Exercise training and resting blood pressure: a large-scale pairwise and network meta-analysis of randomised controlled trials.

OBJECTIVE: To perform a large-scale pairwise and network meta-analysis on the effects of all relevant exercise training modes on resting blood pressure to establish optimal antihypertensive exercise prescription practices. DESIGN: Systematic review and network meta-analysis. DATA SOURCES: PubMed (Medline), the Cochrane library and Web of Science were systematically searched. ELIGIBILITY CRITERIA: Randomised controlled trials published between 1990 and February 2023. All relevant work reporting reductions in systolic blood pressure (SBP) and/or diastolic blood pressure (DBP) following an exercise intervention of ≥2 weeks, with an eligible non-intervention control group, were included. RESULTS: 270 randomised controlled trials were ultimately included in the final analysis, with a pooled sample size of 15 827 participants. Pairwise analyses demonstrated significant reductions in resting SBP and DBP following aerobic exercise training (-4.49/-2.53 mm Hg, p<0.001), dynamic resistance training (-4.55/-3.04 mm Hg, p<0.001), combined training (-6.04/-2.54 mm Hg, p<0.001), high-intensity interval training (-4.08/-2.50 mm Hg, p<0.001) and isometric exercise training (-8.24/-4.00 mm Hg, p<0.001). As shown in the network meta-analysis, the rank order of effectiveness based on the surface under the cumulative ranking curve (SUCRA) values for SBP were isometric exercise training (SUCRA: 98.3%), combined training (75.7%), dynamic resistance training (46.1%), aerobic exercise training (40.5%) and high-intensity interval training (39.4%). Secondary network meta-analyses revealed isometric wall squat and running as the most effective submodes for reducing SBP (90.4%) and DBP (91.3%), respectively. CONCLUSION: Various exercise training modes improve resting blood pressure, particularly isometric exercise. The results of this analysis should inform future exercise guideline recommendations for the prevention and treatment of arterial hypertension.

A multimodal approach to studying the relationship between peripheral glutathione, brain glutamate, and cognition in health and in schizophrenia.

Involvement of oxidative stress in the pathophysiology of schizophrenia (SZ) is suggested by studies of peripheral tissue. Nonetheless, it is unclear how such biological changes are linked to relevant, pathological neurochemistry, and brain function. We designed a multi-faceted study by combining biochemistry, neuroimaging, and neuropsychology to test how peripheral changes in a key marker for oxidative stress, glutathione (GSH), may associate with central neurochemicals or neuropsychological performance in health and in SZ. GSH in dorsal anterior cingulate cortex (dACC) was acquired as a secondary 3T 1H-MRS outcome using a MEGA-PRESS sequence. Fifty healthy controls and 46 patients with SZ were studied cross-sectionally, and analyses were adjusted for effects of confounding variables. We observed lower peripheral total GSH in SZ compared to controls in extracellular (plasma) and intracellular (lymphoblast) pools. Total GSH levels in plasma positively correlated with composite neuropsychological performance across the total population and within patients. Total plasma GSH levels were also positively correlated with the levels of Glx in the dACC across the total population, as well as within each individual group (controls, patients). Furthermore, the levels of dACC Glx and dACC GSH positively correlated with composite neuropsychological performance in the patient group. Exploring the relationship between systemic oxidative stress (in particular GSH), central glutamate, and cognition in SZ will benefit further from assessment of patients with more varied neuropsychological performance.

Left ventricular mechanical, cardiac autonomic and metabolic responses to a single session of high intensity interval training.

PURPOSE: High-intensity interval training (HIIT) produces significant health benefits. However, the acute physiological responses to HIIT are poorly understood. Therefore, we aimed to measure the acute cardiac autonomic, haemodynamic, metabolic and left ventricular mechanical responses to a single HIIT session. METHODS: Fifty young, healthy participants completed a single HIIT session, comprising of three 30-s maximal exercise intervals on a cycle ergometer, interspersed with 2-min active recovery. Cardiac autonomics, haemodynamics and metabolic variables were measured pre-, during and post-HIIT. Conventional and speckle tracking echocardiography was used to record standard and tissue Doppler measures of left ventricular (LV) structure, function and mechanics pre- and post-HIIT. RESULTS: Following a single HIIT session, there was significant post-exercise systolic hypotension (126 ± 13 to 111 ± 10 mmHg, p < 0.05), parallel to a significant reduction in total peripheral resistance (1640 ± 365 to 639 ± 177 dyne⋅s⋅cm5, p < 0.001) and significant increases in baroreceptor reflex sensitivity and baroreceptor effectiveness index (9.2 ± 11 to 24.8 ± 16.7 ms⋅mmHg-1 and 41.8 ± 28 to 68.8 ± 16.2, respectively) during recovery compared to baseline. There was also a significant increase in the low- to high-frequency heart rate variability ratio in recovery (0.7 ± 0.48 to 1.7 ± 1, p < 0.001) and significant improvements in left ventricular global longitudinal strain (- 18.3 ± 1.2% to - 29.2 ± 2.3%, p < 0.001), and myocardial twist mechanics (1.27 ± 0.72 to 1.98 ± 0.72°·cm-1, p = 0.028) post-HIIT compared to baseline. CONCLUSION: A single HIIT session is associated with acute improvements in autonomic modulation, haemodynamic cardiovascular control and left ventricular function, structure and mechanics. The acute responses to HIIT provide crucial mechanistic information, which may have significant acute and chronic clinical implications.

Myocardial work and left ventricular mechanical adaptations following isometric exercise training in hypertensive patients.

PURPOSE: Hypertension is a major risk factor for cardiovascular disease. Isometric exercise training (IET) reduces resting and ambulatory blood pressure; however, few studies have investigated the myocardial adaptations following IET. METHODS: We randomly assigned 24 unmedicated hypertensive patients in a cross-over study design to 4-weeks of IET and control period, separated by a 3-week washout period. Speckle tracking echocardiography was used to measure left ventricular (LV) mechanics, and global myocardial work indices were derived from non-invasive LV pressure-strain loops constructed from global longitudinal strain (GLS) indexed to brachial systolic blood pressure. RESULTS: IET significantly improved GLS (- 2.3 ± 2%, p < 0.001) and global work efficiency (2.8 ± 2%, p < 0.001), and significantly reduced global wasted work (- 42.5 ± 30 mmHg%, p < 0.001) with no significant change during the control period. CONCLUSIONS: This is the first evidence to demonstrate that IET significantly improved cardiac health in a relevant patient population. Our findings have important clinical implications for patients with high blood pressure and support the role of IET as a safe and viable therapeutic and preventative intervention in the treatment of hypertension.

Isometric exercise versus high-intensity interval training for the management of blood pressure: a systematic review and meta-analysis.

OBJECTIVE: We aimed to compare the efficacy of isometric exercise training (IET) versus high-intensity interval training (HIIT) in the management of resting blood pressure (BP). DESIGN: Systematic review and meta-analysis. DATA SOURCES: PubMed (MEDLINE), the Cochrane library and SPORTDiscus were systematically searched. ELIGIBILITY CRITERIA: Randomised controlled trials published between 1 January 2000 and 1 September 2020. Research trials reporting the effects of IET or HIIT on resting BP following a short-term intervention (2-12 weeks). RESULTS: 38 studies were analysed (18 IET and 20 HIIT), including 1583 (672 IET and 911 HIIT) participants, of which 612 (268 IET and 344 HIIT) were controls.IET produced significantly greater reductions in resting BP compared with HIIT with systolic, diastolic and mean BP effect sizes of 8.50 mm Hg vs 2.86 mm Hg (Q=17.10, p<0.001), 4.07 mm Hg vs 2.48 mm Hg (Q=4.71, p=0.03) and 6.46 mm Hg vs 3.15 mm Hg (Q=4.21, p=0.04) respectively. However, HIIT reduced resting heart rate significantly more than IET (3.17bpm vs 1.34bpm, Q=7.63, p=0.006). CONCLUSION: While both modes are efficacious, IET appears to be the superior mode of exercise in the management of resting BP. However, HIIT may achieve wider physiological benefits, with greater reductions in resting heart rate.

Risk of atrial fibrillation in athletes: a systematic review and meta-analysis.

OBJECTIVE: A systematic review, meta-analysis and meta-regression were performed on selected studies to investigate the incidence of atrial fibrillation (AF) among athletes compared with non-athlete controls. DESIGN: Meta-analysis with heterogeneity analysis and subsequent meta-regression to model covariates were performed. The mode of exercise (endurance and mixed sports) and age were the a priori determined covariates. DATA SOURCES: PubMed, MEDLINE, Science Direct, SPORTDiscus and the Cochrane library were searched. ELIGIBILITY CRITERIA: Research articles published after 1990 and before 2 December 2020 were included if they reported the number of AF cases in athletes with non-athlete (physically active or inactive) control groups, were case-control or cohort studies and if data allowed calculation of OR. RESULTS: The risk of developing AF was significantly higher in athletes than in non-athlete controls (OR: 2.46; 95% CI 1.73 to 3.51; p<0.001, Z=4.97). Mode of exercise and risk of AF were moderately correlated (B=0.1259, p=0.0193), with mixed sport conferring a greater risk of AF than endurance sport (B=-0.5476, p=0.0204). Younger (<55 years) athletes were significantly more likely to develop AF compared with older (≥55 years) athletes (B=-0.02293, p<0.001). CONCLUSION: Athletes have a significantly greater likelihood of developing AF compared with non-athlete controls, with those participating in mixed sport and younger athletes at the greatest risk. Future studies of AF prevalence in athletes according to specific exercise dose parameters, including training and competition history, may aid further in delineating those at risk.

The Acute Impact of Endurance Exercise on Right Ventricular Structure and Function: A Systematic Review and Meta-analysis.

There have been many studies since the late 1980s investigating the effect of endurance exercise on the left ventricle. More recently, attention has shifted to the right heart, with suggestions that endurance exercise may have a detrimental effect on the right ventricle. This systematic review and meta-analysis summarizes and critiques 26 studies, including 649 athletes, examining the acute impact of endurance exercise on the right ventricle. We also present a subanalysis contrasting ultraendurance with endurance exercise. Finally, we identify areas for future research, such as the influence of sex, ethnicity, and age.

Treated Primary Cutaneous Malignant Melanoma With Later Metastasis Found in Clinical Presentation of Left Axilla Lymphadenopathy: A Case Report.

This case report details the rare instance of metastatic spread of cutaneous malignant melanoma to the breast in a 50-year-old female. The patient presented with a palpable axillary mass confirmed to be metastasis despite excision and closure of the primary malignancy. The mass seen in clinical and radiological presentations presented with features of complicated differentiation from a primary breast tumor. Biopsy and staining with immunohistochemical markers S100 and Sox10 played a critical role in confirming the melanocytic origin of this metastatic lesion. Breast metastases are associated with poor prognosis, and this case emphasizes the importance of in-depth evaluations for patients with a history of malignant melanoma and the need for ongoing clinical awareness in this field.

Differences in Biomechanical Determinants of ACL Injury Risk in Change of Direction Tasks Between Males and Females: A Systematic Review and Meta-Analysis.

BACKGROUND: Change of direction (COD) movements are associated with non-contact anterior cruciate ligament (ACL) injuries in multidirectional sports. Females appear at increased risk compared to males, which could be attributable to whole body kinematic strategies and greater multiplanar knee joint loads (KJLs) during COD which can increase ACL loading. OBJECTIVE: The aim of this systematic review and meta-analysis was to examine and quantitatively synthesise the evidence for differences between males and females regarding KJLs and their biomechanical determinants (whole body kinematic strategies determining KJLs) during COD tasks. METHODS: Databases including SPORTDiscus, Web of Science, and PubMed were systematically searched (July 2021-June 2023) for studies that compared differences in knee joint loads and biomechanical determinants of KJLs during COD between males and females. Inclusion criteria were: (1) females and males with no prior history of ACL injury (18-40 years); (2) examined biomechanical determinants of KJLs and/ or KJLs during COD tasks > 20°; (3) compared ≥ 1 outcome measure between males and females. Studies published between 2000 and 2023 examining a cutting task > 20° with a preceding approach run that compared KJLs or the whole body multiplanar kinematics associated with them, between sexes, using three-dimensional motion analysis. RESULTS: This meta-analysis included 17 studies with a pooled sample size of 451 participants (227 males, 224 females). Meta-analysis revealed females displayed significantly less peak knee flexion during stance (SMD: 0.374, 95% CI 0.098-0.649, p = 0.008, I2: 0%); greater knee abduction at initial contact (IC) (SMD: 0.687, 95% CI 0.299-1.076, p = 0.001, I2: 55%); less hip internal rotation (SMD: 0.437, 95% CI 0.134-0.741, p = 0.005, I2: 34%) and hip abduction at IC (SMD: -0.454, 95% CI 0.151-0.758, p = 0.003, I2: 33%). No significant differences were observed between males and females for any internal or externally applied KJLs. All retrieved studies failed to control for strength, resistance training or skill history status. CONCLUSION: No differences were observed in KJLs between males and females despite females displaying greater knee abduction at IC and less peak knee flexion during the stance phase of CODs, which are visual characteristics of non-contact ACL injury. Further research is required to examine if this translates to a similar injury risk, considering morphological differences in strain characteristics of the ACL between males and females. This observation may in part explain the disproportionate ACL injury incidence in female multidirectional athletes. Further higher quality controlled research is required whereby participants are matched by skill training history, resistance training history and strength status to ensure an appropriate comparison between males and females.

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.

International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death Tool.

BACKGROUND: Studies reporting on the incidence of sudden cardiac arrest and/or death (SCA/D) in athletes commonly lack methodological and reporting rigor, which has implications for screening and preventative policy in sport. To date, there are no tools designed for assessing study quality in studies investigating the incidence of SCA/D in athletes. METHODS AND RESULTS: The International Criteria for Reporting Study Quality for Sudden Cardiac Arrest/Death tool (IQ-SCA/D) was developed following a Delphi process. Sixteen international experts in sports cardiology were identified and invited. Experts voted on each domain with subsequent moderated discussion for successive rounds until consensus was reached for a final tool. Interobserver agreement between a novice, intermediate, and expert observer was then assessed from the scoring of 22 relevant studies using weighted and unweighted κ analyses. The final IQ-SCA/D tool comprises 8 domains with a summated score of a possible 22. Studies are categorized as low, intermediate, and high quality with summated IQ-SCA/D scores of ≤11, 12 to 16, and ≥17, respectively. Interrater agreement was "substantial" between all 3 observers for summated IQ-SCA/D scores and study categorization. CONCLUSIONS: The IQ-SCA/D is an expert consensus tool for assessing the study quality of research reporting the incidence of SCA/D in athletes. This tool may be used to assist researchers, reviewers, journal editors, and readers in contextualizing the methodological quality of different studies with varying athlete SCA/D incidence estimates. Importantly, the IQ-SCA/D also provides an expert-informed framework to support and guide appropriate design and reporting practices in future SCA/D incidence trials.

The Acute Impact of Endurance Exercise on Right Ventricular Structure and Function: A Systematic Review and Meta-analysis.

There have been many studies since the late 1980s investigating the effect of endurance exercise on the left ventricle. More recently, attention has shifted to the right heart, with suggestions that endurance exercise may have a detrimental effect on the right ventricle. This systematic review and meta-analysis summarizes and critiques 26 studies, including 649 athletes, examining the acute impact of endurance exercise on the right ventricle. We also present a subanalysis contrasting ultraendurance with endurance exercise. Finally, we identify areas for future research, such as the influence of sex, ethnicity, and age.

Myocardial performance index as a measure of global left ventricular function improves following isometric exercise training in hypertensive patients.

As the leading cause of cardiovascular disease and mortality, hypertension remains a global health problem. Isometric exercise training (IET) has been established as efficacious in reducing resting blood pressure (BP); however, no research to date has investigated its effects on the myocardial performance index (MPI). Twenty-four unmedicated hypertensive patients were randomized to 4 weeks of IET and a control period in a crossover design. Tissue Doppler imaging was used to acquire cardiac time intervals pre- and post-IET and during the control periods. IET significantly improved all measures of cardiac time intervals, including isovolumic relaxation time (83.1 ± 10.3 vs. 76.1 ± 11.2 ms, p = 0.006), isovolumic contraction time (84.8 ± 10.3 vs. 72.8 ± 6.4 ms, p < 0.001), ejection time (304.6 ± 30.2 vs. 321.4 ± 20.8 ms, p = 0.015) and the MPI (0.56 ± 0.09 vs. 0.47 ± 0.05, p < 0.001). This is the first study to demonstrate that IET significantly improves cardiac time intervals. These findings may have important clinical implications, highlighting the potential utility of IET in the management of cardiac health in hypertensive patients.

High-Intensity Interval Training and Cardiometabolic Health in the General Population: A Systematic Review and Meta-Analysis of Randomised Controlled Trials.

BACKGROUND: High-intensity interval training (HIIT) remains a promising exercise mode in managing cardiometabolic health. Large-scale analyses are necessary to understand its magnitude of effect on important cardiometabolic risk factors and inform guideline recommendations. OBJECTIVE: We aimed to perform a novel large-scale meta-analysis on the effects of HIIT on cardiometabolic health in the general population. METHODS: PubMed (MEDLINE), the Cochrane library and Web of Science were systematically searched. Randomised controlled trials (RCTs) published between 1990 and March 2023 were eligible. Research trials reporting the effects of a HIIT intervention on at least one cardiometabolic health parameter with a non-intervention control group were considered. RESULTS: This meta-analysis included 97 RCTs with a pooled sample size of 3399 participants. HIIT produced significant improvements in 14 clinically relevant cardiometabolic health parameters, including peak aerobic capacity (VO2) [weighted mean difference (WMD): 3.895 ml min-1 kg-1, P < 0.001), left ventricular ejection fraction (WMD: 3.505%, P < 0.001), systolic (WMD: - 3.203 mmHg, P < 0.001) and diastolic (WMD: - 2.409 mmHg, P < 0.001) blood pressure, resting heart rate (WMD: - 3.902 bpm, P < 0.001) and stroke volume (WMD: 9.516 mL, P < 0.001). Body composition also significantly improved through reductions in body mass index (WMD: - 0.565 kg m-2, P < 0.001), waist circumference (WMD: - 2.843 cm, P < 0.001) and percentage body fat (WMD: - 0.972%, P < 0.001). Furthermore, there were significant reductions in fasting insulin (WMD: - 13.684 pmol L-1, P = 0.004), high-sensitivity C-reactive protein (WMD: - 0.445 mg dL-1, P = 0.043), triglycerides (WMD: - 0.090 mmol L-1, P = 0.011) and low-density lipoprotein (WMD: - 0.063 mmol L-1, P = 0.050), concurrent to a significant increase in high-density lipoprotein (WMD: 0.036 mmol L-1, P = 0.046). CONCLUSION: These results provide further support for HIIT in the clinical management of important cardiometabolic health risk factors, which may have implications for physical activity guideline recommendations.

The effect of isometric exercise training on arterial stiffness: A randomized crossover controlled study.

Isometric exercise training (IET) is an effective intervention for the management of resting blood pressure (BP). However, the effects of IET on arterial stiffness remain largely unknown. Eighteen unmedicated physically inactive participants were recruited. Participants were randomly allocated in a cross-over design to 4 weeks of home-based wall squat IET and control period, separated by a 3-week washout period. Continuous beat-to-beat hemodynamics, including early and late systolic (sBP 1 and sBP 2, respectively) and diastolic blood pressure (dBP) were recorded for a period of 5 min and waveforms were extracted and analyzed to acquire the augmentation index (AIx) as a measure of arterial stiffness. sBP 1 (-7.7 ± 12.8 mmHg, p = 0.024), sBP 2 (-5.9 ± 9.9 mmHg, p = 0.042) and dBP (-4.4 ± 7.2 mmHg, p = 0.037) all significantly decreased following IET compared to the control period. Importantly, there was a significant reduction in AIx following IET (-6.6 ± 14.5%, p = 0.02) compared to the control period. There were also adjacent significant reductions in total peripheral resistance (-140.7 ± 65.8 dynes·cm-5, p = 0.042) and pulse pressure (-3.8 ± 4.2, p = 0.003) compared to the control period. This study demonstrates an improvement in arterial stiffness following a short-term IET intervention. These findings have important clinical implications regarding cardiovascular risk. Mechanistically, these results suggest that reductions in resting BP following IET are induced via favorable vascular adaptations, although the intricate details of such adaptations are not yet clear.

Exercise Mode in Heart Failure: A Systematic Review and Meta-Analysis.

BACKGROUND: Optimising exercise prescription in heart failure (HF) with a preserved (HFpEF) or reduced (HFrEF) ejection fraction is clinically important. As such, the aim of this meta-analysis was to compare traditional moderate intensity training (MIT) against combined aerobic and resistance training (CT) and high-intensity interval training (HIIT) for improving aerobic capacity (VO2), as well as other clinically relevant parameters. METHODS: A comprehensive systematic search was performed to identify randomised controlled trials published between 1990 and May 2021. Research trials reporting the effects of MIT against CT or HIIT on peak VO2 in HFpEF or HFrEF were considered. Left-ventricular ejection fraction (LVEF) and various markers of diastolic function were also analysed. RESULTS: Seventeen studies were included in the final analysis, 4 of which compared MIT against CT and 13 compared MIT against HIIT. There were no significant differences between MIT and CT for peak VO2 (weighted mean difference [WMD]: 0.521 ml min-1 kg-1, [95% CI] = - 0.7 to 1.8, Pfixed = 0.412) or LVEF (WMD: - 1.129%, [95% CI] = - 3.8 to 1.5, Pfixed = 0.408). However, HIIT was significantly more effective than MIT at improving peak VO2 (WMD: 1.62 ml min-1 kg-1, [95% CI] = 0.6-2.6, Prandom = 0.002) and LVEF (WMD: 3.24%, [95% CI] = 1.7-4.8, Prandom < 0.001) in HF patients. When dichotomized by HF phenotype, HIIT remained significantly more effective than MIT in all analyses except for peak VO2 in HFpEF. CONCLUSIONS: HIIT is significantly more effective than MIT for improving peak VO2 and LVEF in HF patients. With the exception of peak VO2 in HFpEF, these findings remain consistent in both phenotypes. Separately, there is no difference in peak VO2 and LVEF change following MIT or CT, suggesting that the addition of resistance exercise does not inhibit aerobic adaptations in HF.

Exercise Training in Heart failure with Preserved and Reduced Ejection Fraction: A Systematic Review and Meta-Analysis.

BACKGROUND: While exercise training (ET) is an established tool in heart failure (HF), no research to date has analysed the efficacy of ET in both preserved (HFpEF) and reduced (HFrEF) ejection fraction phenotypes across the same clinically important parameters. METHODS: A comprehensive systematic search was performed to identify trials published between 1990 and May 2021. Controlled trials of adults reporting pre- and post-ET peak VO2, 6-min walk distance (6MWD), Minnesota Living with Heart Failure Questionnaire (MLHFQ), Kansas City Cardiomyopathy Questionnaire (KCCQ) and left ventricular ejection fraction (LVEF) were considered. Parameters of cardiac diastolic function, brain natriuretic peptides (BNP)/N-terminal prohormone of BNP (NTproBNP) and follow-up hospitalisation and mortality data were also analysed. RESULTS: Ninety-three studies (11 HFpEF and 82 HFrEF) were included in the final analysis, with a pooled sample size of 11,081 participants. HFpEF analysis demonstrated significant improvements in peak VO2 (weighted mean difference: 2.333 ml·min-1·kg-1, Pfixed < 0.001), 6MWD (WMD: 35.396 m, Pfixed < 0.001), MLHFQ (WMD: - 10.932, Prandom < 0.001), KCCQ (WMD: 3.709, Pfixed = 0.037) and E/e' (WMD: - 1.709, [95% CI] = - 2.91-0.51, Prandom = 0.005). HFrEF analysis demonstrated significant improvements in peak VO2 (WMD: 3.050 ml·min-1·kg-1, Prandom < 0.001), 6MWD (WMD: 37.299 m, Prandom < 0.001), MLHFQ (WMD: - 10.932, Prandom < 0.001), LVEF (WMD: 2.677%, Prandom = 0.002) and BNP/NTproBNP (SMD: - 1.349, Prandom < 0.001). Outcome analysis was only performed in HFrEF, which found no significant changes in hospitalisation, all-cause mortality or composite end-points. CONCLUSION: ET significantly improves exercise capacity and quality of life in both HFpEF and HFrEF patients. In HFpEF patients, ET significantly improved an important index of diastolic function, with significant improvements in LVEF and NTproBNP/BNP seen in HFrEF patients only. Such benefits did not translate into significantly reduced hospitalisation or mortality after short-term follow-up.

Mechanisms for blood pressure reduction following isometric exercise training: a systematic review and meta-analysis.

OBJECTIVE: Isometric exercise training (IET) is established as an effective antihypertensive intervention. Despite this, the physiological mechanisms driving blood pressure (BP) reductions following IET are not well understood. Therefore, we aimed to perform the first meta-analysis of the mechanistic changes measured following IET. METHODS: PubMed, Cochrane library and SPORTDiscus were systematically searched for randomized controlled trials published between January 2000 and December 2021 reporting the effects of IET on resting BP and at least one secondary mechanistic parameter following a short-term intervention (2-12 weeks). RESULTS: Eighteen studies with a pooled sample size of 628 participants were included in the final analysis. IET produced significant reductions in resting systolic and diastolic BP of 9.35 mmHg (95% confidence interval [CI] = -7.80 to -10.89, P  < 0.001) and 4.30 mmHg (CI = -3.01 to -5.60, P  < 0.001), respectively. Mechanistically, IET produced a statistically significant reduction in resting heart rate (mean difference [MD]: -1.55 bpm, CI = -0.14 to -2.96, P  = 0.031) and a significant increase in stroke volume (MD: 6.35 ml, CI = 0.35 to 12.60, P  = 0.038), with no significant change in cardiac output. Conversely, total peripheral resistance (TPR) significantly decreased following IET (MD: -100.38 dyne s -1 cm 5 , CI = -14.16 to -186.61, P  = 0.023), with significant improvements in the low frequency to high frequency heart rate variability ratio (MD: -0.41, CI = -0.09 to -0.73, P  = 0.013) and baroreceptor reflex sensitivity (MD: 7.43 ms/mmHg, P  < 0.001). CONCLUSION: This work demonstrates that a reduction in TPR, potentially mediated through enhanced autonomic vasomotor control, is primarily responsible for BP reductions following IET. Furthermore, this novel analysis suggests wall squat interventions to be the most effective IET mode, with clinically relevant differences in BP reductions compared to handgrip and leg extension IET; although future direct comparative research is required.