Moderating Effects of Muscle Fitness on the Associations Between Work Stress, Burnout, and Well-Being Among...

White-collar workers experience a unique dual burden of high psychological demands and prolonged static loading, creating a need to understand how physical resilience may mitigate these stressors. This study investigated the moderating role of specific muscle fitness components in the associations between work stress, burnout, and well-being among white-collar workers. To address the gap in task-specific physical resilience, we employed a cross-sectional design involving 321 full-time employees.

Work stress (job control and demands), burnout, and well-being were assessed via structured questionnaires, while grip strength, abdominal endurance, and back muscle endurance were objectively measured.

Results indicated that the muscle fitness components were not directly associated with either burnout or well-being. However, the moderation model for burnout was significant (F = 15.837, p < 0.001; adjusted R² = 0.278), where back muscle endurance significantly moderated the association between psychological job demands and burnout (β = -0.121, p < 0.05), whereas no such moderating effect was observed for well-being. In contrast, no such moderating effect was observed for well-being, nor did grip strength or abdominal endurance exhibit significant buffering effects on either psychological outcome.

These findings demonstrate the relevance of task-specific physical resources in sedentary environments, specifically that back endurance functions as a buffer against burnout but may be insufficient to directly enhance overall well-being. The results suggest that while integrating task-specific physical assessments is vital for burnout prevention, psychosocial organizational support remains essential for fostering comprehensive well-being.