Changes in skeletal muscle oxygenation during exercise measured by near-infrared spectroscopy on ascent to altitude

Table 3 StO₂ decline between unloaded cycling and VO_{2 max} during exercise at different altitude time points

	Altitude
	Sea level	3,500 m	5,300 m-a	5,300 m-b
StO_{2 rate} from ULC to VO_{2 max} (%/second)	0.063 (0.047 to 0.080)	0.067 (0.050 to 0.083)	0.056 (0.041 to 0.072)	0.099 (0.078 to 0.120)*

Data are presented as mean (95% confidence interval). StO₂, tissue oxygen saturation; ULC, unloaded cycling; VO_{2 max}, maximal oxygen consumption. *Significantly different from sea level (P < 0.05).

ISSN: 1364-8535