Table 1. Muscle blood flow, estimated O2 delivery, and vascular conductance during lower and higher power outputs under altered muscle perfusion pressure (HOR, HDT, and HUT) and inspired O2 fraction (normoxia and hypoxia)
Conditions
VariablesLPOHDT (n = 9)LPOHOR (n = 10)LPOHUT (n = 10)HPOHDT (n = 9)HPOHOR (n = 10)HPOHUT (n = 10)
MBF
(mL·min−1)
Normoxia146.3 ± 34.2a188.7 ± 67.1127.2 ± 58.8a186.8 ± 55.4a227.5 ± 79.7203.3 ± 74.3
Hypoxia167.3 ± 38.1a,c195.8 ± 72.4119.5 ± 53.2a,b221.6 ± 68.7a,c249.5 ± 95.7c210.3 ± 84.2
DO2est
(mLO2·min−1)
Normoxia142.2 ± 33.2a183.4 ± 65.6123.9 ± 57.2a180.9 ± 53.3a221.0 ± 77.3197.0 ± 72.4
Hypoxia152.6 ± 34.3a,c176.9 ± 65.4109.6 ± 48.5a,b,c201.0 ± 60.8a,c228.4 ± 86.7190.8 ± 75.0
VC
(mL·min−1·mmHg−1)
Normoxia2.9 ± 0.8a2.2 ± 0.70.9 ± 0.4a, b3.6 ± 1.0a2.4 ± 0.81.4 ± 0.5a,b
Hypoxia3.3 ± 0.8a, c2.1 ± 0.80.8 ± 0.4a, b4.1 ± 1.2a, c2.5 ± 0.91.4 ± 0.6a,b
Test block OrderA2B1B3B2A3A1
  • Values are mean ± SD. n, Number of participants ; MBF, muscle blood flow; DO2est, estimated O2 delivery, VC, vascular conductance; LPOHOR, lower power output in horizontal; LPOHDT, lower power output in head‐down tilt; LPOHUT, lower power output in head‐up tilt; HPOHOR, higher power output in horizontal; HPOHDT, higher power output in head‐down tilt; HPOHUT, higher power output in head‐up tilt. HDT, head‐down‐tilt; Test Block Order indicates for each of the Blocks.

  • a Significant differences compared with HOR.

  • b HDT within the same gas condition and experimental phase.

  • c Significant differences compared with normoxia within the same body position (P < 0.05).