title: Energetic efficiency in trained and sedentary rats after exposure to normobaric and hyperbaric oxygen.
abstract: BACKGROUND
  Contradictory results have been obtained regarding the beneficial effect of hyperbaric oxygen (HBO) on exercise performance. The purpose of this study was to investigate the effect of different combinations of pressure and time in hyperoxia on the energetic efficiency of trained and sedentary rats.
  
  
  METHODS
  At the end of the training period, rats were exposed to one of three protocols: 1) 100% normobaric oxygen for 24 h; 2) HBO at 2 ATA for 4 h; 3) HBO at 2.5 ATA for 6 h. After the hyperoxic exposures, V(O2max) was evaluated and compared with preexposure values.
  
  
  RESULTS
  The slope of the linear section of the oxygen consumption-velocity curve in the trained rats was significantly steeper after exposure to either 100% normobaric oxygen for 24 h or HBO at 2 ATA for 4 h than before the exposure. The opposite was found for the sedentary rats. After exposure to HBO at 2.5 ATA for 6 h, the slope of the oxygen consumption-velocity curve in the trained rats did not differ from the pre-exposure slope. However, the highest velocity these rats reached was lower than their maximum velocity before this exposure. In the sedentary rats, the slope of the oxygen consumption-velocity curve was found to be steeper after the 2.5 ATA exposure compared with the preexposure slope.
  
  
  CONCLUSIONS
  Our results suggest that exposure to 100% normobaric oxygen for 24 h and HBO at 2 ATA for 4 h induces a reduction in the energetic efficiency of trained rats, but improves energetic efficiency in sedentary rats.
authors.affiliation: Israel Naval Medical Institute, IDF Medical Corps, Haifa, Israel. estie@idf.gov.il
authors.forename: Mirit
authors.initials: M
authors.lastname: Eynan
authors.forename: Offir
authors.initials: O
authors.lastname: Ertracht
authors.forename: Shiran
authors.initials: S
authors.lastname: Yehezkel
authors.forename: Paulina
authors.initials: P
authors.lastname: Svidovsky
authors.forename: Frida
authors.initials: F
authors.lastname: Ne'eman
authors.forename: Ran
authors.initials: R
authors.lastname: Arieli
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D004242:Diving; D004734:Energy Metabolism; D005080:Exercise Test; D006931:Hyperbaric Oxygenation; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010101:Oxygen Consumption; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D057185:Sedentary Behavior