Date of Award
5-2025
Culminating Project Type
Thesis
Styleguide
apa
Degree Name
Industrial/Organizational Psychology: M.S.
Department
Psychology
College
College of Liberal Arts
First Advisor
Dr. Marcy Young Illies
Second Advisor
Dr. Daren Protolipac
Third Advisor
Dr. Melanie Guentzel
Creative Commons License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.
Keywords and Subject Headings
industrial-organizational psychology, occupational health psychology, work-limiting fatigue, aging workforce, physical activity, sleep disturbances
Abstract
This study examines how physical activity, sleep disturbances, affect, and self-rated health influence work-limiting fatigue in older workers. Data from the 2022 Health and Retirement Study (N = 12,939) included adults aged 50 and older, with measures capturing physical activity frequency, sleep disturbances, affective states, self-rated health, and fatigue-limiting work. Correlational and regression analyses revealed that physical activity predicted lower fatigue, while sleep disturbances increased it. Affect and self-rated health mediated these relationships: positive affect and health perceptions reduced fatigue, whereas negative affect and poorer self-rated health exacerbate it. Parallel mediation models demonstrated that physical activity’s protective effect operated both directly and indirectly through positive affect and self-rated health; similarly, sleep disturbances’ detrimental impact was partially mediated by negative affect and self-rated health. These findings build on the Job Demands-Resources framework and Lazarus and Folkman’s transactional model of stress and coping, demonstrating how personal health behaviors and psychological states shape occupational outcomes. Practical implications highlight the need for integrated interventions addressing physical activity, sleep hygiene, and affective regulation to sustain older employees' work capacity. Strategies that foster regular physical activity and improved sleep quality, alongside affect-focused interventions, may enhance work capacity and reduce work-limiting fatigue among older employees. Future research should leverage longitudinal designs and objective health measures to better capture dynamic changes in aging workers' experiences. By identifying these mediating mechanisms, this study enhances our theoretical understanding of work-limiting fatigue in aging workforce populations.
Recommended Citation
Bush, Alex L., "Physical Activity, Sleep, and Affect: Pathways to Work-Limiting Fatigue" (2025). Culminating Projects in Psychology. 24.
https://repository.stcloudstate.edu/psyc_etds/24
Comments/Acknowledgements
I wish to express my gratitude to Dr. Marcy Young-Illies for her significant contribution to this research and my academic development. As my thesis chair, her guidance and support were instrumental to refining the direction and quality of this work. Her encouragement to pursue Industrial-Organizational Psychology at the graduate level was a defining moment in my academic journey and laid the foundation for this research.
I also extend my thanks to Dr. Daren Protolipac and Dr. Melanie Guentzel for their valuable insights and support throughout my graduate school experience and the development of this thesis. As members of my committee, their constructive feedback and diverse perspectives played an important role in strengthening both the arguments and overall quality of this work. Their mentorship has been essential to my academic growth.
I am also appreciative of the mentorship provided by Dr. Alicia Stachowski. Her encouragement of my research pursuits and facilitation of opportunities to further develop my research skills were invaluable. Dr. Stachowski’s guidance led me to the Health and Retirement Study, which formed the empirical foundation of this work.
I am incredibly grateful for the unwavering support of my family. My wife, Dr. Kassie Stalsberg, has been a constant source of motivation and through her unwavering support and encouragement. I also wish to acknowledge Dr. Janet McLean, who nurtured my curiosity for learning from an early age, laying the groundwork for my academic journey. To my twin, Jake, and my family, thank you for your support and encouragement throughout this process.
Finally, this work would not have been possible to without the participants of the Health and Retirement Study. I deeply appreciate their willingness to share their experiences and insights, as well as the researchers whose efforts make this data available.