Finding the Optimal Resistance Training Intensity For Your Bones

Lumbar spine (L1-L4) bone mineral density measured via dual-energy X-ray Absorptiometry (DXA) scan.

Composite outcome of new non-vertebral and vertebral fractures, and progression of existing vertebral fractures. We will report the number in each category separately. We will use a fracture questionnaire for non-vertebral fractures, and vertebral fractures that come to clinical attention. Participants will undergo a DXA scan for Vertebral Fracture Assessment (VFA) at baseline and the 12-months. A vertebral fracture will be defined as having a radiographic presence of ≥25% reduction in anterior, middle, or posterior vertebral height, verified by an experienced radiologist at University Health Network via the Genant visual semi-quantitative method. Baseline VFA will be assessed for vertebral fractures and compared to VFA at 12 months to ascertain if there has been progression of new fractures; progression will be defined as progression to a new Genant level or a change in height of at least 10%.

Participants will be emailed a falls calendar via a survey at the end of each month. Participants will be asked to immediately report any falls to research assistant and to exercise physiologist. Exercise physiologists will report any noted falls to their study coordinator immediately and additional follow-up documentation will be required. Rate of falls and number of people who experience one or more falls will be compared between groups.

Participants will be emailed a falls calendar via a survey at the end of each month. Participants will be asked to immediately report any falls to research assistant and to exercise physiologist. Exercise physiologists will report any noted falls to their study coordinator immediately and additional follow-up documentation will be required. Rate of falls and number of people who experience one or more falls will be compared between groups.

Whole body fat- and bone-free lean mass will be derived from DXA scans.

We will calculate appendicular lean mass (kg) and its index (kg/m^2) from appendicular bone-free lean mass and height (cm).

Height will be a proxy measure of posture.

Occiput-to-wall distance will be a proxy measure of posture.

We will assess isometric knee extension peak torque using a knee extension test with a dynamometer.

We will use the 30 Second Chair Stand Test.

We will use the Four Square Step Test to assess lower extremity muscle power and dynamic balance during functional tasks.

We will assess grip strength of the non-dominant arm using a hand dynamometer.

We will assess gait speed using the 10 Metre Walk Test.

We will assess endurance using the 6 Minute Walk Test.

We will use the QUALEFFO-41 as an osteoporosis specific measure of health-related quality of life.

We will use the EQ5D5L measure as a generic health-related quality of life measure.

We will ask participants to report adverse events, using Health Canada definitions. We will report all serious and non-serious adverse events and identify those attributable to intervention. Safety outcomes will include all falls, fractures, and serious and non-serious adverse events. Any fractures or falls that are attributable to intervention will be considered under both fall or fracture outcomes, and harms.

We will ask participants to report adverse events, using Health Canada definitions. We will report all serious and non-serious adverse events and identify those attributable to intervention. Safety outcomes will include all falls, fractures, and serious and non-serious adverse events. Any fractures or falls that are attributable to intervention will be considered under both fall or fracture outcomes, and harms.

We will be taking a fasted blood sample from participants to measure plasma glucose concentrations using biochemical assay. Blood samples will only be collected from participants at the University of Waterloo site.

We will be taking a fasted blood sample from participants to measure serum insulin concentrations using radioimmunoassay. Blood samples will only be collected from participants at the University of Waterloo site.

We will be taking a fasted blood sample from participants to measure plasma pro- and anti-inflammatory markers using a multiplex kit. Blood samples will only be collected from participants at the University of Waterloo site.

We will be taking a fasted blood sample from participants to measure antioxidant status and markers of oxidative stress using commercially available assays. Blood samples will only be collected from participants at the University of Waterloo site.

We will be taking fasting blood samples from participants to measure peptides synthesized and released by myocytes in muscle tissue via the Luminex Performance Assay. Blood samples will only be collected from participants at the University of Waterloo site.

Bone mineral density of the hip measured via DXA scans

Bone mineral density of the femoral neck measured via DXA scans

Trabecular bone score (TBS) will be calculated using TBS iNsight software. A high TBS value indicates high quality boner structure, whereas a low TBS value demonstrates a lower quality structure. The TBS index ranges from 0.9 - 1.6.

We will use the DXA scanner's hip structural analysis feature to calculate estimates of hip geometry from proximal femur scans.

We will assess direct medical resources (e.g., tests, medications, hospitalization, rehabilitation), direct non-medical resources (e.g., out of pocket expenses, transportation), indirect resources (e.g., iMTA Productivity Cost Questionnaire) and clinical events and management. We will assess resource use for incident falls, fractures or adverse events. Multiplying resources collected by jurisdictional unit costs in Canadian dollars will determine the total cost per exercise program.

We will calculate the ratio of incremental costs between the interventions, determined by trial resources, and clinical outcome (QALY) to achieve an incremental cost per life year gained outcome.

We will assess willingness to pay for various exercise models using a contingent valuation survey.

Body weight in kg measured using scale

We will use Automated Self-Administered 24-hour dietary assessment tool (ASA24) to collect information on the participant's dietary intake through the self-administered 24-hour dietary record. Participants will report all food and beverage items and quantities on 3 days (2 weekday, 1 weekend day) at baseline, 6 months, and 12 months. We will also use the SCREEN2 tool at baseline only. We will report descriptive data on energy, protein, calcium, and vitamin D intake, and perform exploratory analyses of changes in these outcomes over time. We will perform subgroup analyses: 1) Baseline daily calcium (<1000 vs. >1000 mg per day); and 2) Baseline protein intake (<1.2g/kg body weight per day). We will explore changes in participants who are referred to a dietitian for counselling because of low intakes of protein, calcium, or vitamin D.