The relationship between the number of repetitions performed at given intensities is different in endurance and strength trained athletes

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DOI: 10.5604/20831862.1099047 · Source: PubMed
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Abstract
Prescribing training intensity and volume is a key problem when designing resistance training programmes. One approach is to base training prescription on the number of repetitions performed at a given percentage of repetition maximum due to the correlation found between these two measures. However, previous research has raised questions as to the accuracy of this method, as the repetitions completed at different percentages of 1RM can differ based upon the characteristics of the athlete. The objective of this study was therefore to evaluate the effect of an athlete's training background on the relationship between the load lifted (as a percentage of one repetition maximum) and the number of repetitions achieved. Eight weightlifters and eight endurance runners each completed a one repetition maximum test on the leg press and completed repetitions to fatigue at 90, 80 and 70% of their one repetition maximum. The endurance runners completed significantly more repetitions than the weightlifters at 70% (39.9 ± 17.6 versus 17.9 ± 2.8; p < 0.05) and 80% (19.8 ± 6.4 versus 11.8 ± 2.7; p < 0.05) of their one repetition maximum but not at 90% (10.8 ± 3.9 versus 7.0 ± 2.1; p > 0.05) of one repetition maximum. These differences could be explained by the contrasting training adaptations demanded by each sport. This study suggests that traditional guidelines may underestimate the potential number of repetitions that can be completed at a given percentage of 1RM, particularly for endurance trained athletes.
Biology of Sport, Vol. 31 No2, 2014 157
Number of repetitions and intensity
Reprint request to:
Daniel J Cleather
School of Sport, Health and Applied
Sciences
St Mary’s University,
Waldegrave Road, Twickenham.
TW1 4SX
UK
Tel: +44 7973 873 516
Email: daniel.cleather@smuc.ac.uk
Accepted
for publication
21.12.2013
INTRODUCTION
In resistance training programmes, training load for a given set of an
exercise is prescribed in terms of both intensity (the weight to be
lifted relative to the person’s capabilities) and volume (the number
of repetitions) [24]. It has been clearly established that there is an
inverse relationship between the weight to be lifted and the number
of repetitions that can be performed [18,19]. This relationship is of
key importance for a coach in prescribing the appropriate load. For
instance, given a desired intensity, the coach needs to know an ap-
propriate number of repetitions to create a session with the required
difculty.
In contemporary practice, there are two main ways of prescribing
intensity; to prescribe it based on the individual’s repetition maximum
for a given exercise (the exercise is performed with a weight that
would allow a given number of repetitions and no more) or to prescribe
repetitions based on a percentage of that person’s one repetition
maximum (1RM – the greatest weight that the person can lift for
one repetition while maintaining perfect form). If the former method
is used the relationship between intensity and number of repetitions
is clear. However, when using the latter method it is necessary to
THE RELATIONSHIP BETWEEN THE NUMBER
OF REPETITIONS PERFORMED AT GIVEN
INTENSITIES IS DIFFERENT IN ENDURANCE
AND STRENGTH TRAINED ATHLETES
AUTHORS: Richens B., Cleather D.J.
School of Sport, Health and Applied Sciences, St Mary’s University, Waldegrave Road, Twickenham, UK
ABSTRACT: Prescribing training intensity and volume is a key problem when designing resistance training
programmes. One approach is to base training prescription on the number of repetitions performed at a given
percentage of repetition maximum due to the correlation found between these two measures. However, previous
research has raised questions as to the accuracy of this method, as the repetitions completed at different
percentages of 1RM can differ based upon the characteristics of the athlete. The objective of this study was
therefore to evaluate the effect of an athlete’s training background on the relationship between the load lifted
(as a percentage of one repetition maximum) and the number of repetitions achieved. Eight weightlifters and
eight endurance runners each completed a one repetition maximum test on the leg press and completed repetitions
to fatigue at 90, 80 and 70% of their one repetition maximum. The endurance runners completed signicantly
more repetitions than the weightlifters at 70% (39.9 ± 17.6 versus 17.9 ± 2.8; p < 0.05) and 80% (19.8 ±
6.4 versus 11.8 ± 2.7; p < 0.05) of their one repetition maximum but not at 90% (10.8 ± 3.9 versus 7.0 ±
2.1; p > 0.05) of one repetition maximum. These differences could be explained by the contrasting training
adaptations demanded by each sport. This study suggests that traditional guidelines may underestimate the
potential number of repetitions that can be completed at a given percentage of 1RM, particularly for endurance
trained athletes.
KEY WORDS: weight lifting; exercise; adaptation, physiological; physical endurance; exercise prescription;
one repetition maximum
establish the number of repetitions that an athlete can complete at
a given percentage of their 1RM.
Despite the ubiquity of “repetition maximum” tables that present
the number of repetitions that an athlete can be expected to complete
at a given percentage of their 1RM, the literature related to the
topic is limited. In addition, some of the more commonly employed
repetition maximum tables are based upon weight room observations
or “guesstimates” [28] rather than empirical studies. An inuential
example of this is a table presented by Baechle et al. [3] which is
often used to establish the relationship between 1RM and number
of repetitions. In particular, the evidence on which this table is based
is largely taken from non-peer reviewed literature (Table 1; [2,4,
5,8,17–19,27]). It should be noted that Baechle et al. do acknowl-
edge the potential variability in this relationship and in the literature
exploring it, and give appropriate caveats and guidelines for the use
of the table. However, the lack of a scientically established evidence
base for such a table suggests that the relationship between 1RM
and repetitions completed requires further, more rigorous quantica-
tion.
Original Paper Biol. Sport 2014;31:157-161
DOI: 10.5604/20831862.1099047
158
Richens B. & Cleather D.J.
TABLE 1.
REFERENCES FOR THE REPETITION MAXIMUM
TABLE OF BAECHLE ET AL. [3]
The determination of the relationship between intensity and number
of repetitions is complicated by the fact that there may be a large
variance in the repetitions completed at the same percentage of
1RM by different participants in different exercises. For instance,
a number of studies (of varying quality) have shown that trained
participants can lift more repetitions at a given percentage of 1RM
than untrained participants [16,21], although there are some con-
icting results[11].
It also seems intuitively sensible to suggest that there may be
differences between distinct sporting populations due to the adapta-
tions that they gain in training for their sport although only one study
has compared these differences. Desgorces et al. [7] tested 4 groups
of athletes (powerlifters, handball players, rowers and swimmers) in
a 1RM test using the bench press. Repetitions to fatigue at 20, 40,
60, 75 and 85% of 1RM were then conducted. Although no sig-
nicant difference was found between the groups, when the power-
lifter and handball player groups (strength based sports) were paired
against the rowing and swimming groups (endurance based sports),
the endurance group performed signicantly more repetitions at all
percentages. In a very recent study, Panissa and colleagues [20]
showed that aerobically trained participants performed signicantly
more repetitions at 80% of their 1RM in a Smith machine half squat
than their strength trained counterparts.
There is thus preliminary evidence that suggests that there might
be a difference in the number of repetitions completed at a given
percentage of 1RM between athletes with different training back-
grounds, but this fact has yet to be denitively established. Hence
the primary aim of this study was to test the difference in repetitions
completed on the leg press machine between two different groups
of athletes (strength trained and endurance trained) at given percent-
ages of their 1RM. It was hypothesized that there would be a sig-
nicant difference between the two groups, with the endurance trained
group being able to achieve more repetitions at every percentage of
1RM. The secondary aim of this study was to compare the repetitions
achieved at each percentage to those suggested in the coaching
literature in order to assess their likely veracity.
MATERIALS AND METHODS
A total of sixteen male participants were purposively recruited from
the student body of St Mary’s University College to take part in
a cross-sectional observational study. The weightlifting group (WT;
n=8; age 22.4 ± 3.3 years; weight 79.8 ± 10.8 kg; height 177.1
± 3.9 cm) consisted of athletes with at least two years of weightlift-
ing experience and who regularly train with maximal or near maximal
loads ( 6RM). The endurance running group (ET; n=8; age 20.9
± 1.5 years; weight 63.3 ± 1.5 kg; height 176.3 ± 3.0 cm) con-
sisted of runners with at least two year’s experience of training for
track and/or cross country running ( 800m). Participants were also
required to be free from injury and to have had no sustained training
experience in the other group’s mode of training. The participants
provided written informed consent and the study was approved by
the ethics committee of St Mary’s University College. The experiment
reported here was performed in accordance with the ethical standards
of the Helsinki Declaration.
At the rst testing session participants were taught a standardised
technique for the leg press [9]. The participants were instructed to
keep their head, shoulders and hips in contact with the leg press
machine and if technique failed the repetition was not counted.
To ensure all participants lifted with the same range of movement
in the leg press, the end range of the leg press movement was when
the participants’ femurs were parallel to the leg press footplate.
To ensure correct depth and speed of every repetition, participants
were given cues as when to start the concentric phase and feedback
on speed. Cadence was set at three seconds for the eccentric portion
to encourage controlled lifting, with the concentric portion com-
pleted as fast as possible until the legs were fully extended.
Participants’ 1RM was obtained during the rst testing session,
after performing a standardized warm up. Participants then attend-
ed a further three testing sessions, separated by at least 48 hours.
Testing was kept at the same time of day for all participants, to
decrease the effect of the known diurnal uctuations in strength [6].
In each testing session, the participant performed a trial to establish
the maximum number of repetitions that could be completed at
a given percentage of 1RM. The percentages chosen were 90, 80
and 70% of 1RM and the order of testing was randomised for each
participant. These particular percentages were chosen as they are
those most commonly used in resistance training programs [3].
The same standardised warm up used for the 1RM test was com-
References Background and detail of references
Baechle T.R. &
Earle R.W. [2]
The book is no longer in print but in any case
is not a piece of peer reviewed research
literature.
Brzycki [4] Not a piece of scientic research, but an
article detailing strength testing. The author
provides an equation for predicting a 1RM
based on reps-to-fatigue, but does not say on
what information this equation is based.
Chapman et al. [5] The table presented in this study is a
combination of other sources presented in
this table [4,8,17].
Epley [8] A poundage chart, not based on scientic
research.
Lander [17] This formula “began as a ‘guess-timated’
chart that was eventually published without
the author’s knowledge” [28]
Mayhew et al. [18] A study evaluating the accuracy of estimating
1RM from submaximal repetitions.
Morales &
Sobonya [19]
The rst 1RM table is from "Strength
Tech Inc" and is not a study. The second
table does include repetitions achieved at
percentages of 1RM based on the results of
this study.
Wathen [27] This reference is the previous edition of
the book, which contains no peer reviewed
research on the 1RM table data.
Biology of Sport, Vol. 31 No2, 2014
159
Number of repetitions and intensity
TABLE 2.
COMPARISON OF LEG PRESS PERFORMANCE BETWEEN
ENDURANCE (ET) AND WEIGHTLIFTING (WT) GROUPS
pleted and then three warm up sets of three to ve repetitions were
completed at thirty, twenty and ten percent below the actual percent-
age used in the trial. Two minutes rest was taken between each set.
Statistics
A comparison between the two groups of the number of repetitions
completed at 90, 80 and 70 percent of participants’ 1RM was per-
formed with the software package Statistical Package for Social Science
(SPSS Inc version 15.0, Chicago, IL). A repeated measures ANOVA
with post-hoc Bonferroni adjusted t-tests was conducted to test for
differences with the level of signicance set at p 0.05 a priori.
RESULTS
Resistance training experience and 1RM of the participants are de-
tailed in Table 2, with higher 1RM scores and weight training expe-
rience found in the WT group. In both groups (within group analysis)
the amount of repetitions completed increased significantly as
the percentage of 1RM decreased. Comparison of the two groups
revealed that the ET group completed signicantly more repetitions
than the WT group at 70% 1RM and 80% 1RM, however no sig-
nicant difference was found in repetitions to fatigue at 90% 1RM
(Table 2 and Figure 1).
DISCUSSION
The main nding in this study was that the ET group completed
signicantly more repetitions at 70 and 80% of 1RM than the WT
group, although there was no signicant difference between the two
groups at 90% of 1RM. The ability of the ET group to perform more
repetitions than the WT group at lower percentages of 1RM is likely
to be explained, at least in part, by the specicity of adaptations
gained from training in their sport. Increases in capillarisation [1],
mitochondrial content [13], muscle phenotype [26] and lactate buff-
ering [12] have all been found in participants who have completed
endurance training protocols, and all of which may have helped the
endurance athletes perform more repetitions at submaximal intensi-
ties. The present study also suggests that the difference between the
two groups’ repetitions to fatigue widens at lower percentages of
1RM. This is also consistent with the notion that endurance spe-
cic adaptations in the runners (that would be expected to be more
inuential when the number of repetitions performed was higher)
improved their ability to complete a greater number of repetitions.
It should be noted however, that there is potentially an alternative
explanation for this trend. It might be that the lack of familiarity of
the ET group with training at higher loads prevented them from
achieving the level of arousal necessary for maximal performance in
the 1RM test [25]. This would then mean that the weight used for
each repetition maximum test would be relatively lower in compari-
son to the WT group.
The ndings of this study are consistent with the work of Des-
gorces et al. [7]. They found that at 75% of 1RM and below, the
high endurance group (swimmers and rowers) achieved more rep-
etitions than the high strength group (powerlifters and handball play-
ers). This difference increased as the intensity decreased to 20% of
1RM, with the authors proposing this difference between the two
groups may be because of training adaptations gained and the ge-
netic makeup of the athletes. One limitation of the Desgorces study
was that the tests to fatigue at different percentages of 1RM were
completed on the same day after only a 15 minute recovery. This
incomplete recovery of the participants could explain why lower
repetitions were found in the Desgorces study as compared to this
work. The ndings of this study may also be consistent with studies
that found that resistance trained participants were able to perform
more repetitions in resistance exercises than untrained partici-
pants[16,21]. Both of these studies pointed to the specicity of
training adaptations achieved by the resistance trained group which
would permit them to achieve a greater number of repetitions when
compared to untrained participants. It is possible that the resistance
trained participants in the present study would also outperform un-
trained participants, but they are simply outperformed in turn by the
endurance trained athletes.
In this study the endurance runners and weightlifters performed
19.8 ± 6.4 and 11.8 ± 2.7 repetitions respectively at 80% of 1RM.
This is consistent with the results of previous research [11,14]. For
instance, Hoeger et al. [11] found that untrained and trained subjects
Endurance
group
Weightlifting
group
Resistance training
experience (years) 0.0 ± 0.0 4.1 ± 1.0*
1RM leg press score (kg) 188.4 ± 13.8 335.6 ± 48.6*
Repetitions completed:
@ 70% 1RM 39.9 ± 17.6 † 17.9 ± 2.8 †*
@ 80% 1RM 19.8 ± 6.4 † 11.8 ± 2.7 †*
@ 90% 1RM 10.8 ± 3.9 † 7.0 ± 2.1 †
Note: * = signicant difference between ET and WT - p < 0.05; † =
signicant difference within group – p < 0.05
FIG.
1.
COMPARISON OF WEIGHTLIFTING AND ENDURANCE GROUPS
WITH BAECHLE AND EARLE [3] AND MAYHEW ET AL. [18] FOR AMOUNT
OF REPETITIONS COMPLETED AT SELECTED PERCENTAGES OF 1RM.
160
Richens B. & Cleather D.J.
completed 15.2 ± 6.5 and 19.4 ± 9.0 repetitions respectively at
80% of 1RM whereas Jacobs et al. [14] found that trained subjects
completed 13 ± 5 repetitions with the same relative load. Figure 1
presents a comparison of the relationship between intensity and num-
ber of repetitions found in this study and other commonly quoted
relationships. It is apparent that these oft quoted relationships had
poor predictive power for the leg press in the athletes studied here
(and also for the amount of repetitions at 80% of 1RM found in the
other studies referred to here).
The comparison of the different ndings in Figure 1 suggests a
need for the scientic community to revisit this issue to produce more
robust, sport-specic estimates. It is the authors’ opinion that the
wide variation in the number of repetitions that a given individual can
complete with a given relative load is not adequately recognised by
coaches. This need is magnied by the fact that differences have
been found in the relationship between intensity and repetitions com-
pleted between upper body and lower body exercises [11], between
single-joint exercises and multi-joint exercises [10,23], and between
males and females with the same exercise [15]. An alternative is for
practitioners to use alternate methods of prescribing intensity. In a
review by Tan [24] it is suggested that the repetition maximum (RM)
method is more appropriate, as it focuses more on the individual,
rather than a marker of maximal strength they may have achieved
sometime in the past. Poliquin [22] also recommends this method
of prescription and suggests it can also reduce the risk of uninten-
tional under or over-training in a session which may happen when
prescribing intensity by normative 1RM data.
CONCLUSIONS
This study demonstrates the importance of using sport-specic
estimates of the relationship between repetitions and percentage
of 1RM. In addition, this study suggests that traditional guidelines
may underestimate the potential number of repetitions that can be
completed at a given percentage of 1RM, particularly for endurance
trained athletes.
Conict of interest: Authors declared no conict of interest.
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    This study aimed to compare the pattern of repetition velocity decline during a single set to failure performed against four relative loads in the bench press (BP) and full squat (SQ) exercises. Following an initial test to determine 1RM strength and load-velocity relationships, twenty men performed one set of repetitions to failure (MNR test) against loads of 50-60-70-80% 1RM in BP and SQ, on eight random order sessions performed every 6-7 days. Velocity against the load that elicited a ~1.00 m•s-1 (V1 m•s-1 load) was measured before and immediately following each MNR test and it was considered a measure of acute muscle fatigue. The number of repetitions completed against each relative load showed high interindividual variability in both BP (CV: 15-22%) and SQ (CV: 26-34%). Strong relationships were found between the relative loss of velocity in the set and the percentage of performed repetitions in both exercises (R2 = 0.97 and 0.93 for BP and SQ, respectively). Equations to predict repetitions left in reserve from velocity loss are provided. For a given magnitude of velocity loss within the set (15-65%), the percentages of performed repetitions were lower for the BP compared to the SQ for all loads analyzed. Acute fatigue following each set to failure was found dependent on the magnitude of velocity loss (r = 0.97 and 0.99 for BP and SQ, respectively) but independent of the number of repetitions completed by each participant (p > 0.05) for both exercises. The percentage of velocity loss against the V1 m•s-1 load decreased as relative load increased, being greater for BP than SQ. These findings indicate that monitoring repetition velocity can be used to provide a very good estimate of the number (or percentage) of repetitions actually performed and those left in reserve in each exercise set, and thus to more objectively quantify the level of effort incurred during resistance training.
  • Article
    The purpose was to examine the acute skeletal muscle response to high load exercise and low‐load exercise with and without different levels of applied pressure (BFR). A total of 22 participants completed the following four conditions: elbow flexion exercise to failure using a traditional high load [70% 1RM, (7000)], low load [15% 1RM,(1500)], low load with moderate BFR [15%1RM+40%BFR(1540)] or low load with greater BFR [15% 1RM+80%BFR(1580)]. Torque and muscle thickness were measured prior to, immediately post, and 15 min postexercise. Muscle electromyography (EMG) amplitude was measured throughout. Immediately following exercise, the 7000 condition had lower muscle thickness [4·2(1·0)cm] compared to the 1500 [4·4 (1·1)cm], 1540 [4·4(1·1)cm] and 1580 [4·5(1·0)cm] conditions. This continued 15 min post. Immediately following exercise, torque was lower in the 1500 [31·8 (20) Nm], 1540 [28·3(16·9) Nm, P<0·001] and 1580 [29·5 (17) Nm] conditions compared to the 7000 condition [40 (19) Nm]. Fifteen minutes post, 1500 and 1540 conditions demonstrated lower torque compared to the 7000 condition. For the last three repetitions percentage EMG was greater in the 7000 compared to the 1580 condition. Very low‐load exercise (with or without BFR) appears to result in greater acute muscle swelling and greater muscular fatigue compared to high load exercise.
  • Article
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    The purpose of this case study was to evaluate the response in heart rate variability via the parasympathetically-mediated metric of the log-transformed root mean square of successive R-R interval differences (lnRMSSD) to weekly variations in total volume-load (TVL) during an 18-week periodized strength training program in a competitive collegiate hockey athlete. The program consisted of three 60–90 min full-body exercise sessions per week with at least 24-h of rest between each session. Daily lnRMSSD measurements were taken immediately after waking using a validated smartphone application and the pulse-wave finger sensor. The weekly lnRMSSD values were calculated as the mean (lnRMSSDMEAN) and the coefficient of variation (lnRMSSDCV). A Pearson’s bivariate correlation of lnRMSSDMEAN and TVL revealed no statistically significant correlation between the two variables; TVL (r = −0.105, p = 0.678). However, significant correlations were found between lnRMSSDCV and both total load (TL) (r = −0.591, p = 0.013) and total volume (TV) (r = 0.765, p < 0.001). Additionally, weekly ratings of perceived exertion (RPE) mean values were statistically significantly correlated to TVL, r = 0.853, p < 0.001. It was concluded that lnRMSSDCV increased or decreased proportionally to an increase or decrease in TVL during the periodized resistance training program with TV being the strongest, independent indicator of these changes.
  • Article
    Muscle strength is a functional measure of quality of life in humans. Declines in muscle strength are manifested in diseases as well as during inactivity, aging, and space travel. With conserved muscle biology, the simple genetic model C. elegans is a high throughput platform in which to identify molecular mechanisms causing muscle strength loss and to develop interventions based on diet, exercise, and drugs. In the clinic, standardized strength measures are essential to quantitate changes in patients; however, analogous standards have not been recapitulated in the C. elegans model since force generation fluctuates based on animal behavior and locomotion. Here, we report a microfluidics-based system for strength measurement that we call ‘NemaFlex’, based on pillar deflection as the nematode crawls through a forest of pillars. We have optimized the micropillar forest design and identified robust measurement conditions that yield a measure of strength that is independent of behavior and gait. Validation studies using a muscle contracting agent and mutants confirm that NemaFlex can reliably score muscular strength in C. elegans. Additionally, we report a scaling factor to account for animal size that is consistent with a biomechanics model and enables comparative strength studies of mutants. Taken together, our findings anchor NemaFlex for applications in genetic and drug screens, for defining molecular and cellular circuits of neuromuscular function, and for dissection of degenerative processes in disuse, aging, and disease.
  • Thesis
    Velocity-based resistance training (VBT) has been widely considered a hypernym for various methods to regulate resistance training on the basis of feedback on maximum intended movement velocity. While the specific case of competitive powerlifting does not necessarily require the practice of high-velocity movements, it relies on frequent training of the competition exercises (squat, bench press, deadlift). Therefore, reasonable benefit could be expected when applying certain methodological concepts of VBT to regulate training load, volume and neurophysiological exertion, given that the respective concepts provide sufficient validity and reliability. Twenty-four trained powerlifters were assessed for their one-repetition maximum (1-RM) and individual load-velocity profiles in the squat, bench press and deadlift. A total of eighteen different methods were analyzed to estimate the 1-RM from velocity at loads which could be considered representative of a typical range used for specific warm-up and training in powerlifting. All of the investigated methods either failed to provide sufficient accuracy due to substantial over- and underestimation, or resulted in statistically unclear trends due to high inter-individual variability. Therefore, load-velocity based estimation of the 1-RM was considered not to be a valuable reference for adjusting daily training loads.
  • Article
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    O objetivo deste estudo foi determinar a influência de um exercício de resistência aeróbica no desempenho de força e a relação entre a capacidade aeróbica VO2máx e o desempenho de força. 14 homens com 24.37 ± 3.91 anos de idade e 47.92 ± 32.67 meses de treinamento na musculação participaram de quatro sessões de testes: (i) capacidade aeróbica (VO2máx) no cicloergômetro; (ii) teste de uma repetição máxima (1RM) no exercício supino livre, (iii) e (iv) realização de quatro séries do número máximo de repetições a 50% de 1RM, com pausa de 1 min entre as séries e/ou 20 min de exercício aeróbico contínuo em cicloergômetro a 60% da potência máxima antes do exercício supino. O desempenho no exercício supino foi medido pela somatória das repetições ao longo de quatro séries (Σrepetições) e pela diferença entre o número de repetições da primeira para a quarta série [DIF (1ª – 4ª)]. Os resultados não mostraram diferenças entre o número máximo de repetições obtidas nas sessões 3 e 4 (57,32 e 55,46) e ainda indicaram que não houve correlação tanto para VO2máx e Σrepetições (r=0.37; p=0.197) quanto para VO2máx e DIF (1ª – 4ª) (r=0.17; p=0.56).
  • Article
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    Postactivation potentiation is referred to as an acute and temporary enhancement of muscle performance resulting from previous muscle contraction. The purpose of this study was to compare the acute effect of plyometric exercise (PLY) and heavy-resistance exercise (RES) on the blood lactate level (BLa) and physical performance. Fourteen male collegiate soccer players were randomized to performeither RES or PLY first and then crossed over to performthe opposite intervention. PLY consisted of 40 jumps, whereas RES comprised ten single repetitions at 90% of one repetition maximum. BLa and physical performance (countermovement jump height and 20-m sprint) were measured before and at 1 and 10 min following the exercise. No significant difference was observed in the BLa for both exercises (PLY and RES). Relative to baseline, countermovement jump (CMJ) height was significantly better for the PLY group after 1 min (𝑃 = 0.004) and after 10 min (𝑃 = 0.001) compared to that of the RES group.The 20-m sprint time was significantly better for PLY at 10 min (𝑃 = 0.003) compared to that of RES. The present study concluded that, compared to RES, PLY causes greater potentiation, which leads to improved physical performance. This trial is registered with NCT03150277.
  • Article
    Resistance exercise intensity is commonly prescribed as a percent of 1 repetition maximum (1RM). However, the relationship between percent 1RM and the number of repetitions allowed remains poorly studied, especially using free weight exercises. The purpose of this study was to determine the maximal number of repetitions that trained (T) and untrained (UT) men can perform during free weight exercises at various percentages of 1RM. Eight T and 8 UT men were tested for 1RM strength. Then, subjects performed 1 set to failure at 60, 80, and 90% of 1RM in the back squat, bench press, and arm curl in a randomized, balanced design. There was a significant (p < 0.05) intensity x exercise interaction. More repetitions were performed during the back squat than the bench press or arm curl at 60% 1RM for T and UT. At 80 and 90% 1RM, there were significant differences between the back squat and other exercises; however, differences were much less pronounced. No differences in number of repetitions performed at a given exercise intensity were noted between T and UT (except during bench press at 90% 1RM). In conclusion, the number of repetitions performed at a given percent of 1RM is influenced by the amount of muscle mass used during the exercise, as more repetitions can be performed during the back squat than either the bench press or arm curl. Training status of the individual has a minimal impact on the number of repetitions performed at relative exercise intensity.
  • Article
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    The aim of this study was to evaluate the performance, as well as neuromuscular activity, in a strength task in subjects with different training backgrounds. Participants (n = 26) were divided into three groups according to their training backgrounds (aerobic, strength or mixed) and submitted to three sessions: (1) determination of the maximum oxygen uptake during the incremental treadmill test to exhaustion and familiarization of the evaluation of maximum strength (1RM) for the half squat; (2) 1RM determination; and (3) strength exercise, four sets at 80% of the 1RM, in which the maximum number of repetitions (MNR), the total weight lifted (TWL), the root mean square (RMS) and median frequency (MF) of the electromyographic (EMG) activity for the second and last repetition were computed. There was an effect of group for MNR, with the aerobic group performing a higher MNR compared to the strength group (P = 0.045), and an effect on MF with a higher value in the second repetition than in the last repetition (P = 0.016). These results demonstrated that individuals with better aerobic fitness were more fatigue resistant than strength trained individuals. The absence of differences in EMG signals indicates that individuals with different training backgrounds have a similar pattern of motor unit recruitment during a resistance exercise performed until failure, and that the greater capacity to perform the MNR probably can be explained by peripheral adaptations.
  • This study compared the relative accuracy, similarity, and average error of 7 prediction equations (Brzycki, 1993; Epley, 1985; Lander, 1985; Lombardi, 1989; Mayhew, Ball, Arnold, & Bowen, 1992; O'Connor, Simmons, & O´Shea, 1989; Wathen, 1994) for estimating 1-repetition maximum (1-RM) performance of older sedentary adults using Hammer Strength Iso-Lateral resistance exercise machines. Data were collected from 49 apparently healthy volunteers (26 males, 23 females) aged 53.55 ±3.34 (mean ± SD) years. 1-RM scores were obtained for biceps curl, chest press, high latissimus dorsi (lat) pull, incline chest press, leg curl, leg extension, low lat pull, leg press, shoulder press, and triceps extension. Repetitions to fatigue (RTF) for each exercise were determined by assigning each subject a percentage of his or her 1-RM ranging from 50% to 90%. Subjects performed as many repetitions as possible with the predetermined resistance. Predicted 1-RM (1-RMP) was evaluated by relative accuracy (correlation between 1-RM and 1-RMP), similarity (paired t-test between 1-RM and 1-RMP), and average error (sqrt[S(1RMP - 1RM)2/(n - 1)]). Relative accuracy, similarity, and average error improved significantly and gender differences were minimal when RTF £ 10. Accuracy of prediction equations varied over different resistance exercises. The Mayhew, Ball, Arnold et al. (1992), Epley (1985), and Wathen (1994) formulas evidenced the lowest average error (AE) and highest relative accuracy over the resistance exercises examined; however, both absolute AE and AE expressed as a percent of mean 1-RM were quite high for all formulas over all exercises.
  • Article
    The purpose of this study was to determine the accuracy of using relative muscular endurance performance to estimate 1 RM bench press strength. College students (184 men and 251 women) were tested for 1 RM strength following 14 weeks of resistance training. Each subject was then randomly assigned a relative endurance load (rep weight) corresponding to 55-95 percent of the 1 RM and required to perform as many bench press repetitions (reps) as possible in one minute. Men had significantly greater 1 RM strength, rep weight, percent 1 RM, and reps than women. Since the regression of percent 1 RM on reps was not significantly different between the men and women, the data were combined to produce the following exponential equation: percent 1 RM = 52.2 + 41.9e -0.055 reps (r = 0.80, p < 0.001). Bench press strength could be estimated from the equation 1 RM = rep weight/predicted percent 1 RM/l00 with an accuracy of r = 0.98 and a standard error of estimate of +/- 4.8 kg. Applications of these equations to a comparable cross-validation group (70 men and 101 women) indicated acceptable validity (r = 0.98, p < 0.001) with an error of only +/- 5.4 kg. Applying the same equations to high school male athletes (n = 25), high school male nonathletes (n = 74) and college football players (n = 45) also produced good cross validation (r > 0.95, p < 0.001) with relatively small standard errors (+/- 3.1 to +/- 5.6 kg). It appears that relative muscular endurance performance can be used to accurately estimate 1 RM bench press strength in a wide variety of individuals. (C) 1992 National Strength and Conditioning Association
  • Article
    Twenty-three male college athletes performed submaximal repetition tests (70, 75, 80, 85, 90, and 95% 1-RM) in the bench press (BP), squat (S), and power clean (PC) lifts. For each lift the best predictor of 1-RM strength was defined as the maximal number of repetitions performed at a given lifting intensity (i.e., %1-RM) which represented the highest prediction coefficient (multiple R). ANOVA revealed that regardless of lift, the number of repetitions significantly decreased (p < 0.05) as lifting intensity increased. The best predictor for BP was the number of repetitions performed at 95% 1-RM. For S and PC lifts the best predictors corresponded to the number of repetitions at 80 and 90%, respectively. The S best predictor had the highest prediction power (R2 accounted for 26.9% of the variance). The BP and PC best predictors accounted for 11.6 and 19.1% of the variance, respectively. Although the corresponding best predictors (multiple R) for each lift represented different percentages of 1-RM, their respective predictive power (R2) was not significantly different (p > 0.05). (C) 1996 National Strength and Conditioning Association
  • Article
    Maximum strength is the capacity to generate force within an isometric contraction. It is a valuable attribute to most athletes because it acts as a general base that supports specific training in other spheres of conditioning. Resistance training program variables can be manipulated to specifically optimize maximum strength. After deciding on the exercises appropriate for the sport, the main variables to consider are training intensity (load) and volume. The other factors that are related to intensity are loading form, training to failure, speed of contraction, psychological factors, interset recovery, order of exercise, and number of sessions per day. Repetitions per set, sets per session, and training frequency together constitute training volume. In general, maximum strength is best developed with 1-6 repetition maximum loads, a combination of concentric and eccentric muscle actions, 3-6 maximal sets per session, training to failure for limited periods, long interset recovery time, 3-5 days of training per week, and dividing the day's training into 2 sessions. Variation of the volume and intensity in the course of a training cycle will further enhance strength gains. The increase in maximum strength is effected by neural, hormonal, and muscular adaptations. Concurrent strength and endurance training, as well as combination strength and power training, will also be discussed. (C) 1999 National Strength and Conditioning Association
  • Article
    Ninety-one subjects were tested to determine the number of repetitions they could perform at 40, 60, and 80 percent of one repetition maximum (percent 1 RM) for each of seven specified weight training lifts. Thirty-eight subjects from a previous study (18) were also included in the data analysis. The subjects represented four categories: untrained males (n = 38), untrained females (n = 40), trained males (n = 25) and trained females (n = 26). The results indicated that there was a significant difference (p < 0.05) in the number of repetitions that males and females can perform at the selected percent 1 RM among the seven weight training lifts, as well as in the number of repetitions performed at these percentages across lifts. When comparing untrained and trained males, a significant difference (p < 0.05) was found in the number of repetitions performed at all selected percent 1 RM for the arm curl, knee extension and sit-ups. Significant differences (p < 0.05) were also found at 60 percent 1 RM for the leg curl and at 60 and 80 percent 1 RM for the lateral pulldown. No significant differences (p > 0.05) were found for any percent 1 RM for the bench press and the leg press. When comparing untrained and trained females, a significant difference in performance (p < 0.05) was found among all seven lifts at 40 percent 1 RM. Significant differences (p < 0.05) were found at 60 percent 1 RM for the knee extension, bench press, sit-ups, leg curl and leg press; and at 80 percent 1 RM for the bench press, sit-ups and leg press. The findings of this study indicate that a given percent of 1 RM will not always elicit the same number of repetitions when performing dafferent lifts. (C) 1990 National Strength and Conditioning Association