An interventional study of Experimental I (SDT) and Experimental II (Hedonic) in Exercise Frequency, sponsored by Grupo Lusófona. Active, not recruiting at 1 site in Portugal. Open to participants aged 18 Years and older, including healthy volunteers. Per ClinicalTrials.gov, last updated 2026-01-22.
Sponsored by Grupo Lusófona · Not applicable, Interventional, and Treatment
Over recent decades, leading theories of human behavior have been applied across various physical activity (PA) settings, yielding mixed results. While they have provided some valuable insights, they have largely failed to achieve one central aim - to help foster sustained, population-wide increases in PA (Albarracín et al., 2024; Ekkekakis \& Zenko, 2016; Pratt et al., 2020; Rhodes et al., 2019). This gap has prompted concern, as these theories, despite some support for their assumptions, have not translated into meaningful and lasting behavior change. Some have criticized them for their overarching dependency on the decisional balance one may perform given the right set of conditions (e.g., supportive social environments; benefits vs. barriers dyad; self-efficacy appraisal) (Conn et al., 2011; Ekkekakis, 2017; Rhodes et al., 2019); others have pointed to an astonishing lack of experimental efforts testing the expression of those theoretical assumptions (Ekkekakis et al., 2019; Manninen et al., 2022; Ntoumanis \& Moller, 2025), leaving researchers, policymakers and stakeholders (and the theories) hostage to cross-sectional and longitudinal evidence. Either way, new approaches and experimental efforts to address the challenge of supporting PA practices are warranted and urgent.
Three of the most studied motivational theories in PA contexts over the last decades are the Theory of Planned Behavior (Ajzen, 1991), Self-Determination Theory (Deci \& Ryan, 1985), and the Transtheoretical Model (Prochaska \& DiClemente, 1984) (Ntoumanis et al., 2018; Simpson et al., 2025). Without minimizing their usefulness and robust body of evidence, they fall into the category of theories that have struggled, to date, to demonstrate moderate or large effects in programs aiming to improve exercise-related behavior based on their assumptions. Naturally, the complexity of each theory or model brings several challenges that undermine the extent to which we can confidently attribute any limited effect observed in an experimental study solely to the theory's inability to express its assumptions. As such, despite decades of research grounded in several (conceptually) well-established behavioral theories, there remains a need to test their assumptions through experimental approaches and, complementarily - or if necessary, alternatively - to explore new avenues for inquiry and theoretical development (Simpson et al., 2025).
To this end, the present study will address this issue experimentally using two theoretical approaches. The first approach is grounded in a well-established theory of human motivation, Self-Determination Theory (SDT), which offers numerous recommendations for its potential application, particularly in promoting positive impacts on exercise adherence. The second approach is structured in alignment with the general principles of hedonic theory, a recently revitalized approach to the understanding of Human behavior, focusing on the promotion of pleasurable responses during exercise.
9,798 studies on the registry are indexed under Motor Activity; 1,910 are open to participants now.
This study's planned enrollment of 117 is above the median of 60 across 8,388 interventional studies indexed under Motor Activity.
Browse Motor Activity studies →Grupo Lusófona is the lead sponsor of 10 studies on the registry; 5 are open to participants now.
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Professionals
- All exercise professionals in the three clubs
Exercisers
Exclusion Criteria:
FITT-VP 2025 training course
Other: Control group
SDT-based training course
Behavioral: Experimental I (SDT)
Hedonic-based training course
Behavioral: Experimental II (Hedonic)
SDT-based course aiming to inmprove professionals operational interpersonal qualities
Hedonic-based course aiming to inmprove professionals operational interpersonal qualities
FITT-VP bases course aiming to improve exercise prescription
Club attendance
Club attendance during a one-year period collected with the turstile digital system
Time frame: Collected on the last day of each month, and averaged after a one-year period (September 1st to August 31st)
Attrition rate
Attrition rate calculated through the number of cancellations or dropouts / total number of new members × 100 in a one-year period
Time frame: Number of total cancellations or dropouts for each month, collected through the turstile digital record and club payment system, summed throughout 12 months
Exercise habit measured with the Self-reported behavioral automaticity index (SRBAI) - Baseline
Automaticity for exercise practice measured with the Self-reported behavioral automaticity index (SRBAI)
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Exercise habit measured with the Self-reported behavioral automaticity index (SRBAI) - 6 months
Automaticity for exercise practice measured with the Self-reported behavioral automaticity index (SRBAI)
Time frame: After 6 months of enrollment; first two weeks of February, at any given time
Exercise habit measured with the Self-reported behavioral automaticity index (SRBAI) - 12 months
Automaticity for exercise practice measured with the Self-reported behavioral automaticity index (SRBAI)
Time frame: After 12 months, during the last week of August 2026, at any given time
Initial behavioral intention to continue exercising; the intention to exercise questionnaire - Baseline
Behavioral intention as defined by the theory of planned behavior with the intention to exercise questionnaire
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Behavioral intention to continue exercising; the intention to exercise questionnaire - 6 months
Behavioral intention as defined by the theory of planned behavior with the intention to exercise questionnaire
Time frame: After 6 months of enrollment; first two weeks of February, at any given time
Behavioral intention to continue exercising; the intention to exercise questionnaire - 12 months
Behavioral intention as defined by the theory of planned behavior with the intention to exercise questionnaire
Time frame: After 12 months, during the last week of August 2026, at any given time
Exerciser basic psychological needs satisfaction and frustration; the BPNSFS questionnaire - Baseline
Basic psychological needs satisfaction and frustration as defined by the Self-Determination Theory
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Exerciser basic psychological needs satisfaction and frustration; the BPNSFS questionnaire - 6 months
Basic psychological needs satisfaction and frustration as defined by the Self-Determination Theory
Time frame: After 6 months of enrollment; firts two weeks of February, at any given time
Exerciser basic psychological needs satisfaction and frustration; the BPNSFS questionnaire - 12 months
Basic psychological needs satisfaction and frustration as defined by the Self-Determination Theory
Time frame: After 12 months, during the last week of August 2026, at any given time
Exerciser behavioral regulation; the BREQ-4 questionnaire - Baseline
Exercise behavioral regulations as defined by the Self-Determination Theory
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Exerciser behavioral regulation; the BREQ-4 questionnaire - 6 months
Exercise behavioral regulations as defined by the Self-Determination Theory
Time frame: After 6 months of enrollment; firts two weeks of February, at any given time
Exerciser behavioral regulation; the BREQ-4 questionnaire - 12 months
Exercise behavioral regulations as defined by the Self-Determination Theory
Time frame: After 12 months, during the last week of August 2026, at any given time
Exercise enjoyment measured with the Physical Activity Enjoyment Scale (PACES) - Baseline
Exercise enjoyment measured with the the Physical Activity Enjoyment Scale (PACES)
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Exercise enjoyment measured with the Physical Activity Enjoyment Scale (PACES) - 6 months
Exercise enjoyment measured with the the Physical Activity Enjoyment Scale (PACES)
Time frame: After 6 months of enrollment; firts two weeks of February, at any given time
Exercise enjoyment measured with the Physical Activity Enjoyment Scale (PACES) - 12 months
Exercise enjoyment measured with the the Physical Activity Enjoyment Scale (PACES)
Time frame: After 12 months, during the last week of August 2026, at any given time
Subjective exercise experience - Baseline
The attraction-antipathy and the pleasure-displeasure assessed with the affective exercise experiences questionnaire (AFFEXX)
Time frame: Baseline; after club enrollment, in the first two weeks of September 2025, at any given time
Subjective exercise experience - 6 months
The attraction-antipathy and the pleasure-displeasure assessed with the affective exercise experiences questionnaire (AFFEXX)
Time frame: After 6 months of enrollment; firts two weeks of February, at any given time
Subjective exercise experience - 12 months
The attraction-antipathy and the pleasure-displeasure assessed with the affective exercise experiences questionnaire (AFFEXX)
Time frame: After 12 months, during the last week of August 2026, at any given time
Plan to share: No
This study is active, not recruiting, as verified in Aug 2025. You cannot join it, but the record below documents what was studied.
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