457
Pediatric Exercise Science, 2008, 20, 457-469
' 2008 Human Kinetics, Inc.
Effect of Rest Interval Length on
Bench Press Performance in Boys,
Teens, and Men
Avery D. Faigenbaum, Nicholas A. Ratamess, Jim McFarland,
Jon Kaczmarek, Michael J. Coraggio, Jie Kang, and
Jay R. Hoffman
The purpose of this study was to assess the lifting performance of boys (N = 12; age
11.3 ± 0.8 yr), teens (N = 13; age 13.6 ± 0.6 yr), and men (N = 17; age 21.4 ± 2.1 yr)
to various rest interval (RI) lengths on the bench press exercise. Each subject per-
formed 3 sets with a 10 repetition maximum load and a 1, 2, and 3 min RI between
sets. Signicant differences in lifting performance between age groups were observed
within each RI for selected sets with boys and teens performing signicantly more
total repetitions than adults following protocols with 1 min (27.9 ± 3.1, 26.9 ± 3.9,
and 18.2 ± 4.1, respectively), 2 min (29.6 ± 1.0, 27.8 ± 3.5, and 21.4 ± 4.1, respec-
tively) and 3 min (30.0 ± 0.0, 28.8 ± 2.4, and 23.9 ± 5.3, respectively) RIs. Signicant
differences in average velocity and average power between age groups were also
observed. These ndings indicate that boys and teens are better able to maintain
muscle performance during intermittent moderate-intensity resistance exercise as
compared with men.
Resistance training (RT) has been shown to be a safe and effective method for
enhancing muscle strength, power, and endurance in children, adolescents, and
adults (5,10). However, the act of RT itself does not ensure optimal gains in per-
formance will occur. Rather, the systematic structuring of program variables (e.g.,
intensity, volume) along with individual effort and qualied instruction will deter-
mine the outcomes associated with RT. In addition, the length of the rest interval
(RI) in between sets and exercises is of primary importance to coaches, teachers,
athletes, and researchers (36). In adults, the RI between sets has been shown to
affect performance of subsequent sets (21,37), strength improvements (32), and
metabolic and hormonal responses to an acute bout of resistance exercise (17,25).
We have shown a continuum of responses where bench press performance was
reduced in adults in proportion to reductions in RIs between sets (25). Since acute
force and power production may be compromised with short RIs, longer RIs of at
Faigenbaum, Ratamess, Kaczmarek, Kang, and Hoffman are with the Dept. of Health and Exercise
Science, The College of New Jersey, Ewing, NJ. McFarland is with the Dept. of Physical Education,
Hillsborough High School, Hillsborough, NJ. Coraggio is with Hunterdon Pediatric Associates,
Clinton, NJ.

458 Faigenbaum et al.
least 2–3 min for core, multiple-joint exercises are recommended during adult
resistance training programs (15,18).
However, RT recommendations for adults may not be consistent with the
needs and abilities of younger populations. Studies have shown faster recovery
rates from exercise in children than adults (9,27). It has been reported that chil-
dren (compared with adults) have a faster heart rate recovery (13), lower peak
lactate concentrations (11,26), higher oxidative capacity (35), better acid-base
regulation (28), and a tendency toward faster phosphocreatine (PCr) resynthesis
(19,35) following high-intensity exercise. Recently, Zafeiridis and colleagues (40)
showed that recovery following high-intensity 30- and 60-s isokinetic exercise
was faster in boys than in teens and men. Indeed, performance and physiological
functions appear to recover faster in children than in teens and adults following
high-intensity exercise.
Despite these observations, the effects of age and recovery duration on
strength performance in children and teenagers are poorly understood. Most stud-
ies quantifying age-related differences in muscle fatigue have used high-intensity
cycle ergometry (3,11,13,26); only two studies examined resistance exercise
(33,40); and no studies have used RT protocols consistent with current recom-
mendations for children and teens. Because recovery from high-intensity cycle
ergometry or isokinetic exercise may differ from resistance exercise, further
research is needed to quantify strength performance to RI manipulations in chil-
dren, teenagers and adults. Given the acceptance of youth RT by medical and t-
ness organizations (1,2,6), this information is valuable to teachers, coaches, and
health professionals who design and implement youth RT programs.
Therefore, the purpose of this investigation was to quantify bench press per-
formances of boys, teens, and men to various RI lengths. In addition, there is a
paucity of data examining RI effects on kinetic and kinematic proles of a resis-
tance exercise set on a repetition-by-repetition basis. Thus, a secondary purpose
was to investigate the effects of RI length on kinetic and kinematic parameters
(power, velocity) in boys, teens, and men. Due to growth- and maturation-related
differences in response to physical exertion, it was hypothesized that boys and
teens would recover faster than adults from multiset resistance exercise with dif-
ferent RIs.
Methods
Participants
Twelve boys (11.3 ± 0.8 yr), 13 teens (13.6 ± 0.6 yr), and 17 men (21.4 ± 2.1 yr)
volunteered to participate in this study. All participants were healthy and had RT
experience as part of physical education classes, sports conditioning, after-school
programs, or recreational tness workouts. Most participants participated regu-
larly (at least 2–3/week) in basketball, baseball, or soccer. Participant descrip-
tive characteristics are shown in Table 1. All adults and parents of the boys and
teens completed a medical history questionnaire. The exclusionary criteria used
were: (a) subjects with a chronic cardiac, respiratory, renal, or metabolic disease
and (b) subjects with an orthopedic limitation. No participant was taking any med-