title: The effect of rest interval length on metabolic responses to the bench press exercise.
abstract: The purpose of this study was to examine the effects of different rest interval (RI) lengths on metabolic responses to the bench press. Eight resistance-trained men performed 10 randomized protocols [five sets of bench press with 75 or 85% of 1RM for ten (10REP) and five repetitions (5REP), respectively, using different RI (30 s, 1, 2, 3, 5 min)]. Oxygen consumption (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 first 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 ( approximately 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 differences 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 maintained during the first 3-4 sets when 3- and 5-min RI were used.
authors.affiliation: Department of Health and Exercise Science, The College of New Jersey, Ewing, NJ, 08628, USA. ratamess@tcnj.edu
authors.forename: Nicholas A
authors.initials: NA
authors.lastname: Ratamess
authors.forename: Michael J
authors.initials: MJ
authors.lastname: Falvo
authors.forename: Gerald T
authors.initials: GT
authors.lastname: Mangine
authors.forename: Jay R
authors.initials: JR
authors.lastname: Hoffman
authors.forename: Avery D
authors.initials: AD
authors.lastname: Faigenbaum
authors.forename: Jie
authors.initials: J
authors.lastname: Kang
mesh_terms: D000328:Adult; D004734:Energy Metabolism / Q000502:physiology*; D015444:Exercise / Q000502:physiology*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D019344:Lactic Acid / Q000097:blood; D008297:Male; D018763:Muscle Fatigue / Q000502:physiology; D010101:Oxygen Consumption / Q000502:physiology; D010809:Physical Fitness / Q000502:physiology; D015656:Respiratory Mechanics / Q000502:physiology; D012146:Rest / Q000502:physiology*; D014891:Weight Lifting / Q000502:physiology*
chemical_list: D019344:Lactic Acid