Effects of low and high cadence interval training on power output in flat and uphill cycling time-trials

Abstract

This study tested the effects of low-cadence (60 rev min⁻¹) uphill (Int₆₀) or high-cadence (100 rev min⁻¹) level-ground (Int₁₀₀) interval training on power output (PO) during 20-min uphill (TT_up) and flat (TT_flat) time-trials. Eighteen male cyclists ($\dot{V}{\text{O}}_{2\max }$: 58.6 ± 5.4 mL min⁻¹ kg⁻¹) were randomly assigned to Int₆₀, Int₁₀₀ or a control group (Con). The interval training comprised two training sessions per week over 4 weeks, which consisted of six bouts of 5 min at the PO corresponding to the respiratory compensation point (RCP). For the control group, no interval training was conducted. A two-factor ANOVA revealed significant increases on performance measures obtained from a laboratory-graded exercise test (GXT) (P _max: 2.8 ± 3.0%; p < 0.01; PO and $\dot{V}{\text{O}}_{2}$ at RCP: 3.6 ± 6.3% and 4.7 ± 8.2%, respectively; p < 0.05; and $\dot{V}{\text{O}}_{2}$ at ventilatory threshold: 4.9 ± 5.6%; p < 0.01), with no significant group effects. Significant interactions between group and uphill and flat time-trial, pre- versus post-training on PO were observed (p < 0.05). Int₆₀ increased PO during both TT_up (4.4 ± 5.3%) and TT_flat (1.5 ± 4.5%). The changes were −1.3 ± 3.6, 2.6 ± 6.0% for Int₁₀₀ and 4.0 ± 4.6%, −3.5 ± 5.4% for Con during TT_up and TT_flat, respectively. PO was significantly higher during TT_up than TT_flat (4.4 ± 6.0; 6.3 ± 5.6%; pre and post-training, respectively; p < 0.001). These findings suggest that higher forces during the low-cadence intervals are potentially beneficial to improve performance. In contrast to the GXT, the time-trials are ecologically valid to detect specific performance adaptations.