Psychophysiological responses to self-paced treadmill and overground exercise.

UNLABELLED Speculation exists that a positive affective response experienced during exercise may play an important role in predicting exercise adherence. Previous studies using self-paced exercise protocols have been associated with health benefits and pleasant experiences. However, all of these studies were conducted in laboratories, and consequently, the external validity of the findings may be questionable. PURPOSE To determine whether environmental settings (treadmill vs overground) differentially influence physiological, perceptual, and affective responses to exercise at a self-selected pace. METHODS Thirty-four individuals (17 men and 17 women) between 18 and 30 yr volunteered to participate in this study. During the orientation session, individuals underwent an initial screening, anthropometric measurements, and familiarization with the experimental procedures. Next, subjects underwent a maximal treadmill test. In the two experimental trials, participants performed 20-min bouts of treadmill and overground walking at a self-selected pace, which were completed in a counterbalanced order. At least 48 h separated experimental trials. RESULTS Using repeated-measures ANOVA, overground walking speed was significantly faster than treadmill walking speed (P < 0.01) during the 20-min bout of self-paced exercise. However, exercise intensity (%VO2R and %HRR) and perceived exertion during the session of overground walking were significantly lower (P < 0.05) when compared with those during the treadmill session. In addition, affective valence was more positive during the session of overground walking than during the treadmill session (P < 0.01). CONCLUSIONS These data extend previous findings by showing that environmental setting influences physiological, perceptual, and affective responses during exercise at a self-selected pace. Self-paced exercise performed over ground resulted in lower perceptual and more positive affective responses.