Effect of Adding Additional Elastic Band Resistance Training to Waltz Dance on Dyslipidemia in Middle-aged and Elderly Women: a Randomized Controlled Trial

Total cholesterol will be measured in fasting venous blood samples (12-hour fast) using an enzymatic colorimetric method with a clinical chemistry analyzer. The result will be reported in mg/dL. Total cholesterol refers to the overall amount of cholesterol in the blood, which includes LDL-C and HDL-C. High levels are associated with increased cardiovascular risk. Blood samples will be collected at baseline and at the end of the 12-week intervention.

Triglyceride levels will be measured from fasting venous blood samples (12-hour fast) using enzymatic assays with a clinical chemistry analyzer. The result will be reported in mg/dL. Triglycerides are a type of fat found in the blood. Elevated levels are associated with metabolic syndrome and increased risk of heart disease. Blood samples will be collected at baseline and at 12 weeks post-intervention.

HDL-C will be measured from fasting venous blood samples using direct enzymatic assays. HDL-C is often referred to as "good" cholesterol because it helps remove other forms of cholesterol from the bloodstream. Low levels are a risk factor for cardiovascular disease. The result will be reported in mg/dL and assessed at baseline and after the 12-week program.

LDL-C will be measured using the Friedewald equation or direct measurement (depending on TG level) from fasting venous blood samples. LDL-C is known as "bad" cholesterol because it contributes to plaque buildup in arteries. The result will be reported in mg/dL. Blood samples will be taken at baseline and after the 12-week exercise intervention.

Resting systolic and diastolic blood pressure will be measured using a validated automatic digital blood pressure monitor (e.g., Omron HEM-907). Participants will be seated quietly for at least 5 minutes prior to measurement. Three readings will be taken at 1-minute intervals on the non-dominant arm, and the average of the last two will be recorded. Blood pressure is expressed in mmHg and interpreted according to international hypertension guidelines.

Cardiorespiratory fitness will be estimated using the 6-Minute Walk Test (6MWT), a validated submaximal field test. Participants will be instructed to walk at their fastest safe pace along a 30-meter corridor for 6 minutes. Total distance covered will be used to estimate VO₂max using validated predictive equations adjusted for age and sex. This measure reflects aerobic capacity and endurance.

Arterial stiffness and peripheral vascular health will be assessed using a validated vascular testing device (e.g., VaSera VS-1500 or equivalent). Pulse Wave Velocity (PWV) measures the speed of arterial pulse propagation and is a marker of arterial stiffness. Ankle-Brachial Index (ABI) is calculated by dividing the systolic blood pressure at the ankle by that at the brachial artery. Both are non-invasive and widely used indicators of cardiovascular health.

Body composition will be assessed using a validated bioelectrical impedance analysis device (e.g., InBody 720), including body fat percentage, body fat mass, lean body mass, skeletal muscle mass, and body mass index (BMI). Participants will be measured barefoot and in light clothing after an overnight fast, following standard procedures recommended by the manufacturer.

Bone mineral density will be evaluated using an ultrasound bone densitometer (e.g., Sahara Clinical Bone Sonometer), measuring the calcaneal bone (heel). The test is non-invasive, and results will be recorded as T-scores according to WHO criteria.

Static balance will be assessed using the single-leg stance test with eyes closed. The maximum duration (in seconds) the participant can stand unassisted on one leg without touching the ground with the lifted foot will be recorded, up to 60 seconds. Three trials will be conducted and the best result recorded.

Dynamic balance will be measured using the Biodex Balance System SD, performing the Limits of Stability (LOS) test protocol. Participants will stand on a movable platform and shift their center of gravity to targets displayed on a screen. Scores will reflect directional control and stability performance.

Anxiety symptoms will be evaluated using the GAD-7, a validated self-report scale assessing the frequency of anxiety-related symptoms over the past two weeks. Each item is scored from 0 ("not at all") to 3 ("nearly every day"), with a total score range of 0-21. Higher scores indicate greater anxiety severity.

Depressive symptoms will be assessed using the PHQ-9, a widely used 9-item self-report measure based on DSM-IV criteria. Participants rate the frequency of symptoms over the past two weeks. Scores range from 0 to 27, with higher scores indicating more severe depression.

Mood state will be measured using the Profile of Mood States (POMS), a 65-item self-report questionnaire that evaluates six mood dimensions: tension, depression, anger, vigor, fatigue, and confusion. Scores are combined to generate a total mood disturbance score.

Exercise motivation will be measured using the BREQ-3, which evaluates different types of motivational regulation along the self-determination continuum, including intrinsic motivation, identified regulation, introjected regulation, external regulation, and amotivation. The scale uses a 5-point Likert response format.

Global cognitive function will be assessed using the MoCA, a validated screening tool for mild cognitive impairment. The MoCA evaluates attention, memory, language, executive function, visuospatial skills, and orientation. The maximum score is 30, with scores below 26 indicating possible cognitive impairment.