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.

Inclusion criteria

• Aged 90 years or older
• Living in the community (own or family home)
• Able to walk independently or with a walking aid (cane or walker), without third-party assistance
• Minimum cognitive capacity to understand and perform the exercises (MMSE, education-adjusted cutoffs)
• Adequate home conditions to perform the program
• Availability of a family member or caregiver to support the sessions
• Signed informed consent (with legal guardian assistance when needed)

Exclusion criteria

• - Total inability to walk or permanent bedridden condition
• Severe cognitive impairment preventing safe understanding and execution of exercises
• Severe orthopedic, neurological, or rheumatological conditions preventing exercise
• Concurrent participation in another structured exercise program
• Anticipated unavailability (relocation, planned hospitalization, or institutionalization) during the intervention
• Refusal to sign informed consent or absence of a legal guardian when required