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© National Strength and Conditioning Association
Volume 28,Number 3, pages 44–53
Keywords: strength; high intensity exercise endurance; low intensi-
ty exercise endurance
44 June 2006 •Strength and Conditioning Journal
Maximum Strength and Strength Training—
A Relationship to Endurance?
Michael H. Stone, PhD; Meg E.Stone
East Tennessee State University,Johnson City,Tennessee
William A. Sands, PhD
United States Olympic Committee,Colorado Springs, Colorado
Kyle C.Pierce,EdD
USA Weightlifting Development Center,Louisiana State University–Shreveport, Shreveport,Louisiana
Robert U. Newton,PhD, CSCS
Edith Cowan University, Perth, Australia
G. Gregory Haff, PhD,CSCS
West Virginia University,School of Medicine,Morgantown,West Virginia
Jon Carlock,MS
United States Olympic Committee,Colorado Springs, Colorado
Most coaches and athletes would
argue that endurance is a fac-
tor that can affect sports per-
formance. However, definitions of en-
durance vary from sport to sport. For
this discussion, endurance is defined as
the ability to maintain or repeat a given
force or power output.
Although explaining the perfor-
mance–strength relationship in sports is
a multi-factorial concept, evidence in-
dicates that maximum strength is likely
a key component (37, 39, 52). The pur-
pose of this discussion is to consider
briefly the association of measures of
maximum strength and the effects of
strength training in relation to short-
and long-duration endurance and en-
durance-related factors. Particular at-
tention was given to sports performance
related-endurance factors. Evidence
from different types of reviewed cross-
sectional and longitudinal research was
considered; in conceptual areas for
which few reviewed publications could
be found, theses, abstracts, and observa-
tional information were considered in
conjunction with reviewed articles.
Semi-isokinetic device research was not
extensively reviewed for two reasons:
first, questions have been raised as to
the external validity of these devices and
second, coaches and athletes do not typ-
summary
Endurance can be defined as the ability to maintain or to repeat a given force or
power output. The sport performance–endurance relationship is a multi-factorial
concept.However, evidence indicates that maximum strength is a major component.
Conceptually,endurance is a continuum. The literature indicates that (a) maximum
strength is moderately to strongly related to endurance capabilities and associated
factors, a relationship that is likely stronger for high intensity exercise endurance
(HIEE) activities than for low intensity exercise endurance (LIEE); (b) strength train-
ing can increase both HIEE and LIEE,the effec t being greater for HIEE; (c) the volume
of strength training plays a role in endurance adaptation;and (d) mechanical speci-
ficity and training program variables also play a role in the degree of adaptation.
ically have access to these devices and
they are not commonly used in the
training or testing and monitoring of
athletes (53). Collectively, the informa-
tion indicates that the association be-
tween maximum strength and sports
performance-related endurance factors
is stronger than might be expected.
In order to better understand the
strength/endurance relationship, a def-
inition of strength is necessary. Strength
can be defined as the ability to produce
force (48, 50). Thus, the measurement
of strength is, in effect, a measure of an
ability or skill. Because force is a vector
quantity, the display of strength would
have the characteristics of magnitude
(0–100%) and a direction. Further-
more, the generation of force can be
isometric or dynamic and has a rate of
development. The characteristics of
force production are determined by a
number of factors, including the type
of contraction and the magnitude,
rate, and degree of muscle activation.
The direction of force production is re-
lated to the motor unit and muscle ac-
tivation patterns and to anatomical
factors. Thus, the conditions for mea-
surement of strength must be defined
carefully.
The importance of force production can
be ascertained from Newton’s second
law:
F= ma
Thus acceleration (a) of a mass (m), such
as body mass or an external object, de-
pends directly upon the ability of the
musculature to generate force (F). Be-
cause acceleration is derived from veloc-
ity, the velocity an object attains during
movement is a function of the applied
force. Force must be applied for a cer-
tain time, thus creating an impulse that
leads to a change in velocity of the ob-
ject. Furthermore, power production,
which is the product of force and veloci-
ty, is likely the most important factor in
determining success in most sports. For
both short- and long-duration en-
durance activities, it can be argued that
the average power, often derived from
many cyclic repetitions, is a deciding
factor in winning or losing (37, 39, 52).
Therefore, the ability to generate force
(strength), which is an integral part of
power production, may be a key compo-
nent in determining athletic success (52,
53). However, the degree to which these
factors, particularly maximum strength,
influence endurance is still not totally
clear.
Formerly, the endurance–strength rela-
tionship was viewed as a primary func-
tion of the muscular system and was de-
scribed with the term muscular
endurance. The effects of maximum
strength on muscular endurance were
simplistically divided into observations
of absolute and relative “mechanisms”:
• Absolute muscular endurance: the
number of repetitions performed at
an absolute submaximal resistance is
a function of maximum strength—a
stronger person has an advantage, es-
pecially as the load approaches maxi-
mum.
• Relative muscular endurance: at a
given percentage of maximum
strength, the maximum numbers of
repetitions that weaker or stronger in-
dividuals are able to perform are (typ-
ically) approximately equal and pro-
duce equal amounts of “relative”
work (23, 47). However, some studies
indicate that the weaker person has an
advantage in muscular endurance as
a result of less work being performed
in the same time frame (3).
Although these 2 ideas can be used to ex-
plain much of the association between
maximum strength and endurance capa-
bilities, these concepts are really more
observational descriptions rather than
mechanistic descriptions. Furthermore,
these observations do not necessarily ex-
plain the actual underlying mechanisms
associated with increases in endurance
resulting from strength gains for all situ-
ations.. Whereas some sports or events,
such the shot put, discus, and track cy-
cling, depend more upon absolute
strength capabilities, others, such as
road cycling and sprinting, depend more
upon strength in relation to body mass
(54, 55). However, in sports and daily
living, it can be argued that absolute
loads are encountered regularly. Indeed,
there may be few, if any, instances where
loads relative to maximum strength ac-
tually are encountered. Fundamentally,
these 2 observations/mechanisms (ab-
solute and relative muscular endurance)
do not consider additional underlying
mechanistic possibilities.
Other potential mechanisms arising
from increased strength and strength
training include central or peripheral
blood flow and vascular effects, muscle
fiber recruitment alterations, and
changes in movement economy. For ex-
ample:
• Certain types of resistance training
(high volume) may result in small
but significant increases in V
˙
O
2max,
which could contribute to enhanced
endurance (56), particularly among
those with low or average aerobic
power.
• Although typical strength training
has minimal effects on V
˙
O
2max, it
may be possible that stronger ath-
letes are more efficient or economi-
cal in their movements, leading to
enhanced endurance capabilities as a
result of performing less work to ac-
complish a given task (21, 34, 63).
These observations indicate that
gaining strength can have profound
effects on motor control attributes
that may lead to an increased econo-
my of movement. Basically, this
means that an athlete would use less
energy for the same distance trav-
eled, compared with a less move-
ment-efficient athlete. Alterations in
movement efficiency may be a pri-
mary mechanism underlying perfor-
mance enhancement among well-
trained endurance athletes, as a
result of resistance training (40).
45
June 2006 •Strength and Conditioning Journal
• Increases in strength often are ac-
companied by increases in power
and rate of force development (1); it
is possible that these adaptations
may increase endurance by reducing
the relative force (percentage of max-
imum) applied at similar loads, thus
maintaining a greater blood flow, or
by reducing the time of restricted
blood flow during a muscle contrac-
tion, which in turn reduces the limi-
tations to muscle oxygenation and
exchange of substrates/metabolites
(39).
• As a result of strength training that
can affect all motor unit types, the
use (or recruitment) of type 1 motor
units may be enhanced and use of
type 2 motor units reduced per
movement at submaximal loads (13,
19, 35). Additionally, strength train-
ing has been shown to reduce the
amount of muscle activated for a
given load (42), thus there could be a
smaller metabolic demand for the
same force output. This also may in-
dicate that as motor units become
stronger or more powerful, fewer
motor units will be recruited for a
given force output/work rate, thus
creating a motor unit reserve avail-
able for additional work.
• Another potential mechanism for in-
creased endurance deals with the pos-
sible increase in number (and size) of
type IIa fibers (MHC IIa). Type IIa
fibers have high glycolytic and oxida-
tive potential and are relatively fa-
tigue resistant. Resistance training
can result in an increased number of
type IIa fibers with a concomitant
decrease in the proportion of type IIx
fibers. Greater proportions of type
IIa fibers may allow a greater toler-
ance for high-intensity exercise. lead-
ing to greater endurance (10, 14). In-
terestingly, motor unit type may
influence fatigue resistance as a result
of postactivation potentiation (PAP).
PAP may contribute to the ability to
generate a given force at a lower
adenosine triphosphate expenditure,
thus enhancing endurance capabili-
ties (17). Evidence also indicates that
a larger proportion of type IIa fibers
may enhance the effects of certain
types of PAP, resulting in force
restoration and maintenance during
strength training and strength/power
sports, a type of endurance termed
high intensity exercise endurance
(HIEE) (10).
• Some evidence also suggests that fa-
tigue resistance can be improved
through strength training as a result
of prolonged membrane excitation
and enhanced ionic regulation (5,
33).
• Endurance depends upon both aero-
bic and anaerobic mechanisms—en-
hancement of anaerobic capacity as a
result of strength training also can
contribute to enhanced endurance
(40).
• The lactate threshold (LT) also can
be modified markedly through resis-
tance training (31). Perhaps, using
appropriate resistance training, it
may be possible to maintain the LT
at higher values during periods of
primarily aerobic training in which
the anaerobic system is not being
taxed.
As can be ascertained from the foregoing
discussion, there are several potential
reasons why strength training may en-
hance endurance. The discussion dealing
with the effects of strength/strength
training on endurance is divided into
two parts. Part 1 deals with HIEE, which
can be defined as the ability to sustain or
to repeat high intensity exercise and has
been associated with sustained activities
of ≤2 minutes (57). Part 2 deals with
strength training and long-duration en-
durance activities, a type of endurance
that may be termed low intensity exercise
endurance (LIEE). Therefore, LIEE
would be the ability to sustain or to re-
peat low intensity exercise.
The degree to which each of these po-
tential mechanisms contributes to vari-
ous types of endurance along a high-to-
low endurance continuum, particularly
among advanced and elite athletes, is
not well understood. Certainly, the abil-
ity of the coach and athlete to appropri-
ately integrate resistance training into
the training process will have a great
deal of influence on the degree of en-
durance enhancement.
As with any type of training goal (i.e.,
maximum strength, power, endurance),
the impact of the training program de-
pends upon training factors including
mechanical specificity, the training vol-
ume and intensity factors, rest period
length, and the trained state.
Maximum Strength Strength
Training for Strength and
Power Sports
Effects of Enhanced Maximum
Strength Correlational Studies
A correlation represents the strength of
the relationship among variables—the
correlation coefficient (symbolized as r)
ranges from –1.0 to 1.0; the closer the
coefficient is to 1.0, the stronger the re-
lationship. A positive correlation be-
tween 2 variables would mean they in-
crease together, whereas a negative
correlation would mean an inverse rela-
tionship. Hopkins (22) has ranked cor-
relations according to the following r
values: 0.0 (trivial); 0.1 (small); 0.3
(moderate); 0.5 (strong); 0.7 (very
strong); 0.9 (nearly perfect); and 1.0
(perfect).
By multiplying the correlation coeffi-
cient by itself (r2), the shared variance
can be determined. The shared variance
is an estimation of how much of the
variability in one variable is explained by
the variance in another variable.
Using previously strength-trained sub-
jects (n= 33), Robinson et al. (44)
showed that high volume strength train-
ing for 5 weeks could increase power
output and HIEE. Power and HIEE
were measured by fifteen 5-second max-
imum effort cycle rides with 5-second
rest intervals (0.1 kg ×body mass).
46 June 2006 •Strength and Conditioning Journal
Robinson et al. (44) showed that maxi-
mum strength as measured by the 1 rep-
etition maximum (RM) squat had
strong and increasing correlations with
cycle peak power (PP), the average PP
(APP15) over 15 rides, and the average
work accomplished (ATW15) over 15
rides. Pre rvalues were 0.62 (PP), 0.67
(APP15), and 0.64 (ATW15). Post rval-
ues were 0.74 (PP), 0.72 (APP15), and
0.75 (ATW15). This correlational infor-
mation indicates that maximum
strength is associated with both power
output and HIEE and that the relation-
ship gets stronger with training (44).
An important consideration is whether
significant relationships can be estab-
lished between variables in high level
athletes. Stone et al. (52) reported an
investigation of the relationship be-
tween the 1RM parallel squat and tests
of agility, jumping capabilities, and en-
durance using international level Scot-
tish badminton players (n= 13). This
study was part of the ongoing sports
testing-sports science program initiat-
ed by the Scottish Institute of Sport.
The results (52) indicated that the
1RM squat was correlated strongly
with both weighted and unweighted
countermovement and static vertical
jumps, as well as with tests of agility (r
= 0.65–0.87). Additionally, the 1RM
was correlated with a test of agility-en-
durance. A badminton-specific agility
test was designed to simulate the
change-of-direction and metabolic de-
mands of badminton (X-test; M. Glais-
ter; 52), and this test could be repeated
to add an endurance component to the
test protocol. Its test-retest reliability
was excellent. The X-test was repeated
15 times with a 14-second rest interval
for males and a 16-second rest interval
for females (simulating the rest inter-
vals between volleys during a bad-
minton match, as measured from
video). The correlation between the
1RM squat and the repeated X-test (av-
erage time) was r= –0.69. These results
indicate that maximum strength (as
measured by the 1RM squat and 1RM
squat per kg body mass) has significant
relationships with power-, speed-, and
speed-endurance–related variables.
Additional studies indicate that greater
maximum strength can be related to in-
creased power and endurance in various
activities, including sprint swimming
(11, 12, 46) and sprint cycling (55).
These types of studies, dealing with
trained subjects, including high level
athletes, indicate that maximum
strength is related strongly to HIEE.
The studies discussed so far indicate a re-
lationship between maximum strength
and endurance. However, cross-sectional
and correlational data do not necessarily
imply cause and effect.
Effects of Enhanced Maximum
Strength Longitudinal Studies
It has been well established that stronger
athletes have a greater absolute en-
durance capability (3). However, it is
not uncommon for these athletes to un-
dergo periods of strength-endurance
training (high volume strength training)
or power-endurance training (high vol-
ume power training). Typically, these
types of high intensity endurance train-
ing programs take place during the gen-
eral and specific preparation phases and
occasionally for very short periods oc-
curring 4–8 weeks before major compe-
titions. Part of the reason for using a
strength-endurance or power-endurance
phase is the belief that HIEE will be en-
hanced beyond that of typical strength
training. Only a few studies have direct-
ly addressed this issue.
McGee et al. (32) compared 3 different
training groups consisting of low (Gp-
L), moderate (Gp-V), and high volume
(Gp-H) strength training groups. The
Gp-L group (n= 8) performed 1 set of
8–12RM to failure, with one light
warm-up set. The Gp-V group (n= 9)
comprised multiple set variations: 2
weeks at 3 ×10RM, 3 weeks at 3 ×5RM,
and 2 weeks at 3 ×3RM. The Gp-H
group (n= 10) performed 3 ×10RM.
Both the moderate and high volume
groups performed 3 warm-up sets that
progressed from light to moderate in-
tensity.
The subjects trained using large muscle
mass exercises and emphasized leg and
hip strength-endurance. Training was
3d·wk–1 for 7 weeks. Squats and pressing
movements were performed 2d·wk–1
(Monday and Friday) and pulling move-
ments were performed 1d·wk–1
(Wednesday). Total volume of work was
quite different among the 3 groups. For
example, the total planned repetitions
(squats: 2 times·wk–1) at the target sets
were approximately Gp-L = 140; Gp-V =
246; and Gp-H = 420. Considering that
reasonable training loads were used, the
3 groups accomplished very different
total amounts of work. All the subjects
were trained in the same manner for 2
weeks prior to the study. Endurance was
measured by 2 methods: cycle ergometry
to failure (<5 minutes) at a constant load
(4.5 KP) and parallel squats to failure
with increasing loads. Pre- and posttest-
ing found that although all groups im-
proved, the greatest percentage of im-
provement for both tests was Gp-H >
Gp-V > Gp-L. Additionally, it was noted
that although the greatest improvements
were specific (i.e., squats), considerable
improvement in cycle endurance also oc-
curred. The authors concluded that the
degree of strength training–induced
adaptations in HIEE was to a large ex-
tent volume-dependent, agreeing with
the general observations and conclusions
of Stone and Coulter (58).
It is commonly believed that shortening
the rest interval between sets enhances
the HIEE training effect. Unfortunately,
very little study has been conducted that
actually addresses this belief. The avail-
able current research does not support a
strong association between strength
training rest interval and HIEE. Robin-
son et al. (44) used moderately trained
subjects and investigated rest interval ef-
fects on HIEE. Three different interset
rest periods were studied, group 1 (n=
47
June 2006 •Strength and Conditioning Journal
11) used 3-minute rest, group 2 (n= 11)
used 1.5-minute rest, and group 3 (n=
11) used 0.5-minute rest. The subjects
trained 4d·wk–1for 5 weeks using exer-
cises that emphasized the legs and hips.
All subjects performed 5 ×10 repetitions
for all major exercises; only the rest inter-
vals were different. Pre- and posttests in-
cluded the vertical jump (VJ), 1RM
squat, and fifteen 5-second maximum ef-
fort cycle rides with 1-minute rest inter-
vals (0.1 kg ×body mass). Groups 1 and
2 showed nonsignificant improvements
in the VJ, whereas group 3 showed a
nonsignificant decrease, and group 1 sig-
nificantly increased in the squat com-
pared with group 3. All three groups im-
proved significantly on the cycle tests,
with no differences between groups. The
authors (44) concluded that shortening
the rest intervals did not produce an ad-
vantage for developing HIEE, agreeing
with the observations of Nimmons (36)
and Kulling et al. (28).
In an unpublished master’s thesis, Nim-
mons (36) trained 2 groups for 9 weeks
with exercises emphasizing the leg and
hip musculature. Both groups per-
formed a high volume training program
using 3 ×10 repetitions at a target load,
plus light and moderate warm-up sets of
10 repetitions. However, different rest
periods between sets were used: group 1
(n= 8) rested 3 minutes between sets
and group 2 (n= 6) rested 30 seconds
between sets. Training data indicated
that group 1 used substantially higher
loads, a higher relative intensity, and
performed more work over the 9 weeks,
compared with group 2. Maximum
strength (1RM squat) increased 13.1%
in group 1 and 8.8% in group 2 (effect
size, group 1 = 2.29; effect size, group 2
= 1.80). Repetitions to failure at 85% of
the 1RM improved 152% in group 1
and 77% in group 2 (effect size, group 1
= 4.89; effect size, group 2 = 3.33). The
results (36) indicated that short rest pe-
riods did not offer an advantage for in-
creasing HIEE; indeed, the observed
tendency was for short rest periods to
produce inferior effects.
In a similar investigation, reported in an
abstract, Kulling et al. (28) indicated
that longer interset rest periods facilitat-
ed HIEE adaptations. They (28) found
that training with 90-second rest peri-
ods, compared with 30 seconds, resulted
in more repetitions to failure in bench
presses at a percentage of body mass
(60% for men and 40% for women)
after 12 weeks of training. The longer
rest periods allowed a higher training in-
tensity, which facilitated adaptations in
strength and endurance. These data (28,
36, 44) indicate that if interset rest peri-
ods are too short (<90 seconds) then
training intensity (i.e., average load) and
subsequent adaptations can be compro-
mised. Collectively, these observations
bring into question the practice of using
circuit resistance training or other short
interset rest period programs to enhance
strength and strength-endurance. Short
interset rest intervals often are used to
increase the average metabolic expendi-
ture. However, the short rest periods can
compromise resistance exercise loading
parameters and subsequent adaptations
to training. Clearly, more investigation
is needed in this area.
The effects of short interset rest intervals
during resistance training on LIEE are
not known. However, other types of
high-intensity training using short in-
tervals have been shown to substantially
alter metabolic variables, including
V
˙
O
2max, and positively affect endurance
(29, 30, 45). Thus it is possible that
short interset rest period resistance
training protocols may positively affect
aspects of LIEE.
Although not all studies agree, the data
presented indicate that:
• Although specificity is evident,
strength training can produce adap-
tations in endurance, which are
transferable (i.e., adaptations can
take place in exercises not used in the
strength training program). For ex-
ample, weight training transfers to
cycle exercise endurance alterations.
• Higher volume training can affect
measures of endurance to a greater
extent than low volume training.
• Within the context of strength train-
ing, short rest periods (≤90 seconds)
do not enhance endurance beyond
using typical rest periods (3–5 min-
utes) and can compromise strength
and power gains. If rest periods are
too short (≤30 seconds), loading
could be compromised sufficiently
to result in smaller gains in strength
power and possibly HIEE.
• A great deal of research is still neces-
sary to clarify these relationships.
Maximum Strength-Strength
Training For Endurance Sports
Among coaches and athletes, the type
and amount of strength training neces-
sary for LIEE has been controversial (43,
59). Also controversial is the degree to
which strength training affects LIEE.
Recently, data from several longitudinal
studies have indicated that strength-
power training can enhance long-dura-
tion endurance (i.e., LIEE). This brief
review will deal with those studies.
Correlational-Descriptive Studies
Strength or power measures have been as-
sociated with endurance performance in
several studies in various sports. For ex-
ample, studies have shown strong correla-
tions between swimming performance up
to 400 m and maximum strength/power
of the upper body (11, 12, 18, 46, 61).
Among road cyclists, anaerobic power
has been shown to be a major factor sepa-
rating higher and lower ranked athletes
(60). Anaerobic power was a critical fac-
tor determining success among cross-
country runners with similar V
˙
O
2maxval-
ues (8). Additionally, evidence indicates
that distance runners with more power-
ful muscles are more likely to succeed
(37). These data indicate the potential
for strength training and increased maxi-
mum strength to enhance endurance.
Longitudinal Studies
Several longitudinal studies have noted
an association between increased
48 June 2006 •Strength and Conditioning Journal
strength and increased anaerobic power
and measures of endurance as a result of
strength training in untrained or mini-
mally endurance trained subjects (20,
24, 31, 38, 41, 45, 49, 56), including
middle-aged and older subjects (25).
Strength training also has been shown to
produce increases in endurance among
trained subjects and well-trained ath-
letes. Hickson (19) studied the effects of
adding strength training to the overall
training programs of endurance trained
subjects (8 men, 2 women, n= 10). The
subjects were moderately endurance-
trained (>50 mL·kg–1·min–1). Ten weeks
of strength training (3d·wk–1) emphasiz-
ing leg and hip strength resulted in
marked gains in maximum strength
(20–38%). Although there was little
change in V
˙
O
2max, incremental tread-
mill and cycle times were increased sig-
nificantly, as was time to exhaustion on a
cycle ergometer at a constant work rate
(80–85% of V
˙
O
2max). From a practical
standpoint, 10-km running time de-
creased from 42:27 ± 1:59 to 41:43 ±
1:45 (n= 9).
Paavolainen et al. (40) investigated the
effects of “explosive strength training”
on the performance capabilities of 18
well-trained male orienteers (V
˙
O
2max =
65 mL·kg–1·min–1). In an attempt to
partially control for training volume dif-
ferences, endurance training time was
replaced with strength training (32% of
total time) so that the total approximate
training time was equal between experi-
mental (GpE, n=10) and control (GpC,
n= 8) groups. Training lasted 9 weeks.
Interestingly, GpE showed a small de-
crease in V
˙
O
2max over the training peri-
od. However, GpE showed superior
gains compared to the control group in
maximum strength (isometric leg press)
a 20-m sprint, jumping ability, anaero-
bic capacity (VMART), running econo-
my, and most importantly, 5-km time.
Strength training also has been shown
to have beneficial effects on endurance
factors associated with road cycling. An
important aspect of road cycling success
is the ability to maintain high average
power outputs during a race (4). How-
ever, the ability to develop and to main-
tain reasonable levels of power can be
diminished by endurance activities,
such as road cycling training, and may
be related to hormonal alterations (26).
Therefore, interventions allowing
power development and maintenance
may beneficially affect LIEE. Bastiaans
et al. (4), using 14 male competitive
road cyclists, investigated the effects of
explosive strength training on en-
durance-related factors. As with
Paavolainen et al. (40), endurance
training time was replaced with
strength training (37% of total time) so
that the total approximate training time
was equal between experimental (GpE,
n= 6) and control (GpC, n= 8) groups.
Although the addition of strength train-
ing resulted in small increases in power
output and riding efficiency, the major
effect dealt with power development
and “short-duration performance.”
Short-term performance was measured
by calculating mean power output at a
fixed pedal rate (60 rpm) during a 30-
second ergometer test. It was shown
that GpC lost mean power and GpE
showed small increases over the 9-week
period. The authors (4) suggested that
the data indicated strength training at-
tenuated the commonly observed loss in
power and sprint ability associated with
long-duration endurance training. Fur-
thermore, GpE showed slightly greater
improvement in work accomplished
during a 1-hour ergometer time trial,
compared with GpC. These data indi-
cate that replacing a portion of en-
durance training with explosive
strength training can preserve or can en-
hance the ability to maintain high
power outputs, at least for short peri-
ods, and that this can translate into fac-
tors associated with enhanced LIEE
(based on the 1-hour time trial).
These data suggest that (a) maximum
strength can be associated with LIEE;
(b) strength training can improve LIEE
or factors associated with LIEE; and (c)
as with strength/power sports, there is a
degree of specificity in the endurance
adaptations.
Specificity,Training Volume,
Hypertrophy,and Lag-Time
Issues
Not all studies have shown that strength
training enhances endurance (see, for
example, references 6 and 7). There are a
number of reasons for this.
• One possibility is that strength
training has little effect on en-
durance factors. In the authors’
opinions, this factor is unlikely be-
cause (a) there are ample studies in-
dicating an effect can occur, and (b)
athletes and coaches are very prag-
matic. It is the authors’ opinions and
observations that most coaches, par-
ticularly those coaching elite ath-
letes—including endurance ath-
letes—do advocate some form of
strength training in the belief that it
will enhance performance. Over the
long term, it is quite unlikely that
athletes and coaches would continue
to waste time and effort on training
that does not produce reasonable re-
sults.
• One of the most important and vi-
able training principles deals with
mechanical specificity (53). Me-
chanical specificity deals with the
degree of similarity between train-
ing exercises and performance. For
example, it is possible that the type
of resistance training program used
was not specific enough for the
sport or event. Bastiaans et al. (4)
argued that one possible explana-
tion for Bishop and colleagues’ (7)
finding no improvement in en-
durance with strength training
deals with the type of contraction
used. Bishop et al. (7) used typical
heavy slow-velocity strength train-
ing, which may not match the
characteristics of the task (in this
case, high speed endurance cy-
cling). In this context, it is inter-
49
June 2006 •Strength and Conditioning Journal
esting that both Paavolainen et al.
(40) and Bastiaans et al. (4) used
dynamic explosive moments for
the training intervention, which
may have matched the characteris-
tics of the performance task better
than slower movements. However,
Millet et al. (34) used typical heavy
strength training procedures and
found improvements in movement
economy among very well-trained
cross-country skiers. Perhaps the
task-specificity aspects of cross-
country skiing are such that heavy
strength training may produce an
effect on movement economy or
some other factor that enhances
endurance.
• Another factor that may affect the
outcome of training deals with dif-
ferences in the trained state. It may
be possible that strength training be-
comes more or less important as the
athlete evolves in his or her sport.
• Another factor that may affect the
degree of adaptation to training is
total training volume. Both
Paavolainen et al. (40) and Bastiaans
et al. (4) substituted strength train-
ing for endurance activities, thus, to
a point, maintaining total training
volume. Studies adding strength
training to existing training regi-
mens may have increased the total
volume such that accumulated fa-
tigue interfered with adaptations.
One possible mechanism dealing
with poor endurance adaptations
deals with hormonal alterations. The
resting testosterone–cortisol ratio
(T:C) has been shown to be a reason-
able index of anabolic-catabolic sta-
tus and to be related to alterations in
strength and power (16). More re-
cently, gains in HIEE (51) and LIEE
(25) resulting from strength training
also have been associated with rest-
ing testosterone and the T:C. High
volumes of training representing a
large training stress can decrease the
T:C (9, 15, 16). The additional stress
of strength training plus endurance
training may alter the T:C such that
endurance gains are compromised
eventually.
• Lag-time may affect endurance.
During strength training, maxi-
mum strength, power, and specific
performance variables (including
endurance) do not adapt at exactly
the same rate. Often, additional
gains in sports performance may
lag behind strength/power gains
for several weeks or months. It is
possible that the lack of direct cor-
respondence between maximum
strength gains and other perfor-
mance related variables is associat-
ed with a lag-time (2, 53). Lag-
time deals with a period of time in
which the athlete learns how to use
training adaptations, particularly
increased strength; the lag-time
may extend many months in some
cases. It is possible that lag-time
may be reduced by careful coach-
ing strategies in which the poten-
tial link between strength and
technique/endurance is pointed
out to the athlete. This may partly
be accomplished by pointing out
similarities between training exer-
cises (i.e., mechanical specificity)
and performance exercises.
• Performance gain mismatch may be
another factor. It is also possible for
increases in strength to continue
after the changes in sport perfor-
mance, including endurance, be-
come asymptotic. This observation
may indicate that a change in the
type of strength training or types of
exercises being used is necessary
(25).
• The degree to which hypertrophy
and lean body mass gains may influ-
ence endurance is unknown.
Strength training is often, but not al-
ways, accompanied by measurable
hypertrophy. It is reasonable to as-
sume that LIEE in which the body
mass must be supported would be af-
fected negatively by large gains in
body mass, even if the gains were
lean body mass. However, typical ec-
tomorphic endurance athletes are
not likely to gain appreciable body
mass as a result of strength training
regimens (62).
• Also of importance is the role of en-
durance versus recovery. The ability
50 June 2006 •Strength and Conditioning Journal
Figure. A representation of a paradigm illustrating the potential interrelated mech-
anisms that can modify endurance performance.Modified from Paavolainen
et al. (40).
to recover is obviously important
during repeated bouts of exercise.
Although there is little doubt that
endurance capabilities and recovery
capabilities are related, they are not
the same. In this brief review, these 2
aspects are not separately discussed,
because the literature does not al-
ways distinguish the effects of one
aspect independently of the other. It
has been the authors’ observations
that not only are HIEE and LIEE
different in nature (performance and
underlying mechanisms), but one’s
ability to recover from HIEE and
LIEE also differs. For example, being
aerobically fit does not guarantee a
rapid recovery from anaerobic activi-
ties, particularly heavy resistance
training sessions (27). Perhaps there
is also a strong degree of specificity
of recovery.
• It is also possible that strength train-
ing could reduce the injury potential
of endurance activities.
Conclusion
Based on this brief review, the authors
have several suggestions: (a) maximum
strength is associated with endurance
factors, a relationship that is likely
stronger for HIEE activities than for
LIEE; (b) strength training can affect
increases in endurance factors for both
HIEE and LIEE; (c) the volume of
strength training plays a role in the en-
durance adaptation (i.e., higher vol-
umes generally produce greater gains
in endurance); and (d) mechanical
specificity and training program vari-
ables also play a role in the degree of
adaptation. The Figure offers a para-
digm illustrating potential interrelated
mechanisms that can modify en-
durance performance (adapted from
Paavolainen et al. [40]). ♦
References
1. A
AGAARD
, P., E.B. S
IMONSEN
, J.L. A
N
-
DERSEN
, P. M
AGNUSSON
,
AND
P. D
YRE
-
P
OULSEN
. Increased rate of force de-
velopment and neural drive of human
skeletal muscle following resistance
training. J. Appl. Physiol. 93:1318–
1326. 2002.
2. A
BERNETHY
, P.J.,
AND
J. J
URIMAE
.
Cross-sectional and longitudinal uses
of isoinertial, isometric, and isokinetic
dynamometry. Med. Sci. Sports Exerc.
28:1180–1187. 1996.
3. A
NDERSON
, T.,
AND
J.T. K
EARNEY
. Ef-
fects of three resistance training pro-
grams on muscular strength and ab-
solute and relative endurance. Res. Q.
53:1–7. 1982.
4. B
ASTIAANS
, J.J., A.B.
VAN
D
IEMANN
, T.
V
ENBERG
,
AND
A.E. J
EUKENDRUP
. The
effects of replacing a portion of en-
durance training by explosive strength
training on performance in trained cy-
clists. Eur J. Appl. Physiol. 86:79–84.
2001.
5. B
EHM
, D.G.,
AND
D.M.M. S
T
.-
P
IERRE
. The effect of strength training
and disuse on the mechanisms of fa-
tigue. Sports Med. 25:173–189. 1998.
6. B
ISHOP
, D.,
AND
D.G. J
ENKINS
. The
influence of resistance training on the
critical power function and time to fa-
tigue at critical power. Aust. J. Sci.
Med. Sport. 28:101–105. 1996.
7. B
ISHOP
, D., D.G. J
ENKINS
, L.T.
M
ACKINNON
, M. M
C
E
NIERY
,
AND
M.F. C
AREY
. The effects of strength
training on endurance performance
and muscle characteristics. Med. Sci.
Sports Exerc. 31:886–891. 1999.
8. B
ULBUBIAN
, R., A.R. W
ILCOX
,
AND
B.L. D
ARABOS
. Anaerobic contribu-
tion to distance running performance
of trained cross-country runners.
Med. Sci. Sports Exerc. 18:107–118.
1986.
9. B
USSO
, T., K. H
ÄKKINEN
, A. P
AKARI
-
NEN
, C. C
ARASSO
, J.R. L
ACOUR
, P.V.
K
OMI
,
AND
H. K
AUHANEN
. A systems
model of training responses and its re-
lationship to hormonal responses in
the elite weightlifter. Eur. J. Appl. Phys-
iol. 61:48–54. 1990.
10. C
HIU
, L.Z.F., A.C. F
RY
, B.K.
S
CHILLING
, E.J. J
OHNSON
,
AND
L.W.
W
EISS
. Neuromuscular fatigue and po-
tentiation following two successive high
intensity resistance exercise sessions.
Eur. J. Appl. Physiol. 92:403–411. 2000.
11. C
OSTILL
, D., R. S
HARP
,
AND
J. T
ROUP
.
Muscle strength: Contributions to
sprint swimming. Swim. World.
21:29–34. 1980.
12. D
AVIES
, J.F. Effects of training and
conditioning for middle distance
swimming upon various physical mea-
sures. Res. Q. 30:399–412. 1959.
13. G
OLLNICK
, P.D., K. P
IEHL
,
AND
B.
S
ALTIN
. Selective glycogen depletion
pattern in human muscle fibers after
exercise of varying pedal speeds. J.
Physiol. (Lond.). 241:45–57. 1974.
14. G
REEN
, H.J. Muscle power fiber type
recruitment, metabolism and fatigue.
In: Human Muscle Power. N.L. Jones,
N. McCartney, and A.J. McComas,
eds. Champaign, IL: Human Kinetics,
1986. pp. 65–79.
15. H
ÄKKINEN
, K. Neuromuscular and
hormonal adaptations during strength
and power training. J. Sports Med.
29:9–26. 1989.
16. H
ÄKKINEN
, K.A. P
AKARINEN
, M.
A
LEN
,
AND
P. V. K
OMI
. Serum hor-
mones during prolonged training
of neuromuscular performance.
Eur. J. Appl. Physiol. 53:287–293.
1985.
17. H
AMADA
, T., D.G. S
ALE
,
AND
J.D.
M
AC
D
OUGALL
. Postactivation poten-
tiation in endurance-trained male ath-
letes. Med. Sci. Sports Exerc. 32:403–
411. 2000.
18. H
AWLEY
, J.A.,
AND
M.M. W
ILLIAMS
.
Relationship between upper body
anaerobic power and freestyle swim-
ming performance. Int. J. Sports Med.
12:1–5. 1991.
19. H
ICKSON
, R.C., B.A. D
VORAK
, E.M.
G
OROSTIAGA
, T.T. K
UROWSKI
,
AND
C.
F
OSTER
. Potential for strength and en-
durance training to amplify endurance
performance. J. Appl. Physiol. 65:
2285–2290. 1988.
20. H
ICKSON
, R.C., M.A. R
OSENKOET
-
TER
,
AND
M.M. B
ROWN
. Strength
training effects on aerobic power and
short-term endurance. Med. Sci. Sports
Exerc. 12:336–339. 1980.
21. H
OFF
, J., J. H
ELGERUD
,
AND
U.
W
ISLOFF
. Maximal strength training
improves work economy in trained fe-
51
June 2006 •Strength and Conditioning Journal
male cross-country skiers. Med. Sci.
Sports Exerc. 31:870–877. 1999.
22. H
OPKINS
, W. A new view of statistics.
Internet Society for Sport Science Web
site. Available at: http://www.sportsci.
org/resource/stats/. Accessed Decem-
ber 28, 2005.
23. H
UCZEL
, H.A.,
AND
D.H. C
LARKE
. A
comparison of strength and muscle en-
durance in strength-trained and un-
trained women. Eur. J. Appl. Physiol.
64:467–470. 1992.
24. I
NBAR
, O., P. K
AISER
,
AND
P. T
ESCH
.
Relationships between leg muscle fiber
type distribution and leg performance.
Int. J. Sports Med. 2:154–159. 1981.
25. I
ZQUIERDO
, M., K. H
ÄKKINEN
, J.
I
BANEZ
, A. A
NTON
, M. G
ARRUES
, M.
R
UESTA
,
AND
E.M. G
OROSTIAGA
. Ef-
fects of strength training on submaxi-
mal and maximal endurance perfor-
mance capacity in middle-aged and
older men. J. Strength Cond. Res.
17:129–139. 2003.
26. I
ZQUIERDO
, M., J. I
BANEZ
, K.
H
ÄKKINEN
, W.J. K
RAEMER
,
AND
M.
G
OROSTIAG
. Maximal strength and
power, muscle mass, endurance and
serum hormones in weightlifters and
road cyclists. J. Sports Sci. 22:465–
478. 2004.
27. K
ANG
, J., J.R. H
OFFMAN
, J. I
M
, B.A.
S
PIERING
, N.A. R
ATAMESS
, K. R
UN
-
DELL
, S. N
IOKA
, J. C
OOPER
,
AND
B.
C
HANCE
. Evaluation of physiological
responses during recovery following
three resistance exercise programs. J.
Strength Cond. Res. 19:305–309. 2005.
28. K
ULLING
, F.A., B.H. H
ARDISON
, B.H.
J
ACOBSON
,
AND
S.W. E
DWARDS
.
Changes in muscular endurance from
different rest periods between sets in a
resistance training program [supple-
ment abstract 437]. Med. Sci. Sport
Exerc. 31(5):S116. 1999.
29. L
INOSSIER
, M.T., C. D
ENIS
, D. D
OR
-
MOIS
, A. G
EYSSANT
,
AND
J.R. L
ACOUR
.
Ergometric and metabolic adaptation to
a 5-s sprint training programme. Eur. J.
Appl. Physiol. 67:408–414. 1993.
30. M
AC
D
OUGALL
, J.D., A.L. H
ICKS
, A.R.
M
AC
D
ONALD
, R.S. M
C
K
ELVIE
, H.J.
G
REEN
,
AND
K.M. S
MITH
. Muscle per-
formance and enzymatic adaptations
to sprint interval training. J. Appl.
Physiol. 84:2138–2142. 1998.
31. M
ARCINIK
, E.J., J. P
OTTS
, G.
S
CHLABACH
, S. W
ILL
, P. D
AWSON
,
AND
B.F. H
URLEY
. Effects of strength train-
ing on lactate threshold and endurance
performance. Med. Sci. Sports Exerc.
23:739–743. 1991.
32. M
C
G
EE
, D.S., T.C. J
ESSE
, M.H.
S
TONE
,
AND
D. B
LESSING
. Leg and hip
endurance adaptations to three differ-
ent weight-training programs. J. Appl.
Sports Sci. Res. 6:92–95. 1992.
33. M
C
K
ENNA
, M.J., A.R. H
ARMER
, S.F.
F
RASER
,
AND
J.L. L
I
. Effects of training
on potassium, calcium, and hydrogen
ion regulation in skeletal muscle and
blood during exercise. Acta. Physiol.
Scand. 156:335–346. 1996.
34. M
ILLET
, G.P., B. J
AOUEN
, F. B
ORRANI
,
AND
R. C
ANDAU
. Effects of concurrent
endurance and strength training on
running economy and V
˙
O
2kinetics.
Med. Sci. Sports Exerc. 34:1351–1359.
2002.
35. M
ORGAN
, D.W., D.R. B
RANSFORD
,
D.L. C
OSTILL
, J.T. D
ANIELS
, E.T.
H
OWLEY
,
AND
G.S. K
RAHENBUHL
.
Variations in the aerobic demand of
running among trained and untrained
subjects. Med. Sci. Sports Exerc.
27:404–409. 1995.
36. N
IMMONS
, M. High Volume Weight
Training With Different Rest Periods
and Its Effect on Muscle Hypertrophy
[master’s thesis]. Boone, NC, Ap-
palachian State University; 1995.
37. N
OAKES
, T.D. Implications of exercise
testing for prediction of athletic per-
formance: A contemporary perspec-
tive. Med. Sci. Sports Exerc. 20:319–
330. 1988.
38. O’B
RYANT
, H.S., R. B
YRD
,
AND
M.H.
S
TONE
. Cycle ergometer and maxi-
mum leg and hip strength adaptations
to two different methods of weight
training. J. Appl. Sports Sci. Res.
2(2):27–30. 1988.
39. O
STERAS
, H., J. H
ELGERUD
,
AND
J.
H
OFF
. Maximal strength-training ef-
fects on force-velocity and force-
power relationships explain increases
in aerobic performance in humans.
Eur. J. Appl. Physiol. 88:255–263.
2002.
40. P
AAVOLAINEN
, L., K. H
ÄKKINEN
, I.
H
AMALAINEN
, A. N
UMMELA
,
AND
H.
R
USKO
. Explosive-strength training
improves 5-km running time by im-
proving running economy and muscle
power. J. Appl. Physiol. 86:1527–1533.
1999.
41. P
ETERSEN
, S.R., G.D. M
ILLER
, H.A.
W
ENGER
,
AND
H.A. Q
UINNEY
. The
acquisition of muscular strength: The
influence of training velocity and ini-
tial V
˙
O
2max. Can. J. Appl. Sport Sci.
9:176–180. 1984.
42. P
LOUTZ
, L.L., P.A. T
ESCH
, R.L. B
IRO
,
AND
G.A. D
UDLEY
. Effect of resistance
training on muscle use during exercise.
J. Appl. Physiol. 76:1675–1681. 1994.
43. R
EUTER
, B. Strength training for en-
durance athletes? Strength Cond. J.
22:61–62. 2000.
44. R
OBINSON
, J.M., C.M. P
ENLAND
,
M.H. S
TONE
, R.L. J
OHNSON
, B.J.
W
ARREN
,
AND
D.L. L
EWIS
. Effects of
different weight training exercise-rest
intervals on strength, power and high
intensity endurance. J. Strength Cond.
Res. 9:216–221. 1995.
45. R
ODA
, G., J.L. V
ENTURA
, J.A. C
ADE
-
FAU
, R. C
USSO
,
AND
J.A. P
ARRA
. A
short training programme for the rapid
improvement of both aerobic and
anaerobic metabolism. Eur J. Appl.
Physiol. 82:480–486. 2000.
46. S
HARP
, R.L., J.P. T
ROUP
,
AND
D. C
OS
-
TILL
. Relationship between power and
freestyle swimming. Med. Sci. Sports
Exerc. 14:53–56. 1982.
47. S
HAVER
, L.G. Maximum dynamic
strength, relative dynamic endurance
and their relationships. Res. Q. 42:
460–465. 1971.
48. S
IFF
, M. Biomechanical foundations of
strength and power training. In: Bio-
mechanics in Sport. V. Zatsiorsky, ed.
London: Blackwell Scientific Ltd.,
2001. pp. 103-139.
49. S
MITH
, D.J. The relationship between
anaerobic power and isokinetic torque
outputs. Can. J. Appl. Physiol. 12:3–5.
1987.
52 June 2006 •Strength and Conditioning Journal
50. S
TONE
, M.H. Explosive exercise.
NSCAJ. 15:7–15. 1993.
51. S
TONE
, M.H.,
AND
A.C. F
RY
. In-
creased training volume in strength/
power athletes. In: Overtraining in
Sport. R.B. Kreider, A.C. Fry, and M.L.
O’Toole, eds. Champaign, IL: Human
Kinetics, 1998. pp. 87–106
52. S
TONE
, M.H., G. M
OIR
, M. G
LAIS
-
TER
,
AND
R. S
ANDERS
. How much
strength is necessary? Phys. Ther. Sport.
3:88–96. 2002.
53. S
TONE
, M.H., S. P
LISK
,
AND
D.
C
OLLINS
. Training principle: Evalua-
tion of modes and methods of resis-
tance training—A coaching perspec-
tive. Sport Biomech. 1:79–104. 2002.
54. S
TONE
, M.H., K. S
ANBORN
, H.S.
O’B
RYANT
, M.E. H
ARTMAN
, M.E.
S
TONE
, C. P
ROULX
, B. W
ARD
,
AND
J.
H
RUBY
. Maximum strength-power-
performance relationships in collegiate
throwers. J. Strength Cond. Res. 17:
739–745. 2003.
55. S
TONE
, M.H., W.A. S
ANDS
, J. C
AR
-
LOCK
, S. C
ALLAN
, D. D
ICKIE
, D.
D
AIGLE
, J. C
OTTON
,
AND
S.L. S
MITH
.
The importance of isometric maxi-
mum strength and peak rate of force
development in sprint cycling. J.
Strength Cond. Res. 18:878–884. 2004.
56. S
TONE
, M.H., G.D. W
ILSON
, D.
B
LESSING
,
AND
R. R
OZENEK
. Cardio-
vascular responses to short-term
Olympic-style weight training in
young men. Can. J. Appl. Sports Sci.
8:134–139. 1983.
57. S
TONE
, M.H., G.D. W
ILSON
, R.
R
OZENEK
,
AND
H. N
EWTON
. Anaero-
bic capacity: Physiological basis.
NSCAJ. 5:30–71. 1984.
58. S
TONE
, W.J.,
AND
S.P C
OULTER
.
Strength/endurance effects from three
resistance training protocols with
women. J. Strength Cond. Res. 8:231–
234. 1994.
59. S
USLOV
, F. How much strength is
needed in endurance events? Modern
Coach and Athlete. 35:9–12. 1997.
Translated from Legkaya atletika 10.
1992.
60. T
ANAKA
, H., J. B
ASSETT
, T.C.
S
WENSEN
,
AND
R.M. S
AMPEDRO
. Aer-
obic and anaerobic power characteris-
tics of competitive cyclist in the United
States Cycling Federation. Int. J. Sports
Med. 14:334–338. 1993.
61. T
OUSAINT
, H.M.,
AND
K. V
ERVOORN
.
Effects of specific high resistance train-
ing in the water on competitive swim-
mers. Int. J. Sports Med. 11:228–233.
1990.
62. V
AN ETTEN
, L.M., F.T. V
ERSTAPPEN
,
AND
K.R. W
ETERERP
. Effect of body
build on weight-training-induced
adaptations in body composition and
muscular strength. Med. Sci. Sports
Exerc. 26: 515–521. 1994.
63. W
ISLOFF
, U.,
AND
J. H
ELGERUD
. Eval-
uation of a new upper body ergometer
for cross-country skiers. Med. Sci.
Sports Exerc. 30:1314–1320. 1998.
Michael H. Stone is currently the Exer-
cise and Sports Science Laboratory Di-
rector at East Tennessee State University.
Margaret E.Stone is currently a track and
field coach at East Tennessee State Uni-
versity.
William A. Sands is the head of Sports
Biomechanics and Engineering for the
United States Olympic Committee.
Kyle C.Pierce is a professor in the Kinesi-
ology and Health Science Department
and is the Director and Coach of the USA
Weightlifting Development Center at LSU
Shreveport.
Robert U. Newton is the foundation pro-
fessor in Exercise, Biomedical and Health
Sciences at Edith Cowan University, Perth,
Western Australia.
G. Gregory Haff is currently an assistant
professor in the Division of Exercise Physi-
ology in the Department of Human Per-
formance and Applied Exercise Physiolo-
gy at the West Virginia University School
of Medicine in Morgantown, West Vir-
ginia.
Jon Carlock is currently the Strength and
Conditioning Supervisor at the Olympic
Training Center in Lake Placid, New York.
53
June 2006 •Strength and Conditioning Journal
Newton
Haff