Cardiovascular Responses to Occupational Physical Activity are Exaggerated by Work-Related Stress and Low Fitness.

OBJECTIVES: Paradoxical associations between high occupational physical activity (OPA) and cardiovascular disease may be explained by exaggerated cardiovascular responses from high work-related stress or low worker fitness.

METHODS: OPA, blood pressure (BP), heart rate (HR), and rate-pressure product (HR x BP, RPP) were measured objectively for 24-hours in nineteen male workers. Work-related stress was measured using the Stress-in-General Scale. Fitness was estimated using a submaximal treadmill test. Effect modification by work-related stress and fitness on associations between OPA and cardiovascular responses was examined using mixed models with interactions.

RESULTS: Associations between OPA and RPP, HR, and BP were stronger with high stress (p < 0.05). Associations of work-time MVPA and RPP were attenuated with higher fitness (p < 0.05).

CONCLUSIONS: OPA performed under high work-related stress or by workers with low fitness may exaggerate cardiovascular responses to OPA.