Although physical activity occurs in leisure, transport, occupational and domestic domains of life, the contribution of house and garden work (HGW) to the association between total physical activity and well-being is not clear. The aim was to describe the contribution of HGW to total physical activity (TPA) in association with well-being in younger, mid-aged and older women. Younger (25-30 years), mid-aged (50-55 years) and older (76-81 years) participants in the Australian Longitudinal Study on Women's Health completed a mailed survey with questions about leisure, transport and house and garden activities. Well-being was assessed using the physical and mental components scores of the SF-36. Cross-sectional associations between the physical activity variables and well-being were modelled using General Additive Modelling. Correlations between HGW and leisure/transport activity (LTA) were low (r<0.3, p<0.001). Positive curvilinear associations were found between LTA and physical and mental well-being in all three cohorts, and between HGW and physical and mental well-being in mid-aged and older women. In the younger women, an inverse relationship was found between HGW and well-being. When HGW and LTA were summed (TPA), the associations between TPA and well-being were attenuated compared with those for LTA alone and well-being. In mid-aged and older women, relationships between HGW and well-being were similar to, but weaker than seen for LTA and well-being. In young women, well-being declined with increasing HGW. Summing HGW to LTA led to attenuated relationships, suggesting that domains of physical activity should not be summed when studying relationships with well-being. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://group.bmj.com/group/rights-licensing/permissions.
