Data from the fourth and fifth examinations of the Copenhagen City Heart Study will be included for the cross-sectional and long-term associations between heavy occupational lifting and cardiac damage in a nested design. Early subclinical structural changes of the heart will be recognized by advanced echocardiographic analyses. We will compare participants exposed to heavy occupational lifting (cases) with matched participants who are not exposed to heavy occupational lifting (controls) both in the cross-sectional and longitudinal study. Controls will be matched on age and sex. Echocardiographic assessment will focus on early subclinical changes in cardiac structure primarily assessed by cardiac mass, indices of diastolic function, and global strain assessments. Analyses will be adjusted for confounders, including hypertension, diabetes, and BMI. With 200 exposed and 200 unexposed participants included in the echocardiographic analyses, we will have 80% power to detect a between-group difference of 1 in global longitudinal strain (equal to 5% difference based on an expected mean of 20) with a significance level (alpha) of 1.25%. The choice of alpha is adjusted to allow for comparison over several parameters of subclinical structural changes.