Objectives: Affective valence responses to exercise may influence adherence. According to a newly proposed dual-mode model, affective responses have been proposed to vary depending on whether exercise is undertaken above or below the anaerobic threshold. With the model in mind, the study objectives were to explore the impact of an above-lactate, below-lactate, and self-selected exercise condition on acute affective responses in sedentary individuals.

Design: Using a repeated measures design, 12 volunteers participated in two prescribed intensity exercise conditions (above and below-lactate threshold) and one self-selected intensity exercise condition. The three conditions were randomized.

Method: An incremental walking protocol was used to identify exercise intensities that would elicit above- and below-lactate threshold work rates for each participant. The exercise conditions were completed on different days and each lasted for 20 minutes. Physiological and affective responses were recorded pre-exercise, during exercise, and post-exercise.

Results: Affective responses were more negative in the above-lactate condition during exercise compared with the below-lactate and self-selected conditions. There were no differences between the conditions post-exercise. Participants exercised around the lactate threshold and at a significantly higher intensity in the self-selected compared with the below-lactate condition. Inter-individual variability in responses was greatest below the lactate threshold, with similar levels of variability in the self-selected and above-lactate conditions.

Conclusions: Data are consistent with the proposals of the dual-mode model and support the use of self-selected intensity with sedentary individuals to promote positive affective responses.