Cadence effects on cardiorespiratory and muscular responses during eccentric cycling

Eccentric cycling (ECC) enables high mechanical power output at a low metabolic cost, yet the influence of cadence on cardiorespiratory and neuromuscular responses during ECC remains poorly defined. This study examined the interactive effects of cadence and power output on metabolic, cardiovascular, and muscle activation responses during ECC.

Fifteen healthy men performed randomized incremental ECC trials at 50 and 80 rpm, with successive 4-min stages at 80, 200, and 320 W. Oxygen uptake [Formula: see text], gross mechanical efficiency (GME), cardiac output [Formula: see text], heart rate (HR), stroke volume (Qs), arteriovenous O₂ difference (a-v̄O₂), and quadriceps electromyographic activity were measured. Data were analysed using linear mixed-effects models with cadence, power output, and their interaction as fixed effects.

A significant cadence × power interaction was observed for [Formula: see text] (p = 0.006). [Formula: see text] was lower at 80 rpm than at 50 rpm at 200 W (- 0.116 L·min^-1, p = 0.007) and 320 W (- 0.187 L·min^-1, p < 0.001), with no cadence effect at 80 W (p = 0.89). GME also showed a cadence × power interaction (p = 0.035), with lower GME at 80 rpm at 200 W (- 7.3%, p = 0.020) and 320 W (- 11.6%, p < 0.001). Cardiac output increased with power output (p < 0.001) but showed no cadence × power interaction (p = 0.13). Heart rate was modestly higher at 80 rpm only at 320 W (+ 9.1 bpm, p = 0.016). Arteriovenous O₂ difference was consistently higher at 50 rpm across all workloads (p < 0.001). A cadence × power interaction was detected for vastus lateralis EMG (p = 0.039), with greater activation at 50 rpm at 320 W (+ 20.8 mV, p < 0.001), while no cadence effects were observed for vastus medialis or rectus femoris activity.

During eccentric cycling, higher cadence reduces oxygen uptake and vastus lateralis activation at moderate to high power outputs, without altering fundamental cardiovascular-metabolic coupling. These findings indicate that cadence selection modulates the metabolic and neuromuscular cost of eccentric work primarily through contraction mechanics, supporting the use of higher cadences to optimize eccentric cycling in both rehabilitation and performance settings.