Effects of Aquatic Exercise on Post-exercise Hypotension

This is a randomized controlled trial. The present study involves an acute and chronic intervention, which is a water-based exercise (one session: to acute intervention; 12-weeks of aquatic exercise program: to chronic intervention). The sample will be composed by elderly enrolled in university extension program titled "Hidroginastica na Terceira Idade" (Hydrogymnastics in aging). It will be evaluated the effects of water-based exercise on hemodynamics, self-reported sleep quality, depressive symptoms, quality of life, body composition, level of physical activity and functional capacity. The investigators hypothesized that an acute water-based exercise under different intensities promotes hemodynamics changes in elderly. In addition, the investigators hypothesized that 12-weeks of aquatic exercise may lead improvements in self-reported sleep quality, depressive symptoms, quality of life, body composition, level of physical activity and functional capacity in elderly.

To acute session, the participant will not be informed about what aquatic exercise session (light-, moderate-, high-intensity or control) intensity will be performed.

The volunteers will be instructed to remain in an orthostatic position immersed in water up to the imaginary line of the xiphoid process for 45 minutes without performing jerky body movements.

The light-intensity continuou exercise (LICE) session comprises a 45-minute of guide walking into the pool at 55-60% of maximum heart rate (HRmax). The HR will be checked every 2 minutes during the whole session.

The moderate-intensity continuous exercise (MICE) will bem performed divided into 3 phases: warm-up (10 minutes), main part (30 minutes) and cool down (5 minutes). The warm-up and cool down will be performed at 55-60% HRmax. The main part will last 30 minutes and will be performed by 3 sets of 5 exercises lasting 2 minutes each one at 70-75% HRmax. For all phases, HR will be measured every 2 minutes during the whole session.

The high-intensity intervaled exercise (HIIE) will bem performed divided into 3 phases: warm-up (10 minutes), main part (15 minutes) and cool down (5 minutes). The warm-up and cool down will be performed at 55-60% HRmax. The main part will last 15 minutes and will be performed by 2 sets of 5 exercises lasting 30 seconds to each exercise combined with 1 minute of active recovery. The exercise moment will be performed at 80-85% HRmax and the 1-minute active recovery at 55-60% HRmax. For both warm-up and cool down, HR will be measured every 2 minutes. For main part, HR will be measured at the end of each 30-seconds from exercise.

The participants will be submitted to a 12-weeks of aquatic exercise program, twice a week, for 1 hour each day.

No specific exercise will be performed. The participant will walk into the pool accompanied with a researcher for 45 minutes.

The following exercises will be carried out: a) jumping jacks (shoulder abduction and adduction); b) horizontal adduction and abduction of the shoulder; c) stationary running with knee elevation; d) pull and push horizontally with upper limbs; e) pull and push vertically with upper limbs. Note: For exercises 'a' and 'b', the legs alternated in movements in the sagittal plane to provide greater stability to the participant's movement. For exercises 'd' and 'e', the legs simulates a stationary running.

The following exercises will be carried out: a) jumping jacks (shoulder abduction and adduction); b) horizontal adduction and abduction of the shoulder; c) stationary running with knee elevation; d) pull and push horizontally with upper limbs; e) pull and push vertically with upper limbs. Note: For exercises 'a' and 'b', the legs alternated in movements in the sagittal plane to provide greater stability to the participant's movement. For exercises 'd' and 'e', the legs simulates a stationary running.

The sessions of the aquatic exercise training will be divided into 3 phases: warm-up (10 minutes), main part (40 minutes) and cool down. In order to increase intensity to aquatic exercise, the training program will carried out as follows: From week 1 to 4 the instructors will use a 128 bpm musics in both warm-up and cool down. In main part, will be used a 130 bmp musics. From week 5 to 8 the instructors will use a 130 bpm musics in both warm-up and cool down. In main part, will be used a 132 bmp musics. From week 9 to 12 the instructors will use a 132 bpm musics in both warm-up and cool down. In main part, will be used a 135 bmp musics.

Geriatric depressive symptoms (GDS-15) is a validated questionnaire which will be used in order to evaluate depressive symptoms in elderly.

Quality of life will be assessed by the WHOQOL-OLD questionnaire and it consists of 24 items on the likert scale attributed to 6 facets: 1) Sensory functioning, 2) Autonomy, 3) Past, present and future activities, 4) Social participation, 5) Death and dying, and 6) Intimacy. Each facet is composed of 4 items, so for each facet the score can range from 4 to 20. For this evaluation, the higher the score, the higher the quality of life.

The Habitual Physical Activity Questionnaire originated in 1982 by Baecke and colleagues (BAECKE; BUREMA, FRIJTERS, 1982) and was adapted for the elderly and validated later (VORORRIPS et al., 1991) and recently translated into Portuguese (SIMÕES, 2009). It is applied in the form of an interview, and has as reference the last 12 months being divided into 3 sections (1 - Domestic physical activities, 2 - Sporting activities and 3 - Activities in free time). From the scores attributed to each response provided by the elderly, scores equivalent to each section cited above are established. It is suggested that 3 cutoff points be created for the classification of the elderly regarding the level of physical activity (low, moderate and high) based on terciles.

Inclusion Criteria: Elderly (60 years and over) Able to practice physical exercise in water Able to answer all questionnaires Non-smoker Exclusion Criteria: Morbid obese Those who not complete all data collection procedures