Serum eythropoietin in athletes at moderate altitude

The purpose of this study was to determine resting serum erythropoietin concentrations (S‐[epo]) in endurance‐trained sea‐level residents 2 week after arrival at moderate altitude as well as after descent to sea level, and in endurance‐ and strength‐trained residents at moderate altitude. S‐[epo] concentrations were determined in 2 groups of non‐altitude‐acclimatized endurance‐trained athletes normally living at sea level (group UAET, 20 men and 7 women, and group UACCS, 14 men and 6 women); and 2 groups of altitude‐acclimatized athletes, all long‐term residents at 1900 m above sea level (strength‐trained judo athletes, group AST 10 men and 11 women, and endurance‐trained athletes, group AET, 10 men and 10 women). Hematocrit (Hct) but not S‐[ep] was significantly higher in pup AET than group AST Resting S‐[epo] in group UAET was determined l,2,7, and 14 d after arrival from sea level to 1900 m above sea level. The Hct increased significantly from day 1 to day 7 in the women of group UAET. The Hct of the males in group UAET did not change significantly throughout the 2 weeks at altitude. The women in group UAET showed a significant decrease in S‐[epo] from day 1 to day 7, The S‐[epo] in the men of group UAET did not change from day 1 to day 2, but decreased significantly from day 2 to day 14. Resting S‐[epo] in group UACCS was obtained before and at the end of the 2‐week training period at high‐altitude and after high‐altitude training. Only the UACCS men had, in comparison with sea‐level S‐[epo], similar S‐[epo] after 2 weeks of high‐altitude training and significantly lower S‐[epo] 2 d, but not 9 or 19 d after descent to sea level. These data indicate similar resting S‐[epo] levels in acclimatized endurance‐ and strength‐trained athletes, although the former group had higher Hct than the latter. In non‐altitude‐acclimatized endurance athletes, S‐[epo] increased the ht days at altitude and thereafter decreased to similar S‐[epo] as at sea level after 2 weeks of altitude training. After descent to sea level, S‐[epo] decreased transiently but returned to the pre‐altitude level after 9 d