UCLA

PurposeThe lactate threshold (LT), critical power (CP) and maximum oxygen uptake (V˙O2max$$\dot{V}{\text{O}}_{2\text{max} }$$) together partition exercise intensity domains by their common physiological, biochemical and perceptual response characteristics. CP is the greatest power output attainable immediately following intolerance at V˙O2peak$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$, and the asymptote of 3 min all-out exercise. Thus we reasoned that a maximal ‘sprint’ immediately following standard ramp-incremental exercise would allow characterisation of the three aerobic indices in a single test.MethodsTen healthy men (23 ± 3 year, mean ± SD) performed 9 cycle-ergometry tests on different days: (A) two ramp-incremental tests to intolerance (20 W min−1), immediately followed by a 3 min maximal, variable-power effort ramp-sprint test (RST) for LT, V˙O2peak$$\dot{V}{\text{O}}_{{2{\text{peak}}}}$$ and sprint-phase power (SP) determination; (B) four constant-power tests for CP and V˙O2max$$\dot{V}{\text{O}}_{2\text{max} }$$ determination; (C) constant-power tests at 10 W below LT, and 10 W below and above SP to verify intensity domain characterisation. Capillary [lactate] and breath-by-breath V˙O2$$\dot{V}{\text{O}}_{2}$$ were measured.ResultsReproducibility of LT, SP and V˙O2max$$\dot{V}{\text{O}}_{2\text{max} }$$ measurements between RST repeats was within 5 % or less (r ≥ 0.991, p < 0.001). CP (257 ± 46 W) was not different (p = 0.72) from SP (258 ± 42 W). Exercise 10 W below LT and SP resulted in steady state V˙O2$$\dot{V}{\text{O}}_{2}$$ and [lactate]. V˙O2max$$\dot{V}{\text{O}}_{2\text{max} }$$ (4.0 ± 0.6 L min−1), peak [lactate] (11 ± 2 mM) and intolerance were reached 19 ± 5 min into exercise at 10 W above SP.ConclusionsThese data suggest that the key indices of aerobic function may be accurately and reliably estimated during a single exercise test. This test may provide a basis for simplifying assessment and prescription of exercise training and experimental interventions.