This study aimed to examine the effects of wearing compression compared to classic elastic tights and conventional shorts (control trial) on oxygen cost and sensation responses during submaximal running exercise. In part I, aerobic energy cost was evaluated in six trained runners at 10, 12, 14, and 16 km x h(-1). In part II, the increase in energy cost over time (i. e., slow component expressed as difference in VO2 values between min 2 and end-exercise) was determined in six trained runners at a constant running pace corresponding to 80% of maximal VO2 for 15 min duration. All tests were performed on a 200-m indoor track with equivalent thermal stress conditions. VO2 was determined with a portable metabolic system (Cosmed K4b2, Rome, Italy) during all testing sessions. Runners were asked their ratings of perceived exertion (RPE) and perceptions for clothing sweating, comfort, and whole thermal sensations following each trial. Results showed in part I a significant lower energy cost only at 12 km x h(-1) by wearing compression and elastic tights compared to conventional shorts. During part II, wearing compression tights decreased significantly VO2 slow component by 26 and 36% compared to elastic tights and conventional shorts, respectively. There were no differences in sweating and comfort sensations, RPE, and for whole thermal sensation between clothing conditions in parts I and II. Wearing compression tights during running exercise may enhance overall circulation and decrease muscle oscillation to promote a lower energy expenditure at a given prolonged submaximal speed.