Table 3. Leg muscle oxygen saturation (SmO2) and total haemoglobin (THb) before, during and after exercise in older (O60) and younger (U40) endurance-trained individuals. SmO2 (% PRE) Double-leg cycling Single-leg cycling Main effect O60 U40 O60 U40 PRE 100 100 100 100 N/A INT 1 37.3 ± 9.8 38.7 ± 10.2 44.9 ± 15.1 51.3 ± 16 †  POST INT 1 59.8 ± 13.4 67.3 ± 18.5 70.7 ± 19.7 74.1 ± 21.6 †  INT 2 36.3 ± 9.2 37.9 ± 10.5 44.4 ± 12.3 51 ± 14.5 †  POST INT 2 57.4 ± 12.8 60.8 ± 19.9 67.6 ± 19.1 74.5 ± 25.5 †  3 min 111.6 ± 13.9 118.6 ± 13.8 130.6 ± 20.3 132.3 ± 14.1 †  5 min 95.6 ± 16.2 101.3 ± 20.6 95.7 ± 17.8 113.4 ± 18.7 9 min 109.3 ± 10.7 111.9 ± 12.7 116.9 ± 11.6 122.7 ± 14.2 †  THb (% PRE) O60 U40 O60 U40 Main effect PRE 100 100 100 100 N/A INT 1 100 ± 0.9 100.2 ± 1 99.9 ± 0.6 99.5 ± 1.2 POST INT 1 100 ± 1.1 100.3 ± 0.7 100 ± 0.4 99.8 ± 1 INT 2 99.8 ± 0.9 100 ± 0.9 99.8 ± 0.5 99.4 ± 1.3 POST INT 2 100 ± 1.2 100.3 ± 1 99.9 ± 0.5 99.8 ± 1.1 3 min 99.7 ± 1 100.3 ± 1.2 99.6 ± 0.9 99.9 ± 0.9 5 min 99.2 ± 5.2 99.5 ± 4.8 100.4 ± 4.9 101.6 ± 5.1 9 min 99.7 ± 0.7 99.9 ± 0.9 99.6 ± 0.6 99.6 ± 0.7 SmO2, leg muscle oxygen saturation; THb, total haemoglobin. Values are presented as mean ± SD. † , Main effect of modality, comparisons made between DL and SL cycling, regardless of age.