Reduced performance of male and female athletes at 580 m altitude.
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.
Gore
C J
CJ
Australian Institute of Sport, Henley Beach, South Australia.
Little
S C
SC
Hahn
A G
AG
Scroop
G C
GC
Norton
K I
KI
Bourdon
P C
PC
Woolford
S M
SM
Buckley
J D
JD
Stanef
T
T
Campbell
D P
DP
Watson
D B
DB
Emonson
D L
DL
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