title: Aerobic high-intensity intervals improve VO2max more than moderate training.
abstract: OBJECTIVE
  The present study compared the effects of aerobic endurance training at different intensities and with different methods matched for total work and frequency. Responses in maximal oxygen uptake (VO2max), stroke volume of the heart (SV), blood volume, lactate threshold (LT), and running economy (CR) were examined.
  
  
  METHODS
  Forty healthy, nonsmoking, moderately trained male subjects were randomly assigned to one of four groups:1) long slow distance (70% maximal heart rate; HRmax); 2)lactate threshold (85% HRmax); 3) 15/15 interval running (15 s of running at 90-95% HRmax followed by 15 s of active resting at 70% HRmax); and 4) 4 x 4 min of interval running (4 min of running at 90-95% HRmax followed by 3 min of active resting at 70%HRmax). All four training protocols resulted in similar total oxygen consumption and were performed 3 d.wk for 8 wk.
  
  
  RESULTS
  High-intensity aerobic interval training resulted in significantly increased VO2max compared with long slow distance and lactate-threshold training intensities (P<0.01). The percentage increases for the 15/15 and 4 x 4 min groups were 5.5 and 7.2%, respectively, reflecting increases in V O2max from 60.5 to 64.4 mL x kg(-1) x min(-1) and 55.5 to 60.4 mL x kg(-1) x min(-1). SV increased significantly by approximately 10% after interval training (P<0.05).
  
  
  CONCLUSIONS
  : High-aerobic intensity endurance interval training is significantly more effective than performing the same total work at either lactate threshold or at 70% HRmax, in improving VO2max. The changes in VO2max correspond with changes in SV, indicating a close link between the two.
authors.affiliation: Department of Circulation and Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. Jan.Helgerud@ntnu.no
authors.forename: Jan
authors.initials: J
authors.lastname: Helgerud
authors.forename: Kjetill
authors.initials: K
authors.lastname: Høydal
authors.forename: Eivind
authors.initials: E
authors.lastname: Wang
authors.forename: Trine
authors.initials: T
authors.lastname: Karlsen
authors.forename: Pålr
authors.initials: P
authors.lastname: Berg
authors.forename: Marius
authors.initials: M
authors.lastname: Bjerkaas
authors.forename: Thomas
authors.initials: T
authors.lastname: Simonsen
authors.forename: Cecilies
authors.initials: C
authors.lastname: Helgesen
authors.forename: Ninal
authors.initials: N
authors.lastname: Hjorth
authors.forename: Ragnhild
authors.initials: R
authors.lastname: Bach
authors.forename: Jan
authors.initials: J
authors.lastname: Hoff
mesh_terms: D000328:Adult; D015444:Exercise / Q000502:physiology*; D006801:Humans; D008297:Male; D008991:Monitoring, Physiologic; D009664:Norway; D010101:Oxygen Consumption / Q000502:physiology*