Vivifrail Exercise Program in Nonagenarians: Effects on Function, Muscle, and Cognition

This is a three-arm, parallel-group randomized controlled trial evaluating a home-based multicomponent exercise program based on the Vivifrail protocol in community-dwelling nonagenarians (aged 90 years or older). A total of 54 participants (18 per group) will be randomly allocated to one of three groups: G1, performing the Vivifrail program at least twice a week; G2, performing it at least three times a week; or a control group (GC) maintaining usual activities.

Randomization will be performed using Randomizer software (www.randomizer.org) by an independent researcher not involved in the assessments. Allocation is stratified by sex and by baseline functional level, defined by collapsing the six Vivifrail functional categories into two groups (lower function: Types A, B, and B+; higher function: Types C, C+, and D), to ensure balanced distribution of baseline physical function across the three groups. Each participant is still assigned the individualized Vivifrail training passport corresponding to their specific functional category. Given the autonomous, home-based nature of the intervention, participants and interventionists cannot be blinded; however, outcome assessors remain blinded to group allocation throughout the study.

Assessments occur at three timepoints: baseline (T0), 12 weeks (T1), and 24 weeks (T2). The 24-week intervention is individualized according to each participant's functional profile, determined by the Short Physical Performance Battery (SPPB) and the corresponding Vivifrail training passport.

The primary outcome is physical function measured by the total SPPB score (0-12). Secondary outcomes include mobility (Timed Up and Go and cognitive dual-task cost), handgrip strength, lower-limb power (five-times sit-to-stand with linear encoder), gait speed, balance, muscle morphology of the vastus lateralis (ultrasound), cognition (Mini-Mental State Examination), and change in Vivifrail functional category. Data will be analyzed by intention to treat using generalized estimating equations (GEE), examining the group-by-time interaction.

• Mobility - Timed Up and Go (TUG) [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)]
• Mobility under dual task - Cognitive TUG and dual-task cost (DTC%) · [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)).]
• Handgrip strength [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)).]
• Lower-limb muscle power - Five-times sit-to-stand [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)).]
• Gait speed [Срок оценки: aseline (T0), 12 weeks (T1), and 24 weeks (T2)).]
• Balance [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)).]
• Change in Vastus Lateralis Muscle Thickness [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)]
• Change in Vastus Lateralis Echo Intensity (Muscle Quality) [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)]
• Cognition - Mini-Mental State Examination (MMSE) [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)]
• Change in Vivifrail functional category [Срок оценки: Baseline (T0), 12 weeks (T1), and 24 weeks (T2)]