title: Effects of heat acclimation on changes in oxidative stress and inflammation caused by endurance capacity test in the heat.
abstract: BACKGROUND
  The aim was to determine the effect of heat acclimation (HA) on oxidative stress (OxS) and inflammation in resting conditions and on the response pattern of these parameters to exhausting endurance exercise.
  
  
  METHODS
  Parameters of OxS and inflammation were measured in non-heat-acclimated status (NHAS) and after a 10-day HA program (i.e., in heat-acclimated status; HAS) both at baseline and after an endurance capacity (EC) test in the heat.
  
  
  RESULTS
  As a result of HA, EC increased from 88.62 ± 27.51 to 161.95 ± 47.80 minutes (P < 0.001). HA increased OxS level: total peroxide concentration rose from 219.38 ± 105.18 to 272.57 ± 133.39  μmol/L (P < 0.05) and oxidative stress index (OSI) from 14.97 ± 8.24 to 20.46 ± 11.13% (P < 0.05). In NHAS, the EC test increased OxS level: total peroxide concentration rose from 219.38 ± 105.18 to 278.51 ± 125.76  μmol/L (P < 0.001) and OSI from 14.97 ± 8.24 to 19.31 ± 9.37% (P < 0.01). However, in HAS, the EC test reduced OSI from 20.46 ± 11.13 to 16.83 ± 8.89% (P < 0.05). The value of log high-sensitive C-reactive protein increased from -0.32 ± 0.32 to -0.12 ± 0.34 mg/L (P < 0.05) in NHAS and from -0.31 ± 0.47 to 0.28 ± 0.46 mg/L (P < 0.001) in HAS.
  
  
  CONCLUSIONS
  HA increases OxS level. However, beneficial adaptive effects of HA on acute exhaustive exercise-induced changes in OxS and inflammation parameters occur in a hot environment.
authors.affiliation: Institute of Exercise Biology and Physiotherapy, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia ; Estonian Centre of Behavioural and Health Sciences, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia.
authors.forename: Triin
authors.identifier: 0000-0002-2525-749X
authors.initials: T
authors.lastname: Kaldur
authors.affiliation: Institute of Biomedicine and Translational Medicine, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia ; Department of Vascular Surgery, Tartu University Hospital, 8 Puusepa Street, 51014 Tartu, Estonia.
authors.forename: Jaak
authors.initials: J
authors.lastname: Kals
authors.affiliation: Institute of Exercise Biology and Physiotherapy, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia ; Estonian Centre of Behavioural and Health Sciences, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia.
authors.forename: Vahur
authors.initials: V
authors.lastname: Ööpik
authors.affiliation: Institute of Biomedicine and Translational Medicine, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia.
authors.forename: Mihkel
authors.initials: M
authors.lastname: Zilmer
authors.affiliation: Institute of Biomedicine and Translational Medicine, University of Tartu, 19 Ravila Street, 50411 Tartu, Estonia.
authors.forename: Kersti
authors.initials: K
authors.lastname: Zilmer
authors.affiliation: Department of Cardiology, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia.
authors.forename: Jaan
authors.initials: J
authors.lastname: Eha
authors.affiliation: Estonian Centre of Behavioural and Health Sciences, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia ; Department of Cardiology, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia ; Department of Sports Medicine and Rehabilitation, University of Tartu, 18 Ülikooli Street, 50090 Tartu, Estonia ; Sports Medicine and Rehabilitation Clinic, Tartu University Hospital, 1a Puusepa Street, 50406 Tartu, Estonia.
authors.forename: Eve
authors.initials: E
authors.lastname: Unt
mesh_terms: D000064:Acclimatization; D000328:Adult; D002097:C-Reactive Protein / Q000032:analysis; D006358:Hot Temperature; D006801:Humans; D007249:Inflammation / Q000378:metabolism* / Q000473:pathology; D008077:Lipoproteins, LDL / Q000097:blood; D018384:Oxidative Stress; D010100:Oxygen / Q000378:metabolism; D010545:Peroxides / Q000032:analysis; D010807:Physical Endurance; D055815:Young Adult
chemical_list: D008077:Lipoproteins, LDL; D010545:Peroxides; C099252:oxidized low density lipoprotein; D002097:C-Reactive Protein; D010100:Oxygen