Aquatic Exercises Combined With Cognitive Tasks for Older Adults

The validated version of the Trail Making Test (TMT) for the Brazilian population is used to assess aspects of objective cognitive function (Carvalho \& Caramelli, 2020). In the first part of the instrument (TMT-A), which measures visual attention and processing speed, participants must draw a line connecting the numbers 1 to 25 in ascending order. In the second part (TMT-B), which measures cognitive flexibility and executive function, participants connect numbers (1-13) and letters (A-L) in an interleaved numerical and alphabetical order. Participants are instructed to maintain pencil-and-paper contact throughout the test, and shorter completion times indicate better performance.

The Brazilian version of the Cognitive Failures Questionnaire (CFQ) is used to measure the frequency of cognitive failures in everyday life, such as lapses in attention, memory problems, and failures in executing intentional actions (Paula et al., 2017). The questionnaire consists of 25 self-administered items, with responses on a Likert-type scale from 0 to 4, which assess the frequency of cognitive failures in different everyday contexts. The total score ranges from 0 to 100 points, with higher scores indicating a greater perceived frequency of cognitive failures and, therefore, poorer self-perception of cognitive function.

The 6-minute Walk Test (6MWT) is performed to measure aerobic fitness. The course proposed in the original test is 45.72 m rectangular. The course will be adapted for a straight line of 30 m in length, demarcated with cones every 3 m. Participants are instructed to walk for 6 minutes in a flat 30m course, where the total distance walked "as fast as possible" is assessed

The 30-s Chair-Stand test is performed to measure the strength of the lower limbs. Participants are instructed to sit and stand up from a chair 43 cm high from the seat, without the aid of the upper limbs, as many times as possible for 30 s. The total number of complete repetitions performed within the 30 seconds is recorded as the result, with higher values indicating greater lower body strength.

The Arm Curl test is performed to measure the strength of the upper limbs. Starting at full elbow extension and holding a 2 kg dumbbell in each hand, participants are instructed to perform the maximal number of elbow crunches over the full range of motion for 30 s. The test is performed with both upper limbs. The total number of complete repetitions performed within the 30 s is recorded as the result, with higher values indicating greater upper body strength.

The Sit-and-Reach test is performed using a Wells Bench to assess lower limb flexibility, particularly of the hamstring and lower back muscles. Participants sit barefoot on the floor with their legs extended and together, knees fully extended, and the soles of the feet flat against the front of the bench. With arms extended and hands overlapping, they slowly bend forward from the hips, sliding their hands along the measurement scale on the bench, without flexing the knees or using compensatory movements. The maximum reach is held for approximately two seconds, and the greatest distance reached in centimeters in three attempts is recorded.

The Timed Up and Go (TUG) test is performed to measure agility and dynamic balance. Participants are instructed to get up from the chair (43 cm), turn around a marker that will be 3m, and return to the starting position. The shortest time of the two attempts is considered the result.

Dual-task performance involves simultaneously performing the TUG test and a cognitive task. Participants are instructed to do the TUG while reciting alternating letters (e.g., A, C, E, etc.). The time taken for the TUG and the number of correctly recited letters are recorded as test results.

Office systolic blood pressure (SBP) and diastolic blood pressure (DBP) measurements are obtained using calibrated and automated oscillometric devices (HEM-7320, OMRON, China). Participants are kept in a calm environment for 5 min, and then measurements are performed in both arms of the participant. Three measurements, with an interval of 1 to 2 min, are taken in the arm with the highest initial value. The average of the three measurements is considered the subject's office blood pressure.

Blood pressure reactivity is measured as the difference between values recorded during a mental stressor and those obtained at rest. The Stroop Test (Stroop, 1935) is used to induce mental stress, presented via a video on a screen in front of the participant for three minutes. Every two seconds, a visual stimulus consisting of a word written in a specific color will appear, with the color of the word and its meaning being incongruent (for example, the word "blue" written in red). The participant must respond verbally and as quickly as possible to the color of the letters, ignoring the meaning of the word.

Throughout the test, systolic and diastolic blood pressure are measured by the auscultatory method, using a stethoscope and a calibrated aneroid sphygmomanometer, with one reading every minute, for a total of three readings. The reference arm is the same one used for resting BP assessments. After completing the test, participants are asked to rate their perceived stress level using a

Heart rate variability (HRV) is measured with participants seated and resting for 10 minutes, during which time their heart rate is continuously recorded using the Polar H10 chest sensor, a validated and widely used device for HRV analysis. Data collection takes place in a quiet environment, with a controlled temperature between 24°C and 26°C. Data is collected via Bluetooth and stored in the Polar Flow app, later exported in a compatible format (.txt or .csv). The final five minutes of the resting period are considered for analysis, as they offer greater physiological stability. Data are processed in Kubios HRV® software, with automatic artifact correction using a low threshold filter. HRV analysis follows the recommendations of the Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology (1996), considering time-domain parameters such as SDNN (Standard Deviation of NN Intervals), which reflects the global variability of autonomi

The validated version of the HADS for the Brazilian population is used to assess depressive and anxious symptoms (Botega et al., 1995). It is an instrument composed of 14 items, seven of which form the anxiety subscale and the other seven the depression subscale, allowing the assessment of symptoms in the previous week. Each HADS item has four response options ranging from 0 to 3, reaching a maximum of 21 points in each subscale. Participants are instructed to answer the questions based on the last 7 days. Based on the final score of each subscale, participants are categorized as having symptoms of anxiety or depression as "unlikely" (0 to 7 points), "possible" (8 to 11 points), and "probable" (12 to 21 points). Higher scores indicate more severe symptoms and a worse perceived emotional state.

The validated version of the Pittsburgh Sleep Quality Index (PSQI) for the Brazilian population is used to assess subjective sleep quality and related disorders (Bertolazi et al., 2011). The questionnaire consists of 19 items, grouped into seven components: subjective sleep quality, sleep latency, sleep duration, habitual sleep efficiency, sleep disorders, use of sleeping medications, and daytime dysfunction. Each component is scored from 0 (no difficulty) to 3 (severe difficulty), and the sum of the scores results in an overall score ranging from 0 to 21; scores greater than 5 indicate poor sleep quality.

Quality of life is assessed using the WHOQOL-BREF questionnaire, developed by the World Health Organization and previously validated in the Brazilian population (Fleck et al., 2000). The WHOQOL-BREF comprises 26 items divided into four domains: physical, psychological, social relationships, and environment. This instrument is self-administered, with a 5-point Likert scale, and produces standardized scores ranging from 0 to 100, with higher values indicating better perceived quality of life.