Table 1 Data are expressed as the mean (SE). Variables BpVL BpGL LT GET Peak n 31 31 24 31 31 Time (s) 797 (25)*† ‡ 895 (23) 899 (27)‡ 933 (26) 1256 (32) WR (W) 137 (6)*† ‡ 153 (6) 154 (7)‡ 160 (6) 213 (7) VE (mL·min-1) 60.2 (3.1)*† ‡ 70.8 (3.8) 68.8 (4.4) 72.0 (3.7) 134.3 (7.5) VO2 (L·min-1) 2.2 (0.1)*† ‡ 2.5 (0.1) 2.5 (0.2)‡ 2.6 (0.1) 3.9 (0.2) VO2 (mL·min-1·kg-1) 30.6 (1.3)*† ‡ 34.7 (1.5) 34.6 (1.7)‡ 36.5 (1.5) 53.4 (2.2) VCO2 (L·min-1) 2.1 (0.1)*† ‡ 2.5 (0.1) 2.5 (0.2) 2.6 (0.1) 4.3 (0.2) RER 0.96 (0.02)*† ‡ 0.99 (0.02) 0.98 (0.02) 0.98 (0.02) 1.13 (0.02) HR (bpm) 144 (2)*† ‡ 154 (3) 152 (2)‡ 157 (2) 184 (2) [La]b (mM) 3.7 (0.3)*† ‡ 4.2 (0.3) 3.6 (0.2)‡ 4.5 (0.3) 8.8 (0. 5) %VO2peak (%) 57.7 (1.4)*‡ 65.7 (1.7) 64.5 (1.6)‡ 68.7 (1.3) -- n, sample size; WR, work rate; V, ventilation; VO, oxygen uptake; VCO, carbon dioxide output; RER, respiratory exchange ratio; HR, heart rate; [La], blood lactate concen tration; % VO, percentage of VO; BpVL and BpGL, the breakpoints (Bp) of the muscle oxygenation index in the (BpVL) and (BpGL); LT, lactate threshold; GET, gas exchange threshold; Peak, peak values during the incremental exercise. * significantly different from BpGL (p < 0.05); †  significantly different from LT ( < 0.05); ‡ significantly different from GET (p < 0.05). All thresholds (BpVL, BpGL, LT and GET) were significantly different from the Peak values (p < 0.05).