title: The oxygen uptake response running to exhaustion at peak treadmill speed.
abstract: OBJECTIVE
  Peak treadmill speed (V(max)), which is the final speed reached and sustained for a minute during a speed-incremented continuous maximal oxygen uptake ([OV0312]O(2max)) test, is an effective predictor of endurance performance. This study assesses the reliability of V(max) and [OV0312]O(2max), and examines the oxygen uptake response while running to exhaustion at V(max).
  
  
  METHODS
  Eleven recreationally active runners completed two speed-incremented [OV0312]O(2max) tests (test 1 and test 2) to determine [OV0312]O(2max) and V(max). In addition, the subjects completed a constant speed test (test 3) at V(max) to determine time to exhaustion (T(max)).
  
  
  RESULTS
  No significant differences existed between test 1 and test 2 for [OV0312]O(2max) (P = 0.68) and V(max) (P = 0.10). Means (+/- SD) for [OV0312]O(2max) and V(max) were 51.1 +/- 5.8 mL.kg-1.min-1 and 17.4 +/- 1.3 km.h-1, respectively; 95% limits of agreement for V(max) were -0.1 +/- 1.4 km.h-1. However, as heteroscedasticity was present in the [OV0312]O(2max) test data, 95% ratio limits of agreement were reported (1.01 *// 1.08). During test 3, 6 of the 11 subjects attained an oxygen uptake equivalent to their previously recorded [OV0312]O(2max). The time to attain [OV0312]O(2max) was 155.0 +/- 48.0 s, which represented 66.5% of T(max) (237.0 +/- 35.0 s). Although 5 of the 11 subjects did not attain an oxygen uptake response equivalent to that previously recorded, no significant difference existed between the oxygen uptakes for the three tests (P = 0.52).
  
  
  CONCLUSIONS
  The results of this study indicate that V(max) and [OV0312]O(2max) attained during a speed incremented maximal oxygen uptake test were reliable. However, while running at V(max), not all the subjects attained an oxygen uptake response equivalent to that previously recorded during incremental tests 1 and 2.
authors.affiliation: School of Sport, P.E. and Recreation, University of Wales Institute, Cardiff, Cyncoed Campus, Cardiff, UK. simon.harling@btconnect.com
authors.forename: Simon A
authors.initials: SA
authors.lastname: Harling
authors.forename: Richard J
authors.initials: RJ
authors.lastname: Tong
authors.forename: Timothy D
authors.initials: TD
authors.lastname: Mickleborough
mesh_terms: D000328:Adult; D005080:Exercise Test; D005221:Fatigue; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D010807:Physical Endurance / Q000502:physiology*; D015203:Reproducibility of Results; D012129:Respiratory Function Tests; D012420:Running / Q000502:physiology*