Interval eccentric cycling : a promising training modality for sedentary people.

INTRODUCTION

Older adults are prone to deconditioning. High intensity interval training (HIIT) effectively generates functional improvements, but at a high metabolic demand. Eccentric training (ET) is emerging as an efficient method because of its capacity to develop high forces at low metabolic cost. We compared the effects of eccentric HIIT (EI), concentric HIIT (CI) and eccentric continuous (EC) cycling training.

METHODS

43 sedentary adults (61yo) performed EI (n=15), EC (n=15) or CI (n=13) training twice-a-week for 12 weeks. Training intensities ranged from 120 to 135% (EI) and 80 to 90% (CI, EC) of maximal aerobic power (MAP). Maximal oxygen consumption (VO2 max), MAP, quadriceps maximal isometric torque (MIT) and functional abilities were evaluated before and after training. Rate of perceived exertion (RPE), heart rate (HR), cognitive demand and muscle soreness were monitored during training.

RESULTS

EI and EC showed lower mean HR and RPE than CI (HR: 63%; 65%; 85% and RPE: 12; 11; 14, respectively), without onset of soreness. Improvements in MIT (+14%; +17; +24%), 6-minute walking distance (+6%; +6%; +4%) and ten-times sit-to-stand test(+14%; +17%; +11%) were observed in EI, EC and CI. However, only CI provided aerobic improvements (MAP: +4%;+1%; +18% and VO2 max: +1%; -1%; +14%, for EI, EC and CI, respectively).

CONCLUSION

ET can be safely integrated in rehabilitation to improve muscular function and exercise capacity in patients unable to tolerate conventional concentric exercise intensities. EI appears as a promising method in both preventive and rehabilitative settings, but with limited effects on aerobic capacity.

TRIAL REGISTRY: The trial was registered on ClinicalTrial.gov, the 24th September 2025, NCT07189975.