title: Effect of Change in VO2max on Daily Total Energy Expenditure in a Cohort of Norwegian Men: A Randomized Pilot Study.
abstract: OBJECTIVE
  To investigate how a change in VO2max induced through 6 weeks of high intensity aerobic interval training affects daily total energy expenditure (TEE), active energy expenditure (AEE) and mitochondrial function in people not previously exposed to structured high intensity aerobic interval training (AIT).
  
  
  METHODS
  Thirty healthy males (39±6 yrs) not exposed to structured exercise training were randomized to either 1x4 min AIT (1-AIT), 4x4 min AIT (4-AIT), both at 90-95% maximum heart rate (HRmax) or 47 min of MCT at 70% HRmax. TEE, AEE, number of steps, active time, sedentary time, VO2max and mitochondrial function in m. vastus lateralis were measured before and after intervention.
  
  
  RESULTS
  TEE increased 14% (p=0.014) and AEE increased 43% (p= 0.004) after MCT. There was no change in TEE or AEE after 1-AIT or 4-AIT, but 1-AIT had significantly lower TEE (p=0.033) and step-count (p=0.011) compared to MCT post intervention. VO2max increased 7% after 1-AIT (p= 0.004) and 9% after 4-AIT (p=0.004), with no change after MCT. No change was observed in maximal mitochondrial respiration (VMAX) or Citrate Synthase (CS) activity within or between interventions. Basal respiration (V0) increased after 1-AIT (p=0.029) and 4-AIT (p=0.022), with no significant change after MCT.
  
  
  CONCLUSIONS
  AIT interventions that increase VO2max, do not stimulate subjects to increase TEE or AEE. The intensity of exercise seems to play apart, as MCT increased TEE and AEE and AIT did not. Emphasis should be placed on the importance of maintaining everyday activities when introducing structured exercise training to untrained individuals.
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Nina
authors.initials: N
authors.lastname: Zisko
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. ; Central Norway Regional Health Authority P.o.box 464, N-7501 Stjørdal.
authors.forename: Dorthe
authors.initials: D
authors.lastname: Stensvold
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. ; Central Norway Regional Health Authority P.o.box 464, N-7501 Stjørdal.
authors.forename: Katrine
authors.initials: K
authors.lastname: Hordnes-Slagsvold
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Øivind
authors.initials: Ø
authors.lastname: Rognmo
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Javaid
authors.initials: J
authors.lastname: Nauman
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway.
authors.forename: Ulrik
authors.initials: U
authors.lastname: Wisløff
authors.affiliation: K.G. Jebsen - Center for Exercise in Medicine at the Department of Circulation and Medical Imaging, Norwegian University of Science and Technology, Trondheim, Norway. ; Central Norway Regional Health Authority P.o.box 464, N-7501 Stjørdal.
authors.forename: Trine
authors.initials: T
authors.lastname: Karlsen
keywords: VO2max; daily energy expenditure; high intensity training; mitochondria