This study describes differences between oxygen uptake (VO 2 ; ml·min -1 ·kg -1 ) and energy expenditure (EE; kJ·min -1 ·kg -1 ) during treadmill walking at various velocities (3, 4 and 5 km·h -1 ) and inclinations (0, +12 a -12 %). Six men [age 22,83 ± 2,23 y.o., weight (BM) 75,18 ± 4,83 kg, height 180,5 ± 4,51 cm; body fat (PBF) 15,3 ± 3,67 % of BM]. Anthropometric variables and walking test were been performed during one session. Walking test consisted of 5 minutes stages (all combination of 3 velocities and 3 inclination, total test length of 45 minutes) and at the last two minutes of each stage were collected EE and VO 2 in breath-by- breath analysis. Significant difference (p < .05) were discovered between the velocities at same inclination in VO 2 and EE except walking downhill at velocities of 3-4 (p = .074) and 4-5 km (p = .116, reps. p = .106). The most noticeable change is the diversity of VO 2 and EE between the various speeds at different treadmill inclinations. No significant relations were found between anthropometric variables and VO 2 , resp. EE, with the only exception BM vs. EE at 3 km·h -1 +12% (r = .84).