Acute adaptations to eccentric cycling and downhill walking: physiological and neuromuscular responses

This study aimed to compare neuromuscular alterations and cardiorespiratory responses induced by eccentric cycling and downhill walking.

Twenty-two healthy young males completed two separate 30 min sessions of eccentric cycling (ECC) and downhill walking (DW) (- 15% incline) at 55% of their maximum heart rate. Oxygen consumption and perceived exertion were recorded. Neuromuscular function was assessed before and after each session through maximal voluntary contraction (MVC) torque, evoked torque at 100 Hz (Dt100) and 10 Hz (Dt10), and maximal voluntary activation level (VAL).

Oxygen consumption was higher during DW, reaching 30 ± 6% VO₂max, compared to 26 ± 5% VO₂max during ECC. Perceived effort increased from 10 ± 5 in DW to 17 ± 9 in ECC. MVC decreased by 20 ± 11% following ECC, remaining stable after DW (- 3 ± 7%). VAL declined by 5 ± 11% in both conditions, while the Dt10/Dt100 ratio decreased by 16 ± 29% exclusively after ECC.

At the same absolute heart rate, ECC resulted in lower oxygen consumption but was perceived as more challenging than DW. ECC induced greater neuromuscular fatigability, particularly affecting excitation-contraction coupling, whereas DW preserved contractile function. These findings suggest that DW may be better tolerated during exercise. Based on this, a progressive approach beginning with DW followed by ECC could serve as a potential strategy for rehabilitation. However, this proposed progression has not been tested in clinical populations, and future studies are needed to explore its feasibility and efficacy.