We hypothesised that a short-term training programme involving repeated all-out sprint training (RST) would be more effective than work-matched low-intensity endurance training (ET) in enhancing the kinetics of oxygen uptake (VO₂) and muscle deoxygenation ([HHb]) following the onset of exercise. Twenty-four recreationally-active subjects (15 male, mean ± SD: age 21 ± 4 yr, height 173 ± 9 cm, body mass 71 ± 11 kg) were allocated to one of three groups: RST, which completed six sessions of 4-7 repeated 30-s all-out cycle sprints; ET which completed six sessions of work-matched moderate-intensity cycling; and a control group (CON). All subjects completed moderate-intensity and severe-intensity 'step' exercise transitions before and after the 2-week intervention period. Following RST: [HHb] kinetics were speeded and the amplitude of the [HHb] response was increased during both moderate and severe exercise (P<0.05); the phase II VO₂ kinetics was accelerated for both moderate (Pre: 28 ± 8, Post: 21 ± 8 s; P<0.01) and severe (Pre: 29 ± 5, Post: 23 ± 5 s; P<0.05) exercise; the amplitude of the VO₂ slow component was reduced (Pre: 0.52 ± 0.19, Post: 0.40 ± 0.17 L•min^-1; P<0.01); and exercise tolerance during severe exercise was improved by 53% (Pre: 700 ± 234, Post: 1074 ± 431 s; P<0.01). None of these parameters were significantly altered in the ET and CON groups. Six sessions of RST, but not ET, resulted in changes in [HHb] kinetics consistent with enhanced fractional muscle O₂ extraction, faster VO₂ kinetics, and an increased tolerance to high-intensity exercise.