Efficacy of a randomized controlled self-regulation based physical activity intervention for chronic fatigue: Mediation effects of physical activity progress and self-regulation skills.
Examine the medium-term effects of a brief physical activity (PA) self-regulation (SR) based intervention (4-STEPS program) for chronic fatigue, and explore the mediating effects of PA related variables and SR skills.



A two-arm randomized controlled trial (Usual Care vs 4-STEPS) was carried out. The 4-STEPS program consisted of Motivational Interviewing and SR-skills training. Fatigue severity (primary outcome) and impact, PA, health-related quality of life (HrQoL), and somatic and psychological distress were assessed at baseline, post-treatment (12weeks) and 12months follow-up.



Ninety-one patients (45 intervention and 46 controls) were included. At follow-up, there were significant treatment effects on fatigue severity (g=0.72) and fatigue impact, leisure-time PA, and physical and psychological HrQoL. No significant effects were found for number of daily steps and somatic and psychological distress. Fatigue severity at follow-up was partially mediated by post-treatment progress on a personal PA goal (effect ratio=18%).



Results suggest that a brief intervention, focusing on the formulation and pursuit of personal PA goals and the use of SR skills, produces sustained benefits for fatigue severity. Despite these promising results, dropout was high and the intervention was not beneficial for all secondary outcomes.
Interdisciplinary Centre for the Study of Human Performance (CIPER), Faculty of Human Kinetics, University of Lisbon, Portugal; Leiden University, Department of Health, Medical and Neuropsychology, PO Box 9555, 2300 RB Leiden, The Netherlands. Electronic address: martamarques@fmh.ulisboa.pt.
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Marques
Leiden University, Department of Health, Medical and Neuropsychology, PO Box 9555, 2300 RB Leiden, The Netherlands.
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de Gucht
ISPA- University Institute, Rua Jardim do Tabaco, 34, 1149-041 Lisboa, Portugal.
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Leal
Leiden University, Department of Health, Medical and Neuropsychology, PO Box 9555, 2300 RB Leiden, The Netherlands.
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Maes
D000328:Adult; D002908:Chronic Disease / Q000523:psychology; D015444:Exercise / Q000523:psychology; D005221:Fatigue / Q000503:physiopathology / Q000523:psychology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D062405:Motivational Interviewing; D011788:Quality of Life; D000068356:Self-Control