Associations between multiple indicators of socio-economic status and muscle-strengthening activity participation in a nationally representative population sample of Australian adults.

BACKGROUND: Muscle-strengthening activity (MSA) (e.g. weight training), confers unique health benefits. While socioeconomic status (SES) correlates with leisure time physical activity, little is known about its relation with MSA.

METHODS: Cross-sectional study of a representative sample of 8993 Australian adults (>18years) who participated in the National Nutrition and Physical Activity Survey 2011-12. Information was collected on SES (income, education, socio-economic disadvantage and remoteness) and MSA participation.

RESULTS: 17.9% (CI: 16.8-19.0) met the national guidelines for MSA (≥2 sessions/week). Men and younger adults (<35years) met MSA guidelines more than females (19.7%; CI: 18.3-21.1% vs 16.1%; CI: 14.6-17.6%; p<0.001) and older adults respectively (25.0%; CI: 22.4-27.7% vs 10.4%; CI: 8.9-11.8%; p<0.001). All SES indicators were associated with meeting the guidelines in unadjusted analyses. When adjusting for total physical activity and mutually adjusting for each socioeconomic indicator only remoteness (OR for city vs rural=1.65; CI: 1.17-2.32; p<0.001) was associated with MSA participation (education OR=1.09 for high vs low; CI: 0.80-1.47, p=0.748; income OR=1.31 for Q5 vs Q1, CI: 0.93-1.85, p=0.328; social disadvantage OR=1.04 for v.high vs v.low, CI: 0.76-1.43, p=0.855). These associations were further attenuated when adjusting for BMI, smoking status and self-rated health.

CONCLUSION: Remoteness, and to a lesser degree, education, income and social disadvantage, were independently associated with MSA participation. Public health interventions should improve access to strength training facilities, and/or increase home-based muscle-strengthening activity in remote areas.