highly motivated to sustain such
a high volume of weight training, as well as free of any
of the other normal commitments in life that would
preclude such a training regimen.
In contrast to the ACSM’s suggestions an evidence-
based recommendation is that appreciably the same
strength gains can be obtained by working each muscle
once or, at the most twice per week. We would also urge
both trainers and trainees, whatever their experience,
to closely monitor progress in their workouts and in-
vestigate their optimal individual training frequency
using any recommendations as merely a guide.
Variation and Periodization
Periodizationcanbe defined as“the cycling of
specificity, intensity, and volume of training to achieve
peak levels of performance for the most important
competitions” [147]. The ACSM [15] considered this
concept of variation, discussing typical models; linear
(LP);reverselinear(RLP)andundulatingperiodized
routines.LPischaracterizedby‘highinitialtraining
volume and low intensity, and progressed by decreas-
ing volume and increasing intensity’ [15]. The reverse
istrueofRLP,whereasdailyandweeklyundulating
periodization(DUPandWUPrespectively)varythe
load and repetitions either each workout or each week.
Finallyflexible non-linear periodization(FNL) and
autoregulatoryprogressiveresistanceexercise(APRE)
attempt to consider whether a person is physically
and psychologically rested and best prepared to train.
Interestingly the previously noted questionable
definition of intensity reappears within this literature
on this topic. For example the ACSM’s description of
LPcouldbeinterpretedtomeanthateither
• individualsstartaphaseofperiodizationtrain-
ing submaximally, and increase intensity towards
training to momentary muscular failure, or
• individualsshouldgraduallyincreasetheirload
and decrease their training volume (presumably
training to momentary muscular failure through-
out).
BasedonresearchconsideringtheefficacyofLP
where participants have trained to muscular failure
[148, 149] it seems likely that the second example
can be assumed and it is simply the volume being
decreased as the load increases (as opposed to the
incorrectly stated intensity). Indeed, McNamara and
Stearne[150] use FNL periodizationto suggest that
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a person who is not best prepared to train “is given a
workout that utilizes lighter weights and that is less in-
tense”.SincetheauthorsthenprescribedRMworkouts
to each participant we can, once again assume a simple
misuse of the term intensity, and recognize that their
FNLworkoutssimplyvariedtheloadandrepetitions
rather than the intensity.
Of course evidence (given earlier) shows that train-
ing to momentary muscular failure produces more
favourable muscular adaptations. However, the research
surrounding periodization is at best inconclusive as
to which model might be optimal. Buford et al. [151]
reported no significant differences between strength
increasesfromLP,DUP,orWUPprotocols,afinding
confirmedbyotherstudies[149,152].Incontrast,Rhea
etal.[153]reportedthatDUPproducedsignificantly
greaterstrengthincreasesthanLP.Monteiro et al. [148]
found non-linear periodization to be more productive
thanLP,whereas,Mannetal.[154]reportedthatAPRE
producedsignificantlygreaterimprovementsthanLP
in both muscular strength and endurance.
Based on the current lack of clear evidence it is dif-
ficulttosuggestanevidence-basedguideline.Recent
researchconsideringAPRE[154]andFNLperiodiza-
tion [150] would appear to support the logical inclu-
sion of physiological and psychological factors. Both of
these models consider the ‘readiness’ of the participant
by gauging their level of mental and physical fatigue.
Personsshouldalsoconsiderdelayedonsetmuscle
soreness (DOMS) which is common in both recre-
ational trainers and elite athletes between 24 and 72
hours post exercise [155]. Whilst further detail is be-
yond the scope of this article, we should consider that
DOMS has been shown to cause reductions in strength,
power, and flexibility, all of which would hinder athletic
performance (see 155 for a review). This makes the high
volume training recommendations of the ACSM seem
particularly unrealistic for team sport athletes training
during the competitive season, as heavy weight training
in the days immediately prior to matches would likely
have a negative effect on performance, and immediately
following matches such training would likely hinder re-
covery. Therefore, it is difficult to see how such athletes
could fit in the 20+ hours of weight training per week
that is recommended.
The elements discussed above are obviously impor-
tant for variation in training routines and frequency as
well as providing motivation and mental stimulation,
as opposed to following a pre-determined plan. More
research examining recovery and its relationship to other
sporting physiological parameters is needed on this issue
to enable a truly evidence-based approach to be adopted.
Summary:
• Asingle set performedto momentarymuscular
failure can produce appreciably the same gains as
multiple sets in muscle function. Training most
major muscle groups once or twice per week is
sufficient to attain strength gains equal to that of
training at a greater frequency.
• Noperiodizedplanorworkoutscheduleisneces-
sarily most favorable, but rather physical and mental
readiness for each workout is important.
Genetic Factors and Their Implications
Carter and Heath [156] recognized 3 distinctly
different body shapes; endomorph (a higher propor-
tion of body fat, and generally being ‘round’ in shape),
mesomorph (a higher proportion of muscle mass
and generally being ‘square’ shape) and ectomorph
(a decreased body mass in relation to surface area,
and generally ‘skinny’ shape). Somatotypes are well
recognized in exercise physiology text books [157,
158]. However they are almost never mentioned in
strength training textbooks, magazines, and not within
the ACSM position stand [15].
Other genetic factors have all been found to ac-
count for inter-participant variability in muscle
strength or size, including myostatin (an “anti-growth”
genotype, inhibiting muscular development) [159,
160],andInterleukin-15(IL-15).Researchsuggeststhe
geneticvariationintheIL-15RA(receptor-αgene)is
a significant moderator of muscle mass in response to
resistance training [161]. Furthermore other genotypes
include ciliary neurotrophic factor (CNTF), where
theG/GandG/Agenotypeshaveshownsignificantly
greater muscular strength compared with the A/A
homozygotes [162]. There is also alpha-actinin-3
(ACTN3),wheretheR577Xgenotypeisgenerallyas-
sociated with muscle function, contractile properties
and strength/power athletes [163] and could modulate
responsiveness to training [164]. In addition, an-
giotensin converting enzyme (ACE) is important, as
here the D-allele appears to positively affect muscular
strength following resistance training [165]. Stewart
andRittweger[166]provideamorecomprehensive
review of molecular regulators and genetic influences,
and suggest that these genetic effects likely account
for 80-90% of the variation in muscular strength and
cross-sectional area within the research.
Whilst further discussion of these genetic mecha-
nisms is far beyond the scope of this article, it also
seems somewhat redundant to discuss elements that
are beyond the exerciser’s control, which is perhaps a
reason as to why they are so commonly overlooked.
However, their importance is undeniable because
they will predominantly dictate how much muscular
strength and size can be developed to a far greater
degree than training type. For example on a more
simplifiedlevelVanEtten,VerstappenandWesterterp
[167] reported significant increases in fat-free mass
for a mesomorphic group after 12 weeks of resistance
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Table 1. Evidence for Resistance Training Recommendations
Topic Recommendation Supporting
Articles SuggestionsforFutureResearch
Intensity Personsshouldtrainuntilmomentarymu-
scular failure to actively recruit all of the
available motor units and muscle fibres, as
opposed to a pre-determined number of
repetitions.
28, 29, 30, 31, 32,
LoadandRepeti-
tionRange
Personsshould self-select a weight >80%
1RMand perform repetitionsto failure.
Evidence suggests this is optimal for maxi-
mising strength and muscular endurance
gains, whilst helping to improve bone mi-
neral density.
44, 45, 46, 47, 48,
54, 57, 51
Investigation as to whether there
are specifically favorable repeti-
tion ranges based on muscle fibre
type, or specific muscles.
ResistanceType Personsshouldselectresistancetypebased
on personal choice, although evidence appe-
ars to suggest that resistance machines might
have a lower risk of injury than free-weights.
There appears to be no difference in strength
gains between using free-weights, machines
or other resistance types.Free weights and
sport specific movements show no enhan-
cement in sporting performance or force
throughout that movement.
77, 78, 79, 80, 82,
87, 105, 106
The effect of balancing a weight
on force productionDirect com-
parison between strength gains
comparing pneumatic resistance
and variable resistances.
RepetitionDura-
tion
Personsshould maintainsteadyforce pro-
duction throughout a range of motion, and
reduce external forces such as momentum;
movements should be of a pace that ma-
intains muscular tension, not ballistic or
explosive in nature.Faster movements cause
greater peaks in both muscular and ground
reaction forces which likely transfer through
joints and connective tissue, potentially
causing injury.
126, 127, 128,
130, 131
Investigation of Olympic li-
fting and plyometric training
in comparison to ‘controlled’
movements with regard to power
output (Wingate test, vertical
jump test, etc.), sprint times,
1RM,agility,and otherphysio-
logical tests.
training, where an ectomorphic group recorded no
significant differences having followed an identical
training routine. Therefore, it appears that those who
are naturally lean and muscular to start with, can
gain strength and size to a much greater degree than
naturally ‘skinny’ individuals.
The genetic factors above are very important to
consider here because persons such as weightlifting
or bodybuilding champions with impressive strength
or size and most likely the very good genetic pre-
disposition for building such, often work as coaches
and personal trainers and will be called upon to offer
training advice to the less genetically gifted. They may
do so based on their experiences that yielded positive
results. However, anyone with less suitable genetics will
almost certainly not attain the same levels of muscular
strength or size regardless of training program. In the
same sense whilst many athletes, trainers, or body-
builders will judge their training a success because of
their progression in size, strength or other physiologi-
cal attributes, it may still be that an alternative training
program would have yielded even better results.
Conclusion
This article presents evidence-based recommenda-
tions for anyone wishing to improve their muscular
size and/or strength and attain the health benefits
associated with resistance training. It specifically
highlights that the high volume approach advocated
by the ACSM [15] is unnecessary and that equal or
better results can be achieved in a minimal amount of
time. Our recommendations based on the research are
provided in the Table 1. A simple method of monitor-
ing individual progress is the use of a training journal
that allows a more specific and individual routine to
be developed. Because training to momentary mus-
cular failure with a repetition duration that maximizes
muscle tension requires psychological and physical
discipline, we suggest that both mental and physical
readiness, in the form of recovery from previous ex-
ercise, be considered before undertaking a workout.
The guidelines herein question some of the common
recommendations of associations, trainers and trainees
alike, and we urge persons reading this article to con-
sider and review their methods in accordance with the
159
Fisher J., Steele J., Bruce-Low S., Smith D. / Medicina Sportiva 15 (3): 147-162, 2011
Topic Recommendation Supporting
Articles SuggestionsforFutureResearch
VolumeofExerci-
se, Frequency and
Periodization
Personscan obtainappreciablythesame
strength gains by performing only a single
set of each exercise 1 x / 2 x week, compared
tohighervolumeworkouts.Personsshould
train when they feel physically and mentally
ready to do so. Both physical and mental
fatigue have the potential to negatively
affect a workout and/or muscular growth
and development.No specific periodized
routine is unequivocally supported within
the literature.
18, 19, 51, 134,
135, 136, 137,
143, 149, 150,
151, 152, 154
Genetics Personsshould considertheir somatotype
and that their genetics will dictate their mu-
scular growth and development.Previous
success with a routine is not evidence that it
is optimal, genetic differences might dictate
interpersonal differences in volume and
frequency.
156, 157, 158,
159, 160, 161,
162, 163, 164,
165, 166, 167
Greaterinvestigationinto how
genotype affects muscular growth
and development.
research findings, focusing on optimal improvements
for themselves or their clients.
References
1. KofflerK, MenkesA, Redmond A, et al.Strengthtraining
accelerates gastrointestinal transit in middle-aged and older
men. Med Sci Sports Exerc 1992; 24: 415-9.
2. Campbell W, Crim M, Young C, et al. Increased energy requ-
irements and changes in body composition with resistance
training in older adults. Am J Clin Nutr 1994; 60: 167-75.
3. Hurley B. Does strength training improve health status?
Strength Cond J 1994; 16: 7-13.
4. StoneM,BlessingD,ByrdR,etal.Physiologicaleffectsofa
short term resistive training program on middle-aged untra-
ined men. Nat Strength Cond Assoc J 1982; 4: 16-20.
5. HurleyB,HagbergJ,GoldbergA, etal.Resistance training
canreducecoronaryriskfactorswithoutalteringVO2 max
or percent body fat. Med Sci Sports Exerc 1988; 20: 150-4.
6. HarrisKA,HollyRG.Physiologicalresponsestocircuitweight
training in borderline hypertensive subjects. Med Sci Sports
Exerc 1987; 19: 246-52.
7. CollianderEB,TeschPA.Blood pressure in resistance trained
athletes. Can J Appl Sport Sci 1988; 13: 31-4.
8. MenkesA,MazelS,RedmondA,etal.Strengthtrainingincre-
ases regional bone mineral density and bone remodelling in
middle-aged and older Men. J Appl Physiol 1993; 74: 2478-84.
9. RallLC,MeydaniSN,KehayiasJJ,et al.Theeffectofpro-
gressive resistance training in rheumatoid arthritis: increased
strength without changes in energy balance or body compo-
sition. Arthritis Rheum 1996; 39: 415-26.
10. NelsonBW,O’ReillyE,MillerM,etal.The clinical effects of
intensive specific exercise on chronic low back pain: A con-
trolled study of 895 consecutive patients with 1-year follow
up. Orthopedics 1995; 18: 971-81.
11. RischS,NowellN,PollockM,etal.Lumbarstrengtheningin
chronic low back pain patients. Spine 1993; 18: 232-8.
12. Westcott W. Keeping Fit. Nautilus 1995; 4: 50-7.
13. MessierSP,DillME.Alterationsinstrengthandmaximum
oxygen consumption consequent to nautilus circuit weight
training. Res Q Exerc Sport 1985; 56: 345-51.
14. Stone, MH. Muscle conditioning and muscle injuries. Med
Sci Sports Exerc 1990; 22: 457-62.
15. RatamessNA,AlvarBA,Evetoch[sic]TK,etal.Progression
models in resistance training for healthy adults. Med Sci Sports
Exerc 2009; 41: 687-708.
16. PollockML,GaesserGA,ButcherJD,etal.Therecommended
quantity and quality of exercise for developing and mainta-
ining cardiorespiratory and muscular fitness, and flexibility
in healthy adults. Med Sci Sports Exerc 1998; 30: 975-91.
17. KraemerWJ,AdamsK,CafarelliE,etal.Progressionmodels
in resistance training for healthy adults. Med Sci Sports Exerc
2002; 34: 364-80.
18. CarpinelliR,OttoRM,WinettRA.A critical analysis of the
ACSM position stand on resistance training: insufficient
evidence to support recommended training protocols. J Exerc
Physiol 2004; 7: 1-60.
19. CarpinelliR. Challengingthe American Collegeof Sports
Medicine 2009 position stand on resistance training. Med
Sport 2009; 13: 131-7.
20. KraemerWJ,FleckSJ,DeschenesM. A review: factors in
exercise prescription of resistance training. Strength Cond J
1988; 10: 36-41.
21. Tan B. Manipulating resistance training program variables
to optimize maximum strength in men: a review. J Strength
Cond Res 1999; 13: 289-304.
22. WillardsonJM,BurkettLN.Theeffectofdifferentrestinte-
rvals between sets on volume components and strength gains.
J Strength Cond Res 2008; 22: 146-52.
23. Fry AC. The role of resistance exercise intensity on muscle
fibre adaptations. Sports Med 2004; 34: 663-79.
24. HoegerWW,Barette,SL,HaleDF,etal.Relationshipbetween
repetitions and selected percentages of one repetition maxi-
mum. J Appl Sport Sci Res 1987; 1: 11-3.
25. HoegerWWK,HopkinsDR,BaretteSL,etal.Relationship
between repetitions and selected percentages of one repetition
maximum: a comparison between untrained and trained
males and females. J Strength Cond Res 1990; 4: 46-54.
26. ShimanoT, Kraemer WJ, Spiering BA, et al. Relationship
between the number of repetitions and selected percentages
of one repetition maximum in free weight exercises in trained
and untrained men. J Strength Cond Res 2006; 20: 819-23.
27. DourisPC, White BP, Cullen RR, et al. Therelationship
between maximal repetition performance and muscle fibre
type as estimated by non-invasive technique in the quadriceps
of untrained women. J Strength Cond Res 2006; 20: 699-703.
28. CarpinelliR. Thesize principle and a criticalanalysisof
the unsubstantiated Heavier-is-better recommendation for
resistance training. J Exer Sci Fit 2008; 6: 67-86 .
29. WillardsonJM.Theapplicationoftrainingtofailureinpe-
riodized multiple set resistance exercise programs. J Strength
Cond Res 2007; 21: 628-31.
160
Fisher J., Steele J., Bruce-Low S., Smith D. / Medicina Sportiva 15 (3): 147-162, 2011
30. RodneyKJ,HerbertRD,BalnaveRJ.Fatiguecontributesto
the strength training stimulus. Med Sci Sports Exerc 1994;
26: 1160-4.
31. SchottJ,McCullyK,RutherfordOM.Theroleofmetabolites
in strength training: Short versus long isometric contractions.
Eur J Appl Physiol 1995; 71: 337-41.
32. DrinkwaterEJ,LawtonRP,LindsellRP,etal.Trainingleading
to repetition failure enhances bench press strength increases
in elite junior athletes. J Strength Cond Res 2005; 19: 382-8.
33. FollandJP,IrishCS,RobertsJC,etal.Fatigueisnotanecessary
stimulus for strength gains during resistance training. Br J
Sports Med 2002; 36: 370-4.
34. IzquierdoM,IbanezJ,Gonzalez-BadilloJJ,etal.Differential
effects of strength training to failure versus not to failure on
hormonal responses, strength and muscle power increases. J
Appl Physiol 2006; 100: 1647-56.
35. BorgGA. Psychophysicalbases of perceivedexertion.Med
Sci Sports Exerc 1982; 14: 377-81.
36. SuminskiRR,RobertsonRJ,ArslanianS,etal.Perceptionof
effort during resistance exercise. J Strength Cond Res 1997;
11: 261-5.
37. Gearhardt,Jr.R,Goss FL, LagallyKM,et al. Standardized
scaling procedures for rating of perceived exertion during
resistance exercise. J Strength Cond Res 2001; 15: 320-5.
38. Gearhardt,Jnr.R, Goss FL,Lagally KM, etal. Ratings of
perceived exertion in active muscle during high-intensity
and low-intensity resistance exercise. J Strength Cond Res
2002; 16: 87-91.
39. DayML,McGuiganMR,BriceG,etal.Monitoringexercise
intensityduring resistancetrainingusingthe session RPE
scale. J Strength Cond Res 2004; 18: 353-8.
40. SweetTW,FosterC,McGuiganMR,etal.Quantitationofre-
sistance training using the session rating of perceived exertion
method. J Strength Cond Res 2004; 18: 796-802.
41. LagallyKM,McCawST,YoungGT,etal.Ratingsofperceived
exertion and muscle activity during the bench press exercise
in recreational and novice lifters. J Strength Cond Res 2004;
18: 359-64.
42. DuncanMJ,Al-NakeebY,ScurrJ.Perceivedexertionisrelated
to muscle activity during leg extension exercise. Res Sports
Med 2006; 14: 179-89.
43. WickwirePJ,McLesterJR,GreenJM,etal.Acuteheartrate,
blood pressureandRPE responses during super slowvs.
traditional machine resistance training protocols using small
muscle group exercises. J Strength Cond Res 2009; 23: 72-9.
44. O’Shea,P.Effects of selected weight training programs on
the development of strength and muscle hypertrophy. Res Q
1966; 37: 95-102.
45. GravesJE,PollockML,JonesAE,etal.Numberofrepetitions
does not influence the initial response to resistance training
in identical twins [abstract]. Med Sci Sports Exerc 1999; 26
Supplement 5: S74.
46. WeissLW,ConeyHD,ClarkFC.Differentialfunctionalada-
ptations to short-term, low-, moderate-, and high-repetition
weight training. J Strength Cond Res 1999; 13: 236-41.
47. Tanimoto M, Ishii N. Effects of low intensity resistance exerci-
se with slow movement and tonic force generation on muscu-
lar function in young men. J Appl Physiol 2006; 100: 1150-7.
48. Tanimoto M, Sanada K, Yamamoto K, et al. Effects of whole-
-body low-intensity resistance training with sow movement
and tonic force generation on muscular size and strength in
young men. J Strength Cond Res 2008; 22: 1926-38.
49. CamposGER, Luecke TJ, WendelnHK, et al. Muscular
adaptations in response to three different resistance-training
regimens: specificity of repetition maximum training zones.
Eur J Appl Physiol 2002; 88: 50-60.
50. SmithD,Bruce-Low S. Strength training andthe work of
ArthurJones.J Exerc Physiol 2004; 7: 52-68.
51. VincentKR, BraithRW. Resistance exerciseand the bone
turnover in elderly men and women. Med Sci Sports Exerc
2002; 34: 17-23.
52. JonesA. The lumbar spine, the cervical spine and the knee;
testing and rehabilitation.Ocala,FL:MedXCorporation,1993.
53. Darden E, The New Bodybuilding for Old School Results. Co-
loradoSprings,USA;TestosteronePublishing,2006.
54. StoneWJ,CoulterSP.Strength/enduranceeffectsfromthree
resistance training protocols with women. J Strength Cond
Res 1994; 8: 231-4.
55. HicksonRC,HidakaK,FosterC.Skeletalmusclefibre-type,
resistance training, and strength-related performance. Med
Sci Sports Exerc 1994; 26: 593-8.
56. MazzettiSA,KraemerWJ,VolekJS,et al.TheInfluenceof
direct supervision of resistance training on strength perfor-
mance. Med Sci Sports Exerc 2000; 32: 1175-84.
57. AndersonT,KearneyJT.Effectsofthreeresistancetraining
programs on muscular strength and absolute and relative
endurance. Res Q 1982; 53: 1-7.
58. FrostDM,CroninJ,NewtonRU.A biomechanical evaluation
of resistance; fundamental concepts for training and sports
performance. Sports Med 2010; 40: 303-26.
59. Darden E. New High Intensity Bodybuilding. New York, USA:
PedigreeBooks,1990.
60. IssurinVB,LiebermannDG,TenenbaumG.Effectofvibra-
tory stimulation training on maximal force and flexibility. J
Sport Sci 1994; 12: 561-6.
61. Spennewyn KC. Strength outcomes in fixed versus free-form
resistance equipment. J Strength Cond Res 2008; 22: 75-81.
62. SchwanbeckS,ChilibeckPD,BinstedG.Acomparisonoffree
weight squat to smith machine squat using electromyography.
J Strength Cond Res 2009; 23: 2588-91.
63. SchickEE, Coburn JW,BrownLE,et al. Acomparisonof
muscle activation between a smith machine and free weight
bench press. J Strength Cond Res 2010; 24: 779-84.
64. GoodmanCA,PearceAJ,NicholesCJ,et al. No difference
in1RM strength and muscle activationduring thebarbell
chest press on a stable and unstable surface. J Strength Cond
Res 2008; 22: 88-94.
65. RoelantsM,VerschuerenSMP,DelecluseC,etal.Whole-bo-
dy-vibration-induced increase in leg muscle activity during
different squat exercises. J Strength Cond Res 2006; 20: 124-9.
66. MoranK, McNamaraB, LuoJ.Effectofvibrationtraining
inmaximaleffort(70%1RM)dynamicbicepcurls.Med Sci
Sports Exerc 2007; 39: 526-33.
67. HazellTJ,KennoKA,JakobiJM.Evaluationofmuscleacti-
vity for loaded and unloaded dynamic squats during vertical
whole body vibration. J Strength Cond Res 2010; 24: 1860-5.
68. DeLucaC,MerlettiR.Surfacemyoelectricsignalcross-talk
among muscles of the leg. Electroen Clin Neuro 1988; 69;
568-75.
69. DeLucaC.Theuseofsurfaceelectromyographyinbiome-
chanics. J Appl Biomech 1997; 13: 135-63.
70. WakelingJM, Pascual SA,Nigg BM, et al. Surface EMG
shows distinct populations of muscle activity when measured
during sustained submaximal exercise. Eur J Appl Physiol
2001; 86: 40-7.
71. Roman-LiuD,TokarskiT.EMGofarmforearmmuscleacti-
vities with regard to handgrip force in relation to upper limb
location. Acta Bioeng Biomech 2002; 4: 33-48
72. FarinaD,MerlettiR,EnokaR M.Theextractionof neural
strategiesfromthe surface EMG. J Appl Physiol 2004; 96:
1486-95.
73. Semmler JG, TuckerKJ, Allen TJ,et al.Eccentric exercise
increasesEMGamplitudeandforcefluctuationsduringsub-
maximal contractions of elbow flexor muscles. J Appl Physiol
2007; 103: 979-89.
74. RobertsTJ,GabaldonAM.Interpretingmusclefunctionfrom
EMG:lessonslearnedfromdirectmeasurementsofmuscle
force. Integ Comp Biol 2008; 48: 312-20.
75. SoderbergGL,CookTM.Electromyographyinbiomechanics.
Phys Ther 1984; 64: 1813-20.
76. HowardJD,Enoka RM. Maximum bilateral contractions
are modified by neutrally mediated interlimb effects. J Appl
Physiol 1991; 70: 306-16.
77. Sanders MT. A comparison of two methods of training on the
development of muscular strength and endurance. J Orthop
Sport Phys 1980; 1: 210-3.
161
Fisher J., Steele J., Bruce-Low S., Smith D. / Medicina Sportiva 15 (3): 147-162, 2011
78. SilvesterLJ,StigginsC,McGownC,etal.Theeffectofvariable
resistance and free weight training programs on strength and
vertical jump. Strength Cond J 1981; 3: 30-3.
79. Boyer BT. A comparison of the effects of three strength tra-
ining programs on women. J Appl Sport Sci Res 1990; 4: 88-94.
80. ManningRJ, Graves JE, CarpenterDM,et al. Constantvs
variable resistance knee extension training. Med Sci Sports
Exerc 1990; 22; 397-401.
81. McCawST,FridayJJ.Acomparisonofmuscleactivitybetween
a free weight and machine bench press. J Strength Cond Res
1994; 8: 259-64.
82. WilloughbyDS,GillespieJW.Acomparisonofisotonicfree
weights and omnikinetic exercise machines on strength. J
Hum Movement Stud 1990; 19: 93-100.
83. HunterGR,CulpepperMI.Jointanglespecificityoffixedmass
versus hydraulic resistance knee flexion training. J Strength
Cond Res 1995; 9: 13-6.
84. PaulusDC,ReiserIIRF,TroxellWO.Pneumaticstrengthas-Pneumaticstrengthas-
sessment device: design and isometric measurement. Biomed
Sci Instrum 2004; 40: 277-82.
85. PuthoffML,NielsenDH.Relationshipsamongimpairments
in lower-extremity strength and power, functional limitations,
and disability in older adults. Phys Ther 2007; 87:1334-47.
86. Kerksick C, Thomas A, Campbell B, et al. Effects of a popular
exercise and weight loss program on weight loss, body com-
position, energy expenditure and health in obese women.
Nutrition Metab 2009; 6(23). DOI: 10.1186/1743-7075-6-23.
87. DorgoS,KingGA,RiceCA.Theeffectsofmanualresistance
training on improving muscular strength and endurance. J
Strength Cond Res 2009; 23: 293-303.
88. KerrZY,CollinsCL,ComstockRD.Epidemiologyofweight
training-related injuries presenting to United States emergen-
cy departments, 1990-2007. Am J Sport Med 2010; 38: 765-71.
89. Cardinale M, Bosco C. The use of vibration as an exercise
intervention. Exerc Sport Sci Rev 2003; 31: 3-7.
90. Bazett-JonesDM, FinchHW, Dugan EL. Comparingthe
effects of various whole body vibration accelerations on
counter-movement jump performance. J Sports Sci Med
2008; 7: 144-50.
91. MarinPJ,RheaMR.Effectsofvibrationtrainingonmuscle
power: a meta-analysis. J Strength Cond Res 2010; 24: 871-8.
92. RheaMR,BunkerD,MarinPJ,etal.EffectofiTonicwhole
body vibration on delyaed-onset muscle soreness among
untrained individuals. J Strength Cond Res 2009; 23: 1677-82.
93. RonnestadB.Comparingtheperformance-enhancingeffects
of squats on a vibration platform with conventional squats
in recreationally resistance-trained men. J Strength Cond Res
2004; 18: 839-45.
94. RonnestadB.Acuteeffectsofvariouswholebodyvibration
frequencieson1RM in trainedanduntrained subjects. J
Strength Cond Res 2009; 23: 2068-72.
95. LuoJ,McNamaraB,MoranK.Effectofvibrationtrainingon
neuromuscular output with ballistic knee extensions. J Sport
Sci 2008; 26: 1365-73.
96. Nordlund MM , Thorstensson A. Strength training effects of
whole body vibration. Scand J Med Sci Sports 2007; 17: 12-7.
97. RoelantsM,DelecluseC,GorisM,etal.Effectsof24weeks
of whole body vibration training on body composition and
muscle strength in untrained females. Int J Sports Med 2004;
25: 1-5.
98. LiebermannDG,IssurinV.Effortperceptionduringisotonic
muscle contractions with superimposed mechanical vibratory
stimulation. J Hum Mov Stud1997; 32: 171-86.
99. LuoJ,McNamaraB,MoranK.Theuseofvibrationtraining
to enhance muscle strength and power. Sports Med 2005;
35: 23-41.
100. MarinPJ,RheaMR.Effectsofvibrationtrainingonmuscle
strength: a meta-analysis. J Strength Cond Res 2010; 24:
548-56.
101. JordanMJ, Norris SR, Smith DJ,et al.Vibrationtraining:
an overview of the area, training consequences, and future
considerations. J Strength Cond Res 2005; 19: 459-66.
102. DrowatzkyJN,ZuccatoFC.Interrelationshipsbetweense-
lected measures of static and dynamic balance. Res Q 1967;
38: 509-10.
103. MountJ.Effect of Practice ofathrowingskill in one body
position on performance of the skill in an alternate position.
Percept Mot Skills 1996; 83: 723-32.
104. Brewer C. Strength and Conditioning for Sport: A Practical
Guide for Coaches.Leeds,UK:SportsCoachUK,2008.
105. SaleDG.Neuraladaptationstoresistancetraining.Med Sci
Sports Exerc 1988; 20: 135-45.
106. MontoyaBS,BrownLE,CoburnJW,etal.Effectsofwarm-up
with different weighted bats on normal bat velocity. J Strength
Cond Res 2009; 23: 1566-9.
107. KiblerWB,PressJ,Sciascia A.Theroleof corestabilityin
athletic function. Sports Med 2006; 36: 189-98.
108. AkuthotaV,FerreiroA,MooreT,etal.Corestabilityexercise
principles. Curr Sports Med Rep 2008; 7: 39-44.
109. ZattaraM,BouissetS.Posture-kineticorganisationduringthe
early phase of voluntary upper limb movement. 1. Normal
Subjects. J Neurol Neurosurg Psychiatry 1988; 51: 956-65.
110. HodgesPW,RichardsonCA.Inefficient muscular stabili-
zation of the lumbar spine associated with low back pain:
a motor control evaluation of transversus abdominis. Spine
1996; 21: 2640-50.
111. HodgesPW,RichardsonCA.Alteredtrunkmusclerecruit-
ment in people with low back pain with upper limb movement
at different speeds. Arch Phys Med Rehabil 1999; 80: 1005-12.
112. Shiba Y, Obuchi S, Saitou C, et al. Effects of bilateral upper-
-limb exercise on trunk muscles. J Phys Ther Sci 2001; 13: 65-7.
113. Cosio-LimaLM, Reynolds KL,WinterC, et al. Effects of
physio-ball and conventional floor exercises on early phase
adaptations in back and abdominal core stability and balance
in women. J Strength Cond Res 2003; 17: 721-5.
114. StanforthD,StanforthPR,HahnSR,etal.A 10 week training
study comparing resistaball and traditional trunk training. J
Dance Med Sci 1998; 2: 134-40.
115. BehmDG,AndersonKG.Theroleofinstabilitywithresistan-The role of instability with resistan-
ce training. J Strength Cond Res 2006; 20: 716-22.
116. BehmDG, LeonardA,YoungW,et al.TrunkmuscleEMG
activity with unstable and unilateral exercises. J Strength Cond
Res 2005; 19: 193-201.
117. AndersonKG,Behm DG. Maintenanceof EMG activity
and loss of force output with instability. J Strength Cond Res
2004; 18: 637-40.
118. SparkesR,BehmDG.Training adaptations associated with an
8-week instability resistance training program with recreatio-
nally active individuals. J Strength Cond Res 2010; 24: 1931-41.
119. CowleyPM, Swenson T,Sforzo GA. Efficacy of instability
resistance training. Int J Sports Med 2007; 28: 829-35.
120. KibeleA,BehmDG.Sevenweeksofinstabilityandtraditional
resistance training effects on strength, balance and functional
performance. J Strength Cond Res 2009; 23: 2443-50.
121. WillardsonJM.Theeffectivenessofresistanceexercisesper-
formed on unstable equipment. Strength Cond J 2004; 26: 70-4.
122. LedermanE.Themythofcorestability.J Bodyw Mov Ther
2007; 14: 80-97.
123. LachancePF,HortobagyiT.Influenceofcadenceonmuscular
performance during push-up and pull-up exercises. J Strength
Cond Res 1994; 8: 76-9.
124. MorrisseyMC,HarmanEA,FrykmanPN,etal.Earlyphase
differential effects of slow and fast barbell squat training. Am
J Sport Med 1998; 26: 221-30.
125. SakamotoA,SinclairPJ.Effectofmovementvelocityonthe
relationship between training load and the number of repe-
titions of bench press. J Strength Cond Res 2006; 20: 523-7.
126. JohnstonBD.Movingtoo rapidlyin strengthtrainingwill
unload muscles and limit full range strength development
adaptation: a case study. J Exerc Physiol 2005; 8: 36-45.
127. HayJG,AndrewsJG,VaughanCL.Effectsofliftingrateon
elbow torques exerted during arm curl exercises. Med Sci
Sports Exerc 1983; 15: 63-71.
128. TranQT,DochertyD,BehmD.Theeffectsofvaryingtime
under tension and volume load on acute neuromuscular
responses. Eur J Appl Physiol 2006; 98: 402-10.
162
Fisher J., Steele J., Bruce-Low S., Smith D. / Medicina Sportiva 15 (3): 147-162, 2011
Authors’ contribution
A – Study Design
B – Data Collection
C – Statistical Analysis
D – Data Interpretation
E – Manuscript Preparation
F – Literature Search
G – Funds Collection
129. Bruce-LowS,SmithD.Explosiveexerciseinsportstraining:
a critical review. J Exerc Physiol 2007; 10: 21-33.
130. CrockettHC, Wright JM, Madsen MW,etal. Sacral stress
fracture in an elite college basketball player after the use of a
jumping machine. Am J Sport Med 1999; 27: 526-8.
131. BentleyJR, AmonetteWE,DeWittJK,etal. Effectsofdif-
ferent lifting cadences on ground reaction forces during the
squat exercise. J Strength Cond Res 2010 24: 1414-20.
132. PetersonMD,RheaMR,AlvarBA.Maximisingstrengthde-
velopments in athletes: a meta-analysis to determine the dose
response relationship. J Strength Cond Res 2004; 18: 377-82.
133. PetersonMD,RheaMR,AlvarBA.Applicationsofthedose
response for muscular strength development: a review of
meta-analytic efficacy and reliability for designing training
prescription. J Strength Cond Res 2005; 19: 950-8.
134. CarpinelliRN, Otto RM. Strengthtraining:single versus
multiple sets. Sports Med 1998; 26: 73-84.
135. CarpinelliRN.Bergerinretrospect: effect ofvariedweight
training programmes on strength. Br J Sports Med 2002; 36:
319-24.
136. WinettRA. Meta-analyses do notsupportperformance of
multiple sets or higher volume resistance training. J Exerc
Physiol 2004; 7: 10-20.
137. OttoRM,CarpinelliRN.Acriticalanalysisofthesingleversus
multiple set debate. J Exerc Physiol 2006; 9: 32-57.
138. KriegerJ.Singleversusmultiplesetsofresistance exercise:
a meta-regression. J Strength Cond Res 2010; 23: 1890-901.
139. KraemerWJ.The physiologicalbasisforstrength training
in American football: fact over philosophy. J Strength Cond
Res 1997; 11: 131-42.
140. KemmlerWK,LauberD,EngelkeK,etal.Effects of single-
vs. multiple-set resistance training on maximum strength
and body composition in trained postmenopausal women. J
Strength Cond Res 2004; 18: 689-94.
141. RheaMR,AlvarBA,BurkettLN.Singleversusmultiplesets
for strength: a meta-analysis to address the controversy. Res
Q Exercise Sport 2002; 73: 485-8.
142. Rhea MR, Alvar BA,BurkettN, et al. Ameta-analysis to
determine the dose response relationship for strength deve-
lopment. Med Sci Sports Exerc 2003; 35: 456-64.
143. HoffmanJR,KraemerWJ,Fry AC,et al.Theeffectofself-The effect of self-
-selection for frequency of training in a winter conditioning
program for football. J Strength Cond Res 1990; 3: 76-82.
144. HakkinenK,PakarinenA,AlenM,etal.Neuromuscular and
hormonal responses in elite athletes to two successive strength
training sessions in one day. Eur J Appl Physiol 1988; 57: 133-9.
145. ZatsiorskyV,KraemerWJ.Science and Practice of Strength
Training. 2ndEd.ChampaignIL:HumanKinetics,2006.
146. Hakkinen K, Kallinen M. Distribution of strength training
volume into one or two daily sessions and neuromuscular
adaptations in female athletes. Electro Clin Neurophysiol
1994; 34: 117-24.
147. GrahamJ.Periodizationresearchandanexampleapplication.
Strength Cond J 2002; 24: 62-70.
148. Monteiro AG, Aoki MS, EvangelistaAL, etal. Nonlinear
periodization maximizes strength gains in split resistance
training routines. J Strength Cond Res 2009; 23: 1321-6.
149. PrestesJ,FrolliniAB,DeLimaC,etal.Comparison between
linear and daily undulating periodized resistance training
to increase strength. J Strength Cond Res 2009; 23: 2437-42.
150. McNamaraJM,StearneDJ.Flexiblenonlinearperiodization
in a beginner college weight training class. J Strength Cond
Res 2010; 24: 17-22.
151. BufordTW,RossiSJ,SmithDB,etal.Acomparisonofperio-
dization models during nine weeks with equated volume and
intensity for strength. J Strength Cond Res 2007; 21: 1245-50.
152. KokL,HamerPW,BishopDJ.Enhancingmuscularqualities
in untrained women: linear versus undulating periodization.
Med Sci Sports Exerc 2009; 41: 1797-807.
153. RheaMR,BallSD,PhillipsWT,etal.Acomparisonoflinear
and daily undulating periodized programs with equated
volume and intensity for strength. J Strength Cond Res 2002;
16: 250-5.
154. MannJB,ThyfaultJP,IveyPA,etal.Theeffectofautoregu-
latory progressive resistance exercise vs. linear periodization
on strength improvement in college athletes. J Strength Cond
Res 2010; 24: 1718-23.
155. CheungK,HumePA,MaxwellL.Delayedonsetmuscleso-
reness; treatment strategies and performance factors. Sports
Med 2003; 33: 145-64.
156. CarterJEL,HeathBH.Somatotyping: development and appli-
cations.Cambridge,UK:CambridgeUniversityPress,2000.
157. EstonR,ReillyT.Kinanthropometry and exercise physiology
laboratory manual: tests, procedures and data. 2nd ed. volume
1: anthropometry.London,UK:Routledge,2007.
158. PowersSK,HowleyET.Exercise physiology; theory and ap-
plication to fitness and performance. 7th Ed. New York, USA:
McGraw-Hill,2008.
159. TaylorWE,BhasinS,ArtazaJ,etal.Myostatininhibitscell
proliferation and protein synthesis in C2C12 muscle cells. Am
J Physiol Endocrinol Metab 2001; 280: E221-8.
160. KimJS, PetrellaJK,Cross JM,etal.Load-mediateddown-
regulationofmyostatinmRNAisnotsufficienttopromote
myofiber hypertrophy in humans: a cluster analysis. J Appl
Physiol 2007; 103: 1488-95.
161. RiechmanSE,BalasekaranG,RothSM,etal.Associationof
interleukin-15 protein and interleukin-15 receptor genetic
variation with resistance exercise training responses. J Appl
Physiol 2004; 97: 2214-9.
162. RothSM,Schrager MA, Ferrell RE,et al. CNTF genotype
is associated with muscular strength and quality in humans
across the adult age span. J Appl Physiol 2001; 90: 1205-10.
163. RothSM,WalshS,LiuD,etal.TheACTN3R577Xnonsense
allele is under represented in elite-level strength athletes. Eur
J Hum Genet 2008; 16: 391-4.
164. NormanB, Esbjörnsson M, RundqvistH, et al. Strength,
power,fiber-types and mRNAexpression in trainedmen
andwomenwithdifferentACTN3R577Xgenotypes.J Appl
Physiol 2009; 106: 959-65.
165. FollandJ, Leach B,Little T,et al.Angiotensin-converting
enzyme genotype affects the response of human skeletal
muscle to functional overload. Exp Physiol 2000; 85: 575-9.
166. StewartCEH, RittwegerJ.Adaptiveprocesses in skeletal
muscle: Molecular regulators and genetic influences. J Mu-
sculoskelet Neuronal Interact 2006; 6: 73-86.
167. VanEttenLMLA,VerstappenFTJ,WesterterpKR.Effect of
body build on weight-training-induced adaptations in body
composition and muscular strength. Med Sci Sports Exerc
1994; 26: 515-21.
Received:October10,2010
Accepted:July02,2011
Published:August05,2011
Address for correspondence:
JamesFisher
Department of Health, Exercise and Sport Science
Southampton Solent University
EastParkTerrace
Southampton SO14 0YN, UK
Tel. +44 2380 319 000
E-mail: james.fisher@solent.ac.uk