Eur J Appl Physiol (2007) 100:1–17
DOI 10.1007/s00421-007-0394-yORIGINAL ARTICLE
The eVect of rest interval length on metabolic responses
to the bench press exercise
Nicholas A. Ratamess · Michael J. Falvo ·
Gerald T. Mangine · Jay R. HoVman ·
Avery D. Faigenbaum · Jie Kang
Accepted: 23 December 2006 / Published online: 20 January 2007
 Springer-Verlag 2007
Abstract The purpose of this study was to examine
the eVects of diVerent rest interval (RI) lengths on met-
abolic responses to the bench press. Eight resistance-
trained men performed 10 randomized protocols [Wve
sets of bench press with 75 or 85% of 1RM for ten
(10REP) and Wve repetitions (5REP), respectively,
using diVerent RI (30 s, 1, 2, 3, 5 min)]. Oxygen con-
sumption (VO
2
) was measured during exercise and for
30 min post exercise. For 30-s and 1-min RI: reductions
(15–55%) in resistance and volume were observed (set
5 < 4 < 3 < 2 < 1). For 2-min RI: performance was
maintained during the Wrst two sets but was reduced by
8–29% during sets 3–5. For 3-min RI: a reduction was
observed in volume where sets 4 and 5 were lower than
sets 1–3 (»21%). For 5-min RI: only a reduction in set
5 was observed. Mean VO
2
and ventilation (V
E
) were
progressively higher as RI length was shortened. VO
2
area under the curve indicated 10REP > 5REP for all
RI except 1-min. Respiratory exchange ratio (RER)
was elevated similarly for each protocol. Post exercise,
VO
2
, V
E
, and RER were elevated through 30 min. No
diVerences between RI were observed following
10REP; however, VO
2
after 30-s was higher than 2-, 3-,
and 5-min and 1-min was higher than 5-min during
5REP. Fatigue rate was correlated (r = 0.30–0.49) to all
metabolic variables. A continuum of performance
reductions and metabolic responses were observed.
The largest reductions in performance occurred with
very short RI (<1 min), and performance was main-
tained during the Wrst 3–4 sets when 3- and 5-min RI
were used.
Keywords Bench press · Strength training · Oxygen
consumption · Respiratory exchange ratio · EPOC
Introduction
The length of the rest intervals (RI) used during resis-
tance training is a variable of primary importance to
the researcher, athlete, coach, Wtness trainer, and/or
practitioner. RI length depends on the training inten-
sity, as well as an individual’s training goals, Wtness
level, and the energy system targeted for response. The
RI between sets and exercises has been shown to aVect
the metabolic (Haltom et al. 1999; Kraemer et al. 1987)
and hormonal (Kraemer et al. 1990, 1991) responses to
an acute bout of resistance exercise, as well as perfor-
mance of subsequent sets (Kraemer 1997) and muscu-
lar strength improvements (Pincivero et al. 1997;
Robinson et al. 1995). A few studies have shown that
during sets performed at near or to muscular exhaus-
tion, repetition number and total work decrease with
each set in succession when 1–2 min RI are used (Rich-
mond and Godard 2004; Willardson and Burkett 2005,
2006b). In addition, the acute reduction in resistance
exercise volume observed with short RI results in a
slower rate of strength gains compared to longer RI
(Pincivero et al. 1997; Robinson et al. 1995). Because
acute force and power production may be compro-
mised with short RI, the American College of Sports
Medicine (ACSM) has recommended longer RI for
core exercises during intermediate and advanced
strength training (ACSM 2002).
N. A. Ratamess (&) · M. J. Falvo · G. T. Mangine ·
J. R. HoVman · A. D. Faigenbaum · J. Kang
Department of Health and Exercise Science,
The College of New Jersey, Ewing, NJ 08628, USA
e-mail: ratamess@tcnj.edu123

2 Eur J Appl Physiol (2007) 100:1–17The acute metabolic demands of resistance exercise
have been investigated (Collins et al. 1989). Collec-
tively, these studies have shown signiWcantly larger ele-
vations in oxygen consumption and energy expenditure
for large versus small muscle mass exercises (Kalb
et al. 1991; Scala et al. 1987), slow-to-moderate versus
fast (Ballor et al. 1987) and super-slow (Hunter et al.
2003) lifting velocities, high (80–90% of 1RM), > mod-
erate (60–70% of 1RM), > low intensity (20–50% of
1RM) (Collins et al. 1989; Hunter et al. 1988; Wil-
loughby et al. 1991), and high (multiple sets) versus
low volume (single sets) (Haddock and Wilkin 2006).
However, the acute metabolic responses to manipula-
tion of RI length are not well understood. A few stud-
ies have compared traditional resistance exercise to
circuit weight training (Elliot et al. 1992) and 20 versus
60-s RI during circuit weight training (Haltom et al.
1999) and reported that short RI elicited a substantial
acute and post-exercise metabolic response. However,
these studies examined relatively short RI lengths and
RI during resistance training span a wide continuum
depending on the training goals. Thus, the metabolic
responses to resistance exercise using a wide range of
RI lengths have not been adequately addressed. Con-
sidering that the acute metabolic responses to resis-
tance exercise have important ramiWcations for
eliciting changes in body composition, further research
is warranted quantifying the metabolic response to RI
manipulation. In addition, most studies quantifying the
metabolic responses to resistance exercise have only
reported a mean exercise value (Byrd et al. 1988; Scala
et al. 1987) or the immediate post-exercise value (Kang
et al. 2005); only one study has provided data obtained
during »30% of the total sets completed (Haltom et al.
1999); and none have quantiWed the acute metabolic
responses during each RI within the protocol. There-
fore, the purpose of the present investigation was to
thoroughly examine and quantify the acute metabolic
responses and subsequent lifting performances of the
bench press exercise to various RI lengths (e.g., 30 s, 1,
2, 3, 5 min). In addition, the acute metabolic responses
to two protocols of diVerent intensity/volume (e.g., 75
vs. 85% of one-repetition maximum, 1RM) were exam-
ined and quantiWed.
Methods
Experimental design and approach to the problem
In order to examine the primary hypotheses of the
present investigation, a within-group study design was
used. All subjects performed a bench press protocol in
two blocks each consisting of Wve sessions. Each block
consisted of performing the bench press protocols (Wve
sets) with either 75% of 1RM for ten repetitions or
85% of 1RM for Wve repetitions; and within each block
various RI lengths were investigated (e.g., 30 s, 1, 2, 3,
5 min). The intensities of 75 and 85% of 1RM were
selected because they are quite commonly used in
many resistance training programs and correspond
nearly to 10 and 5 RM, respectively, for the bench
press (Kraemer and Ratamess 2004). This study design
enabled us to directly compare the acute metabolic and
performance responses to an upper-body exercise
using Wve RI lengths of diVerent duration, in addition
to examining an interaction between RI length and
intensity/volume. Because the intent of the study was
to thoroughly quantify the metabolic responses of each
protocol, only one upper-body exercise was selected.
Blood lactate, heart rate, absolute and relative oxygen
consumption (VO
2
), respiratory exchange ratio
(RER), and ventilation (V
E
) were measured to quan-
tify the metabolic responses to each protocol and for
30 min post exercise.
Subjects
Eight healthy, resistance-trained (minimum 3 years of
experience with the bench press exercise) men were
selected for the present investigation. The subject
(N = 8) characteristics were: age = 21.4 § 2.4 years;
height = 178.9 § 7.7 cm; body mass = 92.8 § 25.9 kg;
resistance training experience = 6.6 § 3.3 years; 1RM
bench press = 126.7 § 31.4 kg; and percent body
fat = 12.2 § 4.5%. Each subject initiated the study in a
trained state, and none were taking any medications,
anabolic steroids, or nutritional supplements known to
aVect energy metabolism or resistance exercise perfor-
mance. This study was approved by The College of
New Jersey’s Institutional Review Board and each sub-
ject subsequently signed a written informed consent
document prior to participation. In addition, no subject
had any physiological or orthopedic limitations that
could have aVected lifting performance as determined
by completion of a health history questionnaire prior
to initiating the study.
Strength testing
One-repetition maximum (1RM) bench press was
assessed prior to initiation of the study using a standard
protocol (Kraemer et al. 2006). A warm-up set of Wve
to ten repetitions was performed using 40–60% of the
perceived 1RM. After a 1-min RI, a set of two to three
repetitions was performed at 60–80% of the perceived123