Differing six minute pacing strategies affect anaerobic contribution, oxygen uptake, muscle deoxygenation and cycle performance

BACKGROUND: This study compared an all-out start (AO) to a constant power start strategy (CON) during a 6 min cycle performance on utilization of W' (energy above critical power [CP]), muscle deoxygenation (HFIb), oxygen uptake (V0₂) and performance in recreationally active individuals. The AO strategy was similar to that employed by rowers. METFIODS: Eight healthy males (age =24±3 y) completed a ramp test to fatigue (V0_2peat =4.42±0.54 L·min^-1; peak power =385±35 W) and a 3-min all-out test to determine CP and the CON work rate. The AO strategy began with a 12 s sprint, followed by 258 s at 5%<CON. The CON work rate was calculated as CP^∗W +(W'J/360 s) and performed for the initial 270 s of the ride. Both groups increased their effort, in 30 s intervals, over the last 90 s of each trial. The last 30 s was a sprint. RESULTS: Total W' utilized was higher during CON vs. AO (18,109±5439 J vs. 13.754±3543 J. P<0.05). The HHb/V0₂ ratio reflected a duration mismatch between O₂ provision to O₂ utilization during CON compared to AO (118 s vs. 58 s, P<0.05). Mean work rate was higher in CON compared to AO (315±21 Wiw. 302±64 W. P<0.05). CONCLUSIONS: CON yielded a greater utilization of W' and a higher mean work rate compared to AO during a traditional rowing stratagem during a 6-min cycle performance in recreationally active individuals.