Short-Term Effects of Land-Based Versus Water-Based Resistance Training Protocols on Post-Exercise Hypotension in Normotensive Men: A Crossover Study.

Considering that water immersion may acutely reduce blood pressure (BP) and that exercise may elicit positive post-exercise hypotension (PEH) responses, we aimed to analyze the presence of PEH in normotensive individuals and compare its magnitude between two resistance training sessions performed in aquatic or land environments. Ten physically active men (23.2 ± 3.1 years) performed the two training protocols in a randomized, counterbalanced fashion. BP measurements were performed for 30 min (at 5 min intervals) both prior to (resting) and after each of the protocols. No differences were observed between protocols at baseline (p > 0.05). Only the water-based resistance training protocol resulted in a systolic BP reduction from 10 to 20 min post-exercise (all p < 0.05) compared to baseline. Compared to the land-based session, systolic BP was lower in the water-based protocol from 10 to 25 min post-exercise (all p < 0.05). On the other hand, diastolic BP showed a similar PEH effect between water and land-based protocols for the entire 30 min post-session period (all p < 0.001). Our results suggest that water-based resistance training holds the potential as a nonpharmacological strategy to lower BP levels following exercise.

Magnitude of vertical ground reaction force during water-based exercises in women with obesity.

Individuals with obesity are recommended to practice physical activity with reduced weight bearing, such as water-based exercises. However, the magnitude of the vertical ground reaction force (Fz) during these exercises is unknown in this population. This study aimed to verify the magnitude of peak Fz (Fzpeak) in women with obesity during different exercises performed in water and on land and at different intensities. Ten adult women with obesity class 1 (body mass index: 31.6 ± 0.57 kg·m-2) completed two randomised sessions, one performed on land and other in water, composed by three exercises (stationary running, frontal kick, butt kick) performed at cadences of 80 b·min-1, 100 b·min-1 and maximal. Fzpeak value was determined in each situation. Data were analysed using repeated-measures three-way ANOVA (α = 0.05). Significant lower Fzpeak values were observed in water (p < 0.001), with no significant differences between the exercises. A significant difference in the Fzpeak was verified between maximal cadence and 80 b·min-1 (p = 0.01). Water-based exercises performed by women with obesity revealed a Fzpeak reduction from land to water corresponding to 41-67%. Also, the three water-based exercises resulted in similar Fzpeak values, while an increase was observed 80 b·min-1 to the maximal cadence.

Kinetic parameters during land and water walking performed by individuals with Down Syndrome.

BACKGROUND: Down Syndrome (DS) is a genetic condition presenting delay in acquisition of main motor milestones, such as walking. Although studies have been investigating the biomechanical parameters during land walking performed by individual with DS, the literature is scarce regarding kinetic parameters analysis in this population, specially during water walking. RESEARCH QUESTION: This study sought to assess the vertical ground reaction force (Fz) of walking performed in water and on land at different speeds by individuals with DS. METHODS: Fourteen adults with DS (age: 27.9 ± 7.9 years; body mass: 58.4 ± 12.9 kg; height: 1.4 ± 0.1 m, body mass index: 29.2 ± 5.4 kg.m-2) completed two sessions of data collection, one on land and another in aquatic environment. The protocol consisted of walking performed at three self-selected speeds (slow, comfortable and fast) in randomized order. The Fz was assessed with a waterproof force plate in each condition. Two-way repeated-measures ANOVA (environment and speed), with Bonferroni's post hoc tests, were used for analysis. A significance level was set as α = 0.05. RESULTS: Significant differences were observed between environments (p < 0.001), with reduced first peak of Fz (68-73%), second peak of Fz (66-70%), loading rate (75-78%) and impulse (40-41%) in the water walking for all speeds analyzed. In the aquatic environment, no significant difference was observed for the first and second Fz peaks with the increasing speed of walking. Moreover, the loading rate significantly increased (p = 0.019) as the impulse significantly reduced (p < 0.001) in the higher speeds. SIGNIFICANCE: Individuals with DS present reduced Fz outcomes during water walking in comparison to land. Therefore, water walking may be performed by individuals with DS with safe vertical loads on lower limbs regardless the self-selected speed for rehabilitation, correction of gait and training purposes.

Water-based continuous and interval training in older women: Cardiorespiratory and neuromuscular outcomes (WATER study).

The purpose of this study was to investigate the effects of two water-based aerobic programs on cardiorespiratory and neuromuscular outcomes in older women. Forty-one women (60 to 75 years old) volunteered to participate in the study. Participants were randomized into a water-based continuous (CTG; n = 21; 63.9 ± 2.5 years) or an interval (ITG; n = 20; 64.8 ± 3.6 years) aerobic training group. Both training programs were performed for 12 weeks (45-min sessions twice a week), with exercise intensity based on rating of perceived exertion (Borg's RPE 6-20 Scale). Pre and post training assessments of cardiorespiratory and neuromuscular outcomes were performed. Data analyses were conducted using Generalized Estimating Equations and Bonferroni post-hoc test (α = 0.05). After the intervention, the CTG and the ITG displayed similar improvements in time to exhaustion (8% vs. 11%), peak oxygen uptake (9% vs. 7%), maximal dynamic knee extension strength (5% vs. 6%), dynamic muscular endurance of knee extensors (10% vs. 11%), maximal vastus lateralis electromyographic signal amplitude (13% vs. 35%), as well as an increase in muscle thickness (5% vs. 6%) and decrease in muscle echo intensity (-2% vs. -3%) of the quadriceps femoris. In conclusion, older women benefited from water-based exercise training prescribed based on participants' RPE, with both the interval and the continuous training programs resulting in similar increases in the cardiorespiratory and neuromuscular parameters.

Vertical Ground Reaction Force During a Water-Based Exercise Performed by Elderly Women: Equipment Use Effects.

Purpose: The present study aimed to compare the vertical ground reaction force responses during the performance of the stationary running water-based exercise with and without equipment at different cadences by elderly women. Method: Nineteen elderly women (age: 68.6 ± 5.0 years; body mass: 69.0 ± 9.5 kg; height: 154.9 ± 5.6 cm) completed one session consisting of the performance of the water-based stationary running with elbow flexion and extension immersed to the xiphoid process depth. The exercise was performed in three conditions, without equipment, with water-floating and with water-resistance equipment, at three cadences (80 b·min-1, 100 b·min-1 and maximal) in a randomized order. Peak and impulse of vertical ground reaction force were collected during the exercise using an underwater force plate. Repeated measures two-way ANOVA was used (α = 0.05). Results: Peak vertical ground reaction force (p < .001) and impulse (p ≤ 0.002) resulted in lower values for the water-floating use (0.42-0.48 BW and 0.07-0.13 N.s/BW) in comparison to the water-resistance equipment use (0.46-0.60 BW and 0.09-0.16 N.s/BW) and to the non-use of equipment (0.45-0.60 BW and 0.07-0.17 N.s/BW), except for the impulse at the maximal cadence. In addition, peak vertical ground reaction force at 80 b·min-1 (p = .002) and impulse at the maximal cadence (p < .001) showed lower values compared to the other cadences. Conclusion: The use of water-floating equipment minimizes the vertical ground reaction force during the stationary running water-based exercise performed by elderly women regardless of the cadence.

Water-based exercises in pregnancy: Apparent weight in immersion and ground reaction force at third trimester.

BACKGROUND: The morphological alterations during pregnancy may affect the biomechanical loads during exercise practice. Aquatic exercises may suit pregnant women, who are recommended to exercise with low vertical ground reaction force loads. Therefore, the study aimed to determine the apparent weight reduction during immersion and the vertical ground reaction force of three specific water-based exercises in pregnant women at the third trimester. METHODS: Eleven pregnant women volunteered to take part in the study [32.0 (SD 1.3) weeks, 28.1 (SD 5.7) years, 72.5 (SD 10.1) kg]. The protocol started with the participants immersed to the xiphoid process depth for the apparent weight assessment. Then, three water-based exercises (stationary running, frontal kick and butt kick) were randomly performed at a pre-selected cadence, with 5-min interval. The vertical ground reaction force was measured in each exercise and peak, impulse, contact time and swing time were determined. Repeated measures ANOVA was used (α = 0.05). FINDINGS: The apparent weight reduction resulted a mean of 82.9 (SD 6.5)% of body weight. Peak, impulse, contact time and swing time revealed no significant difference between exercises (P > 0.05). Values of peak of vertical ground reaction force ranged from 0.67 to 0.72 units of body weight. INTERPRETATION: Pregnant women at the third trimester can benefit from the apparent weight reduction during immersion for exercising. The three water-based exercises presented similar vertical ground reaction force values, which are considered as low odds for musculoskeletal injuries. Therefore, these findings highlight the safety of the water-based exercise program during pregnancy.

Neuromuscular adaptations to sixteen weeks of whole-body high-intensity interval training compared to ergometer-based interval and continuous training.

The neuromuscular adaptations between ergometer-based high-intensity interval training (HIIT-T; n = 15), whole-body high-intensity interval training (HIIT-WB; n = 12) and moderate-intensity continuous training (MICT; n = 14) were compared in forty-one healthy men randomized to 16 weeks of training (3x per week). Two-way repeated measures analysis of variance (ANOVA) showed countermovement (CMJ) and squat (SJ) jump height (HIIT-T: 8.5 ± 13.3%; 3.1 ± 9.7%, HIIT-WB: 6.4 ± 9.8%, 10.4 ± 16.1% and MICT: 2.2 ± 9.5%; 4.4 ± 12.1%, respectively), SJ peak power (HIIT-T: 1.7 ± 3.9%; HIIT-WB : 6.4 ± 7.9%; MICT: 0.5 ± 6.5%) and CMJ rate of force development (HIIT-T: 58.1 ± 50.5%; HIIT-WB: 36.9 ± 54.2%; MICT: 38.4 ± 64.3%) improved similarly in all training groups (all p < 0.05). CMJ peak power increased only after HIIT-T (4.3 ± 5.5%) and HIIT-WB (4.5 ± 5.2%), while no differences were observed in both the rectus femoris and vastus lateralis maximal electromyographic amplitude. Finally, marked improvements were also observed in the number of repetitions in the HIIT-WB protocol at the eighth week, with no further improvement at the sixteenth week. These data suggest that 16 weeks of HIIT-WB is capable to improve neuromuscular function to a similar extent as HIIT-T and MICT.

Water-based aerobic and combined training in elderly women: Effects on functional capacity and quality of life.

This study aimed to investigate the effects of two water-based training programs (aerobic and combined) and a non-periodized physical activity program on functional capacity and quality of life (QoL) of elderly women. Forty-one elderly female volunteers (65 ±â€¯4 years) were divided into three groups: aerobic training group (WBA, n = 13), combined training (sequence: resistance/aerobic; WBC; n = 11) and a control group of non-periodized physical activity program (CG, n = 9). The participants performed the water-based trainings twice a week for 12 weeks. The resistance training sets were performed at maximal effort and the aerobic training was performed in the percentage of the heart rate corresponding to the anaerobic threshold (85-110%) determined in an aquatic progressive test. Assessments of QoL perception (WHOQOL-BREF) and functional tests 30-Second Chair Stand, 6-Minute Walk and 8-Foot Up-and-go were performed before and after training. The data were analyzed using Generalized Estimating Equations (GEE), and Bonferroni post-hoc test (α = 0.05). In CG, QoL perception in the physical domain decreased (12 ±â€¯10%) and there was no difference in the other domains. On the other hand, QoL perception was significantly increased in the water-based training groups after the training period in the physical (WBC: 13 ±â€¯16%), psychological (WBA: 9 ±â€¯16%; WBC: 10 ±â€¯11%), social relationships (WBA: 19 ±â€¯42%; WBC: 16 ±â€¯21%) and environmental (WBA: 10 ±â€¯17%; WBC: 16 ±â€¯28%) domains and overall QoL (WBA: 17 ±â€¯22%). No significant difference was observed in the physical domain for WBA and in the overall for WBC. Significant improvements were observed for all groups in the functional tests 30-Second Chair Stand (WBA: 32 ±â€¯11%; WBC: 24 ±â€¯14%; CG: 20 ±â€¯9), 6-Minute Walk (WBA: 10 ±â€¯7%; WBC: 7 ±â€¯6%; CG: 7 ±â€¯5%) and 8-Foot Up-and-go (WBA: 11 ±â€¯5%; WBC: 10 ±â€¯9%; CG: 10 ±â€¯6%). Based on the results observed in this study, it can be concluded that both water-based trainings (aerobic and combined) are effective in improving functional capacity and QoL perception of elderly women. Although non-periodized physical activities seem to be sufficient to positively modify the functional capacity of this population, they are not efficient in improving QoL perception.

Postexercise hypotension during different water-based concurrent training intrasession sequences in young women.

The purpose of the study was to compare the acute effects of water-based resistance-aerobic (RA) and aerobic-resistance (AR) sequences on systolic blood pressure, diastolic blood pressure (DBP), and mean blood pressure (MBP) in young women. Thirteen active women participated in four sessions: (1) exercises familiarization, (2) aquatic maximal test to determine the heart rate (HR) corresponding to the anaerobic threshold (HRAT), (3) concurrent protocol RA, and (4) concurrent protocol AR. Both protocols were initiated with the blood pressure measurements at rest in supine position. After that, either RA or AR concurrent protocol was performed. At the end of both protocols, blood pressure was measured throughout 60 minutes (every 10 minutes). The water-based resistance protocol was made up by exercises at maximal velocity, and the water-based aerobic protocol was performed at ±5 bpm of HRAT continuously. Two-way analysis of variance with repeated measures was used to analyze the data (α = 0.05). There was no hypotensive effect on systolic blood pressure among the time points (P = .235) in both water-based intrasession exercise sequences (P = .423). Regarding the DBP and MBP, both intrasession exercise sequences presented similar (DBP: P = .980; MBP: P = .796) hypotensive effects in the first 10 minutes (DBP: P = .003; MBP: P = .008) at the end of RA and AR sessions (DBP: -4 vs. -13 mm Hg; MBP: -3 vs. -10 mm Hg). It was concluded that both RA and AR water-based concurrent training sessions resulted in postexercise hypotension (DBP and MBP) in normotensive young women.

Horizontal ground reaction forces to stationary running performed in the water and on dry land at different physiological intensities.

The aim of the present study was to compare the peak anterior-posterior (Fy) and medio-lateral (Fx) ground reaction forces (GRFs) of women performing stationary running at different intensities in aquatic and dry land environments. Fourteen young women performed the stationary running exercise at three cadences (first ventilatory threshold, second ventilatory threshold and maximum effort, as determined during exercise in water) in aquatic and dry land environments. Two-way repeated measures ANOVA was used to analyse the data (α = .05). As a result, significantly lower peak Fy anterior, Fy posterior, Fx medial and Fx lateral values were observed for the aquatic environment, except for the Fy posterior at the first ventilatory threshold. Significant differences were observed between cadences in the peak Fy anterior, Fy posterior, Fx medial and Fx lateral values, with higher values for the cadence corresponding to maximum effort compared to the first ventilatory threshold, except for the Fy posterior and Fx medial in the aquatic environment. The results indicate that the horizontal GRFs are reduced in the aquatic environment and depend on the intensity of stationary running exercise performance.