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INFLUENCE OF STRENGTH LEVEL ON THE REST
INTERVAL REQUIRED DURING AN UPPER-BODY POWER
TRAINING SESSION
JOSE LUIS HERNÁNDEZ DAVÓ, JAVIER BOTELLA RUIZ, AND RAFAEL SABIDO
Sport Research Center, Miguel Hernández University of Elche, Elche, Alicante, Spain
ABSTRACT
Hernández Davó, JL, Botella Ruiz, J, and Sabido, R. Influence of
strength level on the rest interval required during an upper-body
power training session. J Strength Cond Res 31(2): 339–347,
2017—The present study aimed to investigate the influence of
subjects’ strength level on both the ability to maintain power
output performance and the physiological and perceived exertion
responses during a power training session when different rest
intervals (RI) are used. Thirty-eight (18 men and 20 women)
subjects were divided into a stronger or weaker group based
on their ability to produce peak power output. Testing was per-
formed using the same protocol (5 sets of 8 repetitions with
40% of 1 repetition maximum) in the bench press throw exercise,
but differing the RI between sets (1, 2, and 3 minutes). During
the sessions, mechanical (peak power), physiological ([La2]) and
perceptual (RPE) variables were measured. In addition, delayed
onset muscular soreness (DOMS) 24 and 48 hours after the
training session was reported. Both stronger and weaker (men
and women) groups showed significant impairments in mechan-
ical, physiological, and perceptual data when resting 1 minute.
Nevertheless, although stronger groups were able to sustain
power output over the sets when using the 2-minute RI, weaker
groups needed at least 3 minutes to maintain power output
performance. Therefore, strength level heavily influences the rest
interval required during a power training session and should be
taken into account when prescribing such training sessions.
KEY WORDS strength training, power training, bench press
INTRODUCTION
M
aximal power output can be defined as the
explosive nature of force production (11).
The importance of power output on athletic
performance has long been established because
many sport movements (e.g., jumping, sprinting, changes of
direction, throwing) require the production of force over short
time intervals (22). Consequently, several authors have shown
differences in power output development (and dynamic per-
formance) in a variety groups such as well-trained athletes vs.
untrained controls (5), power-type athletes vs. endurance ath-
letes (4), rugby players involved in national vs. state compet-
itions (2), as well as stronger vs. weaker individuals in a pool
of resistance-trained men (36).
Among the wide range of factors affecting power training
prescription, including volume, intensity, velocity or rest
interval (RI) between sets, the last RI has received less
attention. As consecutive power output performance has been
linked to the phosphagen system (which requires a minimum
of 4 minutes for its full replenishment) (14), some authors have
recommended a RI of at least 3 minutes when training for
power development (1,26). For instance, Ratamess et al. (27)
showed that at least 3 minutes of RI is necessary to maintain
bench press performance over 3–4 sets. Nevertheless, other
authors have shown that a 2-minute RI is enough to maintain
both the number of repetitions completed (34) and power
output production (15) when using the bench press exercise.
In addition, Nibali et al. (23) showed no differences in acute
power output production when comparing long (4 minutes)
with short (1 minute) RIs across multiple sets of jump squats,
whereas Robinson et al. (30) did not find any differences in
vertical jump power output adaptations after 5 weeks of train-
ing with different RIs (30 vs. 90 vs. 180 seconds). However, all
of these studies used homogeneous samples and did not study
the possible influence of strength level on the power output
responses to different RIs.
The discrepancies showed in the previously mentioned
studies can be partially explained by differences in experimen-
tal design, such as the variable used to quantify fatigue (i.e.,
volume completed vs. power output), or the intensities
employed (i.e., body mass vs. 70% of 1 RM). Although
training with the load that maximized power output (i.e.,
40% of 1RM in the bench press throw exercise) (16–18) has
been suggested to be an effective stimulus to optimize power
output adaptations and improve dynamic athletic performance
(41), very few studies have previously analyzed the influence of
different RIs during an upper-body power training session,
Address correspondence to Jose Luis Hernández Davó, jlhdez43@
gmail.com.
31(2)/339–347
Journal of Strength and Conditioning Research
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VOLUME 31 | NUMBER 2 | FEBRUARY 2017 | 339
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much less taken into account the subjects’ strength level. It has
been shown in the literature that individuals with higher
strength levels have clearly superior ability to develop power
output than those with lower strength levels (4,5,21,36,38).
The superior capability of stronger individuals to generate
greater power output has been linked to both mechanical
and neuromuscular characteristics. For instance, greater mus-
cle pennation angle and larger muscle cross-sectional area
(especially more pronounced hypertrophy of type II fibers)
lead to greater level of strength (3,19) and consequently,
because of this greater maximal strength, it strongly deter-
mines power ability (7). In addition, several neural factors,
such as firing frequency, motor unit recruitment and intermus-
cular coordination, are partially responsible for the difference
seen in power output production between stronger and weak-
er individuals (12,22). All of these variables may affect not only
power output production, but also the RI required to maintain
power output over consecutive sets.
Thus, despite the influence of strength level on the
magnitude and mechanisms of adaptations after strength
training has been widely studied (9,13,31,40), to the best of
the authors’ knowledge, no previous studies have examined
the influence of strength level on the ability to maintain
power output production or the RI required during a power
training session based on subjects’ strength level. Therefore,
the aim of this study was to check the influence of strength
level on the ability to sustain power output and both the
physiological and perceived exertion responses during the
bench press throw exercise when different RIs are used.
METHODS
Experimental Approach to the Problem
The study used a within-subjects study design that evaluated
the influence of strength levels on the ability to maintain
power output and measured psycho-biological responses
when using different RIs in the bench press throw exercise.
Each subject attended 4 testing sessions in a 4-week period.
The first session consisted of a 1RM bench press test, whereas
the other 3 sessions consisted of the same protocol (i.e., 5
sets 3 8 reps of bench press throw exercise) using 40% of
1RM, but differing in the RI used (i.e., 1, 2, or 3 minutes).
During testing sessions, peak power (PP) output, lactate
concentration ([La2]), and rating of perceived exertion (Borg
0–10 scale) were measured. In addition, delayed onset mus-
cular soreness (DOMS) 24 hours and 48 hours postsession
was recorded. To avoid experimental variability, the same
researcher conducted all testing sessions, and subjects were
scheduled at the same time for each session.
Subjects
Eighteen physically active men and 20 physically active
women took part in the study. For statistical analysis, both
men and women were divided into a “stronger” and “weaker”
group based on their peak power output, establishing 4 differ-
ent groups: stronger males (SM; n = 9), weaker males (WM;
n = 9), stronger females (SF; n = 8), and weaker females (WF;
n = 12). Sample size estimation based onsubjects’ power out-
put performance (80% power, p = 0.05) revealed that a sample
size of 4 subjects was needed to find significant differences.
Subjects were classified into each group by dividing the entire
sample in 2 halves (the stronger and the weaker) and then
reorganizing (if necessary) to achieve the following criteria.
The difference in PP between subjects of each group had to
be at least 10% (Table 1). All subjects had at least 12 months of
experience in strength training and were currently carrying out
strength training sessions at least 2 d$wk21. All subjects com-
pleted a health history questionnaire to document that they
were free of cardiovascular diseases, physiological disorders, or
any other illness that may have increased the risk of participa-
tion or introduced unwanted variability into the results. All
subjects were instructed to maintain their normal life habits.
Throughout the investigation, participants were requested to
maintain their regular diets and normal hydration state, not to
take any nutritional supplementation or anti-inflammatory
medications, and to refrain from caffeine intake in the 3 hours
before each testing session. Strength training sessions were not
allowed at least 72 hours before the experimental sessions.
Before participation, each subject provided written informed
consent approved by the Ethics Committee of the Miguel
Hernandez University of Elche in accordance with the Decla-
ration of Helsinki. All subjects were over 18 years old.
Testing
Maximal Dynamic Strength Assessment. The 1RM test for the
bench press was performed using a Smith machine (Multi-
power M953; Technogym, Gambettola, Italy). The 1RM
bench press was assessed using a previously established
protocol (8), which requires that subjects progressively
increase resistance across attempts until the 1RM is achieved.
The rest period between trials was at least 5 minutes. Subjects
began by lying horizontally with the feet, gluteus maximus,
lower back, upper back, and head firmly planted on the bench
with elbows fully extended and gripping the bar. Subjects
lowered the bar until it lightly touched the chest, approxi-
mately 3 cm above the xiphoid process. The elbows were
extended equally with the head, hips, and feet remaining in
contact with the floor throughout the lift. No bouncing or
arching of the back was allowed. Testing was conducted by
the same researcher and all conditions were standardized.
Power Output Measurements. Three minutes after a warm-up
consisting of 2 sets of 10 repetitions with the individual
participant using 50% of 1RM, subjects performed 5 sets of 8
repetitions with a load representing 40% of 1RM. Subjects
performed the experimental protocol in 3 sessions that
varied the RI between sets (1, 2, or 3 minutes). The order
of the sessions was randomized. Through each set, subjects
were encouraged to throw the barbell as high as possible,
and during each throw, they were required to keep their
head, shoulders, and trunk in contact with the bench and
Influence of Strength Level on Rest Interval
340 Journal of Strength and Conditioning Research
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their feet in contact with the floor. No bouncing of the
barbell was allowed. Kinematic data were recorded by
linking a rotary encoder to one end of the bar (T-Force
system, Ergotech, Spain), which recorded the position of the
bar with an analog-to-digital conversion rate of 1,000 Hz and
an accuracy of 0.0002 m. The linear transducer was interfaced
to a personal computer by means of a 14-bit analog-to-digital
data acquisition board, where a specialized software applica-
tion (T-Force Dynamic Measurement System) automatically
calculated the relevant kinematic and kinetic parameters. Bar
velocity was calculated by differentiation of bar displacement
data with respect to time; then, instantaneous acceleration (a)
was obtained through differentiation of velocity–time data.
Instantaneous force (F) was calculated as F = m (a + g), where
m is the moving mass (in kilograms) manually entered into
the software, and g is acceleration because of gravity. Finally,
instantaneous mechanical power output (P) was calculated as
the product of vertical force and bar velocity (P = F 3 V).
Peak power was taken as the maximum value of the power–
time curve. The validity and reliability of this system have
been previously established, with ICC values ranging from
0.81 to 0.91 and a coefficient of variation 3.6% (10). For the
data analysis, the following variables were calculated: PP in
each set, and PP of each repetition.
[La-] Measures. [La2] was determined from 25 ml capillary
blood samples drawn from the earlobe and analyzed with a por-
table device (Lactate Scout; Senselab, Leipzig, Germany), with
an accuracy of 0.1 mmol$L21 (37). Samples were taken 1 min-
ute before and after each protocol and analyzed at these time
points by the portable lactate analyzer. For statistical analysis,
the difference between prevalues and postvalues was used.
Perceptual Variables. The Borg category scale (CR-10) aimed
at determining the degree of heaviness and strain experi-
enced in physical work (35) and was used to determine the
subjects’ localized (upper body musculature) rating of per-
ceived exertion during exercise. The CR-10 scale was
defined by the following anchor points: “rest” (0) and “max-
imal (10).” Subjects were asked, “How hard do you feel the
exercise was?” immediately after the last set of each protocol.
Before participation, all perceived exertion scales were con-
scientiously explained and all subjects declared themselves to
be familiarized with the CR-10 scale.
Delayed onset muscular soreness was reported by the subjects
24 hours and 48 hours after each session. Subjects were asked,
“How painful do your muscles feel?”, giving their subjective
feeling on a 0–10 scale (0 = no pain; 10 = a lot of pain) (25).
All subjects reported no DOMS before all testing sessions.
TABLE 1. Descriptive data of each group.*
Age (y) Weight (kg) Height (m) 1RM (kg) 1RM/BM PP (W)
SM 25 6 6.5 78.8 6 6.8† 1.81 6 0.04 102 6 15† 1.27 6 0.15† 719 6 149†
WM 23.8 6 1.6 74.3 6 6.2 1.79 6 0.06 74 6 5 1.04 6 0.11 489 6 82
SF 22.3 6 5.3 66.7 6 9.8† 1.69 6 0.03† 47.5 6 3.2† 0.76 6 0.07† 286 6 58†
WF 22.4 6 2.6 59.8 6 4.1 1.64 6 0.05 39.1 6 2.9 0.66 6 0.06 175 6 22
*Data are shown as mean 6 SD.
†Significant difference between stronger and weaker group (p # 0.05).
Figure 1. Peak power output by set and RI in men for weaker (A) and stronger group (B). * = significant difference with the 3-minute RI; # = significant
difference with the 2-minute RI (p # 0.05).
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Statistical Analyses
All data were analyzed using the statistical package SPSS
18.0 (SPSS Inc., Chicago, IL, USA). The normality of the
outcome measures was tested using the Kolmogorov–
Smirnov test. In each male and female strength level
group (stronger and weaker), a single-way ANOVA was
used to evaluate the physiological ([La2]) and perceptual
(RPE and DOMS) variables with each RI, whereas
a repeated measures ANOVA was used to evaluate inter-
set and intraset mechanical (PP) data. Statistical signifi-
cance was set at p # 0.05. In addition, to better evaluate
the treatment effect (different strength levels and RIs),
Cohen’s d and the standardized mean difference were
used to calculate effect sizes (ES; mean difference/pooled
SD) and interpreted for a recreationally trained sample (sub-
jects with strength training experience ranging from 1 to 5
years) according to Rhea (28), as d , 0.35 (trivial), 0.35–0.80
(small), 0.80–1.50 (moderate), and 1.5 (large) aiming at deter-
mining the relative magnitude of the ES calculated.
RESULTS
Peak Power Output
Peak power datafor each RI in each group are showed in
Figure 1 (WM and SM groups) and 2 (WF and SF groups).
In men, when comparing the values between RIs, the WM
group showed lower PP values with the 1-minute RI in the
second (p = 0.015, d = 0.37; p = 0.007, d = 0.59), third (p =
0.007, d = 0.45; p = 0.007, d = 0.75), fourth (p = 0.019, d = 0.49;
p = 0.01, d = 0.88), and fifth (p = 0.013, d = 0.65; p = 0.013, d =
1.03) set than the 2-minute and 3-minute RI, respectively. In
addition, when using 2-minute RI, PP values were significantly
lower than with the 3-minute RI in the second (p = 0.005, d =
0.23) and third (p = 0.028, d = 0.33) set. Similarly, the SM
group showed lower PP values with the 1-minute RI in the
second set (p = 0.026, d = 0.43) than the 3-minute RI, and in
the third (p = 0.022, d = 0.46; p = 0.022, d = 0.47), and fourth
(p = 0.004, d = 0.66; p = 0.002, d = 0.65) set than the 2-minute
and 3-minute RI respectively, whereas no differences were
found between the 2- and 3-minute RI.
In women, the WF group
showed lower PP values in the
second (p = 0.005, d = 0.37),
third (p = 0.019, d = 0.54), fourth
(p = 0.003, d = 0.83), and fifth
(p = 0.002, d = 1.08) set when
comparing the 1-minute RI with
the 3-minute RI. In the SF
group, only the fifth set (p =
0.017, d = 0.69) showed lower
PP values when comparing the
1-minute RI with the 3-minute
RI (Figure 2).
When comparing PP values
over the sets within groups,
with the 1-minute RI, the SM
group showed lower PP output
(p = 0.005, d = 0.35; p = 0.005,
d = 0.51; p = 0.004, d = 0.74;
Figure 2. Peak power output by set and RI in women for weaker (A) and stronger group (B). * = significant difference with the 3-minute RI; # = significant
difference with the 2-minute RI (p # 0.05).
TABLE 2. Data of peak power (W) by group in each set and RI in men.*
Set 1 Set 2 Set 3 Set 4 Set 5
1 min
SM 716 6 135 669 6 133† 648 6 135† 620 6 123† 631 6 156†
WM 488 6 79 456 6 81† 428 6 82† 400 6 79† 380 6 78†
2 min
SM 724 6 137 710 6 136 712 6 145 702 6 125 695 6 132
WM 501 6 74 486 6 79 464 6 78† 441 6 87† 430 6 76†
3 min
SM 739 6 151 731 6 156 715 6 157 708 6 148 702 6 137
WM 511 6 80 505 6 85 491 6 85 471 6 83 466 6 89
*RI = rest interval; SM = stronger males; WM = weaker males.
†Significant difference with the first set (p . 0.05).
Influence of Strength Level on Rest Interval
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p = 0.004, d = 0.58) in the second, third, fourth, and fifth set,
respectively, compared with the first set. Nevertheless, when
using both 2-minute and 3-minute RIs, the SM group did not
show significant differences over the 5 sets. In the WM
group, compared with the first set, PP values were significant
lower in the second set (p = 0.035, d = 0.4) in the 1-minute
RI, and in the third (p = 0.009, d = 0.75; p = 0.001, d = 0.47),
fourth (p = 0.001, d = 1.11; p = 0.005, d = 0.73), and fifth (p =
0.001, d = 1.38; p = 0.001, d = 0.93) set in both the 1-minute
and 2 minute RI, whereas no significant differences were
found with the 3-minute RI (Table 2).
In women, when comparing PP values over the sets within
groups (Table 3), with the 1-minute RI, the SF group showed
lower PP output (p = 0.043, d = 0.24; p = 0.035, d = 0.6) in
the second and fifth set, respectively, compared with the first
set. When using both the 2-minute and 3-minute RI, no
differences were found over the sets. In the WF group,
compared with the first set, when using the 1-minute RI,
PP values were significantly lower in the second (p =
0.003, d = 0.47), third (p = 0.017, d = 0.78), fourth (p =
0.006, d = 1.23), and fifth (p =
0.003, d = 1.49) set. In addition,
when using the 2-minute and 3-
minute RI, significantly lower
PP values were found in the
fourth (p = 0.034, d = 0.54;
p = 0.03, d = 0.51) and fifth
(p = 0.016, d = 0.73; p = 0.043,
d = 0.63) set compared with the
first set.
Intraset PP
When comparing the same rep-
etition over the sets when using
the 1-minute RI, all groups
showed significant differences in
the 8 repetitions, independently
of the group. Thus, ES ranged
from 0.38 (p # 0.05) to 1.56 (p , 0.01) (WM), from 0.19 (p #
0.05) to 0.83 (p, 0.01) (SM), from 0.28 (p# 0.05) to 1.75 (p,
0.01) (WF), and from 0.4 (p # 0.05) to 1.03 (p , 0.01) (SF).
Comparisons in PP by repetition over the sets with the
2-minute RI are shown in Figure 3 (WM and SM groups)
and Figure 4 (WF and SF groups). Both WM and WF
groups showed significant decreases in PP commencing
from the first repetition, whereas these decreases were only
significant commencing from the sixth (SM group) and the
fifth repetition (SF group). Moreover, ES were considerably
greater in both weaker groups, ranging from 0.27 (p# 0.05) to
1.18 (p , 0.01) (WM) and 0.23 (p # 0.05) to 0.95 (p , 0.01)
(WF), whereas for the stronger groups they ranged from 0.18
to 0.35 (p # 0.05) (SM) and from 0.26 to 0.39 (p # 0.05) (SF).
When the 3-minute RI was used, the WM group showed
significant PP decreases commencing from the second
repetition, whereas these decreases commenced from the
first repetition in the WF group. ES values ranged from 0.37
(p # 0.05) to 0.7 (p , 0.01) in the WM group and from 0.25
(p # 0.05) to 0.75 (p , 0.01) in the WF group. Contrarily,
TABLE 3. Data of peak power (W) by group in each set and RI in women.*
Set 1 Set 2 Set 3 Set 4 Set 5
1 min
SF 318 6 49 306 6 53† 306 6 53 300 6 55 286 6 58†
WF 211 6 26 199 6 25† 193 6 20† 182 6 21† 175 6 22†
2 min
SF 336 6 75 333 6 76 320 6 75 318 6 77 311 6 86
WF 209 6 28 206 6 26 200 6 25 195 6 24† 190 6 24†
3 min
SF 320 6 52 325 6 52 330 6 63 327 6 62 328 6 64
WF 210 6 23 208 6 23 204 6 21 199 6 20† 197 6 18†
*RI = rest interval; SF = stronger females; WF = weaker females.
†Significant difference with the first set (p # 0.05).
Figure 3. Intraset PP with the 2-minute RI in the WM group (left) and SM group (right). *Significant difference with the first set (p # 0.05).
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the SF group did not show any differences in PP output
independently of the repetition analyzed, whereas the SM
group only showed slight PP decreases in the second repe-
tition and in the last repetitions of the set, with trivial ES
(d = 0.14–0.34; p # 0.05).
Physiological and Perceptual Variables
Data of physiological and perceptual variables are shown in
Table 4. No difference between groups (stronger vs. weaker)
was found in any variable in the men. Nevertheless, the WF
group showed significantly greater [La2] increase in both the
2-minute RI (d = 1.17; p, 0.01) and the 3-minute RI (d = 1.8;
p , 0.01) compared with SF group. In addition, the WF
group experienced greater DOMS48h after the 3-minute RI
(d = 1.07; p , 0.01) compared with the SF group. When
comparing the influence of the different RIs within the same
group, greater [La2] were found with the 1-minute RI com-
pared with both the 2-minute (d = 0.99 SM; 1.48 SF; 1.37
WF; p , 0.01) and the 3-minute RI (d = 1.39 SM; 1.72 WM;
1.73 SF; 1.77 WF; p , 0.01). Furthermore, [La2] was also
higher in the WM group when comparing the 2-minute RI
with the 3-minute RI (d = 1.11; p , 0.01). RPE values were
significantly higher in the SM, WM, and WF groups between
1-minute and 3-minute RI protocols (d = 1.03, 1.02 and 0.81,
respectively; p , 0.01) and in both SM and WM groups
between the 1-minute and the 2-minute RI (d = 0.62 and
0.8, respectively). For DOMS 24 hours, only the WM group
showed greater values when comparing the 1-minute RI with
the 3-minute RI, and the 2-min-
ute RI with the 3-minute RI in
the SF group (d = 1.0; p ,
0.01). Finally, only the WM
group showed significantly
greater values of DOMS 48
hours when comparing the 1-
minute RI with the 3-minute
RI (d = 0.9; p , 0.01).
DISCUSSIONThe primary finding of this
study was that subjects’
strength level highly influences
the rest interval required to
sustain power output produc-
tion. This was shown by the
ability of both the male and
the female stronger groups to
maintain peak power output
over the sets when using both
the 2-minute and the 3-minute
RI, whereas weaker male and
female groups needed at least
Figure 4. Intraset PP with the 2-minute RI in the WF group (left) and SF group (right). *Significant difference with the first set (p # 0.05).
TABLE 4. Physiological and perceptual variables by group and RI.
[La2] increase
(mmol$L21) RPE (0–10) DOMS 24 h DOMS 48 h
1 min
SM 2.4 6 1*† 5.6 6 1.5*† 2.4 6 1.7 1.4 6 1.1
WM 2.6 6 0.9† 6.6 6 1.6*† 2.9 6 2† 2 6 1.6†
SF 2 6 1.3*† 5.9 6 2 2.7 6 2 1.3 6 1.5
WF 1.9 6 0.4*† 4.7 6 1.4† 2 6 1.7 0.9 6 1
2 min
SM 1.5 6 0.8 4.6 6 1.7 2 6 1.6 1 6 0.9
WM 2.1 6 0.8† 5.4 6 1.4 3.5 6 2.6 2.4 6 2.8
SF 0.5 6 0.6 5.2 6 2 3 6 1.7† 1.2 6 1.5
WF 1.2 6 0.6z 4.3 6 2 2 6 1.3 1 6 1
3 min
SM 1.2 6 0.7 4 6 1.6 1.4 6 0.9 0.4 6 0.5
WM 1.4 6 0.4 5 6 1.5 1.6 6 1.9 0.8 6 1
SF 0.3 6 0.5 4.2 6 1.7 1.6 6 1 0.2 6 0.4
WF 1 6 0.6z 3.6 6 1.3 1.5 6 1.4 0.9 6 0.8z
*Significant difference with the 2-minute RI.
†Significant difference with the 3-minute RI (p # 0.05).
zSignificant difference between stronger and weaker group.
Influence of Strength Level on Rest Interval
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a 3-minute RI to maintain it. In addition, physiological var-
iables ([La2]) also showed greater values when comparing
weaker and stronger groups (although only in women). Nev-
ertheless, perceptual variables (RPE and DOMS) seemed to
be a less sensitive tool for strength level comparisons in the
protocol (and sample) used in the current study, as it only
showed clear differences between the 1-minute RI and both
the 2-minute and the 3-minute RI, independently of subjects’
strength level.
Despite a couple of studies showing that 1-minute RI did
not entail PP production impairments (20,23), the results of
the present study agree with several authors who showed
significant performance reductions when short (1 minute)
RIs were used (1,34,39). Thus, over the sets, significant PP
output decreases were found with the 1-minute RI indepen-
dently of the strength level and gender analyzed, commenc-
ing from the second set in all groups. However, when using
longer (2 minutes and 3 minutes) RIs, the results differ de-
pending on strength level, as the stronger male (SM) group
did not show PP decreases, whereas the weaker male (WM)
group showed decreases commencing from the third set
(2 minutes RI) (Table 2). Similarly, the weaker female
(WF) group also showed significant PP decreases commenc-
ing from the fourth set (with both the 2-minute and
3-minute RI), whereas the stronger female (SF) group
showed significant decreases commencing from the second
set (1-minute RI), but did not show impairments when using
the 2-minute RI (Table 3). Therefore, stronger subjects
seemed to have a superior ability to recover and repeat
power output performance, which may be hypothetically
explained by an optimized neuromuscular behavior such as
enhanced motor unit recruitment and intermuscular coordi-
nation (6,31). Even so, other neuromuscular mechanisms
such as changes in neural functions (e.g., muscle coactiva-
tion) may also be responsible for the impairments found
when short (1 minute) RIs were used (24,32). Analysis of
intraset PP is of great importance when comparing stronger
and weaker groups. For instance, when the same repetition
of each set was compared over the sets, both WM and WF
groups showed significant PP decreases even from the first
and second repetition (and commencing from the second
and third set), even while using the 3-minute RI. Neverthe-
less, these PP decreases were found much later (i.e., fifth
repetition in the SF group and sixth repetition in the SM
group) when using the 2-minute RI. Furthermore, no differ-
ences were found between any repetitions over the sets
when the SF group rested for 3 minutes. Previous studies
revealed that PP decrements within a set increase as the
number of performed repetitions in a set approaches the
maximum predicted number (16,33) although these studies
showed much greater values of performance decreases,
probably due to the lighter load (40% of 1RM) used in the
current study.
Strength level seems to play a role in lactate responses, at
least in women, because the WF group showed greater
[La2] increases compared with the SF group when using
2-minute and 3-minute RIs (Table 4). From a physiological
perspective, the greater decreases found in PP output with
the 1-minute RI compared with both 2-minute and 3-minute
RI were accompanied by significantly greater [La2] in-
creases in all groups, these results being in line with those
showed by Abdessemed et al. (1) and reflecting a greater
contribution of the glycolytic system as a source of energy
production. The use of rating of perceived exertion scales
has been described previously as a sensitive tool to control
the intensity of training sessions (29). Thus, RPE values were
significantly higher in the SM, WM, and WF groups when
the 1-minute RI was used compared with the 3-minute RI,
and compared with the 2-minute RI in both SM and WM
groups. These results are in line with Scudese et al. (34) who
showed greater RPE values when using 1-minute RI in
comparison with 3-minute RI. Nevertheless, no differences
between stronger and weaker groups were found with the 3
different RIs used in the current study, neither in DOMS24h
or DOMS48h (with the exception of greater DOMS48h after
the 3-minute RI in WF). Consequently, in spite of the sensi-
tivity of these tools in measuring the intensity of training
sessions, it seems that strength levels do not highly influence
subjects’ perceptual responses when practitioners of recrea-
tional/intermediate strength levels performed a bench press
throw power training session (5 3 8 at 40% of 1RM). It
should be tested if these kinds of perceived scales could show
differences between groups of broader strength levels (e.g.,
novice vs. elite athletes).
The current study presents some limitations including
both the lack of direct measures of central/neural fatigue
(i.e., electromyography) and the lack of hormonal response
measurements that could provide additional information.
Furthermore, the effect of different strength/power levels on
the RI required should be further investigated with different
ranges of loads and in different and more complex exercises
(e.g., weightlifting/power movements).
PRACTICAL APPLICATIONS
The results of the present study highlight the influence of
subjects’ strength level on the ability to maintain power out-
put production during a session of bench press throw exer-
cise with a power load. Thus, scientists and coaches should
take into account athletes’ strength level when designing
research experiments or when programming power training
sessions, as a 2-minute RI could be enough to maintain
power output over 5 sets in the stronger population, whereas
with the weaker population, even when using the long (3 mi-
nutes) RI, significant power decreases can be expected after
the third set. Nevertheless, these considerations should be
investigated in other exercises (e.g., lower body, weightlifting
movements) and populations (e.g., elderly).
ACKNOWLEDGMENTS
No funding was received to carry out this study.
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