OBJECTIVE: To assess the safety and acute effects of a procedure using perceived exertion during a prior submaximal concentric (CON) test to individualize eccentric (ECC) cycling exercise intensity. DESIGN: Prospective, monocentric open study. SETTING: Technological investigation platform at a physical medicine and rehabilitation department in a university hospital. PARTICIPANTS: Healthy subjects (N=18; 15 men, 3 women) aged between 22 and 37 years. INTERVENTIONS: The subjects performed 3 cycling exercises: (1) incremental CON test to determine the comfortable pedaling power (CPP) corresponding to a Borg scale rating of 12 (rate of perceived exertion); (2) steady-state CON exercise at the CPP workload to determine the corresponding plantar pressure; and (3) steady-state ECC exercise with an imposed resistance corresponding to the CPP plantar pressure. MAIN OUTCOME MEASURES: Rate of perceived exertion on Borg scale, oxygen uptake (V o2), heart rate, cardiac output, and stroke volume using inert gas rebreathing techniques were measured during steady-state CON and ECC exercises. Muscle soreness was rated on a visual analog scale immediately, 24, and 48 hours after the tests. RESULTS: No adverse effects were reported. V o2 was about 5 times the resting value during CON exercise, while it was twice that during ECC exercise. Cardiac output was lower during ECC exercise (P<.05). This moderate increase of cardiac output was exclusively linked to a greater increase in stroke volume during ECC exercise than during CON exercise (P<.05). CONCLUSIONS: Moderate-intensity ECC cycling exercise tailored according to perceived exertion during a prior CON test is well tolerated. It corresponds to a limited muscular use of oxygen and to an isolated increase in stroke volume. It appears to be a feasible procedure for preconditioning before ECC training.