Primary Prevention
Conditions
Keywords
accelerometry, aerobic fitness, metabolic thresholds, moderate to vigorous physical activity
Brief summary
The purpose of this study is to accurately assess weekly physical activity levels of postmenopausal women using lactate thresholds to individualize the accelerometer cut-points.
Detailed description
This observational study aims to accurately assess weekly physical activity levels of postmenopausal women using lactate thresholds to individualize the accelerometer cut-points. Postmenopausal women will be recruited from local advertisements in public health centers. Each woman will perfom on different days a progressive discontinuous submaximal walking-running test and several constant speed tests wearing an accelerometer to identify the individual lactate threshold (LT), the maximal lactate steady state (MLSS) and the corresponding accelerometer activity counts/min (cpm). Participants then will wear an actigraph accelerometer (wGT3X-BT) for seven days. Linear regression equations will be developed for each participant to determine accelerometer activity counts for each intensity level: 1) sedentary behaviour (\<200 cpm), 2) light intensity (200 cpm to activity counts at LT), 3) moderate intensity (activity counts between LT and MLSS) and 4) vigorous intensity (activity counts \>MLSS). Physical activity levels will be measured using both, individualized approach and Sasaki, Jonh and Freedson´s (2011) absolute cut-points obtained through walking and running activities eliciting 3-6 MET intensities (2689-6166 cpm), considering it a moderate effort.
Interventions
None listed
Sponsors
University of the Basque Country (UPV/EHU)
Centro de Estudios, Investigación y Medicina del Deporte
Study design
Observational model
CASE_ONLY
Time perspective
CROSS_SECTIONAL
Eligibility
Sex/Gender
FEMALE
Age
50 Years to 70 Years
Healthy volunteers
Yes
Inclusion criteria
* Age between 50 and 70 years * Surgical or natural menopause (no menstrual periods during at least the last 6 months)
Exclusion criteria
* Body mass index less than 39kg/m2 (obesity class III) * Osteoporosis * Presence of low-trauma fractures or severe arthrosis at hip, knees or feet * Functional limitation to walk fast or altered gait patters and instability * Presence of any chronic disesase that would impair the cardiovascular (e.g. myocardial infarction, stroke, chronic heart failure), musculoskeletal (osteoporosis, low-trauma fractures) and respiratory systems (COPD) or any disease or medication known to affect bone metabolism (glucocorticoids)
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Time spent in moderate-to-vigorous physical activities | 1 week | The time spent in moderate-to-vigorous physical activities during a week (The participants have to wear an accelerometer attatched at the hip on an elastic belt for a period of 7 days) |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| accelerometer intensity cut-points | an average of 1 month | accelerometer activity counts corresponding to each woman´s lactate thresholds will determine each intensity level (These thresholds are determined on the walking-running tests performed on different days with a minimum of one week in between. These tests are independent, they are performed at constant speed during 20min to determine the highest speed at which the lactate concentration remains in a steady state between the minute 10 and 20 of the test) |
| Number of vertical acceleration peaks during the day | 1 week | raw acceleration data will be measured to describe daily exposure to potentially osteogenic vertical impacts (The participants have to wear an accelerometer attatched at the hip on an elastic belt for a period of 7 days) |
| aerobic fitness | an average of 1 month | determination of the speeds corresponding to the lactate thresolds during the walking-running test |
Other
| Measure | Time frame | Description |
|---|---|---|
| Maximum Strength | 1 day | hand grip, leg and bench press maximum lifted weight (kg) |
| Heart rate variability | an average of 1 month | the heart rate variability response during the walking-running tests and during the weekly physical activity assessment |
Countries
Spain
Outcome results
None listed