Characteristics associated with responsiveness to isometric handgrip training in medicated hypertensive patients: secondary data analysis.

OBJECTIVE: Isometric handgrip training (IHT) has been shown to reduce blood pressure (BP) in hypertensive patients. However, factors that predict responsiveness to IHT are largely unknown. The aim of this study was to investigate the patient characteristics associated with the antihypertensive response to IHT using a recommended statistical approach for evaluating interindividual responses. METHODS: Data from four randomized controlled trials were joined, totaling 81 patients undergoing IHT (48.8% women; 60 ±â€Š11 years) and 90 control patients (45.6% women; 62 ±â€Š12 years). IHT consisted of 4 × 2 min isometric contractions at 30% of maximal voluntary contraction, performed three times/week for 8-12 weeks. BP was measured at baseline and following IHT and control interventions. The interindividual variation was assessed by the standard deviation of the individual responses (SDir), and linear regression analyses were conducted to explore response predictors. RESULTS: IHT significantly decreased both SBP (-5.4; 95% confidence interval (CI) -9.5 to -1.3 mmHg) and DBP (-2.8; 95% CI -5.1 to -0.6 mmHg). The interindividual variation of BP change was moderate for systolic (SDir = 5.2 mmHg, 0.30 standardized units) and low for diastolic (SDir = 1.7 mmHg, 0.15 standardized units). Sex, age, and BMI were not associated with the antihypertensive effect of IHT. However, a higher baseline SBP (b = -0.467, P < 0.001) and absence of dihydropyridine calcium channel blockers use (b = 0.340, P = 0.001) were associated with greater BP reductions. CONCLUSION: IHT reduced BP in medicated hypertensive patients regardless of age, sex, and BMI. Patients with a higher baseline SBP and those not prescribed dihydropyridine calcium channel blockers were more responsive to IHT.

Evening but not morning aerobic training improves sympathetic activity and baroreflex sensitivity in elderly patients with treated hypertension.

The blood pressure-lowering effect of aerobic training is preceded by improving cardiovascular autonomic control. We previously demonstrated that aerobic training conducted in the evening (ET) induces a greater decrease in blood pressure than morning training (MT). To study whether the greater blood pressure decrease after ET occurs through better cardiovascular autonomic regulation, this study aimed to compare MT versus ET on muscle sympathetic nerve activity (MSNA) and baroreflex sensitivity (BRS) in treated patients with hypertension. Elderly patients treated for hypertension were randomly allocated into MT (n = 12, 07.00-10.00 h) or ET (n = 11, 17.00-20.00 h) groups. Both groups trained for 10 weeks, 3 times/week, cycling for 45 min at moderate intensity. Beat-to-beat blood pressure (finger photoplethysmography), heart rate (electrocardiography) and MSNA (microneurography) were assessed at the initial and final phases of the study at baseline and during sequential bolus infusions of sodium nitroprusside and phenylephrine (modified-Oxford technique) to evaluate cardiac and sympathetic BRS. Mean blood pressure decreased significantly after ET but not after MT (-9 ± 11 vs. -1 ± 8 mmHg, P = 0.042). MSNA decreased significantly only after ET with no change after MT (-12 ± 5 vs. -3 ± 7 bursts/100 heart beats, P = 0.013). Sympathetic BRS improved after ET but not after MT (-0.8 ± 0.7 vs. 0.0 ± 0.8 bursts/100 heart beats/mmHg, P = 0.052). Cardiac BRS improved similarly in both groups (ET: +1.7 ± 1.8 vs. MT: +1.4 ± 1.9 ms/mmHg, Pphase  ≤ 0.001). In elderly patients treated for hypertension, only ET decreased mean blood pressure and MSNA and improved sympathetic BRS. These findings revealed that the sympathetic nervous system has a key role in ET's superiority to MT in blood pressure-lowering effect. KEY POINTS: Reducing muscle nerve sympathetic activity and increasing sympathetic baroreflex sensitivity plays a key role in promoting the greater blood pressure reduction observed with evening training. These findings indicated that simply changing the timing of exercise training may offer additional benefits beyond antihypertensive medications, such as protection against sympathetic overdrive and loss of baroreflex sensitivity, independent markers of mortality. Our new findings also suggest new avenues of investigation, such as the possibility that evening aerobic training may be beneficial in other clinical conditions with sympathetic overdrive, such as congestive heart failure and hypertrophic cardiomyopathy.

Effects of exercise training on heart rate variability in individuals with lower extremity arterial disease and claudication: A systematic review.

PURPOSE: To perform a systematic review of studies assessing the effects of regular exercise on heart rate variability (HRV) in individuals with lower extremity arterial disease (LEAD) and symptoms of claudication. METHODS: A systematic search in the electronic databases MEDLINE, Embase, and Scielo, was conducted and updated on January 21, 2023. Randomized clinical trials investigating patients with LEAD and IC, assessing ≥ 4 wk of exercise interventions, and reporting at least one HRV measure (e.g., time or frequency domains) at baseline and follow-up were included. Two reviewers independently screened studies for inclusion, performed data extraction, and quality assessment of included studies. RESULTS: Data from 7 trials were included (i.e., 5 walking, 1 resistance, and 1 isometric handgrip training), totaling 327 patients (66% males; range: 61 - 68 yr; ankle brachial index: 0.4 - 0.7). Following exercise training, three studies investigating walking training reported an increase in parasympathetic modulation indices and/or a decrease in sympathetic modulation indices (n = 2) as well as an increase in non-linear indices (n = 1). CONCLUSION: The current evidence is weak, and larger randomized controlled trials are needed to confirm the efficacy of exercise training in improving HRV. Additionally, the high divergence in the methodology of studies indicated the need for standard tools to improve the quality of HRV measurements in exercise trials. It is recommended to use standard procedures in future trials investigating HRV.

Effects of dynamic, isometric and combined resistance training on blood pressure and its mechanisms in hypertensive men.

Although dynamic resistance training (DRT) and isometric handgrip training (IHT) may decrease blood pressure (BP) in hypertensives, the effects of these types of training have not been directly compared, and a possible additive effect of combining IHT to DRT (combined resistance training-CRT), has not been investigated. Thus, this study compared the effects of DRT, IHT and CRT on BP, systemic hemodynamics, vascular function, and cardiovascular autonomic modulation. Sixty-two middle-aged men with treated hypertension were randomly allocated among four groups: DRT (8 exercises, 50% of 1RM, 3 sets until moderate fatigue), IHT (30% of MVC, 4 sets of 2 min), CRT (DRT + IHT) and control (CON - stretching). In all groups, the interventions were administered 3 times/week for 10 weeks. Pre- and post-interventions, BP, systemic hemodynamics, vascular function and cardiovascular autonomic modulation were assessed. ANOVAs and ANCOVAs adjusted for pre-intervention values were employed for analysis. Systolic BP decreased similarly with DRT and CRT (125 ± 11 vs. 119 ± 12 and 128 ± 12 vs. 119 ± 12 mmHg, respectively; P < 0.05), while peak blood flow during reactive hyperaemia (a marker of microvascular function) increased similarly in these groups (774 ± 377 vs. 1067 ± 461 and 654 ± 321 vs. 954 ± 464 mL/min, respectively, P < 0.05). DRT and CRT did not change systemic hemodynamics, flow-mediated dilation, and cardiovascular autonomic modulation. In addition, none of the variables were changed by IHT. In conclusion, DRT, but not IHT, improved BP and microvascular function in treated hypertensive men. CRT did not have any additional effect in comparison with DRT alone.

Walking Training Increases microRNA-126 Expression and Muscle Capillarization in Patients with Peripheral Artery Disease.

Patients with peripheral artery disease (PAD) have reduced muscle capillary density. Walking training (WT) is recommended for PAD patients. The goal of the study was to verify whether WT promotes angiogenesis in PAD-affected muscle and to investigate the possible role of miRNA-126 and the vascular endothelium growth factor (VEGF) angiogenic pathways on this adaptation. Thirty-two men with PAD were randomly allocated to two groups: WT (n = 16, 2 sessions/week) and control (CO, n = 16). Maximal treadmill tests and gastrocnemius biopsies were performed at baseline and after 12 weeks. Histological and molecular analyses were performed by blinded researchers. Maximal walking capacity increased by 65% with WT. WT increased the gastrocnemius capillary-fiber ratio (WT = 109 ± 13 vs. 164 ± 21 and CO = 100 ± 8 vs. 106 ± 6%, p < 0.001). Muscular expression of miRNA-126 and VEGF increased with WT (WT = 101 ± 13 vs. 130 ± 5 and CO = 100 ± 14 vs. 77 ± 20%, p < 0.001; WT = 103 ± 28 vs. 153 ± 59 and CO = 100 ± 36 vs. 84 ± 41%, p = 0.001, respectively), while expression of PI3KR2 decreased (WT = 97 ± 23 vs. 75 ± 21 and CO = 100 ± 29 vs. 105 ± 39%, p = 0.021). WT promoted angiogenesis in the muscle affected by PAD, and miRNA-126 may have a role in this adaptation by inhibiting PI3KR2, enabling the progression of the VEGF signaling pathway.

Comparison of morning versus evening aerobic-exercise training on heart rate recovery in treated hypertensive men: a randomized controlled trial.

Heart rate recovery (HRR) is a marker of cardiac autonomic regulation and an independent predictor of mortality. Aerobic-exercise training conducted in the evening (evening training) produces greater improvement in resting cardiac autonomic control in hypertensives than morning training, suggesting it may also result in a faster autonomic restoration postexercise. This study compared the effects of morning training and evening training on HRR in treated hypertensive men. Forty-nine treated hypertensive men were randomly allocated into three groups: morning training, evening training and control. Training was conducted three times/week for 10 weeks. Training groups cycled (45 min, moderate intensity) while control group stretched (30 min). In the initial and final assessments of the study, HRR60s and HRR300s were evaluated during the active recovery (30 W) from cardiopulmonary exercise tests (CPET) conducted in the morning and evening. Between-within ANOVAs were applied (P ≤ 0.05). Only evening training increased HRR60s and HRR300 differently from control after morning CPET (+4 ± 5 and +7 ± 8 bpm, respectively, P < 0.05) and only evening training increased HRR300s differently from morning training and control after evening CPET (+8 ± 6 bpm, P < 0.05). Evening training improves HRR in treated hypertensive men, suggesting that this time of day is better for eliciting cardiac autonomic improvements via aerobic training in hypertensives.

Walking Training Improves Systemic and Local Pathophysiological Processes in Intermittent Claudication.

OBJECTIVE: This study examined the impact of submaximal walking training (WT) on local and systemic nitric oxide (NO) bioavailability, inflammation, and oxidative stress in patients with intermittent claudication (IC). METHODS: The study employed a randomised, controlled, parallel group design and was performed in a single centre. Thirty-two men with IC were randomly allocated to two groups: WT (n = 16, two sessions/week, 15 cycles of two minutes walking at an intensity corresponding to the heart rate obtained at the pain threshold interspersed by two minutes of upright rest) and control (CO, n = 16, two sessions/week, 30 minutes of stretching). NO bioavailability (blood NO and muscle nitric oxide synthase [eNOS]), redox homeostasis (catalase [CAT], superoxide dismutase [SOD], lipid peroxidation [LPO] measured in blood and muscle), and inflammation (interleukin-6 [IL-6], C-reactive protein [CRP], tumour necrosis factor α [TNF-α], intercellular adhesion molecules [ICAM], vascular adhesion molecules [VCAM] measured in blood and muscle) were assessed at baseline and after 12 weeks. RESULTS: WT statistically significantly increased blood NO, muscle eNOS, blood SOD and CAT, and muscle SOD and abolished the increase in circulating and muscle LPO observed in the CO group. WT decreased blood CRP, ICAM, and VCAM and muscle IL-6 and CRP and eliminated the increase in blood TNF-α and muscle TNF-α, ICAM and VCAM observed in the CO group. CONCLUSION: WT at an intensity of pain threshold improved NO bioavailability and decreased systemic and local oxidative stress and inflammation in patients with IC. The proposed WT protocol provides physiological adaptations that may contribute to cardiovascular health in these patients.

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 (SD IR), and linear regression analyses were conducted to explore the predictors. Results: PREH showed moderate interindividual variation for systolic (SBP, SD IR=4.4mmHg; 0.35 standardised units) and diastolic blood pressures (DBP, SD IR=3.6mmHg; 0.32 standardised units). For systolic PREH, multivariate regression analysis (R 2=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 (R 2=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 >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.

Local and Systemic Inflammation and Oxidative Stress After a Single Bout of Maximal Walking in Patients With Symptomatic Peripheral Artery Disease.

OBJECTIVE: The aim of this study was to assess the effects of a single bout of maximal walking on blood and muscle nitric oxide (NO) bioavailability, oxidative stress, and inflammation in symptomatic peripheral artery disease (PAD) patients. METHODS: A total of 35 men with symptomatic PAD performed a graded maximal exercise test on a treadmill (3.2 km/h, 2% increase in grade every 2 minutes). Plasma samples and gastrocnemius muscle biopsies were collected preexercise and postexercise for assessment of NO bioavailability (plasma NO and muscle, endothelial NO synthase), oxidative stress and antioxidant function (lipid peroxidation [LPO], catalase [CAT], and superoxide dismutase), and inflammation (interleukin-6, C-reactive protein, tumor necrosis factor-α, intercellular adhesion molecules, and vascular adhesion molecules). The effects of the walking exercise were assessed using paired t tests or Wilcoxon tests. RESULTS: After maximal walking, plasma NO and LPO were unchanged (P > .05), plasma CAT decreased, and all blood inflammatory markers increased (all P ≤ .05). In the disease-affected skeletal muscle, endothelial NO synthase, CAT, LPO, and all inflammatory markers increased, whereas superoxide dismutase decreased (all P ≤ .05). CONCLUSION: In patients with symptomatic PAD, maximal exercise induces local and systemic impairments, which may play a key role in atherogenesis. Exercise strategies that avoid maximal effort may be important to reduce local and systemic damage and enhance clinical benefits.

Poor sleep quality is associated with cardiac autonomic dysfunction in treated hypertensive men.

Hypertensives present cardiac autonomic dysfunction. Reduction in sleep quality increases blood pressure (BP) and favors hypertension development. Previous studies suggested a relationship between cardiovascular autonomic dysfunction and sleep quality, but it is unclear whether this association is present in hypertensives. Thus, this study evaluated the relationship between sleep quality and cardiac autonomic modulation in hypertensives. Forty-seven middle-aged hypertensive men under consistent anti-hypertensive treatment were assessed for sleep quality by the Pittsburgh Sleep Quality Index (PSQI-higher score means worse sleep quality). Additionally, their beat-by-beat BP and heart rate (HR) were recorded, and cardiac autonomic modulation was assessed by their variabilities. Mann-Whitney and t tests were used to compare different sleep quality groups: poor (PSQI > 5, n = 24) vs good (PSQI ≤ 5, n = 23), and Spearman's correlations to investigate associations between sleep quality and autonomic markers. Patients with poor sleep quality presented lower cardiac parasympathetic modulation (HR high-frequency band = 26 ± 13 vs 36 ± 15 nu, P = .03; HR total variance = 951 ± 1373 vs 1608 ± 2272 ms2 , P = .05) and cardiac baroreflex sensitivity (4.5 ± 2.3 vs 7.1 ± 3.7 ms/mm Hg, P = .01). Additionally, sleep quality score presented significant positive correlation with HR (r = +0.34, P = .02) and negative correlations with HR high-frequency band (r = -0.34, P = .03), HR total variance (r = -0.35, P = .02), and cardiac baroreflex sensitivity (r = -0.42, P = .01), showing that poor sleep quality is associated with higher HR and lower cardiac parasympathetic modulation and baroreflex sensitivity. In conclusion, in treated hypertensive men, poor sleep quality is associated with cardiac autonomic dysfunction.

Blood Pressure Increase in Hypertensive Individuals During Resistance Training Protocols With Equated Work to Rest Ratio.

Introduction: Despite growing evidence regarding the benefits of resistance training in hypertension, the large and abrupt rise of systolic blood pressure (SBP) observed during resistance exercise execution has resulted in concern about its safety. However, the manipulation of the resistance training protocol (RTP) organization, maintaining the work to rest ratio equated between protocols (W:R-equated), may reduce the SBP increase. Purpose: To compare cardiovascular responses during two W:R-equated RTPs (3 × 15:88 s vs. 9 × 5:22 s - sets × reps: rest between sets) performed in exercises for the lower and upper limbs. Methods: Twelve medicated hypertensives (48 ± 8 years) randomly performed two RTPs in the bilateral leg extension (BLE) and unilateral elbow flexion (UEF) exercises at 50% 1RM. Increases (Δ) of SBP, heart rate (HR) and rate pressure product (RPP) during the exercises were measured by photoplethysmography. Results: In both BLE and UEF exercises, Δ SBP was significantly greater during 3 × 15:88 s than 9 × 5:22 s (peak values: BLE = + 84 ± 39 vs. + 67 ± 20 mm Hg, and UEF = + 46 ± 25 vs. + 37 ± 18 mm Hg, respectively, both p < 0.05). ΔHR and ΔRPP were significantly higher in the 3 × 15:88 s than 9 × 5:22 s in BLE (peak values + 45 ± 17 vs. + 30 ± 8 bpm, and + 15,559 ± 5570 vs. + 10,483 ± 2614 mm Hg. bpm). Conclusion: In medicated hypertensives, a RTP combining more sets with less repetitions per set and shorter rest intervals between sets (i.e., 9 × 5:22 s) produced a smaller increase in cardiovascular load (ΔSBP, ΔHR and ΔRPP) during its execution than a protocol with fewer longer sets (i.e., 3 × 15:88 s).

Effects of ACEi and ARB on post-exercise hypotension induced by exercises conducted at different times of day in hypertensive men.

BACKGROUND: Post-exercise hypotension (PEH) is greater after evening than morning exercise, but antihypertensive drugs may affect the evening potentiation of PEH. Objective: To compare morning and evening PEH in hypertensives receiving angiotensin-converting enzyme inhibitors (ACEi) or angiotensin II receptor blockers (ARB). METHODS: Hypertensive men receiving ACEi (n = 14) or ARB (n = 15) underwent, in a random order, two maximal exercise tests (cycle ergometer, 15 watts/min until exhaustion) with one conducted in the morning (7 and 9 a.m.) and the other in the evening (8 and 10 p.m.). Auscultatory blood pressure (BP) was assessed in triplicate before and 30 min after the exercises. Changes in BP (post-exercise - pre-exercise) were compared between the groups and the sessions using a two-way mixed ANOVA and considering P < .05 as significant. RESULTS: In the ARB group, systolic BP decrease was greater after the evening than the morning exercise, while in the ACEi group, it was not different after the exercises conducted at the different times of the day. Additionally, after the evening exercise, systolic BP decrease was lower in the ACEi than the ARB group (ARB = -11 ± 8 vs -6 ± 6 and ACEi = -6 ± 7 vs. -8 ± 5 mmHg, evening vs. morning, respectively, P for interaction = 0.014). CONCLUSIONS: ACEi, but not ARB use, blunts the greater PEH that occurs after exercise conducted in the evening than in the morning.

Hydration Does Not Change Postexercise Hypotension and Its Mechanisms.

BACKGROUND: Drinking water is recommended before and after exercise to avoid dehydration. However, water ingestion may mitigate or prevent postexercise hypotension. This study investigated the effects of intentional hydration on postaerobic exercise hemodynamics and autonomic modulation. METHODS: A total of 18 young men randomly underwent 4 experimental sessions as follows: (1) control with intentional hydration (1 L of water in the previous night, 500 mL 60 min before the intervention, and 1 mL for each 1 g of body mass lost immediately after the intervention); (2) control without intentional hydration (ad libitum water ingestion before the intervention); (3) exercise (cycle ergometer, 45 min, 50% of VO2peak) with intentional hydration; and (4) exercise without intentional hydration. Hemodynamic and autonomic parameters were measured before and after the interventions and were compared by 3-way analysis of variance. RESULTS: Intentional hydration did not change any postexercise hemodynamic nor autonomic response. Exercise decreased systolic blood pressure and stroke volume (-4.1 [0.8] mm Hg and -4.9 [1.5] mL, P < .05), while increased cardiac sympathovagal balance (0.3 [0.3], P < .05) during the recovery. In addition, it abolished the increase in diastolic blood pressure and the decrease in heart rate observed in the control sessions. CONCLUSION: Intentional hydration does not modify the hypotensive effect promoted by previous aerobic exercise and did not alter its hemodynamic and autonomic mechanisms.

Reproducibility of post-exercise heart rate recovery indices: A systematic review.

Heart rate recovery (HRR) has been widely used to evaluate the integrity of the autonomic nervous system with a slower HRR being associated with greater cardiovascular risk. Different HRR indices have been proposed. Some evaluate HR changes from the end of exercise to a specific recovery moment (e.g. 60s - HRR60s; 120s - HRR120s; 300s - HRR300s) and others calculate time-constant decays of HR for different recovery intervals (e.g. first 30s - T30; the entire period - HRRt). Several studies have examined the reproducibility of these commonly-used HRR indices, but reported discordant findings. Thus, this systematic review was designed to synthesize the reproducibility of HRR. We included studies that evaluated short-term (<1 year) reproducibility of HRR after dynamic exercise by employing typical measures of reliability (intraclass correlation coefficient, ICC) and agreement (coefficient of variation, CV). The electronic database PubMed/Medline was searched for relevant studies published up to July 2018. From the initial 120 records identified, 15 studies were retained for the qualitative synthesis of 24 experimental conditions. During most experimental conditions, high ICC and desirable CV were reported for HRR60s (62.5 and 76.2%, respectively), HRR120s (55.6 and 71.4%) and HRR300s (50.0 and 100.0%). While, it were reported during the minority of conditions for HRRt (37.5 and 42.9%) and in none condition for T30 (0.0 and 0.0%). In conclusion, HRR60s, HRR120s and HRR300s exhibited good reproducibility for evaluating HRR in predominantly healthy males within research and clinical settings. In contrast, caution should be taken when employing other HRR indices (T30, HRRt) due to their poorer reproducibility.

Effect of Time of Day on Sustained Postexercise Vasodilation Following Small Muscle-Mass Exercise in Humans.

INTRODUCTION: Previous studies observed diurnal variation in hemodynamic responses during recovery from whole-body exercise, with vasodilation appearing greater after evening versus morning sessions. It is unclear what mechanism(s) underlie this response. Since small muscle-mass exercise can isolate peripheral effects related to postexercise vasodilation, it may provide insight into possible mechanisms behind this diurnal variation. METHODS: The study was conducted in ten healthy (5F, 5M) young individuals, following single-leg dynamic knee-extension exercise performed in the Morning (7:30-11:30 am) or the Evening (5-9 pm) on two different days, in random order. Arterial pressure (automated auscultation) and leg blood flow (femoral artery Doppler ultrasound) were measured pre-exercise and during 120 min postexercise. Net effect for each session was calculated as percent change in blood flow (or vascular conductance) between the Active Leg and the Inactive Leg. RESULTS: Following Morning exercise, blood flow was 34.9 ± 8.9% higher in the Active Leg versus the Inactive Leg (p < 0.05) across recovery. Following Evening exercise, blood flow was 35.0 ± 8.8% higher in the Active Leg versus the Inactive Leg (p < 0.05). Likewise, vascular conductance was higher in the Active Leg versus the Inactive Leg (Morning: +35.1 ± 9.0%, p < 0.05; Evening: +33.2 ± 8.2%, p < 0.05). Morning and Evening blood flow (p = 0.66) and vascular conductance (p = 0.64) did not differ. CONCLUSION: These data suggest previous studies which identified diurnal variations in postexercise vasodilation responses are likely reflecting central rather than peripheral modulation of cardiovascular responses.

Blood Pressure Response During Resistance Training of Different Work-to-Rest Ratio.

Paulo, AC, Tricoli, V, Queiroz, ACC, Laurentino, G, and Forjaz, CLM. Blood pressure response during resistance training of different work-to-rest ratio. J Strength Cond Res 33(2): 399-407, 2019-Changes in the work-to-rest ratio (W:R) of resistance training protocols (RTPs) (i.e., decreasing work or increasing rest) reduce the marked elevation in blood pressure (BP) that occurs during RTP execution. However, whether changes in RTP structure without changing W:R can change BP responses to RTP is unknown. To investigate the effect of different structures of rest intervals and number of repetitions per set on BP response among RTP equated and nonequated for W:R, 20 normotensive participants (25 ± 4 years) performed 4 different RTP of the leg extension exercise with the same work but different W:R structures. Two protocols followed the recommendations for cardiovascular disorders: (a) HIGHW:R-3×15:44s-3×15:44s (set×reps:rest between sets), which has high W:R (45reps:88s) and (b) LOWW:R-3×15:88s-3×15:88s, which has low W:R (45reps:176s). The other 2 protocols were W:R-equated to LOWW:R (45reps:176s): (c) LOWW:R-9×5:22s and (d) LOWW:R-45×1:4s. Systolic BP (ΔSBP) and diastolic BP (ΔDBP) were assessed by finger photoplethysmography. There were significant main effects for ΔSBP after RTP (p ≤ 0.05): HIGHW:R-3×15:44s = LOWW:R-3×15:88s > LOWW:R-45×1:4s > LOWW:R-9×5:22s (+87 ± 5 and +84 ± 5 vs. +61 ± 4 vs. 57 ± 4 mm Hg). For ΔDBP, there was a significant interaction between RTP and moment (p ≤ 0.05). Thus, HIGHW:R-3×15:44 > LOWW:R-3×15:88s > LOWW:R-45×1:4s > LOWW:R-9×5:22s (+53 ± 5 vs. +49 ± 5 vs. +44 ± 4 vs. +38 ± 3 mm Hg). HIGHW:R-3×15:44s produced the highest increase in ΔDBP, and LOWW:R-9×5:22s produced the lowest increase in ΔSBP and ΔDBP. Our findings may help the development of RTP protocols that may mitigate pressure peaks without changing important exercise variables (i.e., volume or duration).

Morning versus Evening Aerobic Training Effects on Blood Pressure in Treated Hypertension.

INTRODUCTION: The acute blood pressure (BP) decrease is greater after evening than morning exercise, suggesting that evening training (ET) may have a greater hypotensive effect. OBJECTIVE: This study aimed to compare the hypotensive effect of aerobic training performed in the morning versus evening in treated hypertensives. METHODS: Fifty treated hypertensive men were randomly allocated to three groups: morning training (MT), ET, and control (C). Training groups cycled for 45 min at moderate intensity (progressing from the heart rate of the anaerobic threshold to 10% below the heart rate of the respiratory compensation point), while C stretched for 30 min. Interventions were conducted 3 times per week for 10 wk. Clinic and ambulatory BP and hemodynamic and autonomic mechanisms were evaluated before and after the interventions. Clinic assessments were performed in the morning (7:00-9:00 AM) and evening (6:00-8:00 PM). Between-within ANOVA was used (P ≤ 0.05). RESULTS: Only ET decreased clinic systolic BP differently from C and MT (morning assessment -5 ± 6 mm Hg and evening assessment -8 ± 7 mm Hg, P < 0.05). Only ET reduced 24 h and asleep diastolic BP differently from C and MT (-3 ± 5 and -3 ± 4 mm Hg, respectively, P < 0.05). Systemic vascular resistance decreased from C only in ET (P = 0.03). Vasomotor sympathetic modulation decreased (P = 0.001) and baroreflex sensitivity (P < 0.02) increased from C in both training groups with greater changes in ET than MT. CONCLUSIONS: In treated hypertensive men, aerobic training performed in the evening decreased clinic and ambulatory BP due to reductions in systemic vascular resistance and vasomotor sympathetic modulation. Aerobic training conducted at both times of day increases baroreflex sensitivity, but with greater after ET.

Reproducibility of Hemodynamic, Cardiac Autonomic Modulation, and Blood Flow Assessments in Patients with Intermittent Claudication.

BACKGROUND: The aim of this study is to identify, in patients with peripheral artery disease and intermittent claudication (IC), the reproducibility of heart rate (HR), blood pressure (BP), rate pressure product, heart rate variability (HRV), and forearm and calf blood flow (BF) and vasodilatory assessments. METHODS: Twenty-nine patients with IC underwent test and retest sessions, 8-12 days apart. During each session, HR, BP, HRV, BF, and vasodilatory responses were measured by electrocardiogram, auscultation, spectral analysis of HRV (low frequency, LFR-R; high frequency, HFR-R), and strain gauge plethysmography (baseline BF, post-occlusion BF, post-occlusion area under the curve). Reproducibility was determined by intra-class correlation coefficient (ICC), typical error, coefficient of variation (CV), and limits of agreement. RESULTS: The ICC for HR and BP was >0.8 with CV <9%. For most HRV measures, ICC was >0.9 while CV was <7%, except for LF/HF (ICC = 0.737, CV = 93.8%). The ICC for forearm and calf baseline BF assessments was >0.9 while CV was <19%; variable ICC and CV for vasodilatory responses were exhibited for calf (0.653-0.770, 35.2-37.7%) and forearm (0.169-0.265, 46.2-55.5%). CONCLUSIONS: In male patients with IC, systemic hemodynamics (HR and BP), cardiac autonomic modulation (LFR-R and HFR-R), and forearm and calf baseline BF assessments exhibited excellent reproducibility, whereas the level of reproducibility for vasodilatory responses were moderate to poor. Assessment reproducibility has highlighted appropriate clinical tools for the regular monitoring of disease/intervention progression in patients with IC.