PremanonAltitudeStudy_04
Professional triathlete AJ Baucco winces as he ices his legs after a hard training run on Oct. 7, 2010 in Prémanon, FR. Baucco had been struggling with a sore leg after receiving his first of two muscle biopsy's for the study. "It feels like Mike Tyson gave me a charlie-horse", said Baucco.