Population ageing is associated with declines in motor and cognitive functions, which compromise autonomy and increase the risk of falls and cognitive impairment. Dual-task training programs have demonstrated additional benefits for physical and cognitive health compared with motor exercise alone. Aquatic environments provide unique advantages for older adults, facilitating movement execution and increasing adherence. However, evidence comparing aquatic dual-task training with conventional aquatic exercise remains scarce.

This randomized, controlled, double-blind trial aims to compare the effects of an aquatic dual-task training program with those of a conventional aquatic exercise program on cognitive and motor functions in cognitively preserved older adults. Eighty-four participants aged 65 years or older were recruited, screened for eligibility, and randomly assigned to one of two groups: the Dual-Task Aquatic Group (n = 42) or the Conventional Aquatic Exercise Group (n = 42). The 12-week intervention consisted of two weekly sessions of 45 minutes. Cognitive (Montreal Cognitive Assessment; Mini-Mental State Examination) and motor outcomes (Timed Up and Go Test; Berg Balance Scale) were assessed pre- and post-intervention. Statistical analyses included intra- and inter-group comparisons using non-parametric tests, with a significance level of 5%.

The dual-task group demonstrated significant improvements in balance, functional mobility, and cognitive performance, while the control group showed improvements only in motor outcomes. Between-group comparisons revealed superior cognitive gains in the dual-task group, with no differences in motor outcomes. Adherence exceeded 95% in both groups.

Population ageing introduces challenges associated with progressive motor and cognitive decline, increasing dependence, fall risk, and vulnerability to neurocognitive disorders. Dual-task training-combining simultaneous motor and cognitive tasks-has shown promising benefits in older adults, outperforming isolated motor exercise in several domains. The aquatic environment presents additional therapeutic advantages such as reduced joint load, enhanced balance safety, and increased adherence. Despite these strengths, few studies have rigorously compared aquatic dual-task training with conventional aquatic exercise.

This randomized, controlled, double-blind trial investigates the effects of a 12-week aquatic dual-task intervention versus conventional aquatic exercise in cognitively preserved older adults accustomed to aquatic environments. Eighty-four participants aged ≥65 years were recruited from the community and screened based on predefined eligibility criteria.

Dual-Task Aquatic Group (GDTA; n = 42): Participants performed motor exercises combined with progressively complex cognitive tasks (e.g., verbal fluency, attention, memory tasks), structured into three progressive phases across 12 weeks.

Conventional Aquatic Exercise Group (GEAC; n = 42): Participants completed a matched program of aquatic motor exercises without cognitive demands.

Both groups received two supervised 45-minute sessions per week in a therapeutic pool. Cognitive and motor functions were assessed immediately before and after the intervention using the Montreal Cognitive Assessment, Mini-Mental State Examination, Timed Up and Go Test, and Berg Balance Scale.

Non-parametric statistical analyses (Wilcoxon and Mann-Whitney tests) were conducted with a significance level of 5%. The GDTA demonstrated significant improvements in cognitive performance, balance, and functional mobility. The GEAC showed significant motor improvements but no cognitive gains. Between-group comparisons confirmed superior cognitive improvement in the GDTA, while motor outcomes did not differ significantly between groups. Adherence to both interventions exceeded 95%.

This study supports the integration of cognitive tasks into aquatic physiotherapy programs for older adults as a strategy to enhance cognitive outcomes while maintaining motor benefits.

Inclusion Criteria:

• Adults aged 65 years or older.
• Cognitively preserved, defined as a Mini-Mental State Examination (MMSE) score equal to or above reference values adjusted for education: illiterate ≥16; 1-11 years of schooling ≥23; more than 11 years ≥28.
• Prior experience of 3-6 months with regular aquatic physical therapy (2 sessions per week) to ensure familiarity and adaptation to the aquatic environment.
• Medically cleared to perform moderate-intensity aquatic exercise, confirmed by:
• Orthopedic Assessment: No severe musculoskeletal conditions preventing safe participation.
• Clinical Risk Classification: Low to moderate risk according to the American College of Sports Medicine (ACSM) Risk Stratification.
• Functional Capacity: Duke Activity Status Index score ≥7.

Exclusion Criteria:

• Requirement for walking aids, as this interferes with safety and exercise execution.
• Previous diagnosis of progressive and severe neurological diseases, such as Parkinson's disease, Amyotrophic Lateral Sclerosis, or dementias, that could compromise response to intervention.
• Clinical conditions preventing safe aquatic exercise, including unstable cardiovascular disease, urinary or fecal incontinence, transmissible infectious or dermatological diseases, severe psychiatric disorders, severe respiratory conditions, or acute musculoskeletal limitations.
• Participation in other physical or cognitive training programs during the intervention period.
• Inability to understand or sign the informed consent form.