Effect of pedal cadence on the accumulated oxygen deficit, maximal aerobic power and blood lactate transition thresholds of high-performance junior endurance cyclists

Abstract

In this study we investigated the effect of pedal cadence on the cycling economy, accumulated oxygen deficit (AOD), maximal oxygen consumption (V˙O_2max) and blood lactate transition thresholds of ten high-performance junior endurance cyclists [mean (SD): 17.4 (0.4) years; 183.8 (3.5) cm, 71.56 (3.75) kg]. Cycling economy was measured on three ergometers with the specific cadence requirements of: 90–100 rpm for the road dual chain ring (RDCR_90–100rpm) ergometer, 120–130 rpm for the track dual chain ring (TDCR_120–130rpm) ergometer, and 90–130 rpm for the track single chain ring (TSCR_90–130rpm) ergometer. AODs were then estimated using the regression of oxygen consumption (V˙O₂) on power output for each of these ergometers, in conjunction with the data from a 2-min supramaximal paced effort on the TSCR_90–130rpm ergometer. A regression of V˙O₂ on power output for each ergometer resulted in significant differences (P<0.001) between the slopes and intercepts that produced a lower AOD for the RDCR_90–100rpm [2.79 (0.43) l] compared with those for the TDCR_120–130rpm [4.11 (0.78) l] and TSCR_90–130rpm [4.06 (0.84) l]. While there were no statistically significant V˙O_2max differences (P = 0.153) between the three treatments [RDCR_90–100rpm: 5.31 (0.24) l · min⁻¹; TDCR_120–130rpm; 5.33 (0.25) l · min⁻¹; TSCR_90–130rpm: 5.44 (0.27) l · min⁻¹], all pairwise comparisons of the power output at which V˙O_2max occurred were significantly different (P < 0.001). Statistically significant differences were identified between the RDCR_90–100rpm and TDCR_120–130rpm tests for power output (P = 0.003) and blood lactate (P = 0.003) at the lactate threshold (Th_la−), and for power output (P = 0.005) at the individual anaerobic threshold (Th_iat). Our findings emphasise that pedal cadence specificity is essential when assessing the cycling economy, AOD and blood lactate transition thresholds of high-performance junior endurance cyclists.