Combined effects of exposure to hypoxia and cool on walking economy and muscle oxygenation profiles at tibialis anterior.

We investigated combined effects of ambient temperature (23°C or 13°C) and fraction of inspired oxygen (21%O or 13%O) on energy cost of walking (: J·kg·km) and economical speed (ES). Eighteen healthy young adults (11 males, seven females) walked at seven speeds from 0.67 to 1.