title: Respiratory gas exchange and lactate measures during competitive orienteering.
abstract: OBJECTIVE
  In the past, orienteering sports analyses were based on heart rate (HR) and lactate (LA) measures. This study assessed additional respiratory gas exchange measures (RGEM) to provide further information regarding the physiological requirements of orienteering competitions (OTC).
  
  
  METHODS
  Eleven elite male athletes performed simulated OTC. RGEM were performed using a portable system. LA was determined after each section (total of six) of OTC. Athletes were also subjected to treadmill testing (TT).
  
  
  RESULTS
  Average values for the entire OTC were [OV0312]O(2OTC): 56.4 +/- 4.5 mL.kg-1.min-1 (83.0 +/- 3.8% of [OV0312]O(2max) of TT), HR(OTC): 172 +/- 11 bpm, and LA(OTC): 5.16 +/- 1.5 mmol.L-1. The highest measured [OV0312]O(2OTC) of an athlete in this study was 64.4 +/- 2.9 mL.kg-1.min-1. [OV0312]O(2OTC) was 94.6 +/- 5.2% of [OV0312]O(2IAT) (IAT= individual anaerobic threshold), HR(OTC) was 98.0 +/- 2.9% of HR(IAT), respiratory exchange ratio was 97 +/- 3.8% and LA(OTC) was 143.9 +/- 24.2% of LA(IAT). In contrast to [OV0312]O(2) and LA, average HR were similar in all sections of OTC despite topographical differences of the course. No correlations were found between running time of OTC and variables of endurance performance. Running time correlated with running distance (P < 0.001; r = 0.83) and running speed (r = 0.98; P < 0.001).
  
  
  CONCLUSIONS
  1) Energy requirements during OTC were derived predominately via aerobic metabolism. 2) The highest [OV0312]O(2OTC) value of 64.4 mL.kg-1.min-1 may be regarded as the reference for intensities of OTC. 3) During OTC, most athletes avoid high-intensity periods of long duration. 4) Performance in OTC was essentially influenced by technical abilities. 5) Using only LA for evaluation may lead to overestimation of energy demands during OTC. 6) HR measures were not sufficiently sensitive to ascertain energy requirements of the OTC. Therefore, RGEM provided additional information regarding energy expenditure of OTC compared with LA and HR measures alone.
authors.affiliation: Institute of Sports Sciences, Department of Sport Physiology of University Vienna, Vienna, Austria.
authors.forename: Gerhard
authors.initials: G
authors.lastname: Smekal
authors.forename: Serge P
authors.initials: SP
authors.lastname: Von Duvillard
authors.forename: Rochus
authors.initials: R
authors.lastname: Pokan
authors.forename: Karl
authors.initials: K
authors.lastname: Lang
authors.forename: Ramon
authors.initials: R
authors.lastname: Baron
authors.forename: Harald
authors.initials: H
authors.lastname: Tschan
authors.forename: Peter
authors.initials: P
authors.lastname: Hofmann
authors.forename: Norbert
authors.initials: N
authors.lastname: Bachl
mesh_terms: D000328:Adult; D004734:Energy Metabolism; D005080:Exercise Test; D006339:Heart Rate; D006801:Humans; D019344:Lactic Acid / Q000097:blood*; D008297:Male; D009949:Orientation; D010101:Oxygen Consumption; D011659:Pulmonary Gas Exchange / Q000502:physiology*; D012420:Running / Q000502:physiology*; D013177:Sports
chemical_list: D019344:Lactic Acid