Association between changes in habitual physical activity and changes in bone density, muscle strength, and functional performance in elderly men and women

OBJECTIVES: To investigate the long-term effects of habitual physical activity on changes in musculoskeletal health, functional performance, and fracture risk in elderly men and women.

DESIGN: Ten-year prospective population-based study.

SETTING: Malmö-Sjöbo Prospective Study, Sweden.

PARTICIPANTS: Participants were 152 men and 206 women aged 50, 60, 70, and 80 who were followed for 10 years.

MEASUREMENTS: Distal radius bone mineral density (BMD) (single photon absorptiometry), upper limb muscle (grip) strength, balance, gait velocity, occupational and leisure-time activity, and fractures (interview-administered questionnaire) were reassessed after 10 years. Annual changes for all measures were compared between participants with varying habitual physical activity histories at baseline and follow-up: inactive–inactive (n=202), active–inactive (n=47), inactive–active (n=49), and active–active (n=60). Data for men and women were pooled, because there were no sex-by-activity group interactions. To detect possible differences in fracture incidence between the varying habitual activity groups, participants were classified into two activity groups based on their activity classification at baseline and follow-up: inactive:less active versus active:more active.

RESULTS: The annual rate of bone loss was 0.6% per year less in individuals classified as active at both time points than in those classified as inactive at both time points (P<.01). Similar results were observed for balance, but there was no effect of varying habitual activity on changes in muscle strength or gait velocity. There were also no differences in fracture incidence between individuals categorized as active:more active and those categorized as inactive:less active during the follow-up (adjusted hazard ratio=0.90, 95% confidence interval (CI)=0.42–1.90).

CONCLUSION: This study showed that elderly men and women who maintained a habitually active lifestyle over 10 years had lower bone loss and retained better balance than those who remained habitually inactive.

Reducing psychological distress and obesity in Australian farmers by promoting physical activity

Background: Studies have confirmed that the rate of mental illness is no higher in rural Australians than that of urban Australians. However, the rate of poor mental health outcomes, and in particular suicide, is significantly raised in rural populations. This is thought to be due to lack of early diagnosis, health service access, the distance-decay effect, poor physical health determinants and access to firearms. Research conducted by the National Centre for Farmer Health between 2004 and 2009 reveals that there is a correlation between obesity and psychological distress among the farming community where suicide rates are recognised as high. Chronic stress overstimulates the regulation of the hypothalamic-pituitary-adrenal (HPA) axis that is associated with abdominal obesity. Increasing physical activity may block negative thoughts, increase social contact, positively influence brain chemistry and improve both physical and mental health. This paper describes the design of the Farming Fit study that aims to identify the effect of physical activity on psychological distress, obesity and health behaviours such as diet patterns and smoking in farm men and women.
Methods/Design: For this quasi-experimental (convenience sample) control-intervention study, overweight (Body Mass Index ≥25 kg/m2) farm men and women will be recruited from Sustainable Farm Families™ (SFF) programs held across Victoria, Australia. Baseline demographic data, health data, depression anxiety stress scale (DASS) scores, dietary information, physical activity data, anthropometric data, blood pressure and biochemical analysis of plasma and salivary cortisol levels will be collected. The intervention group will receive an exercise program and regular phone coaching in order to increase their physical activity. Analysis will evaluate the impact of the intervention by longitudinal data (baseline and post intervention) comparison of intervention and control groups.
Discussion: This study is designed to examine the effect of physical activity on psychological health and other comorbidities such as obesity, impaired glucose tolerance, hypertension and dyslipidaemia within a high-risk cohort. The outcomes of this research will be relevant to further research and service delivery programs, in particular those tailored to rural communities.

Physical activity based professional development for teachers : the importance of whole school involvement

Objective: This study sought to investigate teachers’ perceptions of a physical activity-related professional development intervention.
Design: Interview-based qualitative approach founded on the interpretive paradigm.
Setting: Purposive selection of one high-rated independent, and one low-rated public primary school from Auckland, New Zealand.
Method: A qualitative approach was used, incorporating a questionnaire used for purposive sampling and a total of eighteen semi-structured interviews with six teachers from two primary schools.
Results: Participants highly valued the inclusion of all teachers in onsite professional development and felt supported by a strong, positive organizational culture.
Conclusion: Participant teachers believed physical activity played an important role within the school setting, and recognized their role in the provision of opportunities for their students. However, they did not necessarily feel confident and competent to facilitate opportunities. A specific professional development intervention was introduced as one form of support to address this need. Teachers valued first-hand experience of professional development and reported particular enjoyment if they participated alongside their colleagues.

Biological maturity and primary school children's physical activity : influence of different physical activity assessment instruments

Biological maturation may attenuate hypothesized sex differences in children’s physical activity but overall the evidence for this is equivocal. In this study, we investigated how the selection of different physical activity assessment instruments affects the detected relationship between biological maturation and late primary school children’s physical activity. Altogether, 175 children (97 girls, 78 boys) aged 10.690.3 years completed the PAQ-C self-report questionnaire and wore ActiGraph GT1M accelerometers for 5 consecutive days. Maturity status was predicted by estimating attainment of age at peak height velocity. Following initial exploration of sex differences in PAQ-C (t-test) and multiple ActiGraph outcome variables (MANOVA), the influence of maturity status was controlled using ANCOVA and MANCOVA. Unadjusted analyses revealed that boys were significantly more active than girls according to the PAQ-C (PB0.0001, d0.52) and ActiGraph (PB0.0001, d0.360.72). After controlling for maturity status, the differences in PAQ-C scores increased (P0.001, d0.64), but the significant differences disappeared for the ActiGraph data (P0.36, d0.170.33). The detected relationship between maturity status and late primary school children’s physical activity is dependent on the physical activity assessment tool employed, reflecting the different aspects of physical activity captured by the respective measures.

Policy change to create supportive environments for physical activity and healthy eating : which options are the most realistic for local government?

The objective is to identify and test regulatory options for creating supportive environments for physical activity and healthy eating among local governments in Victoria, Australia. A literature review identified nine potential areas for policy intervention at local government level, including the walking environment and food policy. Discussion documents were drafted which summarized the public health evidence and legal framework for change in each area. Levels of support for particular interventions were identified through semi-structured interviews conducted with key informants from local government. We conducted 11 key informant interviews and found support for policy intervention to create environments supportive of physical activity but little support for policy changes to promote healthy eating. Participants reported lack of relevance and competing priorities as reasons for not supporting particular interventions. Promoting healthy eating environments was not considered a priority for local government above food safety. There is a real opportunity for action to prevent obesity at local government level (e.g. mandate the promotion of healthy eating environments). For local government to have a role in the promotion of healthy food environments, regulatory change and suitable funding are required.

Multidimensional correlates of preschool children's physical activity

This thesis identified a number of factors which are associated with preschool children’s physical activity and were previously unexplored. The findings are important as they help identify possible targets for interventions to support healthy levels of physical activity in young children.

A reverse pathway? Actual and perceived skill proficiency and physical activity

Purpose: Motor skills are considered a prerequisite to physical activity, yet the relationship may be reciprocal and perceived sports competence might mediate associations.
Methods: In 2006/2007, 215 adolescents completed motor skill proficiency (Get Skilled Get Active), perceived sport competence (Physical Self-Perception Profile) and physical activity assessments (Adolescent Physical Activity Recall Questionnaire) as part of the Physical Activity and Skills Study. Using AMOS (Version 7.0), reciprocal relationships were examined between motor skill (object control and locomotor) and moderate to vigorous physical activity (MVPA). Both models were then run in different versions to understand the role of perceived sports competence as a potential mediator.
Results: Mean age was 16.4 yr (SD = 0.6), 51.6% (111/215) were females. A reciprocal relationship between object control and MVPA and a one-way relationship from MVPA to locomotor skill was found. When perceived sports competence was examined as a mediator, the best-fitting model versions explained 16% (R² = 0.16)
MVPA variation, and 30% object control (R² = 0.30), and 12% locomotor skill variation (R² = 0.12) (reverse relationship). Perceived sports competence partially mediates the relationship between object control proficiency and physical activity for both directions and fully mediates the relationship between physical activity and locomotor skill; but only when locomotor skill is the outcome.
Conclusions: If the relationship between object control skill and physical activity is viewed as a ‘‘positive feedback loop,’’ skill development and increasing physical activity should simultaneously be targeted in physical activity interventions. Increasing perceived sport competence should also be an intervention focus.

Differences in physical activity during school recess

BACKGROUND: School recess provides a daily opportunity for physical activity engagement. The purpose of this study was to examine physical activity levels during recess by gender, ethnicity, and grade, and establish the contribution of recess to daily school physical activity levels.
METHODS: Two hundred and ten children (45% boys) from grades 3 to 6 in 4 elementary schools had their physical activity during school quantified using uni-axial accelerometry every 5 seconds for 5 consecutive school days. Data were collected in fall 2009. The proportion of time spent engaged in physical activity during daily school recess was determined using existing age-appropriate cutpoints. The relative contribution of recess to school day physical activity was also determined.
RESULTS: Boys were more active than girls during recess. Girls engaged in more sedentary activity than boys. No main effects for ethnicity were observed. Children in grades 3 and 5 were more active than children in grades 4 and 6. Recess contributed 17.9% and 15.5% toward boys’ and girls’ school day moderate-to-vigorous physical activity, respectively.
CONCLUSION: Children engaged in physical activity during recess, though interventions may be needed to increase the intensity of activity in this context.