Effects of a combined exercise programme on physical fitness, heart-rate regulation and continued physical activity in older adults

INTERVENTION: The study comprises two consecutive phases. Recruitment begins on 4 June 2018 through advertisements, leaflets, notices and direct invitations addressed to older adults attending two institutions in Monterrey, Nuevo León, Mexico. Before recruitment, meetings are held with the authorities of each participating centre and the required institutional permissions are obtained. Eligible volunteers within each institution are assigned anonymous identification codes and selected through a simple random‐selection procedure until 30 participants have been enrolled at each centre. This random procedure is used only to select participants within each institution and does not determine allocation to the intervention condition. Participants recruited from the Centro de Salud y Bienestar of Servicios Médicos, Universidad Autónoma de Nuevo León, constitute the experimental group. Participants recruited from DIF Casa Club del Adulto Mayor Los Altos constitute the concurrent control group. Therefore, the first phase uses a quasi‐experimental, non‐randomised, parallel‐group design with a non‐equivalent control group. All participants receive a verbal and written explanation of the study procedures, potential benefits and risks and provide written informed consent before baseline testing. Baseline assessments are conducted between 13 and 24 August 2018 over two consecutive weeks, with one group assessed each week. Measurements are performed at the participating centres and at the Faculty of Sports Organization of the Universidad Autónoma de Nuevo León. The experimental group begins supervised multicomponent training on 27 August 2018. The initial programme comprises 24 effective weeks, with three 60‐minute sessions per week. Each session consists of a 10‐minute warm‐up, a 40‐minute main section and a 10‐minute cool‐down. The programme combines resistance, aerobic‐endurance, flexibility, balance and coordination exercises. Training begins with an adaptation period and progresses through planned changes in exercise difficulty, intensity, volume and density according to participants’ responses and tolerance. Resistance training is performed approximately twice per week for about 20 minutes, targeting the major upper‐ and lower‐body muscle groups. Training comprises approximately 1–3 sets of 8–12 repetitions, with progression from light intensities of approximately 40–50% to moderate intensities of approximately 60–80% of one‐repetition maximum. Exercises include bodyweight activities, free movements and elastic resistance. Aerobic‐endurance training is performed three times per week for approximately 20 minutes per session, progressing from light or moderate to more vigorous perceived intensity. Activities include dance, marching, light jogging and movement drills, with intensity monitored through perceived exertion. Balance and coordination are trained approximately twice per week for about 10 minutes using static and dynamic tasks, changes of direction, obstacle courses, body‐weight transfer and coordinated movements with hoops, balls, ropes, cones and mats. CONDITION: Healthy ageing, including physical fitness, functional performance, cardiometabolic health, cardiac autonomic modulation and physical activity adherence in older adults ; Other PRIMARY OUTCOME: Anthropometry, body composition, and bone health: Body mass and standing height measured using a seca 700 mechanical scale and seca 220 height rod, respectively, and body mass index is calculated as kg/m2. These measurements are obtained at baseline (T1), month 3 (T2), month 6 (T3), month 7 (T4), month 9 (T5), and month 12 (T6). Fat mass, lean mass, bone mineral content, and bone mineral density are measured using dual‐energy X‐ray absorptiometry with a Lunar Prodigy scanner (GE Healthcare) at baseline (T1), month 6 (T3) and month 12 (T6). The original control group is not assessed after T3. Cardiometabolic health: Systolic and diastolic blood pressure measured using manual auscultation using an aneroid sphygmomanometer and stethoscope. Fasting capillary glucose, total cholesterol, and triglycerides are measured using the Accutrend Plus system. These measures are obtained at baseline (T1), month 3 (T2), month 6 (T3), month 7 (T4), month 9 (T5), and month 12 (T6). The original control group is assessed only at T1, T2, and T3. Functional performance: Lower‐extremity functional performance measured using the Short Physical Performance Battery (SPPB), comprising standing balance, usual gait speed, and repeated chair‐rise tasks. It is assessed at baseline (T1), month 3 (T2), month 6 (T3), month 7 (T4), month 9 (T5), and month 12 (T6). The original control group is assessed only at T1, T2, and T3. Heart rate variability as an indicator of cardiac autonomic modulation measured using 10‐minute seated beat‐to‐beat heart‐rate recordings obtained in the morning using the Polar Team2 system after 10–12 minutes of seated rest in a quiet, temperature‐controlled environment at baseline (T1), 3 effective months (T2) and 6 effective months (T3) in the control and experimental groups; months 7 (T4), 9 (T5) and 12 (T6) in the maintenance and programme cessation groups. The original control group is not assessed during the second phase. Physical activity adherence and stage of behavioural change measured using the short Stages of Change for Exercise Questionnaire (CEC‐E) and based on the Transtheoretical Model at baseline (T1), 3 effective months (T2), 6 effective months (T3), month 7 (T4), month 9 (T5) and month 12 (T6) Physical fitness: Lower‐ and upper‐body muscular strength measured using the number of complete repetitions performed in the 30‐second chair‐stand and 30‐second arm‐curl tests, respectively. Lower‐ and upper‐body flexibility are measured as the distance achieved in the chair sit‐and‐reach and back‐scratch tests, respectively. Aerobic endurance is measured as the number of complete steps performed in the 2‐minute step test, and agility and dynamic mobility are measured as the completion time in the 8‐foot up‐and‐go test. All measures form part of the Senior Fitness Test and are obtained at baseline (T1), month 3 (T2), month 6 (T3), month 7 (T4), month 9 (T5), and month 12 (T6). The original control group is assessed only at T1, T2, and T3. INCLUSION CRITERIA: 1. Men and women aged 60 years or older 2. Functionally autonomous older adults able to perform the physical assessments and exercise activities required by the study 3. Apparently healthy or presenting one or more stable, clinically controlled chronic conditions without associated complications that contraindicated exercise 4.Available and willing to attend the study assessments and, when applicable, the supervised multicomponent training programme 5. Able to understand and follow the instructions required for study participation