Aging, Autonomic Nervous System, Hemodynamics
Conditions
Keywords
Aerobic exercise, Circuit training, Heart rate variability, Arterial stiffness, Blood pressure, Older adults, Digital health
Brief summary
This study was conducted in collaboration with a community-based retirement facility to evaluate the clinical effectiveness of a smart, technology-assisted circuit exercise intervention for community-dwelling older adults. Traditional exercise prescriptions for older adults often lack real-time monitoring of individual physiological responses, which can increase the risk associated with exercise participation. This program integrated real-time physiological monitoring (including heart rate reserve, HRR) to guide individualized exercise intensity within a moderate-intensity range (50%-60% HRR). The study was conducted in two stages with different allocation designs: Stage 1 (Randomized Controlled Design): Participants were randomly assigned to either an intervention group or a control group. The intervention group received the smart circuit exercise program, while the control group did not receive the exercise intervention and underwent pre- and post-assessment only. This stage allowed for between-group comparison of intervention effects. Stage 2 (Single-Group Extension): Following completion of Stage 1, the facility extended the exercise program to a broader group of community residents as part of a real-world implementation and scale-up initiative, in order to evaluate the program under routine practice conditions and to provide equitable access to the intervention across the community. A concurrent control group was not maintained during this stage, consistent with its focus on real-world effectiveness evaluation rather than efficacy comparison. Participants in both stages received circuit-based exercise training three times per week (24 sessions total over approximately 8 weeks), with intensity controlled at 50%-60% heart rate reserve (HRR). Outcome measures assessed before and after the intervention period included: cardiac autonomic activity and hemodynamic function (including blood pressure and heart rate variability), arterial stiffness, body composition (including skeletal muscle mass, body fat mass, and body fat percentage), functional fitness (including lower limb muscle strength and dynamic balance), clinical blood biochemistry indicators (including HbA1c), depressive symptoms (CESD-10), and sleep quality (Pittsburgh Sleep Quality Index, PSQI). Statistical analyses varied by stage and publication. For Stage 1 between-group comparisons, linear mixed models (LMM) with participant as a random intercept were used to test Time × Group interactions, adjusting for age, sex, and height. For broader cohort analyses, two-way mixed-design analysis of variance and paired-samples t-tests were used. Statistical significance was set at alpha = .05 for all analyses.
Detailed description
This study was conducted in collaboration with a community-based retirement facility to evaluate the clinical effectiveness of a smart, technology-assisted circuit exercise intervention for community-dwelling older adults. Traditional exercise prescriptions for older adults often lack real-time monitoring of individual physiological responses, which can increase the risk associated with exercise participation. This program integrated real-time physiological monitoring (including heart rate reserve, HRR) to guide individualized exercise intensity within a moderate-intensity range (50%-60% HRR). The study was conducted in two stages with different allocation designs: Stage 1 (Randomized Controlled Design): Participants were randomly assigned to either an intervention group or a control group. The intervention group received the smart circuit exercise program, while the control group did not receive the exercise intervention and underwent pre- and post-assessment only. This stage allowed for between-group comparison of intervention effects. Stage 2 (Single-Group Extension): Following the completion and analysis of Stage 1, which demonstrated the safety and preliminary effectiveness of the smart circuit exercise program, the facility extended the program to a broader group of community residents as part of a real-world implementation and scale-up initiative, in order to evaluate the program's effectiveness under routine practice conditions and to provide equitable access to the intervention across the community. A concurrent control group was not maintained during this stage, consistent with its focus on real-world effectiveness evaluation rather than efficacy comparison. Participants in both stages received circuit-based exercise training three times per week (24 sessions total across approximately 8 weeks), with intensity controlled at 50%-60% heart rate reserve (HRR). Outcome measures assessed before and after the intervention period included: body composition (including skeletal muscle mass, body fat mass, and body fat percentage), blood pressure, functional fitness (lower limb muscle strength and dynamic balance), clinical blood biochemistry indicators (including HbA1c), depressive symptoms (CESD-10), and sleep quality (Pittsburgh Sleep Quality Index, PSQI). Statistical analyses included two-way mixed-design analysis of variance and paired-samples t-tests, with statistical significance set at alpha = .05. Stage 1 data were analyzed as a between-group comparison. Stage 2 data were analyzed independently as a within-group pre-post comparison and were not statistically compared to the Stage 1 control group, given the non-concurrent recruitment timing between stages. Note: This trial is being registered retrospectively. The study was conducted and closed under IRB approval prior to the decision to pursue publication in international peer-reviewed journals, at which point trial registration was completed.
Interventions
BEHAVIORALSmart Circuit Exercise Program
A moderate-intensity circuit-based exercise program incorporating real-time physiological monitoring (including heart rate reserve, HRR) to guide individualized exercise intensity. Sessions were held 3 times per week (24 sessions total over approximately 8 weeks), with intensity controlled at 50%-60% HRR.
Sponsors
Chang Gung Memorial Hospital
Study design
Allocation
NON_RANDOMIZED
Intervention model
PARALLEL
Primary purpose
PREVENTION
Masking
NONE
Masking description
Due to the nature of the exercise intervention, participants and intervention personnel could not be blinded to group assignment. Outcome assessors were not blinded to group allocation during data collection.
Intervention model description
This study employed a two-stage design. Stage 1 used a parallel-group randomized design, with participants randomly assigned to an intervention or control group. Stage 2 was a single-group, non-randomized extension in which additional participants received the intervention without a concurrent control group, conducted to evaluate real-world program effectiveness following the completion of Stage 1.
Eligibility
Sex/Gender
ALL
Age
65 Years to 85 Years
Healthy volunteers
Yes
Inclusion criteria
* Age 65 to 85 years, community-dwelling * Able to walk independently, without assistance * Able to understand study procedures in Mandarin or Taiwanese and voluntarily provide informed consent * Willing to undergo health examinations and testing, and to provide historical health examination records * Completed a health status questionnaire covering medical history, medication use, and comorbidities * Physical Activity Readiness Questionnaire Plus (PAR-Q+) results indicating suitability for exercise training (or written physician clearance obtained if any positive response) * Completed the International Physical Activity Questionnaire (IPAQ), with results not meeting the criterion for regular exercise within the past 6 months (i.e., fewer than 2 sessions/week or less than 30 minutes/session of moderate-intensity aerobic exercise)
Exclusion criteria
* Cognitive impairment or dementia precluding understanding of study procedures or compliance with test instructions * Lower-extremity fracture, joint surgery, or joint replacement within the past 3 months precluding safe completion of sit-to-stand or walking tasks * Severe joint pain precluding safe completion of baseline test movements, as assessed by study personnel * Unexplained syncope or fall history within the past 3 months, or safety concerns as assessed by study personnel * Acute illness (e.g., fever, acute infection) * Cardiac pacemaker or incompatible metal implants affecting bioelectrical impedance analysis (BIA) measurement safety * Meeting the criterion for regular exercise within the past 6 months per the International Physical Activity Questionnaire (IPAQ) (≥2 sessions/week, ≥30 minutes/session of moderate-intensity aerobic exercise) * Physical Activity Readiness Questionnaire Plus (PAR-Q+) screening results indicating unsuitability for exercise training, without written physician clearance * Unstable cardiovascular disease, including unstable angina, uncontrolled atrial or ventricular arrhythmia, uncontrolled resting sinus tachycardia (\>120 beats/min), decompensated congestive heart failure, third-degree atrioventricular block without a pacemaker, acute pericarditis or myocarditis, or recent thrombosis/thrombophlebitis * Uncontrolled diabetes (HbA1c \> 9%, resting blood glucose \> 300 mg/dL, or \> 250 mg/dL with ketosis) or poorly controlled hypertension (systolic blood pressure \> 180 mmHg or diastolic blood pressure \> 100 mmHg) * Use of medications that may interfere with muscle metabolism (e.g., high-dose corticosteroids, immunosuppressants) * Symptomatic orthostatic hypotension (blood pressure drop \> 20 mmHg) * Resting ST-segment depression \> 2 mm * Severe neurological or musculoskeletal disease precluding safe performance of study procedures, as assessed by study personnel * Currently participating in another clinical trial involving an exercise intervention * Severe anemia, acute infectious disease, or other physiological conditions deemed unsuitable for exercise training by the investigator
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Change in Blood Pressure | Baseline and up to 12 weeks | Systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP), measured via upper-arm automatic blood pressure monitor, average of 3 consecutive readings, reported in mmHg. |
| Change in Rate-Pressure Product | Baseline and up to 12 weeks | Cardiac load index calculated as heart rate multiplied by systolic blood pressure, reported in bpm·mmHg. |
| Change in Time-Domain Heart Rate Variability | Baseline and up to 12 weeks | Standard deviation of NN intervals (SDNN) and root mean square of successive differences (RMSSD), derived from 4-minute seated ECG recording, reported in milliseconds. |
| Change in Frequency-Domain Heart Rate Variability | Baseline and up to 12 weeks | Normalized low-frequency (nLF) and high-frequency (nHF) power, derived from 4-minute seated ECG recording, reported in normalized units. |
| Change in Dynamic Heart Rate Variability Reactivity | Baseline and up to 12 weeks | E/I ratio (from 2-minute deep breathing), Valsalva ratio (from 2-minute Valsalva maneuver), and 30:15 ratio (from 2-minute standing), each reported as a ratio. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Change in Waist-Hip Ratio | Baseline and up to 12 weeks | Waist-hip ratio (WHR), reported as a ratio. |
| Change in Visceral Fat Area | Baseline and up to 12 weeks | Visceral fat area (VFA), reported in cm\^2. |
| Change in Digital Volume Pulse Stiffness Index | Baseline and up to 12 weeks | Stiffness Index (SI), derived from photoplethysmography-based digital volume pulse (DVP) pulse contour analysis, reported in m/s. |
| Change in Digital Volume Pulse Contour Reflection Index | Baseline and up to 12 weeks | Reflection Index (RI), derived from pulse contour analysis of the digital volume pulse (DVP) waveform, reported as a ratio. |
| Change in Second-Derivative Photoplethysmogram Amplitude Ratios | Baseline and up to 12 weeks | Second-derivative photoplethysmogram (SDPTG) amplitude ratios (b/a, c/a, d/a, e/a), derived from second-derivative analysis of the digital volume pulse (DVP) waveform, reported as a ratio. |
| Change in Augmentation Index | Baseline and up to 12 weeks | Augmentation Index (AIx) and heart-rate-normalized Augmentation Index (AIx@75), derived from DVP pulse contour analysis, reported as a percentage. |
| Change in Aging Index | Baseline and up to 12 weeks | Aging Index (AGI), derived from second-derivative photoplethysmogram (SDPTG) analysis, reported in arbitrary units. |
| Change in Lower- and Upper-Limb Muscular Strength | Baseline and up to 12 weeks | Lower-limb strength (LowerStr), assessed using the 30-Second Chair Stand Test, and upper-limb strength (UpperStr), assessed using the 30-Second Arm Curl Test, reported in repetitions. |
| Change in Lower- and Upper-Limb Flexibility | Baseline and up to 12 weeks | Lower-limb flexibility (LowerFlex), assessed using the Chair Sit-and-Reach Test, and upper-limb flexibility (UpperFlex), assessed using the Back Scratch Test, reported in cm. |
| Change in Cardiorespiratory Endurance | Baseline and up to 12 weeks | Cardiorespiratory endurance assessed using a 2-minute step test, reported in number of steps. |
| Change in Dynamic and Static Balance | Baseline and up to 12 weeks | Dynamic balance (DynBal), assessed using the Timed Up-and-Go Test, and static balance (StatBal), assessed using the Single-Leg Stance Test (eyes open), reported in seconds. |
| Change in HbA1c | Baseline and up to 12 months following study completion | Glycated hemoglobin (HbA1c), based on voluntary submission of participants' individual routine health examination reports. Assessment timing and laboratory were not standardized by the study protocol, as this measure relied on participant-provided documentation rather than investigator-administered blood collection. Reported as a percentage. |
| Change in Lipid Profile | Baseline and up to 12 months following study completion | Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG), based on voluntary submission of participants' individual routine health examination reports at any point up to 12 months following study completion. Assessment timing and laboratory were not standardized by the study protocol, as this measure relied on participant-provided documentation rather than investigator-administered blood collection. Reported in mg/dL. |
| Change in Skeletal Muscle Mass and Body Fat Mass | Baseline and up to 12 weeks | Skeletal muscle mass (SMM) and body fat mass (BFM), reported in kg. |
| Change in Percent Body Fat | Baseline and up to 12 weeks | Percent body fat (PBF), reported as a percentage. |
| Change in Body Mass Index | Baseline and up to 12 weeks | Body mass index (BMI), calculated from body composition analysis, reported in kg/m\^2. |
Countries
Taiwan
Contacts
PRINCIPAL_INVESTIGATORJong-Shyan WANG, Ph.D.
Chang Gung University, Guishan, Taoyuan 333
Outcome results
None listed