title: Cardiorespiratory fitness level correlates inversely with excess post-exercise oxygen consumption after aerobic-type interval training.
abstract: BACKGROUND
  The purpose of this study was to reveal any association between cardiorespiratory fitness level and excess post-exercise oxygen consumption (EPOC) using three cycling protocols with varying degrees of exercise intensity, i.e., sprint interval training (SIT), high-intensity interval aerobic training (HIAT), and continuous aerobic training (CAT).
  
  
  RESULTS
  Ten healthy men, aged 20 to 31 years, attended a cross-over experiment and completed three exercise sessions: SIT consisting of 7 sets of 30-s cycling at 120% VO2max with a 15-s rest between sets; HIAT consisting of 3 sets of 3-min cycling at 80~90% VO2max with a 2-min active rest at 50% VO2max between sets; and CAT consisting of 40 min of cycling at 60~65% VO2max. During each session, resting VO2, exercise VO2, and a 180-min post-exercise VO2 were measured. The net exercise VO2 during the SIT, HIAT, and CAT averaged 14.7 ± 1.5, 31.8 ± 4.1, and 71.1 ± 10.0 L, and the EPOCs averaged 6.8 ± 4.0, 4.5 ± 3.3, and 2.9 ± 2.8 L, respectively. The EPOC with SIT was greater than with CAT (P < 0.01) and HIAT (P = 0.12). Correlation coefficients obtained between subjects' VO2max and the ratio of EPOC to net exercise VO2 for SIT, HIAT, and CAT were -0.61 (P = 0.06), -0.79 (P < 0.01), and -0.42 (P = 0.23), respectively.
  
  
  CONCLUSIONS
  Our data suggest that cardiorespiratory fitness level correlates negatively with the magnitude of EPOC, especially when performing aerobic-type interval training.
authors.affiliation: Space Biomedical Research Office, Japan Aerospace Exploration Agency (JAXA), 2-1-1, Sengen, Tsukuba, Ibaraki 305-8505, Japan. matsuo.tomoaki@jaxa.jp
authors.forename: Tomoaki
authors.initials: T
authors.lastname: Matsuo
authors.forename: Kazunori
authors.initials: K
authors.lastname: Ohkawara
authors.forename: Satoshi
authors.initials: S
authors.lastname: Seino
authors.forename: Nobutake
authors.initials: N
authors.lastname: Shimojo
authors.forename: Shin
authors.initials: S
authors.lastname: Yamada
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohshima
authors.forename: Kiyoji
authors.initials: K
authors.lastname: Tanaka
authors.forename: Chiaki
authors.initials: C
authors.lastname: Mukai
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D001642:Bicycling; D018592:Cross-Over Studies; D004734:Energy Metabolism; D015444:Exercise; D005080:Exercise Test; D006801:Humans; D007564:Japan; D008297:Male; D009119:Muscle Contraction; D018482:Muscle, Skeletal / Q000502:physiology*; D010101:Oxygen Consumption; D010809:Physical Fitness; D013997:Time Factors; D055815:Young Adult