The objective of the first year is to collect limb occlusion pressure (LOP) measurements in older adults with varying levels of muscle health, which will serve as foundational data for subsequent investigations on blood flow restriction (BFR) combined with resistance training in individuals with dynapenia. This phase aims to examine LOP values and their potential influencing factors, including demographic and physiological characteristics such as age, height, body weight, blood pressure, waist circumference, body fat percentage, medical history of chronic diseases, and habitual physical activity. Muscle-related assessments will include skeletal muscle mass, thigh and calf circumference, handgrip strength, and lower limb muscle strength. Functional performance will be evaluated using the five-times sit-to-stand test and the SARC-F questionnaire for sarcopenia risk screening. LOP of the lower limbs will be measured using a BFR cuff system combined with a laboratory-developed blood flow detection device. The study will further investigate whether LOP values are associated with the aforementioned factors. The objective of the second year is to utilize high-density surface electromyography (dEMG) to analyze the electrophysiological characteristics of muscle contraction in individuals with sarcopenia under varying BFR pressures and resistance intensities. This includes examining motor unit recruitment patterns and recruitment thresholds, with the goal of identifying effective and appropriate BFR exercise parameters for this population. The objective of the third year is to investigate the effects of lower limb BFR combined with resistance training on functional performance in individuals with dynapenia. Building upon the findings from the first year, this phase will implement BFR resistance training interventions and evaluate both short-term and long-term effects. Through an experimental design, the study will assess changes in body composition, muscle strength, and functional performance following a four-month intervention, along with a three-month follow-up period, to determine whether participants can improve to a healthy status and maintain these improvements over time.
Study Type
INTERVENTIONAL
Allocation
RANDOMIZED
Purpose
PREVENTION
Masking
NONE
Enrollment
720
Leg Press Training. two sessions per week. BFR cuff set at 50-65% of Limb Occlusion Pressure, three sets of 30-15-15 repetitions in a total of 3 sets. Intensity set at 20-30% of 1RM. Device: Delfi Personal Tourniquet System (PTS)
Leg Press Training, two sessions per week, three sets per session. 8-10 repetitions each set with intensity ranging from 60%-75%.
Sports Biomechanics Laboratory
Kaohsiung City, No. 100, Shiquan 1st Rd., Sanmin Dist., Kaohsiung City, Taiwan
Baseline Data
Collect data on participants' demographics including gender, age, education level, living situation, lifestyle habits (such as alcohol consumption and smoking), and health status with chronic disease history. Daily activity patterns are assessed using the International Physical Activity Questionnaire - Short Self-Administered Taiwanese Chinese Version (IPAQ), which surveys participants' activities of different intensities over the past seven days.
Time frame: week0(pre-intervention), week16(post-intervention)
Muscle Strength
Hand Grip Strength measured via a Dynamometer, recorded in kg Knee Extensor Strength measured via a hand-held Dynamometer
Time frame: week0(pre-intervention), week16(post-intervention)
Muscle Function: The Short Physical Performance Battery (SPPB)
The Short Physical Performance Battery (SPPB) evaluates lower extremity function through three tasks: standing balance (side-by-side, semi-tandem, tandem), 4-meter gait speed, and a 5-repetition chair stand test. Each task is scored from 0 (inability to complete) to 4 (best performance). The three component scores are summed for a total score ranging from 0 to 12, with higher scores indicating better physical performance. Unit of Measure: scores on a scale (points)
Time frame: week0(pre-intervention), week16(post-intervention)
Height
Standard Measurements: Height, recorded in centimeters.
Time frame: week0(pre-intervention), week16(post-intervention)
Weight
Standard Measurements: Weight, recorded in kilograms(kg)
Time frame: week0(pre-intervention), week16(post-intervention)
BMI
weight and height will be combined to report BMI in kg/m\^2
Time frame: week0(pre-intervention), week16(post-intervention)
Blood Pressure
Measured via a Blood Pressure Monitor, Systolic Blood Pressure and Diastolic Blood Pressure will be recorded in mmHg
Time frame: week0(pre-intervention), week16(post-intervention)
Circumferences
Waist line, Thigh Circumference, Calf Circumference will be using standard tape measure and recorded in centimeter(cm)
Time frame: week0(pre-intervention), week16(post-intervention)
SARC-F Questionnaire
The questionnaire consists of five items, each scored 0, 1, or 2, with higher scores indicating greater difficulty for the participant. The total score ranges from 0 to 10. The items assess difficulty in Strength, Assistance in walking, Rising from a chair, Climbing, and Fall. A SARC-F score greater than 4 indicates a population at risk for sarcopenia.
Time frame: week0(pre-intervention)
Electromyography(EMG)
Electromyography characteristics of Vastus Lateralis and Vastus Medialis
Time frame: week0(pre-intervention), week16(post-intervention)
Limb Occlusion Pressure(LOP)
Measured in a seated position with the knee fully extended, using a laboratory-developed blood flow occlusion detection system. During the measurement, a manually inflated pressure cuff was placed at the proximal thigh near the hip joint, while a photoplethysmography (PPG) sensor and a temperature sensor were positioned over the dorsalis pedis artery on the anterior aspect of the ankle to detect distal PPG and temperature signals.
Time frame: week0(pre-intervention)
Skeletal muscle mass
Measured by Bioelectrical Impedance Analysis(BIA), recorded in kilograms(kg)
Time frame: week0(pre-intervention), week16(post-intervention)
Body fat percentage
Measured by Bioelectrical Impedance Analysis(BIA), recorded in percentage(%)
Time frame: week0(pre-intervention), week16(post-intervention)
Estimated appendicular skeletal muscle mass
Measured by Bioelectrical Impedance Analysis(BIA), recorded in kilograms(kg)
Time frame: week0(pre-intervention), week16(post-intervention)
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