Acute and Chronic Effects of Isometric Handgrip Exercise on Cardiovascular Variables in Hypertensive Patients: A Systematic Review

Isometric Exercise Training and Arterial Hypertension: An Updated Review

Hypertension is recognised as a leading attributable risk factor for cardiovascular disease and premature mortality. Global initiatives towards the prevention and treatment of arterial hypertension are centred around non-pharmacological lifestyle modification. Exercise recommendations differ between professional and scientific organisations, but are generally unanimous on the primary role of traditional aerobic and dynamic resistance exercise. In recent years, isometric exercise training (IET) has emerged as an effective novel exercise intervention with consistent evidence of reductions in blood pressure (BP) superior to that reported from traditional guideline-recommended exercise modes. Despite a wealth of emerging new data and endorsement by select governing bodies, IET remains underutilised and is not widely prescribed in clinical practice. This expert-informed review critically examines the role of IET as a potential adjuvant tool in the future clinical management of BP. We explore the efficacy, prescription protocols, evidence quality and certainty, acute cardiovascular stimulus, and physiological mechanisms underpinning its anti-hypertensive effects. We end the review with take-home suggestions regarding the direction of future IET research.

Central and peripheral mechanisms underlying postexercise hypotension: a scoping review

Blood pressure (BP) reduction occurs after a single bout of exercise, referred to as postexercise hypotension (PEH). The clinical importance of PEH has been advocated owing to its potential contribution to chronic BP lowering, and as a predictor of responders to exercise training as an antihypertensive therapy. However, the mechanisms underlying PEH have not been well defined. This study undertook a scoping review of research on PEH mechanisms, as disclosed in literature reviews. We searched the PubMed, Web of Science, Scopus, Cumulated Index to Nursing and Allied Health Literature (CINAHL), Cochrane Library, and Sport Discus databases until January 2023 to locate 21 reviews - 13 narrative, four systematic with 102 primary trials, and four meta-analyses with 75 primary trials involving 1566 participants. We classified PEH mechanisms according to major physiological systems, as central (autonomic nervous system, baroreflex, cardiac) or peripheral (vascular, hemodynamic, humoral, and renal). In general, PEH has been related to changes in autonomic control leading to reduced cardiac output and/or sustained vasodilation. However, the role of autonomic control in eliciting PEH has been challenged in favor of local vasodilator factors. The contribution of secondary physiological outcomes to changes in cardiac output and/or vascular resistance during PEH remains unclear, especially by exercise modality and population (normal vs. elevated BP, young vs. older adults). Further research adopting integrated approaches to investigate the potential mechanisms of PEH is warranted, particularly when the magnitude and duration of BP reductions are clinically relevant. (PROSPERO CRD42021256569).

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 ± 11 years) and 90 control patients (45.6% women; 62 ± 12 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.

Can postexercise hypotension also be observed in African and Asian populations: a systematic review and meta-analysis of randomized controlled trials

Worldwide, raised blood pressure (BP) or hypertension is the global leading risk factor for the development of cardiovascular diseases and all-cause mortality, with the highest prevalence found in Asian and African origin populations. Post-exercise hypotension (PEH), defined as a sustained reduction in BP after a single bout of exercise is an important physiological phenomenon in BP management. However, little is known about the hypotensive effect of a single bout of exercise in non-Caucasian populations. We systematically summarized the acute effects of a single bout of aerobic exercise on BP in a population of African or Asian origin. We searched the MEDLINE database identifying randomized controlled trials investigating the effect of a single bout of aerobic exercise on BP in African or Asian populations with optimal BP, high normal BP or hypertension published in a peer reviewed journal up to August 2021. A subsequent meta-analysis was performed using random-effect models fitted to estimate effect sizes. We identified 10 aerobic exercise trials performed in individuals of Asian origin (n = 136; mean age: 29.51 (21.2-69) years: 78% male; baseline systolic BP/diastolic BP: 118.9 ± 9.64/68.9 ± 2.69 mmHg) and 11 aerobic exercise trials involving individuals of African origin (n = 157; mean age: 41.05 (29.9-49) years; 59% male; baseline systolic BP/diastolic BP: 134.5 ± 8.65 mmHg/82.2 ± 3.24 mmHg). Non-significant reductions in office systolic BP and diastolic BP at 30 min post exercise (-2.25 [-6.38, 1.88] mmHg, p = 0.28/-1.02 [-2.51, 0.47] mmHg, p = 0.18) and 60 min post exercise (-2.80 [-7.90, 2.28], p = 0.27/-1.95, [-5.66, 1.75], p = 0.3) were observed compared to the control intervention. No statistically significant differences were found between both ethnic groups (p > 0.05). Ambulatory BP was reported only in a few African groups. No effect was found on 24h-systolic BP post exercise, but 24h-diastolic BP was statistically significantly reduced (-1.89 [-3.47, -0.31] mmHg, p < 0.01) after a bout of aerobic exercise compared to the control intervention. The available evidence is insufficient to recommend a single session of aerobic exercise as an efficient tool to lower BP in African and Asian populations. Though, the paucity of data in non-Caucasian populations underscores the need for additional efforts to establish the efficacy of single bouts of exercise, including isometric and dynamic resistance exercise, as a potential non-pharmacological adjunct to help lowering BP in the daily life of descendants of Asian or African origin.

Isometric handgrip training, but not a single session, reduces blood pressure in individuals with hypertension: a systematic review and meta-analysis

Aerobic exercise is a leading strategy for the prevention/management of systemic arterial hypertension, but other modalities of exercise have also been explored. Thus, we examined the acute effect of isometric handgrip exercise (IHGE) and the chronic effect of isometric handgrip training (IHGT) on systolic blood pressure (SBP) and diastolic blood pressure (DBP) in individuals with hypertension without comorbid conditions. We conducted a systematic review with meta-analysis of randomized controlled trials (RCTs) involving adults with hypertension. We searched the electronic databases MEDLINE (PubMed), Cochrane, Web of Science, LILACS, EMBASE and PEDro. We used random-effects model for the analyses, RoB2 tool to assess the risk of bias, and GRADE to assess the strength of evidence. A total of 9 RCTs (2 for IHGE and 7 for IHGT) were selected. Compared to a control condition, IHGE did not have any effect on SBP/DBP. Unlike, the pooled mean effect of IHGT showed SBP was reduced by 6.7 mmHg (95% CI -10.3 to -3.4 mmHg) and DBP by 4.5 mmHg (95% CI -7.3 to -1.7 mmHg) in individuals with hypertension. Also, the 95% prediction interval (95% PI) of IGHT was -10.9 to -2.5 mmHg for SBP and -10.2 to +1.2 mmHg for DBP. In conclusion, while IHGE did not produce post-exercise hypotension in the population studied, IHGT reduced SBP/DBP in individuals with hypertension with clinically important reductions in SBP (-6.7 mmHg) and DBP (-4.5 mmHg). This review was registered in the International Prospective Register of Systematic Reviews (PROSPERO) (CRD 42021217958).

The evidence of effectiveness of isometric resistance training on the management of hypertension in adults: an umbrella review

Hypertension is the leading risk factor for cardiovascular disease yet also one of the most readily preventable causes of death. Isometric resistance training (IRT) has gained increasing popularity in recent times as a viable nonpharmacological management option for hypertension. Whilst there have been several reviews on this topic, with varying findings, this umbrella review aimed to summarize the current evidence underpinning the effectiveness of IRT for hypertension. Quantitative systematic reviews and meta-analyses published in English were considered for inclusion. Commercially produced and grey literature was searched between December 2021 and January 2022. Methodological quality of included reviews was determined using the AMSTAR 2 critical appraisal tool. Customized data extraction tools were developed for this review and data were synthesized using the National Health and Medical Research Council FORM Framework. Twelve reviews published between 2011 and 2021 of varying methodological quality were identified. Isometric handgrip exercise training with four sets of 2-min contractions and 1 min rest period between each set was the most utilized intervention, undertaken three times per week for at least 8 weeks. Collectively, there is consistent evidence to indicate IRT has positive impacts on SBP and DBP as well as mean arterial pressure. These positive impacts were reported for normotensive as well as hypertensive individuals. Given IRT is a readily available, easy-to-use intervention with minimal financial cost, it could be considered a viable treatment option for people with, and at risk of, hypertension.

Cardiovascular and autonomic dysfunction in long-COVID syndrome and the potential role of non-invasive therapeutic strategies on cardiovascular outcomes

A significant percentage of COVID-19 survivors develop long-lasting cardiovascular sequelae linked to autonomic nervous system dysfunction, including fatigue, arrhythmias, and hypertension. This post-COVID-19 cardiovascular syndrome is one facet of "long-COVID," generally defined as long-term health problems persisting/appearing after the typical recovery period of COVID-19. Despite the fact that this syndrome is not fully understood, it is urgent to develop strategies for diagnosing/managing long-COVID due to the immense potential for future disease burden. New diagnostic/therapeutic tools should provide health personnel with the ability to manage the consequences of long-COVID and preserve/improve patient quality of life. It has been shown that cardiovascular rehabilitation programs (CRPs) stimulate the parasympathetic nervous system, improve cardiorespiratory fitness (CRF), and reduce cardiovascular risk factors, hospitalization rates, and cognitive impairment in patients suffering from cardiovascular diseases. Given their efficacy in improving patient outcomes, CRPs may have salutary potential for the treatment of cardiovascular sequelae of long-COVID. Indeed, there are several public and private initiatives testing the potential of CRPs in treating fatigue and dysautonomia in long-COVID subjects. The application of these established rehabilitation techniques to COVID-19 cardiovascular syndrome represents a promising approach to improving functional capacity and quality of life. In this brief review, we will focus on the long-lasting cardiovascular and autonomic sequelae occurring after COVID-19 infection, as well as exploring the potential of classic and novel CRPs for managing COVID-19 cardiovascular syndrome. Finally, we expect this review will encourage health care professionals and private/public health organizations to evaluate/implement non-invasive techniques for the management of COVID-19 cardiovascular sequalae.

[Impact of isometric training on blood pressure: an umbrella study of systematic reviews and meta-analyses]

High blood pressure causes 45% of deaths from heart diseases and 51% of deaths from stroke.

OBJECTIVE

To conduct systematic search and summarize the systematic reviews and/or meta-analyses about impact of isometric training on blood pressure.

MATERIAL AND METHODS

Systematic search for publications in PubMed, Cochrane Library and Epistemonikos databases for the period from January of 2017 yr. to 19 of January 2023 yr. was carried out. The search was done by keywords: isometric exercises, isometric training, blood pressure, arterial hypertension, static resistance training, handgrip test. Methodological quality of included articles was assessed using the «Assessment of methodological quality of systematic reviews» (AMSTAR-2) tool. The number of systematic reviews equal 15 was analyzed.

RESULTS

The overall methodological quality of 15 included reviews, obtained by AMSTAR-2, revealed a very low confidence rate (critically low confidence, 10 publications) for results of systematic review and meta-analyses. In total, analysis and generalization of all results of included systematic reviews about blood pressure decrease by isometric training showed, that systolic blood pressure against the background of this method decreases on average by 6.1±2.0 mm Hg, and diastolic blood pressure - by 3.0±1.0 mm Hg.

CONCLUSION

Authors of 15 systemic reviews, included in an umbrella study, reached a common conclusion about isometric training efficacy in secondary prevention of arterial hypertension.

Effect of isometric handgrip exercise on cognitive function: Current evidence, methodology, and safety considerations

Cognitive function is essential for most behaviors of daily living and is a critical component in assessing the quality of life. Mounting prospective evidence supports the use of isometric handgrip exercise (IHE) as a small muscle mass practice to promote health-related outcomes in clinical and healthy populations. The aim of the present review was to systematically investigate whether IHE is effective in improving the cognitive function of adults (aged ≥18 years). Studies were identified by searching five databases (CINAHL, MEDLINE, SPORTDiscus, PsychINFO, and Web of Science). Eight out of 767 studies met the inclusion criteria, including three types of studies: 1) acute effect for IHE with various intensity protocols (n = 4); 2) acute effect for IHE with one set exhaustion protocol (n = 2); and 3) chronic effect of IHE on cognitive function (n = 2). To assess the methodological quality of studies, the PEDro scale was used (mean score = 6.75). The evidence on whether IHE exerts acute positive effects on cognitive performance is currently rather inconclusive. However, a trend was discernible that implementing IHE can generate a beneficial chronic effect on cognitive function, although the results should be interpreted with caution. The clinical relevance of IHE as a time-efficient type of physical exercise to improve cognitive function warrants further investigation. Methodology and safety considerations were discussed.

Systematic Review Registration: (https://osf.io/gbzp9).

The effect of a single session of isometric handgrip exercise on blood pressure

BACKGROUND: It is unknown whether a session of isometric handgrip (IHG) exercise can influence the blood pressure of hypertensive and normotensive individuals. OBJECTIVE: To compare post exercise hypotension among groups with different resting blood pressure (BP) levels. METHODS: 56 Malay male volunteers (12 normotensive, 14 pre-hypertensive, 19 hypertensive stage 1, and 11 hypertensive stage 2) completed four sets of 2-minute isometric handgrip exercises at 30% of their maximum handgrip contraction with a one-minute break between the sets. Systolic BP (SBP), diastolic BP (DBP), pulse pressure (PP), mean arterial pressure (MAP), resting heart rate (RHR), and handgrip strength (HGS) were measured before and after an hour of IHG exercise. A paired sample t-test, one-way ANOVA, and two-way repeated measure ANCOVA were used to examine the data. RESULTS: All parameters, except RHR and HGS, were significantly changed following the exercise across the BP groups. The SBP, MAP, and HGS were greatly reduced among hypertensive stage 1 (SBP =-6.3 ± 0.6 mmHg; MAP =-4.8 ± 1.1 mmHg; HGS =-6.8 ±-0.4 mmHg) compared to other groups. Meanwhile, the most DBP was reduced among hypertensive stage 2 (mean =-5.2 ± 0.6 mmHg). CONCLUSIONS: The current study discovered a significant reduction in BP among hypertensive stage 1 and 2 individuals after a session of IHG exercise.

Physical Exercise in Resistant Hypertension: A Systematic Review and Meta-Analysis of Randomized Controlled Trials

Physical exercise reduces blood pressure (BP) in patients with hypertension in general but more evidence is needed specifically for a high-risk phenotype associated with intensive medication, resistant hypertension (RH). In this systematic review and meta-analysis, we aimed to summarize current evidence of the exercise effects on BP in patients with RH. A systematic search was conducted in PubMed, Web of Science and Cochrane Library (from inception to 3rd November, 2021). A random effects meta-analysis was performed when at least two trials assessed the effect of either acute or regular exercise (vs. a control condition) on the same outcome. Ten studies (N = 380 participants; 51% female; mean age 52 to 67 years) were included in the review, of which four (N = 58) and six (N = 322) assessed the effects of acute and regular exercise, respectively. Evidence overall suggests that a single bout of acute exercise results in a short-term (≤ 24 h) reduction of BP, although no meta-analysis could be performed. As for regular exercise, three randomized controlled trials (N = 144, 50% female) could be meta-analyzed, which showed that exercise training intervention (8–12 weeks, 3 sessions/week) significantly reduces 24-h (−9.9 mmHg, 95% confidence interval −15.4−4.4 for systolic BP; and −5 mmHg, −7.0−3.0 for diastolic BP) and daytime ambulatory BP (−11.7 mmHg, −17.8−5.7; and −7.4 mmHg, −11.9−2.9). In summary, physical exercise appears as an effective option to reduce BP in patients with RH, although more research is needed to confirm these findings as well as to determine the most effective exercise characteristics.

Acute cardiac autonomic and haemodynamic responses to leg and arm isometric exercise

OBJECTIVES

Acute cardiovascular responses following a single session of isometric exercise (IE) have been shown to predict chronic adaptations in blood pressure (BP) regulation. It was hypothesised that exercises which recruit more muscle mass induce greater reductions in BP compared to exercises using smaller muscle mass. To test this hypothesis, the current study aimed to compare the acute haemodynamic and autonomic responses to a single session of isometric wall squat (IWS) and isometric handgrip (IHG) training.

METHODS

Twenty-six sedentary participants performed a single IWS and IHG session in a randomised cross-over design, with training composed of 4 × 2-min contractions, with 2-min rest, at 95 HR_peak and 30% MVC respectively. Haemodynamic and cardiac autonomic variables were recorded pre, during, immediately post, and 1-h post-exercise, with the change from baseline for each variable used for comparative analysis.

RESULTS

During IWS exercise, there was a significantly greater increase in systolic BP (P < 0.001), diastolic BP (P < 0.001), mean BP (P < 0.001), heart rate (P < 0.001), and cardiac output (P < 0.001), and a contrasting decrease in baroreflex effectiveness index (BEI) and cardiac baroreceptor sensitivity (cBRS). In the 10-min recovery period following IWS exercise, there was a significantly greater reduction in systolic BP (P = 0.005), diastolic BP (P = 0.006), mean BP (P = 0.003), total peripheral resistance (TPR) (P < 0.001), BEI (P = 0.003), and power spectral density (PSD-RRI) (P < 0.001). There were no differences in any variables between conditions 1-h post exercise.

CONCLUSIONS

Isometric wall squat exercise involving larger muscle mass is associated with a significantly greater post-exercise hypotensive response during a 10-min recovery window compared to smaller muscle mass IHG exercise. The significantly greater reduction in TPR may be an important mechanism for the differences in BP response.

Safety, efficacy and delivery of isometric resistance training as an adjunct therapy for blood pressure control: a modified Delphi study

Uncontrolled hypertension remains the major risk factor for cardiovascular disease. Isometric resistance training (IRT) has been shown to be a useful nonpharmacological therapy for reducing blood pressure (BP); however, some exercise physiologists and other health professionals are uncertain of the efficacy and safety of IRT. Experts' consensus was sought in light of the current variability of IRT use as an adjunct treatment for hypertension. An expert consensus-building analysis (Delphi study) was conducted on items relevant to the safety, efficacy and delivery of IRT. The study consisted of 3 phases: (1) identification of items and expert participants for inclusion; (2) a two-round modified Delphi exercise involving expert panelists to build consensus; and (3) a study team consensus meeting for a final item review. A list of 50 items was generated, and 42 international experts were invited to join the Delphi panel. Thirteen and 10 experts completed Delphi Rounds 1 and 2, respectively, reaching consensus on 26 items in Round 1 and 10 items in Round 2. The study team consensus meeting conducted a final item review and considered the remaining 14 items for the content list. A final list of 43 items regarding IRT reached expert consensus: 7/10 items on safety, 11/11 items on efficacy, 10/12 items on programming, 8/10 items on delivery, and 7/7 on the mechanism of action. This study highlights that while experts reached a consensus that IRT is efficacious as an antihypertensive therapy, some still have safety concerns, and there is also ongoing conjecture regarding optimal delivery.

Acute Aerobic Exercise Induces Short-Term Reductions in Ambulatory Blood Pressure in Patients With Hypertension: A Systematic Review and Meta-Analysis

[Figure: see text].

Isometric exercise and inter-individual response differences on resting systolic and diastolic blood pressure in adults: a meta-analysis of randomized controlled trials

PURPOSE

Isometric exercise (IE) has been shown to reduce resting systolic blood pressure (SBP) and diastolic blood pressure (DBP) in adults. However, no one to date has determined whether true inter-individual response differences (IIRD) versus random variability exist with respect to IE and resting SBP and DBP in adults ≥18 years of age. The purpose of the current study was to address this gap.

METHODS AND MATERIALS

Using the meta-analytic approach, randomised controlled trials from a recent meta-analysis that examined the effects of IE on resting SBP and DBP were included. Change outcome standard deviations for SBP and DBP from IE and control groups were used to calculate true IIRD from each study. The inverse variance heterogeneity (IVhet) model was used to pool results.

RESULTS

Pooled changes for true IIRD in SBP (16 studies, 411 participants) were 3.3 mmHg (95% confidence interval, -3.1 to 5.6 mmHg) while tau (τ) was 4.2. For DBP, true IIRD (16 studies, 411 participants) were 2.3 mmHg (95% confidence interval, -0.7 to 3.3 mmHg) while tau (τ) was 2.2. The 95% prediction interval for true IIRD in a future study was -5.8 to 7.4 mmHg for SBP and -2.7 to 4.2 mmHg for DBP. The percent chance, i.e. probability, of a clinically meaningful difference of 2 mmHg was 68% for SBP and 75% for DBP, both of which were only considered as 'possibly clinically important'.

CONCLUSION

While IE reduces resting SBP and DBP in adults, the results of the current study suggest that random variability versus true IIRD account for any potential differences as a result of IE on changes in resting SBP and DBP in adults. Thus, a search for potential moderators and mediators, including potential genetic interactions associated with IE, may not be warranted.

Effects of Isometric Biceps Exercise on Blood Pressure in Adults with Hypertension

We investigated the acute effects of isometric biceps exercise on resting and ambulatory blood pressure in hypertensive adults. A total of 12 medicated hypertensive adults (aged 47±7 years; body mass index 27.2±2.7 kg/m²; resting blood pressure 123±12/74±6 mmHg) performed an isometric biceps exercise session (bilateral biceps exercise; 4×1 min at 30% of 1-RM, 2 min recovery) and a control session (without exercise) in a randomized order separated by a 7 to 10-day period. Resting blood pressure, heart rate, and heart rate variability indexes (SDNN, RMSSD, LF, HF, and LF/HF) were measured pre- and up to 30 min post-sessions. Next, ambulatory blood pressure was monitored during 22-hour post-sessions (awake and asleep periods). No significant changes were observed for resting blood pressure, heart rate, or heart rate variability indexes up to 30 min post-sessions (p>0.05). Furthermore, no significant differences were observed in average ambulatory blood pressure values in 22-hour (126±11/71±6 mmHg vs. 126±15/71±9 mmHg), awake (127±10/74±6 mmHg vs. 130±14/75±10 mmHg), and asleep (123±15/68±6 mmHg vs. 120±17/66±9 mmHg) periods between the control and isometric sessions, respectively (p>0.05). In conclusion, an isometric biceps exercise session does not elicit an acute antihypertensive effect in adults with hypertension, which suggests that its prescription to improve the acute BP control is limited.

Effects of isometric handgrip training on blood pressure among hypertensive patients seen within public primary healthcare: a randomized controlled trial

BACKGROUND

Meta-analyses have demonstrated that isometric handgrip training (IHT) decreases blood pressure in hypertensive individuals. Nonetheless, most studies were conducted in laboratory settings and its effects in real-world settings remain unclear.

OBJECTIVE

To analyze the effects of IHT on office and ambulatory blood pressure in hypertensive patients attended within primary healthcare.

DESIGN AND SETTING

Randomized controlled trial conducted in primary healthcare units within the Family Health Program, Petrolina, Pernambuco, Brazil.

METHODS

63 hypertensive patients (30-79 years old; 70% female) were randomly allocated into IHT or control groups. IHT was performed three times per week (4 x 2 minutes at 30% of maximal voluntary contraction, one-minute rest between bouts, alternating the hands). Before and after the 12-week training period, office and ambulatory blood pressure and heart rate variability were obtained. The significance level was set at P < 0.05 (two-tailed testing) for all analyses.

RESULTS

IHT significantly decreased office systolic blood pressure (IHT: 129 ± 4 versus 121 ± 3 mmHg, P < 0.05; control: 126 ± 4 versus 126 ± 3 mmHg, P > 0.05), whereas there was no effect on diastolic blood pressure (IHT: 83 ± 3 versus 79 ± 2 mmHg, P > 0.05; control: 81 ± 3 versus 77 ± 3 mmHg, P > 0.05). Heart rate variability and ambulatory blood pressure were not altered by the interventions (P > 0.05 for all).

CONCLUSION

IHT reduced office systolic blood pressure in hypertensive patients attended within primary care. However, there were effects regarding diastolic blood pressure, ambulatory blood pressure or heart rate variability.

CLINICALTRIALS.GOV IDENTIFIER

NCT03216317.

Tapering and Peaking Maximal Strength for Powerlifting Performance: A Review

Prior to major competitions, athletes often use a peaking protocol such as tapering or training cessation to improve performance. The majority of the current literature has focused on endurance-based sports such as swimming, cycling, and running to better understand how and when to taper or use training cessation to achieve the desired performance outcome. However, evidence regarding peaking protocols for strength and power athletes is lacking. Current limitations for peaking maximal strength is that many studies do not provide sufficient details for practitioners to use. Thus, when working with athletes such as powerlifters, weightlifters, throwers, and strongman competitors, practitioners must use trial and error to determine the best means for peaking rather than using an evidence-based protocol. More specifically, determining how to peak maximal strength using data derived from strength and power athletes has not been established. While powerlifting training (i.e., back squat, bench press, deadlift) is used by strength and power athletes up until the final days prior to a competition, understanding how to peak maximal strength relative to powerlifting performance is still unclear. Thus, the purpose of this study was to review the literature on tapering and training cessation practices relative to peaking powerlifting performance.

Preconditioning with PDE1 Inhibitors and Moderate-Intensity Training Positively Affect Systemic Redox State of Rats

Taken into consideration that oxidative stress response after preconditioning with phosphodiesterase inhibitors (PDEIs) and moderate physical activity has still not been clarified, the aim of this study was to assess the effects of PDEIs alone or in combination with physical activity, on systemic redox status. The study was carried out on 96 male Wistar albino rats classified into two groups. The first group included animals exposed only to pharmacological preconditioning (PreC) maneuver (sedentary control (CTRL, 1 ml/day saline, n = 12), nicardipine (6 mg/kg/day of NIC, n = 12), vinpocetine (10 mg/kg/day of VIN, n = 12), and nimodipine (NIM 10 mg/kg/day of, n = 12). The second included animals exposed to preconditioning with moderate-intensity training (MIT) on treadmill for 8 weeks. After 5 weeks from the start of training, the animals were divided into four subgroups depending on the medication to be used for pharmacological PreC: moderate-intensity training (MIT+ 1 ml/day saline, n = 12), nicardipine (MIT+ 6 mg/kg/day of NIC, n = 12), vinpocetine (MIT+ 10 mg/kg/day of VIN, n = 12), and nimodipine (MIT+ 10 mg/kg/day of NIM, n = 12). After three weeks of pharmacological preconditioning, the animals were sacrificed. The following oxidative stress parameters were measured spectrophotometrically: nitrites (NO₂⁻), superoxide anion radical (O₂⁻), hydrogen peroxide (H₂O₂), index of lipid peroxidation (TBARS), superoxide dismutase (SOD), catalase (CAT), and reduced glutathione (GSH). Our results showed that PDE1 and MIT preconditioning decreased the release of prooxidants and improved the activity of antioxidant enzymes thus preventing systemic oxidative stress.

Effects of Exercise Intervention on Adults With Both Hypertension and Type 2 Diabetes Mellitus: A Systematic Review and Meta-analysis

BACKGROUND

The positive effect of exercise on blood pressure has been reported in studies that investigated mostly patients with hypertension but without diabetes mellitus. However, the effect of exercise in adults with both hypertension and type 2 diabetes mellitus (T2DM) is unclear, and no systematic review and meta-analysis has been conducted to clarify this effect.

OBJECTIVE

This study was a systematic review and meta-analysis designed to investigate the effects of exercise on adults with both hypertension and T2DM.

METHODS

Studies were selected using electronic databases. Data were extracted using a standardized protocol. The risk of bias was assessed using Cochrane Collaboration's tool. To estimate the effect size, a meta-analysis of the studies was conducted.

RESULTS

Of 3207 publications identified, 8 trials were used to estimate the effect size of exercise. Effect sizes (weighted mean difference [WMD]) were heterogeneous, and random-effects models were used. Exercise was effective for systolic blood pressure (WMD, -5.25 mm Hg; 95% confidence interval [CI], -8.39 to -2.12), diastolic blood pressure (WMD, -3.16 mm Hg; 95% CI, -4.91 to -1.40), body mass index (WMD, -1.47 kg/m; 95% CI, -2.39 to -0.55), and waist circumference (WMD, -2.91 cm; 95% CI, -5.68 to -0.15). In subgroup analyses, aerobic exercise seemed to be the most effective intervention for lowering systolic (WMD, -9.43 mm Hg; 95% CI, -13.63 to -5.23) and diastolic (WMD, -5.90 mm Hg; 95% CI, -7.69 to -4.11) blood pressure.

CONCLUSIONS

Exercise seemed effective in reducing systolic and diastolic blood pressure, with subgroup analyses indicating that this effect was most profound with aerobic exercise.

Effects of Isometric Handgrip Training in Patients With Peripheral Artery Disease: A Randomized Controlled Trial

Background Meta-analyses have shown that isometric handgrip training (IHT) can reduce brachial systolic and diastolic blood pressure (BP) by >6/4 mm Hg, respectively. However, whether IHT promotes these effects among patients with peripheral artery disease, who exhibit severe impairment in cardiovascular function, is currently unknown. This study aimed to evaluate the effects of IHT on the cardiovascular function of patients with peripheral artery disease. Methods and Results A randomized controlled trial with peripheral artery disease patients assigned to either the IHT or control group was conducted. The IHT group performed 3 sessions per week, for 8 weeks, of unilateral handgrip exercises, consisting of 4 sets of isometric contractions for 2 minutes at 30% of maximum voluntary contraction and a 4-minute interval between sets. The control group received a compression ball in order to minimize the placebo effects, representing sham training. The primary outcome was brachial BP. The secondary outcomes were central BP, arterial stiffness parameters, cardiac autonomic modulation, and vascular function. The IHT program reduced diastolic BP (75 [10] mm Hg preintervention versus 72 [11] mm Hg postintervention), with no change in the control group (74 [11] mm Hg preintervention versus 74 [11] mm Hg postintervention), with this between-group difference being significant (P=0.04). Flow-mediated dilation improved in the IHT group (6.0% [5.7] preintervention versus 9.7% [5.5] postintervention), with no change in the control group (7.6% [5.5] preintervention versus 7.4% [5.1] postintervention), with this between-group difference being significant (P=0.04). There was no change in other measured variables over the intervention period. Conclusions IHT reduced brachial diastolic BP and improved local vascular function in patients with peripheral artery disease. Clinical Trial Registration URL: https://www.clinicaltrials.gov/. Unique identifier: NCT02742220.

Cardiovascular responses to low-intensity isometric handgrip exercise in coronary artery disease: effects of posture

BACKGROUND

Coronary artery disease (CAD) lead to cardiovascular autonomic control disfunctions that can worsen exercise and/or posture adjustments.

OBJECTIVES

To verify the cardiovascular responses to low-intensity isometric handgrip exercise performed in different postures in CAD patients. This study tested the hypothesis that the posture influences the cardiovascular responses during isometric handgrip exercise and that the presence of CAD leads to greater cardiovascular stress during this type of exercise.

METHODS

We investigated cardiovascular responses to isometric handgrip exercise in 15 CAD patients (CADG) and 15 health matched-control (CG). The subjects performed isometric handgrip exercise at 30% of maximum voluntary contraction until exhaustion in SUPINE, SITTING and STANDING positions. Systolic arterial pressure, diastolic arterial pressure, mean blood pressure, heart rate, peripheral vascular resistance, cardiac output, stroke volume and double product were measured during rest (baseline), exercise (peak value) and recovery in the 1st minute (REC1). Delta PB (ΔPB, peak minus baseline) and PR1 (ΔPR1, peak minus REC1) were calculated.

RESULTS

Higher ΔPB and ΔPR1 of systolic and mean arterial pressure and double product were observed in STANDING when compared to SITTING and/or SUPINE. CADG showed higher ΔPB of systolic and mean arterial pressure in all postures and higher ΔPR1 of strove volume in the SITTING.

CONCLUSION

We concluded that the posture during isometric handgrip exercise influences the cardiovascular responses with STANDING leading to higher cardiovascular stress. CAD promoted higher arterial pressure responses however these responses were physiological and expected due to the presence of disease and type of exercise.

The impact of high-intensity interval training and moderate-intensity continuous training regimes on cardiodynamic parameters in isolated heart of normotensive and hypertensive rats

This study aimed to assess the impact of high-intensity interval training (HIIT) vs. moderate-intensity continuous training (MIT) on cardiodynamic parameters in isolated rat heart. Wistar albino rats were randomly assigned to groups according to running protocol: sedentary control, MIT, and HIIT; spontaneous hypertensive rat (SHR) sedentary control, SHR + MIT, and SHR + HIIT. HIIT groups performed the running in 5 sprints × 45-55 m/min for 30-90 s, with 2 min of rest after each sprint, while MIT groups performed the running of 10-15 m/min for 1 h with 3 min of rest every 100 m; both protocols were implemented 5 days/week over 4 weeks with 1 week of adaptation before protocols started. Isolated rat hearts were perfused according to Langendorff technique at gradually increased coronary perfusion pressures (40-120 cmH₂O). Using a sensor placed in the left ventricle, we registered maximum and minimum rate of pressure development in the left ventricle, systolic and diastolic left ventricular pressure, and heart rate. Coronary flow was measured flowmetrically. MIT was connected with cardiac depression in normotensive conditions, while HIIT leads to cardiac depression in hypertensive rats. HIIT induced more significant increase of contractile and relaxation parameters of the isolated rat heart, especially in hypertensive animals.

The efficacy of 'static' training interventions for improving indices of cardiorespiratory fitness in premenopausal females

PURPOSE

Cardiovascular disease (CVD) is the leading cause of death worldwide. Many risk factors for CVD can be modified pharmacologically; however, uptake of medications is low, especially in asymptomatic people. Exercise is also effective at reducing CVD risk, but adoption is poor with time-commitment and cost cited as key reasons for this. Repeated remote ischaemic preconditioning (RIPC) and isometric handgrip (IHG) training are both inexpensive, time-efficient interventions which have shown some promise in reducing blood pressure (BP) and improving markers of cardiovascular health and fitness. However, few studies have investigated the effectiveness of these interventions in premenopausal women.

METHOD

Thirty healthy females were recruited to twelve supervised sessions of either RIPC or IHG over 4 weeks, or acted as non-intervention controls (CON). BP measurements, flow-mediated dilatation (FMD) and cardiopulmonary exercise tests (CPET) were performed at baseline and after the intervention period.

RESULTS

IHG and RIPC were both well-tolerated with 100% adherence to all sessions. A statistically significant reduction in both systolic (- 7.2 mmHg) and diastolic (- 6 mmHg) BP was demonstrated following IHG, with no change following RIPC. No statistically significant improvements were observed in FMD or CPET parameters in any group.

CONCLUSIONS

IHG is an inexpensive and well-tolerated intervention which may improve BP; a key risk factor for CVD. Conversely, our single arm RIPC protocol, despite being similarly well-tolerated, did not elicit improvements in any cardiorespiratory parameters in our chosen population.

Acute blood pressure responses after different isometric handgrip protocols in hypertensive patients

OBJECTIVE

The present study analyzed blood pressure responses after a single session of isometric handgrip exercise performed with different volumes and intensities by patients with hypertension.

METHODS

This randomized crossover trial submitted 12 hypertensive patients (58±5 years old) to four isometric handgrip exercise sessions in a random order: 4 x 2 min at 30% of the maximal voluntary contraction (S30%); 4 x 2 min at 50% of the maximal voluntary contraction (S50%2min); 4 x 3 min at 30% of the maximal voluntary contraction (S30%3min); and a control session. The systolic and diastolic blood pressure, heart rate, and rate-pressure product were measured pre- and post-exercise (30th min).

RESULTS

No significant changes were observed in cardiovascular variables after any session (p>0.05 for all comparisons). Similarly, individual analyses revealed heterogeneity in the responses, including increases in blood pressure observed in some sessions. Patients with reduced blood pressure after an isometric handgrip exercise session exhibited a higher body mass index, diastolic blood pressure and heart rate (p<0.05). They also tended to be younger (p=0.07).

CONCLUSION

Isometric handgrip exercise performed with different intensities and volumes did not reduce the blood pressure of hypertensive patients.

The impact of aerobic and anaerobic training regimes on blood pressure in normotensive and hypertensive rats: focus on redox changes

This study was aimed to assess the impact of aerobic and anaerobic type of exercise on blood pressure and redox status in normotensive and hypertensive rats. After 1 week of preconditioning feeding and 1 week of preconditioning running regimen, Wistar albino rats (n = 72; bw: 270 ± 50 g) were randomly assigned to three groups according to running protocol (high-intensity interval training (HIIT) or moderate-intensity training (MIT)): sedentary control, MIT, HIIT; spontaneous hypertensive sedentary control (SHR), SHR + MIT and SHR + HIIT. Blood pressure (BP) measurement was performed by a tail-cuff noninvasive method BP system. After 48 h of rest following the final training, the rats were fasted for 24 h and sacrificed under ketamine/xylazine anesthesia and blood samples were collected. The level of the next prooxidants were measured: superoxide anion radical (O₂^-); hydrogen peroxide (H₂O₂); nitrite level (NO₂^-) and index of lipid peroxidation (thiobarbituric acid reactive substances), and the activity of antioxidative enzymes: reduced glutathione (GSH) superoxide dismutase (SOD) and catalase (CAT) activity. After the last week of running, HIIT strongly affected SP, DP, and HR in SHR rats compared to other hypertensive rats, as well as after MIT in normotensive conditions. We have found that HIIT training protocol induced a higher increase of O₂^- and H₂O₂ as compared to MIT. Findings of the present study pointed out that contrary to normotensive conditions, in hypertensive conditions both training regimes reduced the BP levels, which was more prominent in case of HIIT. In addition, MIT seems to be connected with milder disturbance of pro-oxidant production and better antioxidant response.

Supervised, but Not Home-Based, Isometric Training Improves Brachial and Central Blood Pressure in Medicated Hypertensive Patients: A Randomized Controlled Trial

Meta-analyses have shown that supervised isometric handgrip training reduces blood pressure in hypertensives. However, the mechanism(s) underlying these effects in medicated hypertensive patients, as well as the effects from home-based exercise training, is uncertain. The purpose of this study was to compare the effects of supervised and home-based isometric handgrip training on cardiovascular parameters in medicated hypertensives. In this randomized controlled trial, 72 hypertensive individuals (38–79 years old, 70% female) were randomly assigned to three groups: home-based, supervised isometric handgrip training or control groups. Home-based and supervised isometric handgrip training was completed thrice weekly (4 × 2 min at 30% of maximal voluntary contraction, with 1-min rest between bouts, alternating the hands). Before and after 12 weeks brachial, central and ambulatory blood pressures (BP), arterial stiffness, heart rate variability, vascular function, oxidative stress and inflammation markers were obtained. No significant (p > 0.05) effect was observed for ambulatory BP, arterial stiffness, heart rate variability, vascular function and oxidative stress and inflammatory markers in all three groups. Brachial BP decreased in the supervised group (Systolic: 132 ± 4 vs. 120 ± 3 mmHg; Diastolic: 71 ± 2 vs. 66 ± 2 mmHg, p < 0.05), whereas no significant differences were observed in the home-based (Systolic: 130 ± 4 vs. 126 ± 3 mmHg; diastolic: 73 ± 3 vs. 71 ± 3 mmHg) and control groups (p > 0.05). Supervised handgrip exercise also reduced central BP systolic (120 ± 5 vs. 109 ± 5 mmHg), diastolic (73 ± 2 vs. 67 ± 2 mmHg); and mean BP (93 ± 3 vs. 84 ± 3 mmHg), whereas no significant effects were found in the home-based (Systolic: 119 ± 4 vs. 115 ± 3 mmHg; Diastolic: 74 ± 3 vs. 71 ± 3 mmHg) and control groups (p > 0.05). In conclusion, supervised, but not home-based, isometric training lowered brachial and central BP in hypertensives.