Back to basics
Lana R. Fred, Davis-Monthan Air Force Base Health and Wellness Center program coordinator, instructs U.S. Air Force Senior Airman Yevgeniy Sokolov, 355th Aircraft Maintenance Squadron crew chief, how to wear a VO2 max facemask at Davis-Monthan AFB, Ariz., Sept. 2, 2015. The mask covers both the mouth and nose while it measures the body’s oxygen intake though a tube connected to both the facemask and computer. (U.S. Air Force photo by Airman 1st Class Ashley N. Steffen/Released)