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

Abstract

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 (RPP; HR × BP) were measured objectively for 24 hours in 19 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 moderate and vigorous physical activity 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.

Trial registration: ClinicalTrials.gov NCT04075279.

Figure 1 –

24-hour rate pressure product by occupational physical activity, work-related stress, and worker fitness Footnotes: a) Rate pressure product values are presented as adjusted least square means b) All models are adjusted for age, BMI, fitness, smoking status, and resting rate pressure product Abbreviations: MVPA=moderate-to-vigorous physical activity, LPA=light physical activity, VO₂max=maximum rate of oxygen consumption (i.e., fitness)