The cardiovascular effects of resistance exercise, matched with metabolic and peripheral O₂ utilisation data, are still poorly understood. The present project characterizes cardiovascular, metabolic and muscle functional responses during leg press resistance exercise in young subjects. Subjects were 8 males (25±2 yy; 177±5 cm; 72±12 kg): they were equipped with a K₄B² metabolimeter to collect respiratory data, a PORTAPRES finger cuff on a free hand to collect hemodynamic data and a NIRS on the right vastolateral muscle, to test muscle oxygen extraction. A 1RM indirect test (Brzycki method) was performed to determine the individual maximal voluntary dynamic force, followed, in separate sessions by two sets of 3 series of leg extensions (10 minute recovery between series) of 12 repetitions at 70% and 80% 1RM, respectively. Averaged results of the 3 series of each set are reported at control, after 10 sec and at the end of each exercise. Most of the changes we documented were load related, since they were higher in the second set (80% 1RM) than in the first set (70% 1RM). Both systolic and diastolic pressures rose during the efforts, wile stroke volume was slightly reduced and cardiac output did not change. Heart rate rose in parallel with oxygen consumption, that corresponded to a mild aerobic exercise. Muscle oxygen extraction increased by 60%. We conclude that active muscles largely rely on increased extraction during isometric contractions.