Does erythrocyte infusion improve 3.2-km run performance at high altitude?

The effects of autologous erythrocyte infusion on improving exercise perfor mance at high altitude have not previously been studied. The effects of ery throcyte infusion on 3.2-km (2-mile) run performance were evaluated during 3 days (HA3) and 14 days (HA14) exposure to high altitude (4300 m) in eryth rocyte-infused (ER) and control (CON) subjects that were initially matched (P > 0.05; n = 8 in each group) for age, body size and aerobic fitness. Aft er sea-level runs (SL; 50m), unacclimated-male subjects received either 700 mi of saline and autologous erythrocytes (42% hematocrit; ER) or saline al one (CON). The 3.2-km run times (min:s) did not differ (P > 0.05) between g roups at SL [mean (SEM) ER, 13:14 (00:19); CON, 13:39 (00:32)] or during HA 3 [ER, 19:02 (00:18); CON, 19:44 (00:43)] and HA14 [ER, 17:44 (00:27); CON, 18:45 (00:55)] but times were slower (P < 0.05) when comparing HA3 or HA14 to SL. Heart rates (HR) did not differ between groups at SL [ER, 188 (3) b eats min(-1); CON, 191 (3) beats.min(-1)], or during HA3 [ER, 170 (4)beats. min(-1); CON, 178 (4)beats.min(-1)] and HA14 [ER, 162 (6) beats min CON, 16 9 (5) beats.min(-1)] but HR were lower (P < 0.05) when comparing HA3 or HA1 4 to SL. Ratings of perceived exertion (local, central, and overall ratings ) did not differ between groups at SL, HA3 or HA14, but local ratings were higher(P < 0.05) at HA3 and HA14 compared to SL, and overall ratings were h igher for HA3 than SL. Analysis of covariance (adjusted fbr SL group run ti mes) revealed (min:s) 00:14 (HA3) and 00:28 (HA14) mean improvement tendenc ies (P > 0.05) for ER compared to CON. Thus, no significant improvements in 3.2-km run performance were associated with erythrocyte infusion, although the ER group showed a tendency to run slightly faster at high altitude.