Edited by: Teresa Maria Seccia, University of Padova, Italy
Reviewed by: Marzena Chrostowska, Medical University of Gdansk, Poland; Yuko Gando, National Institutes of Biomedical Innovation, Health and Nutrition, Japan
Specialty section: This article was submitted to Hypertension, a section of the journal Frontiers in Cardiovascular Medicine
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Hypertension is a chronic disease that affects about 30% of the world’s population, and the physical exercise plays an important role on its non-pharmacological treatment. Anywise, the
World data have shown that systemic arterial hypertension (SAH) has one of the largest number of occurrences (about 30%), and it was indirectly responsible for about 9.4 million deaths in 2010 (
There are some possibilities for SAH treatment, including non-pharmacological therapy. It includes changes in behavioral factors, among which physical exercise presents one of the most effective and safe intervention (
Post-exercise hypotension is termed by the post-exercise period in which are registered lower BP values than those measured in the pre-exercise or in a control day (
Some studies (
Since 2004, many studies have analyzed the BP kinetics after CE (
To the best of our knowledge, this was the first study to investigate the effect of a CE session performed in the morning, evening, and fractionated sessions (50% in the morning and the other 50% at night) and evaluating the acute BP kinetics and its reactivity after sessions in hypertensive middle-aged women. Therefore, this study aimed to analyze the acute BP kinetics after 1 h of exercises and the BP reactivity after different CE sessions and its fractioning of hypertensive middle-aged women. The hypothesis of our study was that the CE session fractionized throughout the day would promote better PEH than the other sessions.
All sessions, exercise, and control were performed in common time for all volunteers (08:00 h and 18:00 h), as well as randomized and with a minimum interval of 72 h between each, to obtain uniformity and minimize bias that could influence BP kinetics regarding the different day times. Moreover, all experimental sessions were conducted by three qualified professionals, yielding a ratio of 3:2 (professional:participant) at all times during the study.
The volunteers were instructed to maintain a moderate rate of movement during the RE (2 s for the concentric phase and 2 s for the eccentric phase), breathing freely to avoid Valsalva maneuver and ingest water
Eleven hypertensive middle-aged women (57.5 ± 5.1 years) voluntarily participated of this study and had at least 3 months of CE experience. The anthropometric and hemodynamics characteristics of the study group are presented in Table
| Mean ± SD | CI (95%) | |
|---|---|---|
| Age (years) | 57.5 ± 5.1 | 54.0–60.9 |
| Body mass (kg) | 70.1 ± 10.6 | 62.9–77.2 |
| Height (m) | 1.5 ± 0.6 | 1.5–1.6 |
| BMI (kg/m2) | 30.7 ± 3.9 | 28.1–33.4 |
| AC (cm) | 98.8 ± 12.2 | 90.5–107.0 |
| WC (cm) | 90.4 ± 11.9 | 82.4–98.3 |
| HC (cm) | 102.4 ± 9.3 | 95.8–109.1 |
| WHR | 0.9 ± 0.1 | 0.8–1.0 |
| SBP (mmHg) | 121 ± 6.4 | 117–125 |
| DBP (mmHg) | 75 ± 7.1 | 70–80 |
| MAP (mmHg) | 89 ± 7.0 | 84–94 |
| HR (bpm) | 70 ± 8.6 | 64–76 |
| DP (mmHg × bpm) | 8,404 ± 975.2 | 7,749–9,059 |
The present study has been approved by the Research Ethics Committee of Federal University of Sergipe (CAAE: 49154515.2.0000.5546) and followed the norms advocated by the Declaration of Helsinki (
The body mass (kg) and height (cm) of all volunteers were obtained using an anthropometric balance (Welmy SA, Santa Barbara do Oeste, Brazil), with a maximum capacity of 150 kg, and 0.1 kg of scale. From these two variables, the body mass index (BMI) was estimated.
Subsequently, the abdominal circumference (AC), waist circumference (WC), and hip circumference (HC) were measured using an anthropometric metal tape (Sanny, São Bernardo do Campo, Brazil) with 0.1 mm scale. With these values, the waist–hip ratio of all volunteers was estimated. All measurements were made following the World Health Organization protocol (
The intensity of the exercises was estimated and controlled using the SPE of each participant, which was obtained from the visual analog scale OMNI-GSE (
After three familiarization sessions with the exercises and following the proposed protocol, the volunteers underwent a test for estimation of the maximum loads, applied in 2 days and with a 72 h minimum interval between each of them. This interval allows to obtain greater reliability and reproducibility of results (
This test consisted in an execution of eight maximum repetitions (
Each volunteer performed three attempts for the following exercises: Leg Press, Machine Row, Deadlift, and Bench Press, with a two to five rest-minutes period between them. These exercises were performed in alternating body segments order to facilitate recovery and minimize fatigue. It is noteworthy that prior standardized instructions and verbal encouragement were given in order to obtain results as close as possible to their maximum (
All BP measurements were performed on the left arm having the volunteer comfortably sat in a quiet room at the controlled temperature of 25°C, using an automatic, calibrated and validated device (Microlife, model BP 3AC1-1) (
Once the volunteers arrived at the laboratory, they were instructed to sit, and the BP was measured over 20 min, measuring the BP each 5 min in order to get the arithmetic mean of BP at rest. After this period, the sessions were conducted.
At the end of each session, the volunteers were led to a rest room in the laboratory, and they were instructed to remain sat for 1 h. During this time, the BP was measured every 15 min (Rec15, Rec30, Rec45, and Rec60). Finally, the volunteers underwent the cold pressor test (CPT) to analyze the BP reactivity.
The BP reactivity is a hemodynamic variable characterized by sudden BP increase after a stressful event of physical or psychological nature, and some studies involving physical exercise (
The morning and night sessions consisted of three sets of 10 repetitions (3 × 10 at 75% of 8-RM) with active rest between sets (1 min of moderate walk at 5–6 SPE scale), since this recover is suggested to enhance the PEH (
The fractionized session (FS) was performed by the fragmentation of the proposed exercises before described. Thus, the volunteers reported to the laboratory in both shifts, in the morning (0800 hours) and at night (1800 hours) of the same day.
Once the volunteers arrived in the morning, the BP at rest was measured following the procedures described previously. After that, they performed three sets of 10 repetitions (3 × 10 at 75% of 8-RM) in the Leg Press and Machine Row, with active rest between sets (1 min of moderate walk at 5–6 SPE scale), plus 10 min of cycling at moderate–severe intensity (at 7–8 SPE scale). Subsequently, the volunteers were released to their respective daily activities.
When the volunteers returned to the laboratory at night, they performed three sets of 10 repetitions (3 × 10 at 75% of 8-RM) in the Deadlift and Bench Press, with active rest between sets (1 min of moderate walk at 5–6 SPE scale), plus 10 min of cycling at moderate–severe intensity (at 7–8 SPE scale). After these procedures, the volunteers were conducted to the rest room to record BP of 1 h post-exercise, and then they underwent the CPT.
The results were expressed using elements of descriptive statistics (mean, SD, absolute and relative frequencies) for all values obtained. Data normality was tested from the Shapiro–Wilk test and the homogeneity by the Levene test.
Analysis of variance with repeated measures was used to compare the delta variations [BPrest − (Rec15 or Rec30 or Rec45 or Rec60 or CPT)], adjusting for the main effect of Bonferroni. As for possible differences between sessions, the analysis of covariance, with multiple comparisons between pairs of Bonferroni, was applied.
All analyses were adjusted from the inclusion of antihypertensive drugs categorized as dichotomous covariates (
The power of the sample size was calculated using the G*Power, version 3.1.9.2 (Erdfelder, Faul, & Buchner, 1996, Kiel, Germany), considering the sample size of this study and α = 0.05, obtaining a statistical power (1 − β) of 0.96 for the performed analysis. The data were analyzed using SSPSS (Version 22.0; IBM Corp., Armonk, NY, USA), adopting a significance level of 5% (
Figure
Figure
The percentage of variance from the acute response after CPT, taking CS as reference, is presented in Table
| CS (mmHg) | MS (mmHg) (%Δ) | NS (mmHg) (%Δ) | FS (mmHg) (%Δ) | |
|---|---|---|---|---|
| CPT (SBP) | 53.7 | 30.0 (−44.2)# | 39.4 (−26.6) | 39.5 (−26.5) |
| CPT (DBP) | 28.4 | 11.7 (−58.8)# | 19.3 (−32.1) | 22.4 (−21.3) |
The main findings of the present study were (a) the exercise session performed during the morning was more effective in promoting PEH for SBP than the other sessions; (b) the morning session was the only to promote attenuation of BP reactivity to SBP and DBP, compared to the CS; (c) the FS neither optimized PEH nor the attenuation of BP reactivity.
No differences were observed for the PEH for SBP between the MS and NS, yet de Brito et al. (
The age and pathological condition of our volunteers as well as our exercise prescription may have influenced the results of the present study. The physiological changes caused by the aging process, the chronic presence of hypertension (
The results for DBP in the present study did not show reductions after exercise sessions. It can be associated with the methodological aspects adopted since an indirect and subjective method for controlling the intensity of aerobic session was used, which may be underestimated the desired exercise intensity (moderate to severe), although the scale used is a validated instrument (
The findings of the present study contrast with our hypothesis, since some studies showed that AE sessions performed throughout the day (3–4 sessions of 10 min) were associated with a better cardiovascular post-exercise response (
Furthermore, it is also known that other variables can influence the magnitude and duration of PEH, so understanding them is a key factor for the development of an effective physical exercise intervention. In this, some aspects can be highlighted as the ethnic and genetic factors (
Additionally, Keese et al. (
For the BP reactivity, the MS was better to attenuate the BP reactivity compared to the day without exercise. Analyzing the change on BP after the CPT between MS and CS (MSCPT − CSCPT), there were significant differences of −23.7 ± 16.0 and −16.7 ± 13.9 mmHg for SBP and DBP, respectively. In agreement with these findings, Moreira et al. (
Despite the fact that significant BP attenuation was not observed after FS and NS for SBP and DBP in the present study (Table
All these data have great clinical and practical relevance, since sudden increases in BP favor the occurrence of some cardiovascular events, such as the rupture of atherosclerotic plaques, myocardial infarction, sudden cardiac death, and ischemic stroke (
The present study has some limitations such as (a) the non-balance of volunteers by antihypertensive drug classes, such factor enables investigation, in fact, the interference of this variable in the PEH; (b) the non-utilization of a direct protocol for prescribing aerobic intensity; (c) the non-balance of the volunteers by the menopause stages, a feature that would allow analyzing the kinetic BP expressed from equivalent serum concentrations of estrogen hormones; (d) the non-standard regarding the drug administration schedule.
Despite the reported limitations, this study has high practical application, since most of the programs for control and treatment of hypertension, using physical exercise, concentrate their actions only in the aerobic component. Additionally, it is suggested that further studies based on the present proposal could be carried out, since due the daily duties, many people fail to practice physical activity for low availability of time, in this sense, the dissociation of a concurrent protocol seems to be an effective solution to maintain their health status preventing cardiovascular diseases. Moreover, applying new models of fractionated CEs to better understanding its cardiovascular benefits for hypertensive subjects must be investigated.
Additionally, the findings of the present study reinforce the security and benefits promoted by a physical exercise program performed following the American College of Sports Medicine (ACSM) guidelines, since significant acute reductions, as well as a cardioprotection state after the MS, were observed. It is important to highlight that the protocol adopted was performed around the inferior limit than suggested by ACSM (60–80% of 1-RM), and it was still effective to promote benefits in hypertensive middle-aged women.
In summary, the CE session proposed when performed in the morning is more effective for promoting PEH to SBP than the NS and FS, as well as showing greater attenuation of BP reactivity for SBP and DBP when compared to NS, FS, and CS in hypertensive middle-aged women. The NS also resulted some moments of PEH in relation to CS; however, there were no PEH for SBP after FS and for DBP after all sessions. Finally, the FS and NS provided good reductions, but not significant, for BP reactivity in relation to CS, with ~40% of reduction for SBP and ~20.5% of reduction for DBP.
LA, AS, and LS contributed to the design of the work, the acquisition, analysis, and interpretation of data, drafted the work; EP and JA contributed to the design of the work, the acquisition, analysis, and interpretation of data, drafted the work, and revisited it critically for important intellectual content; MF and RS contributed to the design of the work, the interpretation of data, revisited the work critically for important intellectual content. All authors approved the version to be published and agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.
The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest.
This work was supported by the State Agency to support Research and Technological Innovation of Sergipe (FAPITEC/SE).
The Supplementary Material for this article can be found online at
8-RM, eight repetition maximum test; ACSM, American College of Sports Medicine; AE, aerobic exercise; BMI, body mass index; BP, blood pressure; CE, concurrent exercise; CPT, cold pressor test; CS, control session; DBP, diastolic blood pressure; DP, double product; FS, fractionized session; HC, hip circumference; HR, heart rate; ICC, intraclass correlation coefficient; MAP, mean arterial pressure; MS, morning session; NS, night session; PEH, post-exercise hypotension; RE, resistance exercise; SAH, systemic arterial hypertension; SBP, systolic blood pressure; SPE, subjective perception of effort; WC, waist circumference; WHO, World Health Organization; WHR, waist–hip ratio.