Discussion
SECONDARY, SUDECK
In this work, we designed and evaluated a novel 3-month multimodal exercise programme focussing on specific facets of PAHCO in patients who recently underwent bariatric surgery. We found that the multimodal exercise programme was successful in enhancing control competence for physical training and PA-specific self-control and positively influenced self-reported exercise and subjective vitality. Conversely, we found no statistically significant positive effects on PA-specific affect regulation, motivational competence, and device-based PA.The observed positive impact on participants’ control competence for physical training can be considered as large and in line with a previous intervention study (Volk et al., A possible explanation for the lack of a positive treatment effect on the PA-specific affect regulation may be that it was not sufficiently addressed by the exercise programme (see Table 1 in the supplementary material). It is important to note that promoting affect regulation, or in other words, the competence to steer PA in order to optimise psychological wellbeing, remains an under-researched area. Future research should focus on which personal, environmental, and activity-related factors influence intra-individual differences in affective response to PA (e.g., valence, arousal; see Bourke et al., Although the present study revealed medium effects of the exercise programme on motivational competence, they remained non-significant, probably influenced by our rather small sample size. However, compared to a previous study with less active, healthy adults (Schorno et al., With regard to PA-specific self-control, this study showed a positive, medium treatment effect at the end of the exercise programme. This means that participants felt more competent in implementing regular PA in daily life. This result is in line with prior studies with less active but healthy adults (Schorno et al., A secondary outcome of this trial was self-reported exercise behaviour. The exercise programme resulted in increased self-reported exercise for members of the IC compared to those of the CG. In absolute terms, members of the IG were able to raise their exercise level by 28 min/week. This is an increase that has shown to be associated with positive health effects (e.g., a reduction mortality; see Wen et al., A large effect was found for the multimodal exercise programme on subjective vitality at follow-up, meaning that members of the IG felt more energised and vital compared to the CG. This result is in line with findings of previous observational studies (Carl, Grüne, et al., The strengths of the present RCT include its rigorous design and the novel application of the PAHCO model in the bariatric surgery population. However, we acknowledge some limitations. Firstly, participants included mostly had a rather high PA level at baseline (see Table 4 in supplementary material), which may limit the generalisability of the present findings to all bariatric surgery patients. Secondly, we did not examine the effect of the exercise programme on movement competence, which is also integrated in the PAHCO model alongside control competence and self-regulation competence (Sudeck & Pfeifer, 