Post-exercise hypotension and its hemodynamic determinants depend on the calculation approach

A single session of aerobic exercise reduces systolic blood pressure at rest and in response to stress in women with rheumatoid arthritis and hypertension

Rheumatoid arthritis (RA) is an autoimmune inflammatory disease characterized by increased risk of cardiovascular disease and hypertension (HT). A single session of aerobic exercise may reduce blood pressure (BP) in different clinical groups; however, little is known about the acute effects of exercise on BP in RA patients. This is a randomized controlled crossover study that assessed the effects of a single session of aerobic exercise on resting BP, on BP responses to stressful stimuli, and on 24-h BP in women with RA and HT. Twenty women with RA and HT (53 ± 10 years) undertook sessions of 30-min treadmill exercise (50% VO2max) or control (no exercise) in a crossover fashion. Before and after the sessions, BP was measured at rest, and in response to the Stroop-Color Word Test (SCWT), the Cold Pressor Test (CPT), and an isometric handgrip test. After the sessions, participants were also fitted with an ambulatory BP monitor for the assessment of 24-h BP. A single session of exercise reduced resting systolic BP (SBP) (-5 ± 9 mmHg; p < 0.05), and reduced SBP response to the SCWT (-7 ± 14 mmHg; p < 0.05), and to the CPT (-5 ± 11 mmHg; p < 0.05). Exercise did not reduce resting diastolic BP (DBP), BP responses to the isometric handgrip test or 24-h BP. In conclusion, a single session of aerobic exercise reduced SBP at rest and in response to stressful stimuli in hypertensive women with RA. These results support the use of exercise as a strategy for controlling HT and, hence, reducing cardiovascular risk in women with RA.Clinical Trial Registration: This study registered at the Brazilian Clinical Trials ( https://ensaiosclinicos.gov.br/rg/RBR-867k9g ) at 12/13/2019.

Post-dynamic, isometric and combined resistance exercise responses in medicated hypertensive men

This study investigated the effects of dynamic resistance exercise (DRE), isometric handgrip exercise (IHE) and combined resistance exercise (DRE+IHE) on post-exercise hypotension (PEH) and its hemodynamic, autonomic, and vascular mechanisms. For that, 70 medicated hypertensives men (52 ± 8 years) were randomly allocated to perform one of the following interventions: DRE (3 sets, 8 exercises, 50% of 1RM), IHE (4 sets, 2 min, 30% of MVC), CRE (DRE+IHE) and control (CON, seated rest). Before and after the interventions, blood pressure (BP), systemic hemodynamics, cardiovascular autonomic modulation and brachial vascular parameters were evaluated. After the DRE and CRE, systolic and mean BP decreased (SBP = -7 ± 6 and -8 ± 8 mmHg; MBP -4 ± 5 and -5 ± 5 mmHg, respectively, all P < 0.05), vascular conductance increased (+ 0.47 ± 0.61 and +0.40 ± 0.47 ml.min-1.mmHg-1, respectively, both P < 0.05) and baroreflex sensitivity decreased (-0.15 ± 0.38 and -0.29 ± 0.47 ms/mmHg, respectively, both P < 0.05) in comparison to pre-exercise values. No variable presented any significant change after IHE. The responses observed after CRE were similar to DRE and significantly different from CON and IHE. In conclusion, DRE, but not IHE, elicits PEH, which happens concomitantly to skeletal muscle vasodilation and decreased baroreflex sensitivity. Moreover, adding IHE to DRE does not potentiate PEH and neither changes its mechanisms.Clinical Trial Registration: Data from this study derived from an ongoing longitudinal clinical trial approved by the Institution's Ethics Committee of Human Research (process 2.870.688) and registered at the Brazilian Clinical Trials (RBR-4fgknb) at http://www.ensaiosclinicos.gov.br .

Post-exercise hypotension in male spontaneously hypertensive rats: The issue of calculation method

In spontaneously hypertensive rats, exercise can lead to a post-exercise decrease in blood pressure, named post-exercise hypotension (PEH). This can be following physical training but also after a single bout of mild to moderate exercise when measured with tail-cuff or externalized catheter methods. Our aim was to assess the PEH obtained with different calculation methods and to compare the magnitude of this effect induced by a moderate-intensity continuous exercise or a high-intensity intermittent exercise. Thirteen 16-week-old male spontaneously hypertensive rats performed two types of aerobic exercise (continuous or intermittent) on a treadmill. Arterial pressure was recorded by telemetry for 24 h which was started 3 h before physical exercise. Based on the literature, PEH was first evaluated with two different baseline values, and then with three different approaches. We observed that the identification of PEH depended on the method used to measure the rest value, and that its amplitude was also influenced by the calculation approach and the type of exercise performed. Hence, the calculation method and the amplitude of the detected PEH can significantly influence their physiological and pathophysiological inferences.

A Single Dosage of l-Arginine Oral Supplementation Induced Post-Aerobic Exercise Hypotension in Hypertensive Patients

Lowering of peripheral vascular resistance is one of the primary processes involved in blood pressure decrease. Nitric oxide plays a significant role in this process and the availability of l-arginine is a crucial element in nitric oxide biosynthesis. Oral l-arginine supplementation may therefore be a potentiating element in post-exercise hypotension, mediated by its vasodilator action. Thus, the purpose of this study was to investigate if a single dose of l-arginine oral supplementation might impact the post-aerobic exercise blood pressure responses in treated hypertensive individuals. A double-blind, randomized, placebo-controlled crossover trial was conducted. The sample included male (4) and female (6) subjects [62 ± 10 years]. The participants were randomized to ingest one sachet containing 8 grams of l-arginine or placebo (corn starch) dissolved in water (100 ml). The substances were self-administered 120 min before the experimental or control session. The exercise was conducted on a treadmill and consisted of: a 5 min warm-up (50-65% HRreserve); 40 min of running/walking at 60-70% HRreserve; and a 5 min progressive cooldown. After the exercise sessions, blood pressure was measured every 10 min for 60 min. The l-arginine supplementation arm led to significant post-exercise systolic hypotension (mean post-exercise) in relation to rest period (117 ± 12 vs 125 ± 15 mmHg - p = 0.004 [l-arginine] and 121 ± 11 vs 125 ± 15 - p = 0.341 [placebo]). In addition, a systolic net effect of -6.9 ± 3.6 mmHg [p = 0.046] was identified for the mean post-exercise values. Therefore, this study showed that a single dosage of l-arginine oral supplementation induced post-aerobic exercise hypotension in hypertensive patients.

Evaluating the Methodological Quality of Postexercise Hypotension Aerobic Exercise Interventions

Background

Postexercise hypotension (PEH) is the immediate reduction in blood pressure (BP) of 5–8 mmHg that occurs after a single bout of aerobic exercise among adults with hypertension. Across PEH studies, there are variations in the level of rigor of the study designs and methods that limit the conclusions that can be made about PEH.

Objective

To develop and then apply a methodological study quality evaluation checklist to aerobic exercise PEH studies to provide methodological guidance.

Methods

We developed a PEH checklist (PEH√list) based upon contemporary methodological study quality standards. The PEH√list contains 38 items divided into three categories: sample (n = 10 items), study (n = 23 items), and intervention characteristics (n = 5 items). We then systematically searched six databases to January 2019 to identify and then evaluate studies that: (1) enrolled adults ≥18 years with hypertension and without other chronic diseases or conditions; (2) included a bout of aerobic exercise and a non-exercise control session; and (3) were published in English.

Results

Of 17,149 potential studies, 64 qualified. Participants (N = 1,489) were middle-aged (38.6 ± 15.6 year), overweight (26.1 ± 2.5 kg/m2) mostly men (64.4%) with elevated BP (systolic BP 129.5 ± 15.2/diastolic BP 81.0 ± 10.1 mmHg). Overall, the qualifying studies satisfactorily reported 53.9 ± 13.3% (24.2–82.8%) of the relevant items on the PEH√list. Of note, only 20.3% of the studies disclosed BP was measured following professional guidelines, 18.8% reported BP was taken by the same assessor pre- and post-intervention, and 35.5% stated participants abstained from caffeine, alcohol, and physical activity prior to testing. Half (51.5%) indicated they statistically controlled for pre-exercise/baseline BP. Meanwhile, 100% of the studies reported the setting in which the BP measurements were taken, time from the end of the exercise to the start of the BP measurements, and if relevant, the length of the ambulatory BP monitoring period.

Conclusion

Overall, the PEH√list items were not well satisfied; especially items with potential confounding effects on PEH. We contend the PEH√list provides guidance to investigators on the important methodological study considerations in PEH aerobic exercise studies that should be attended to in the future.

Systematic Review Registration

[https://www.crd.york.ac.uk/PROSPERO/], identifier [#CRD42020221996].

Post-dynamic Resistance Exercise Hypotension: Exploring Individual Responses and Predictors

Background: Post-dynamic resistance exercise hypotension (PREH) has been largely demonstrated. However, little is known regarding the interindividual variation of PREH magnitude and its predictors (i.e. factors of influence).

Aims: To assess the interindividual variation of PREH and its predictors related to the characteristics of the individuals and the exercise protocol.

Methods: This study retrospectively analysed data from 131 subjects included in seven controlled trials about PREH (including at least one dynamic resistance exercise and one control session) conducted by two research laboratories. The interindividual variation was assessed by the standard deviation of the individual responses (SDIR), and linear regression analyses were conducted to explore the predictors.

Results: PREH showed moderate interindividual variation for systolic (SBP, SDIR=4.4mmHg; 0.35 standardised units) and diastolic blood pressures (DBP, SDIR=3.6mmHg; 0.32 standardised units). For systolic PREH, multivariate regression analysis (R2=0.069) revealed higher baseline SBP (B=−0.157, p=0.008) and higher number of sets (B=−3.910, p=0.041) as significant predictors. For diastolic PREH, multivariate regression analysis (R2=0.174) revealed higher baseline DBP (B=−0.191, p=0.001) and higher exercise volume (i.e. number of exercises *sets per exercise *repetitions per sets &gt;150; B=−4.212, p=0.001) as significant predictors.

Conclusion: PREH has a considerable interindividual variation. Greater PREH magnitude is observed in individuals with higher baseline blood pressure and after exercise protocols that comprehend higher number of sets and exercise volume.

Consistency of hemodynamic and autonomic mechanisms underlying post-exercise hypotension

Post-exercise hypotension (PEH) is a clinically relevant phenomenon, but its mechanisms vary between different studies and between the participants within each study. Additionally, it is possible that PEH mechanisms are not consistent in each individual (i.e. within-individual variation), which has not been investigated yet. Thus, the aim of the current study was to assess the within-individual consistency of PEH hemodynamic and autonomic mechanisms. For that, 30 subjects performed 4 sessions divided in 2 blocks (test and retest). In each block, an exercise (cycling, 45 min, 50%VO₂peak) and a control (seated rest, 45 min) session was randomly conducted. Blood pressure (BP) and its mechanisms were evaluated pre- and post-interventions. In each block, individual responses were calculated as post-exercise minus post-control, and a response was considered present when its magnitude reached the typical error of the measurement. Consistencies were evaluated by comparing test and retest responses through kappa coefficient (k). PEH consistency was calculated using role sample, while mechanisms consistency was evaluated in those with consistent PEH. Twenty-one (70%) participants showed consistent PEH, 5 (17%) presented PEH in only test or retest and 4 (13%) had absent PEH response, characterising a good consistency (k = 0.510). Regarding mechanisms' responses, good consistency was found for heart rate (k = 0.456), sympathovagal balance (k = 0.438), and baroreflex sensitivity (k = 0.458); while systemic vascular resistance (k = 0.152), cardiac output (k = -0.400), stroke volume (k = -0.055), and sympathetic vasomotor modulation (k = -0.096) presented marginal consistencies. Thus, PEH is a highly consistent physiological phenomenon, although its mechanisms present variable consistencies.

Post-exercise hypotensive response in stroke patients following acute moderate or high intensity cycling session

BACKGROUND

Hypertension is highly prevalent in stroke patients and reducing blood pressure is a priority. Aerobic exercise is known to induce post-exercise hypotensive responses, but limited studies have documented this concept in stroke patients. The purpose was to investigate the effect of a single bout of moderate intensity continuous training (MICT) and high intensity interval training (HIIT) on post-exercise ambulatory blood pressure with patients with prior ischemic stroke or transient ischemic attack (TIA).

METHODS

Ten hypertensive adults (mean age: 70 ± 9 years) with prior ischemic stroke or TIA participated using a randomized crossover design. Ambulatory blood pressure was monitored for up to 8 hours after isocaloric either ergocycle MICT or HIIT of respectively 50% and 95% of peak power output. Blood pressure was compared to pre-exercise resting measure.

RESULTS

HIIT and MICT induced a decrease of systolic blood pressure of -11.0 ± 9.2 mmHg and -4.7 ± 4.5 mmHg respectively (p= 0.03) immediately after the exercise. Ambulatory systolic blood pressure showed a steady linear increase (R2 = 0.90; p< 0.001) of ~1.2 mmHg/hour and returned to pre-exercise measure after 8 hours. Effect of the two exercise conditions over time did not significantly differ (p= 0.278). Diastolic blood pressure was not affected by both exercises.

CONCLUSIONS

Those results suggest that HIIT induce a systolic blood pressure reduction of greater magnitude than MICT immediately after cycling exercise among patients with prior ischemic stroke or TIA. For both exercises, effects on ambulatory blood pressure are similar and persist up to 8 hours.

Post-exercise hypotension time-course is influenced by exercise intensity: a randomised trial comparing moderate-intensity, high-intensity, and sprint exercise

Reductions in blood pressure (BP) induced by exercise training may be associated with the acute reduction in BP observed minutes to hours following an exercise session, termed post-exercise hypotension (PEH). However, the magnitude and time-course of PEH, including the optimal exercise characteristics to maximise it, are still unclear. Using a randomised crossover design, 16 normotensive participants (median age (range) 22 (19-31) years; 50% female) undertook three different exercise sessions: sprint interval exercise (SIE, 30 × 8-s sprints with 32 s recovery), high-intensity interval exercise (HIIE, 15 × 1-min intervals at 90% peak heart rate (HR) with 1-min recovery), and moderate-intensity continuous exercise (MICE, 48 min at 65% peak HR). BP and HR were monitored before and up to 90 min following each session. The three exercise sessions each showed distinct PEH and of similar overall magnitude up to 90 min post exercise; however, there were distinct differences in the time-course. Systolic BP was lower 40 min after MICE compared to HIIE (-7.7 (-13.9 to -2.4) mmHg) and diastolic BP was higher 5 min after HIIE compared to SIE (8.5 (2.3-14.7) mmHg). MICE induced lower HR up to 40 min after exercise compared to HIIE and SIE. HIIE and SIE induced PEH of similar magnitude to MICE. A phasic or 'W-shaped' time-course of PEH observed following HIIE and SIE contrasted to a distinct 'V-shaped' PEH following MICE, indicating the physiological mechanisms driving BP regulation after exercise are influenced by exercise intensity.

A brief experimental examination of post-exercise hypotension and the impact of calculation method

PURPOSE

There is great variability in the reported values of post-exercise hypotension (PEH), with inconsistent calculation methods employed across primary research. This study aimed to explore the influence of the mathematical calculation method on PEH variability, with the hypothesis that the method of identifying the lowest single reduction point (LSRP) would yield false-positive results.

METHODS

Young, normotensive (108 ± 7/69 ± 5 mmHg), apparently healthy, male (n = 20) were included in this study. Participants completed three random-order experimental sessions, with blood pressure and heart rate measured before (10 min) and after (30 min) an acute bout of either isometric handgrip exercise, aerobic cycling, or a nonexercise control. Three PEH calculation methods were analyzed: LSRP, 30-min average across the full post-exercise recovery, and 15-min binned averages with two recovery windows (0-15 min, 15-30 min).

RESULTS

The only calculation method to consistently identify PEH was the LSRP method, which identified PEH for SBP, DBP, and mean arterial pressure, across handgrip exercise, aerobic cycling, and even nonexercise control (P < 0.001). All other calculation methods inconsistently identified PEH across experimental sessions, supporting the hypothesis that LSRP inaccurately overreports PEH.

CONCLUSION

Mathematical calculation method appears to be one source of variability contributing to the inconsistency in reported PEH among young, healthy males. This brief experimental examination reveals that the LSRP method should be avoided as it inaccurately overreports PEH. Alternatively, binned averages of smaller time windows across the recovery period may be a potentially advantageous approach and require further examination to determine to ideal level of granularity.