Effect of a multicomponent exercise programme (VIVIFRAIL) on functional capacity in frail community elders with cognitive decline: study protocol for a randomized multicentre control trial

Participants randomly assigned to the usual care group will receive normal outpatient care, including physical rehabilitation when needed.

The multicomponent physical exercise programme will be the VIVIFRAIL programme which was developed in Europe (Erasmus+ programme of the European Union). The VIVIFRAIL [26, 27] multicomponent exercise intervention programme consists of resistance training, gait re-training and balance training, which appear to be the best strategy for improving gait, balance and strength, as well as reducing the rate of falls in older individuals and consequently maintaining their functional capacity during ageing [26, 27]. This type of intervention has also been proven as the most effective to delay disability, cognitive impairment and depression [33] as well as effective to reverse the functional decline associated with acute hospitalization in very old patients [28].

The VIVIFRAIL exercise programme offers a general guideline to design a multicomponent physical exercise programme for frailty and falls treatment and prevention among people aged older than 70 years [26]. The programme is personalized, depending on the older person’s functional capacity level (serious limitation, moderate limitation and slight limitation as evaluated by the SPPB and a walking speed test) and the risk of falling. VIVIFRAIL works on the following components of physical fitness: arm and leg strength and power, balance and coordination to prevent falls, flexibility and cardiovascular endurance (i.e. walking).

All of the exercises outline the procedure, guidelines for starting, frequency and progression to be able to correctly monitor the instructions prescribed to the patient and improve their health [26].

To individualize the exercise programme we will assess the initial functional capacity and determine the risk of falling. Different functional capacity levels will be determined based on the scores obtained from the Short Physical Performance Battery Test (SPPB) and the 6-m gait velocity test (GVT) (see Fig. 3), with each leading to the recommendation of a certain customized multi-component physical exercise programme (Program A, B, C1, C2 or D) (see Fig. 3). Two sub-types will be defined in order to more accurately recommend a particular cardiovascular endurance programme for the group with slight limitation (frail/pre-frail) based on the maximum time they can walk without help. If the person can walk for 10–30 min, they are known as C1; and if they can walk for 30–45 min, they are known as C2 [26].

This classification will be complemented according to the risk of falling, assessed by the answer to some simple questions (see Fig. 3). If a risk for falling is detected, the frequency of the exercise will be increased and some additional measures will be adopted, as depicted in the lower part of the right-hand side of Fig. 3. Finally, the participant will be assessed for potential contraindications or need of medical evaluation (left-hand side of Fig. 3) [26].

Once the patient has been assigned to one of the six categories, a multicomponent programme taking 12 weeks will be implemented. The general characteristics of the different programmes are shown in Fig. 4.

The primary outcome measure is the change in functional and cognitive status during the study period. The functional capacity of patients will be evaluated by the Short Physical Performance Battery (SPPB) [34], which evaluates, balance, gait ability and leg strength using a single tool. The total score ranges from 0 (worst) to 12 points (best). The SSPB test has been shown to be a valid instrument for screening frailty and predicting disability, institutionalization and mortality. A total score of less than 10 indicates frailty and a high risk of disability and falls. A 1-point change in the score has clinical relevance [35, 36].

Loss of handgrip in the dominant hand is a useful tool for the measurement of functional capacity. This characteristic is a strong predictor of disability, morbidity and mortality as well as one of the components of Fried’s frailty phenotype [4]. Furthermore, the functional status of patients will also be assessed at recruitment with the Barthel Index [37], an international and validated tool of disability. The score ranges from 0 (severe functional dependence) to 100 (functional independence). At baseline, gait ability will be assessed using the 6-m gait velocity test (GVT). Starting and ending limits will be marked on the floor with tapelines for a total distance of 8 m. Participants will be instructed to walk at their self-selected usual pace for two attempts. The best result of both trials will be registered. The first and last metre, considered the warm-up and deceleration phases, respectively, will not be included in calculations of the gait assessment. Dual-task conditions (gait evaluation during the simultaneous performance of a cognitive task) have recently been recognized as a sensitive assessment method for interactions among cognition, gait, falls and frailty. Changes in gait parameters (i.e. gait velocity and gait variability) while performing a dual-task test (dual-task cost) may be early predictors of fall risk [38, 39] and may be useful tools for functional evaluations in frail older patients. Exercise can modify the dual-task cost and, consequently, the fall risk and functional capacity [40]. The dual-task paradigm [37] will be used in the 6-m habitual GVT. Two trials will be conducted to assess gait velocity while the patient is performing a verbal or counting task (verbal GVT and arithmetic GVT, respectively). During the verbal dual-task condition (verbal GVT), we will measure gait velocity while participants are naming animals aloud. During the arithmetic dual-task condition (arithmetic GVT), we will assess gait velocity while participants are counting backwards aloud from 100 in ones. The cognitive score will be measured by counting the number of animals named (dual-task with verbal performance) or determining how many numbers were counted backwards (dual-task with arithmetic performance). Isometric upper limb (dominant hand grip) and lower limb (right knee extensors and hip flexors) muscle strength will be measured using a manual dynamometer. Maximal dynamic strength will be assessed using the 1RM test in the bilateral leg press exercise using exercise machines (Matrix, Johnson Health Tech, Ibérica, S.L., Torrejón de Ardoz, Spain; and Exercycle S.L., BH Group, Vitoria, Spain). In the first assessment, the subjects will warm up with specific movements for the exercise test. Each subject’s maximal load will be determined in no more than five attempts, with a 3-min recovery period between attempts. After the 1RM values are determined, the subjects will perform 10 repetitions at maximal velocity and at intensities of 50% of 1RM to determine the maximum power (W) and the loss of power during the 10 repetitions in the leg press exercise [41]. The power will be recorded by connecting a velocity transducer to the weight plates (T-Force System, Ergotech, Murcia, Spain). During all neuromuscular performance tests, strong verbal encouragement will be given to each subject to motivate them to perform each test action as optimally and rapidly as possible. Distribution of the training sessions throughout the day should minimize cumulative fatigue and help to maintain adherence. Adherence to the exercise programme will be documented in an individual daily log of the sessions. Changes in cognitive-affective status after the intervention will be measured using the Spanish validated versions of the Minimental Cognitive Exam (MEC-Lobo) [42] in the case of dementia and the MOCA [43] in the case of MCI. The Yesavage GDS [44] and Trail Making part A [45] will be performed to assess depression and executive dysfunction. During functional tasks (such as balance, gait and rising from a chair) and cognitive evaluations (dual tasking), an inertial sensor unit (IU) will be attached over the lumbar spine (L3) to record the acceleration data in control and intervention participants [46, 47]. Primary and secondary variables are presented in Table 1.