Table 1. Blood lactate concentration [La-] and arterial oxygen saturation (SpO2) measured in team-sport athletes before, during, and immediately after performing the RSR444 (4 sets of 4, 4-s sprints) in normoxic (21%) and hypoxic (14%) conditions. Data are means (±SD). Variable Condition Baseline Pre-test Post- sprint 8 Post- sprint 16 [La-] mmol·L-1 Normoxia 1.0 (.3) 1.7 (1.4) 7.1 (2.0) 8.6 (2.6)             Hypoxia 1.0 (.2) 2.9 (1.6)* 8.0 (2.2) 10.2 (2.5) * SpO2 (%)             Normoxia - 97.2 (1.5) 93.8 (3.6) 94.5 (2.5)             Hypoxia - 89.0 (2.0) * 78.0 (6.3) * 75.3 (6.3) * * Different from normoxia (p < 0.05). Baseline measurements were obtained in normoxic conditions before the warm up. Pre-test measurements were performed in the environmental condition, after the warm up and immediately before the commencement of the RSR444.