title: Reduced performance of male and female athletes at 580 m altitude.
abstract: This study examined the effect of mild hypobaria (MH) on the peak oxygen consumption (VO2peak) and performance of ten trained male athletes [x (SEM); VO2peak = 72.4 (2.2) ml x kg(-1) x min(-1)] and ten trained female athletes [VO2peak = 60.8 (2.1) ml x kg(-1) x min(-1)]. Subjects performed 5-min maximal work tests on a cycle ergometer within a hypobaric chamber at both normobaria (N, 99.33 kPa) and at MH (92.66 kPa), using a counter-balanced design. MH was equivalent to 580 m altitude. VO2peak at MH decreased significantly compared with N in both men [-5.9 (0.9)%] and women [-3.7 (1.0)%]. Performance (total kJ) at MH was also reduced significantly in men [-3.6 (0.8)%] and women [-3.8 (1.2)%]. Arterial oxyhaemoglobin saturation (SaO2) at VO2peak was significantly lower at MH compared with N in both men [90.1 (0.6)% versus 92.0 (0.6)%] and women [89.7 (3.1)% versus 92.1 (3.0)%]. While SaO2 at VO2peak was not different between men and women, it was concluded that relative, rather than absolute. VO2peak may be a more appropriate predictor of exercise-induced hypoxaemia. For men and women, it was calculated that 67-76% of the decrease in VO2peak could be accounted for by a decrease in O2 delivery, which indicates that reduced O2 tension at mild altitude (580 m) leads to impairment of exercise performance in a maximal work bout lasting approximately 5 min.
authors.affiliation: Australian Institute of Sport, Henley Beach, South Australia.
authors.forename: C J
authors.initials: CJ
authors.lastname: Gore
authors.forename: S C
authors.initials: SC
authors.lastname: Little
authors.forename: A G
authors.initials: AG
authors.lastname: Hahn
authors.forename: G C
authors.initials: GC
authors.lastname: Scroop
authors.forename: K I
authors.initials: KI
authors.lastname: Norton
authors.forename: P C
authors.initials: PC
authors.lastname: Bourdon
authors.forename: S M
authors.initials: SM
authors.lastname: Woolford
authors.forename: J D
authors.initials: JD
authors.lastname: Buckley
authors.forename: T
authors.initials: T
authors.lastname: Stanef
authors.forename: D P
authors.initials: DP
authors.lastname: Campbell
authors.forename: D B
authors.initials: DB
authors.lastname: Watson
authors.forename: D L
authors.initials: DL
authors.lastname: Emonson
mesh_terms: D000328:Adult; D000531:Altitude; D005260:Female; D006801:Humans; D008297:Male; D010101:Oxygen Consumption / Q000502:physiology*; D012727:Sex Characteristics; D013177:Sports / Q000502:physiology*; D013647:Task Performance and Analysis