RESUMO
Affective responses have been considered key determinants for exercise adherence, but research on affective responses to stretching activities is scarce. Given the role of these responses in exercise adherence, our aim in this review was to explore (a) the utility and feasibility of core affect in stretching-related activities as measured by the Feeling Scale (FS) and/or the Felt Arousal Scale (FAS); (b) the timing of administering these scales; and (c) the scales' applicability and interpretability in this context. Inclusion criteria for studies in this review were experimental and non-experimental studies written in English that based affect assessment on the FS and/or FAS and that applied these scales to participants engaged in physical activity, individually or in groups. We also considered studies that focused on stretching activities that were either isolated or components of a class/activity and studies that used healthy participants of any age. Exclusion criteria were populations with mental health problems, cancer, diabetes, hypertension, cardiovascular disease, or diseases likely to alter pain perception or be associated with chronic pain, instrument validation studies, gray literature, and systematic reviews. We searched PubMed, SPORTDiscus and PsycINFO databases, and we added studies retrieved manually from reference sections while following PRISMA guidelines. We used the Effective Public Health Practice Project tool for judging methodological quality of research articles. Our final analyses were based on 12 empirical studies published between 2003 and 2021with a total of 718 participants. Both scales were found to be useful and feasible in the most usual places for exercise, but core affect results cannot be properly interpreted due to variability of study protocols and the absence of guidelines for adequate baseline assessment. Most studies recorded affect responses pre-session, during session, and post-session. We observed no standardized timing or frequency of assessment, and there was high heterogeneity among stretching protocols. Currently, research in core affect assessment of stretching-related activities lacks sufficient methodological quality to draw generalizable conclusions.