Acute effects of different resistance training loads on cardiac autonomic modulation in hypertensive postmenopausal women

Whole-Body Cold Stimulation Improves Cardiac Autonomic Control Independently of the Employed Temperature

Background/Objectives: The autonomic nervous system (ANS) is considered one of the mechanisms mediating the benefits of whole-body cold stimulation (WBC). Nevertheless, different treatment protocols, different methodologies employed to assess the ANS, and, in particular, difficulties in interpreting the numerous variables obtained represent important barriers to understanding the effects of WBC on the ANS. The present study aimed to explore the effects of WBC on cardiac autonomic control (CAR) as assessed using a single composite percentile-ranked proxy of autonomic balance (ANSI), considering two different WBC temperatures and the same WBC protocol. Methods: Heart rate variability (HRV) was employed to assess the ANS in 23 subjects with obesity who underwent 10 WBC sessions, studied before and after 2 min WBC at -55 °C (15 subjects) or 2 min WBC at -110 °C (8 subjects) both at the first session (T1) and the last one (T10). To overcome some important barriers in data interpretation and age/sex bias, we considered the Autonomic Nervous System Index (ANSI), a single composite percentile-ranked proxy of autonomic control. Results: We observed an improvement in CAR independently of the employed temperature. Both treatments, without distinction, caused a significant increase in the ANSI post-WBC treatment both at T1 and T10 and a significant betterment of the total power of the RR interval variability from pre- to post-treatment at T1 and overall from T1 to T10. Conclusions: WBC was capable of inducing an immediate change in the ANS control (pre- vs. post-treatment both at T1 and T10) and a long-term modulation in cardiac autonomic control (T1-pre vs. T10-pre).

Validity and reliability of a wearable blood flow restriction training device for arterial occlusion pressure assessment

PURPOSE

The blood flow restriction (BFR) training is an effective approach to promoting muscle strength, muscle hypertrophy, and regulating the peripheral vascular system. It is recommended to use to the percentage of individual arterial occlusion pressure (AOP) to ensure safety and effectiveness. The gold standard method for assessing arterial occlusive disease is typically measured using Doppler ultrasound. However, its high cost and limited accessibility restrict its use in clinical and practical applications. A novel wearable BFR training device (Airbands) with automatic AOP assessment provides an alternative solution. This study aims to examine the reliability and validity of the wearable BFR training device.

METHODS

Ninety-two participants (46 female and 46 male) were recruited for this study. Participants were positioned in the supine position with the wearable BFR training device placed on the proximal portion of the right thigh. AOP was measured automatically by the software program and manually by gradually increasing the pressure until the pulse was no longer detected by color Doppler ultrasound, respectively. Validity, inter-rater reliability, and test-retest reliability were assessed by intraclass correlation coefficients (ICC) and Bland-Altman analysis.

RESULTS

The wearable BFR training device demonstrated good validity (ICC = 0.85, mean difference = 4.1 ± 13.8 mmHg [95% CI: -23.0 to 31.2]), excellent inter-rater reliability (ICC = 0.97, mean difference = -1.4 ± 6.7 mmHg [95% CI: -14.4 to 11.7]), and excellent test-retest reliability (ICC = 0.94, mean difference = 0.6 ± 8.6 mmHg [95% CI: -16.3 to 17.5]) for the assessment of AOP. These results were robust in both male and female subgroups.

CONCLUSION

The wearable BFR training device can be used as a valid and reliable tool to assess the AOP of the lower limb in the supine position during BFR training.

Lower heart rate variability is associated with loss of muscle mass and sarcopenia in community-dwelling older Chinese adults

BACKGROUND/PURPOSE

Autonomic nervous system (ANS) disorders may occur in skeletal muscle disease, but the link between them has not been fully established. Studying the relationship between them may yield insights into the mechanisms and treatment of disease. This study aimed to explore the association between heart rate variability (HRV), sarcopenia, and subscales of sarcopenia (muscle mass, muscle strength, and physical mobility).

METHODS

2514 community-dwelling older Chinese participants were included in this study. The Asian Working Group for Sarcopenia guidelines were used to define sarcopenia. HRV was measured by 90-s electrocardiogram RR interval data. All HRV parameters were transformed using natural logarithms. Multiple regression analysis and multivariate linear regression was performed using potential correlates.

RESULTS

The overall prevalence of sarcopenia was 15.1 % (18.5 % in males and 12.6 % in females). In the logistic regression analysis model, there was a significant association between log-transformed standard deviation of RR interval (lnSDNN) (OR = 0.736, p = 0.019), log-transformed coefficient of variation of RR intervals (lnCVRR) (OR = 0.751, p = 0.020), log-transformed low-frequency power (lnLF) (OR = 0.861, p = 0.008), log-transformed high-frequency power (lnHF) (OR = 0.864, p = 0.003) and sarcopenia in the general population after adjusting for age, sex, body mass index (BMI), daily activity levels, hypertension, heart disease and cardiac drugs. In addition, in multivariate linear regression, lnSDNN (β = 0.146, p = 0.001), lnCVRR (β = 0.120, p = 0.010), lnLF (β = 0.066, p = 0.002) and lnHF (β = 0.065, p < 0.001) remained significantly positively associated with muscle mass, but there were no significant differences in grip strength and walking speed.

CONCLUSION

Sarcopenia was independently associated with lower heart rate variability in a community-dwelling elderly Chinese population. In addition, muscle mass was positively associated with heart rate variability in the elderly.

Regulation of exercise on heart rate variability in perimenopausal and postmenopausal women

Heart rate variability (HRV) is a non-invasive quantitative measure of cardiac autonomic nervous activity. Due to the increase of age and the decrease of estrogen level in perimenopausal and postmenopausal women, the cardiac autonomic nervous function is abnormal, increasing the risk of cardiovascular disease. Proper exercise can increase estrogen levels, improve cardiovascular health, regulate cardiac autonomic nervous activity, and reduce the risk of cardiovascular disease. Low-moderate intensity aerobic exercise, resistance exercise, aerobic combined resistance exercise and mind-body exercise have positive effects on HRV in perimenopausal and postmenopausal women. Therefore, summarizing the effects of different exercise modes on HRV in perimenopausal and postmenopausal women, as well as the mechanism of exercise training improvement on HRV, so as to adopt better exercise strategies to improve HRV of perimenopausal and postmenopausal women, and thus reduce the risk of cardiovascular diseases and improve the health level and quality of life of perimenopausal and postmenopausal women.

Resistance Training to Muscle Failure with Variable Load Intensities: Implications for Post-Exercise Blood Pressure and Heart Rate Variability in Trained Men

Background: The modulation of cardiac sympathovagal balance alters following acute resistance training (RT) sessions. Nevertheless, the precise influence of RT at varying load intensities on this physiological response remains to be fully elucidated. Therefore, the aim of this study was to compare the time course of recovery following low- (40%), moderate- (60%), and high- (80%) load-intensity RT protocols performed up to muscle repetition failure in resistance-trained men. Method: Sixteen young, resistance-trained men (mean age: 21.6 ± 2.5 years, mean height: 175.7 ± 8.9 cm, mean weight: 77.1 ± 11.3 kg) participated in a randomized crossover experimental design involving three sessions, each taken to the point of muscle failure. These sessions were characterized by different load intensities: low (40% of 1-repetition maximum, 1RM), moderate (60% of 1RM), and high (80% of 1RM). The exercise regimen comprised four exercises-back squat (BS), bench press (BnP), barbell row (BR), and shoulder press (SP)-with each exercise consisting of three sets. Throughout each session, heart rate variability (HRV) and blood pressure (BP) parameters were assessed both pre-exercise and during a 40 min post-exercise period, segmented into 10 min intervals for stabilization. Statistical analysis involved the use of a repeated measures ANOVA. Results: It was observed that the 40% and 60% RT sessions resulted in a significantly higher root mean square of successive R-R intervals (RMSSD) value compared to the 80% RT session in the post-exercise recovery process in 30 min (respectively, p = 0.025; p = 0.028) and 40 min (respectively, p = 0.031; p = 0.046), while the 40% and 60% RT sessions produced similar responses. The 40% RT session was significantly higher in the high frequency (HF) value post-exercise in 40 min compared to the 80% RT session (p = 0.045). Conclusions: Our findings suggest that engaging in resistance training (RT) sessions to muscle failure at an intensity of 80% induces acute increases in sympathetic activity, potentially leading to elevated cardiovascular stress. For individuals with normal blood pressure, it is advisable to opt for lighter loads and higher repetition volumes when prescribing RT, as heavier-load RT may carry an increased risk of cardiac-related factors.

Effect of exercise modalities on postexercise hypotension in pre- and postmenopausal women: a systematic review and meta-analysis

Hormonal changes associated with menopause increase the risk of hypertension. Postexercise hypotension (PEH) is an important tool in the prevention and management of hypertension; however, menopause may alter this response. The aim of this systematic review and meta-analysis [International Prospective Registered of Systematic Review (PROSPERO): CRD42023297557] was to evaluate the effect of exercise modalities (aerobic, AE; resistance, RE; and combined exercise, CE: AE + RE) on PEH in women, according to their menopausal status (premenopausal or postmenopausal). We searched controlled trials in PubMed, Web of Science, EBSCO, and Science Direct published between 1990 and March 2023. Inclusion criteria were normotensive, pre- and hypertensive, pre- and postmenopausal women who performed an exercise session compared with a control session and reported systolic blood pressure (SBP) and diastolic blood pressure (DBP) for at least 30 min after the sessions. Methodological quality was assessed using the PEDro scale. Standardized mean differences (Hedge's g) and their 95% confidence intervals (CIs) were calculated, and Q-test and Z-test were conducted to assess differences between moderators. Forty-one trials with 718 women (474 menopausal) were included. Overall, we found with moderate evidence that SBP and DBP decreased significantly after exercise session (SBP: g = -0.69, 95% CI -0.87 to -0.51; DBP: g = -0.31, 95% CI -0.47 to -0.14), with no difference between premenopausal and postmenopausal women. Regarding exercise modalities, RE is more effective than AE and CE in lowering blood pressure (BP) in women regardless of menopausal status. In conclusion, women's menopausal status does not influence the magnitude of PEH, and the best modality to reduce BP in women seems to be RE.NEW & NOTEWORTHY This meta-analysis has demonstrated that a single bout of exercise induces postexercise hypotension (PEH) in women and that the hormonal shift occurring with menopause does not influence the magnitude of PEH. However, we have shown with moderate evidence that the effectiveness of exercise modalities differs between pre- and postmenopausal women. Resistance and combined exercises are the best modalities to induce PEH in premenopausal women, whereas resistance and aerobic exercises are more effective in postmenopausal women.

Can mixed circuit training elicit the recommended exercise intensity and energy expenditure in people after stroke?

PURPOSE

To investigate whether mixed circuit training (MCT) elicits the recommended exercise intensity and energy expenditure in people after stroke, and to establish the between-day reproducibility for the percentages of heart rate reserve (%HRR), oxygen uptake reserve (%VO2R), and energy expenditure elicited during two bouts of MCT.

METHODS

Seven people aged 58 (12) yr, who previously had a stroke, performed a cardiopulmonary exercise test, a non-exercise control session, and two bouts of MCT. The MCT included 3 circuits of 10 resistance exercises at 15-repetition maximum intensity, with each set of resistance exercise interspersed with 45-s of walking. Expired gases were collected during the MCT and control session and for 40 min afterward. Control session was necessary to calculate the net energy expenditure associated with each bout of MCT.

RESULTS

Mean %VO2R (1st MCT: 51.1%, P = .037; 2nd MCT: 54.0%, P = .009) and %HRR (1st MCT: 66.4%, P = .007; 2nd MCT: 67.9%, P = .010) exceeded the recommended minimum intensity of 40%. Both %VO2R (P = .586 and 0.987, respectively) and %HRR (P = .681 and 0.237, respectively) during the 1st and 2nd bouts of MCT were not significantly different to their corresponding gas exchange threshold values derived from cardiopulmonary exercise testing. Mean net total energy expenditure significantly exceeded the minimum recommend energy expenditure in the 1st (P = .048) and 2nd (P = .023) bouts of MCT. Between-day reproducibility for %HRR, %VO2R, and energy expenditure was excellent (ICC: 0.92-0.97).

CONCLUSIONS

MCT elicited physiological strain recommended for improving health-related fitness in people after stroke and these responses demonstrated excellent between-day reproducibility.

Monitoring of the regulatory ability and regulatory state of the autonomic nervous system and its application to the management of hypertensive patients: a study protocol for randomised controlled trials

INTRODUCTION

Many causes lead to sympathetic-vagus imbalance, which promotes the development of hypertension and accelerates the process of target organ damage. Many studies have shown that exercise training and heart rate variability (HRV) biofeedback can improve diseases caused by autonomic nerve dysfunction, such as hypertension. Based on these theories and the Yin-Yang balance theory of traditional Chinese medicine and Cannon's homeostasis theory, we have developed an assessment system of autonomic nerve regulation system and a harmony instrument. In this study, we aimed to find a new way to control blood pressure of hypertensive patients via cardiopulmonary resonance indices-based respiratory feedback training.

METHODS AND ANALYSIS

This is a prospective, randomised, parallel-controlled clinical trial, which aims to evaluate the effectiveness and safety of biofeedback therapy and exercise rehabilitation combined intervention in hypertension management. 176 healthy individuals will be recruited to get their autonomic nerve function parameters as normal control, while 352 hypertensive patients will be enrolled and randomly divided into a conventional treatment group and an experiment group in a ratio of 1:1. All patients will continue to receive standard hypertension blood pressure treatment, except that patients in the experiment group will have to complete additional daily respiratory training for 6 months. The primary outcome is the difference of clinical systolic blood pressure (SBP) between the two groups after 6 months of intervention. The secondary outcomes include the changes in the mean SBP and diastolic blood pressure (DBP) by 24-hour blood pressure monitoring, home SBP, clinical and home DBP, clinical and home heart rate, the standard-reaching rate of clinic and home SBP and the incidence of composite endpoint events at 6 months.

ETHICS AND DISSEMINATION

This study has been approved by the clinical research ethics committee of China-Japan Friendship Hospital (No. 2018-132 K98-2), the results of this study will be disseminated via peer-reviewed publications or conference presentations.

TRIAL REGISTRATION NUMBER

Chinese Clinical Trial Registry, ChiCTR1800019457, registered on 12 August 2018.

Manipulating the Resistance Training Volume in Middle-Aged and Older Adults: A Systematic Review with Meta-Analysis of the Effects on Muscle Strength and Size, Muscle Quality, and Functional Capacity

BACKGROUND

Effective manipulation of the acute variables of resistance training is critical to optimizing muscle and functional adaptations in middle-aged and older adults. However, the ideal volume prescription (e.g., number of sets performed per exercise) in middle-aged and older adults remains inconclusive in the literature.

OBJECTIVE

The effects of single versus multiple sets per exercise on muscle strength and size, muscle quality, and functional capacity in middle-aged and older adults were compared. Moreover, the effects of single versus multiple sets per exercise on muscular and functional gains were also examined, considering the influence of training duration.

METHODS

Randomized controlled trials and non-randomized controlled trials comparing single versus multiple sets per exercise on muscle strength, muscle size, muscle quality, or functional capacity in middle-aged and older adults (aged ≥ 50 years) in the PubMed/MEDLINE, Web of Science, and Scopus databases (01/09/2021, updated on 15/05/2022) were identified. A random-effects meta-analysis was used.

RESULTS

Fifteen studies were included (430 participants; 93% women; age 57.9-70.1 years). Multiple sets per exercise produced a greater effect than single sets on lower-limb strength (standardized mean difference [SMD] = 0.29; 95% confidence interval [CI] 0.07-0.51; mean difference [MD] = 1.91 kg; 95% CI 0.50-3.33) and muscle quality (SMD = 0.40; 95% CI 0.05-0.75) gains. There were no differences between single versus multiple sets per exercise for upper-limb strength (SMD = 0.13; 95% CI - 0.14 to 0.40; MD = 0.11 kg; 95% CI - 0.52 to 0.75), muscle size (SMD = 0.15; 95% CI - 0.07 to 0.37), and functional capacity (SMD = 0.01; 95% CI - 0.47 to 0.50) gains. In addition, there were no differences between single versus multiple sets on muscle strength and size gains for training durations ≤ 12 weeks or > 12 weeks.

CONCLUSIONS

Multiple sets per exercise produced greater lower-limb strength and muscle quality gains than single sets in middle-aged and older adults, although the magnitude of the difference was small. In contrast, single sets per exercise were sufficient to improve upper-limb strength, muscle size, and functional capacity in these populations. Despite these findings, researchers should conduct future high-quality, pre-registered, and blinded randomized controlled trials to strengthen the scientific evidence on this topic.

Effect of Physical Exercise on Cardiac Autonomic Modulation in Hypertensive Individuals: A Systematic Review and Meta-analysis

BACKGROUND

Cardiac autonomic dysfunction is associated with hypertension and exercise training (ET) in healthy individuals is found to improve cardiac autonomic modulation (CAM). However, the effects of physical exercise on CAM in hypertensive individuals are under debate.

OBJECTIVE

The aim of the review is to systematically evaluate the literature on the effects of physical exercise on CAM in hypertensive individuals and analyse comparative differences in the effects of exercise between hypertensive and normotensive individuals.

METHODS

Electronic databases, such as Pubmed, PEDro, Scopus, and Web of Science, were systematically searched from inception up to February, 2022, evaluating the effect of ET on CAM either by heart rate variability (HRV), baroreflex sensitivity or heart rate recovery. Fifteen studies were included in the review. The risk of bias was assessed using the Cochrane risk of bias tool version 2 and the risk of bias in studies of intervention (ROBINS-I) tool. The overall quality of evidence was assessed using the grading of recommendations, assessment, development, and evaluation approach. Ten studies were included in the quantitative analysis. The meta-analysis and sensitivity analysis were performed using review manager 5.4.1; publication bias was assessed using Jamovi 2.2.5 software.

RESULTS

The qualitative analysis revealed low to moderate certainty of evidence for ET and moderate for aerobic training. For the effect of overall ET, the analysis revealed that the standardized mean differences (SMD) showed a significant effect of ET on HF (SMD 1.76, p = 0.04) and RMSSD (SMD 1.19, p < 0.0001) and a significant decrease in LF (SMD -1.78, p = 0.04). Aerobic training revealed nonsignificant improvement in HRV parameters. In the comparative analysis, ET did not show a significant difference in improvement between hypertensive and normotensive individuals.

CONCLUSION

This review suggests an improvement in CAM with physical exercise in hypertensive individuals, but the overall effect of ET in hypertensive individuals must be interpreted with caution as the robustness of the data is compromised in the sensitivity analysis of the trials. High-quality future trials focusing on different modes of ET interventions are needed to strengthen the findings of the present review.

Are Trainees Lifting Heavy Enough? Self-Selected Loads in Resistance Exercise: A Scoping Review and Exploratory Meta-analysis

BACKGROUND

Traditionally, the loads in resistance training are prescribed as a percentage of the heaviest load that can be successfully lifted once (i.e., 1 Repetition Maximum [1RM]). An alternative approach is to allow trainees to self-select the training loads. The latter approach has benefits, such as allowing trainees to exercise according to their preferences and negating the need for periodic 1RM tests. However, in order to better understand the utility of the self-selected load prescription approach, there is a need to examine what loads trainees select when given the option to do so.

OBJECTIVE

Examine what loads trainees self-select in resistance training sessions as a percentage of their 1RM.

DESIGN

Scoping review and exploratory meta-analysis.

SEARCH AND INCLUSION

We conducted a systematic literature search with PubMed, Web of Science, and Google Scholar in September 2021. We included studies that (1) were published in English in a peer-reviewed journal or as a MSc or Ph.D. thesis; (2) had healthy trainees complete at least one resistance-training session, composed of at least one set of one exercise in which they selected the loads; (3) trainees completed a 1RM test for the exercises that they selected the loads for. Eighteen studies were included in our main meta-analysis model with 368 participants.

RESULTS

Our main model indicated that on average participants select loads equal to 53% of their 1RM (95% credible interval [CI] 49-58%). There was little moderating effect of training experience, age, sex, timing of the 1RM test (before or after the selected load RT session), number of sets, number of repetitions, and lower versus upper body exercises. Participants did tend to select heavier loads when prescribed lower repetitions, and vice versa (logit(yi) =  - 0.09 [95% CI - 0.16 to - 0.03]). Note that in most of the analyzed studies, participants received vague instructions regarding how to select the loads, and only completed a single session with the self-selected loads.

CONCLUSIONS

Participants selected loads equal to an average of 53% of 1RM across exercises. Lifting such a load coupled with a low-medium number of repetitions (e.g., 5-15) can sufficiently stimulate hypertrophy and increase maximal strength for novices but may not apply for more advanced trainees. Lifting such a load coupled with a higher number of repetitions and approaching or reaching task failure can be sufficient for muscle hypertrophy, but less so for maximal strength development, regardless of trainees' experience. The self-selected load prescription approach may bypass certain limitations of the traditional approach, but requires thought and further research regarding how, for what purposes, and with which populations it should be implemented.

Tracking the Fatigue Status after a Resistance Exercise through Different Parameters

The purpose of the study was to investigate the sensitivity of back squat bar velocity, isometric mid-thigh pull, heart rate variability parameters, perceived recovery scale and step counts for tracking the muscular fatigue time-course (reduction in countermovement jump [CMJ] performance) after strenuous acute lower limb resistance exercise. Sixteen healthy men performed heart rate variability assessment, perceived recovery scale, CMJ, back squat bar velocity, isometric mid-thigh pull, and daily step counts before and 24 h, 48 h and 72 h post a strenuous acute lower limb resistance exercise (8×10 repetitions). The CMJ height decreased at 24 and 48 h after exercise session (p≤0.017), evidencing the muscular fatigue. The perceived recovery scale presented lower values compared to baseline until 72 h after exercise session (p<0.001 for all). The heart rate variability parameters and step counts were not significantly different across time. At 24 h post, only mean force of mid-thigh pull was decreased (p=0.044), while at 48 h post, only peak force of mid-thigh pull was decreased (p=0.020). On the last day (72 h), only bar velocity (mean) presented reduction (p=0.022). Therefore, the perceived recovery scale was the only variable sensible to tracking muscular fatigue, i. e. presenting a similar time-course to CMJ height.

Low-Intensity Resistance Exercise Combined With Blood Flow Restriction is More Conducive to Regulate Blood Pressure and Autonomic Nervous System in Hypertension Patients-Compared With High-Intensity and Low-Intensity Resistance Exercise

Background: The effect of resistance exercise on the autonomic nervous system of patients with hypertension has not been identified.

Objective: To explore a suitable resistance training method for hypertension patients to regulate blood pressure (BP) and autonomic nervous system function.

Method: Forty-five hypertension patients aged between 55 and 70 years were randomly equally divided into three groups: the high-intensity resistance exercise (HE) group, the low-intensity resistance exercise combined with blood flow restriction (LE-BFR) group, and the low-intensity resistance exercise (LE) group. All patients performed quadriceps femoris resistance exercise. The exercise intensity of HE, LE-BFR and LE group was 65, 30 and 30% of one repetition maximum (1RM), respectively. The LE-BFR group used pressure cuffs to provide 130% of systolic pressure to the patient’s thighs during resistance exercise. The training program was 20 times/min/set with a 1-min break after each set, and was conducted five sets/day and 3 days/week, lasting for 12 weeks. The heart rate (HR), BP, root-mean-square of difference-value of adjacent RR intervals (RMSSD), low frequency (LF) and high frequency (HF) were evaluated before and after the first training and the last training.

Result: Significant differences in HR were observed in both recovery states after the first and last training (p < 0.01). After 12 weeks of training, the recovery speed of HR in the LE-BFR group increased significantly (p < 0.01). The systolic blood pressures in the HE and LE-BFR group were significantly reduced (p < 0.05 and p < 0.01), and the differences among groups were significant (p < 0.01). In the last recovery state, the RMSSD of the LE group was significantly lower than that in the first recovery state (p < 0.01). The LF/HF ratios of the HE and LE groups in the resting and recovery states were increased significantly (all p < 0.01). LF/HF ratios in the LE-BFR group in the resting and recovery state were decreased significantly (both p < 0.01).

Conclusion: Compared to HE and LE, LE-BFR could effectively decrease systolic pressure and regulate the autonomic nervous system function in hypertension patients.

[Recommendations for outpatient respiratory rehabilitation of long COVID patients]

The appearance of COVID-19 has been a problem for public health on a global scale, putting pressure on health care systems. The after-effects of this illness have highlighted the importance of rehabilitation in long COVID patients involv-ing different health professionals. The treatment of the respiratory after-effects of this disease in an outpatient setting is a specialized field. It is appropriate to offer a series of practical recommendations of cardio-respiratory rehabilitation that are helpful to the professionals involved in the after-effects when ending hospitalisation. This review of the literature includes ten key aspects of respiratory physiotherapy that range from assessment, parameters to monitor, signs of alarm and respiratory rehabilitation techniques and other exercises for this population.

Is resistance training alone an antihypertensive therapy? A meta-analysis

Evidence concerning the prescription of isolated resistance training (RT) to hypertensive individuals is limited. Guidelines are divergent concerning RT inclusion for prehypertensive and hypertensive persons. A meta-analysis investigating data with larger sample sizes provides more robust effect size estimates and allows for inferences on clinical choices concerning the effectiveness of RT alone. In this context, the aim of this meta-analysis was to assess the effects of RT alone on the systolic (SBP) and diastolic (DBP) blood pressures in prehypertensive and hypertensive individuals. Data from 13 studies involving 417 participants (207 assigned to RT and 210 controls) were obtained. The results indicate significant reductions in SBP (-6.16 mmHg CI -8.27 to -4.04; I²: 31.0% P value for heterogeneity = 0.136 and effect size = -0.59) and DBP (-3.70 mmHg CI -5.19 to -2.21; I²: 18.3% P value for heterogeneity = 0.106 and effect size = -0.55) when compared to control groups. In conclusion, RT alone is able to reduce SBP and DBP in prehypertensive and hypertensive subjects, especially in elderly individuals.

Postexercise hypotension due to resistance exercise is not mediated by autonomic control: A systematic review and meta-analysis

Changes in autonomic control have been suggested to mediate postexercise hypotension (PEH). We investigated through meta-analysis the after-effects of acute resistance exercise (RE) on blood pressure (BP) and autonomic activity in individuals with normal and elevated BP. Electronic databases were searched for trials including: adults; exclusive RE interventions; and BP and autonomic outcomes measured pre- and postintervention for at least 30 min. Analyses incorporated random-effects assumptions. Thirty trials yielded 62 interventions (N = 480). Subjects were young (33.6 ± 15.6 yr), with systolic BP (SBP)/diastolic BP (DBP) of 124.2 ± 8.9/71.5 ± 6.6 mm Hg. Overall, RE moderately reduced SBP (normal BP: ~1 to 4 mm Hg, p < 0.01; elevated BP: ~1 to 12 mm Hg, p < 0.01) and DBP (normal BP: ~1 to 4 mm Hg, p < 0.03; elevated BP: ~0.5 to 7 mm Hg, p < 0.01), which was in general parallel to sympathetic increase (normal BP: g = 0.49 to 0.51, p < 0.01; elevated BP: g = 0.41 to 0.63, p < 0.01) and parasympathetic decrease (normal BP: g = -0.52 to -0.53, p < 0.01; elevated BP: g = -0.46 to -0.71, p < 0.01). The meta-regression showed inverse associations between the effect sizes of BP vs. sympathetic (SBP: slope - 0.19 to -3.45, p < 0.01; DBP: slope - 0.30 to -1.60, p < 0.01), and direct associations vs. parasympathetic outcomes (SBP: slope 0.17 to 2.59, p < 0.01; DBP: slope 0.21 to 1.38, p < 0.01). In conclusion, changes in BP were concomitant to sympathetic increase and parasympathetic decrease, which questions the role of autonomic fluctuations as potential mechanisms of PEH after RE.

Strengthening the Case for Cluster Set Resistance Training in Aged and Clinical Settings: Emerging Evidence, Proposed Benefits and Suggestions

Resistance training (RT) is a fundamental component of exercise prescription aimed at improving overall health and function. RT techniques such as cluster set (CS) configurations, characterized by additional short intra-set or inter-repetition rest intervals, have been shown to maintain acute muscular force, velocity, and 'power' outputs across a RT session, and facilitate positive longer-term neuromuscular adaptations. However, to date CS have mainly been explored from a human performance perspective despite potential for application in health and clinical exercise settings. Therefore, this current opinion piece aims to highlight emerging evidence and provide a rationale for why CS may be an advantageous RT technique for older adults, and across several neurological, neuromuscular, cardiovascular and pulmonary settings. Specifically, CS may minimize acute fatigue and adverse physiologic responses, improve patient tolerance of RT and promote functional adaptations (i.e., force, velocity, and power). Moreover, we propose that CS may be a particularly useful exercise rehabilitation technique where injury or illness, persistent fatigue, weakness and dysfunction exist. We further suggest that CS offer an alternative RT strategy that can be easily implemented alongside existing exercise/rehabilitation programs requiring no extra cost, minimal upskilling and/or time commitment for the patient and professional. In light of the emerging evidence and likely efficacy in clinical exercise practice, future research should move toward further direct investigation of CS-based RT in a variety of adverse health conditions and across the lifespan given the already demonstrated benefits in healthy populations.

Use of low volume, high effort resistance training to manage blood pressure in hypertensive patients inside a public hospital: a proof of concept study

Physical exercise has been shown to have an important role in the prevention and treatment of arterial hypertension. However, the general exercise recommendations are time consuming, which might be detrimental to exercise adoption. Based on this, minimal doses of exercise have been suggested as an alternative approach and this report investigates the feasibility and effects of low volume and high effort resistance training for hypertensive patients in a hospital setting. This is a pilot non-randomized prospective study where 15 sedentary hypertensive patients (11 women and 4 men) performed 24 resistance training sessions over 12 weeks at a public hospital. The resistance training sessions consisted of two sets of four exercises, with a rest interval of two minutes between sets. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured 10 minutes before and 10 minutes after each training. No injuries or intercurrence were reported during the study. SBP decreased significantly when compared the first and last sessions, when the measures were performed at rest (152 ± 16 mmHg vs. 122 ± 9 mmHg vs, p<0.05), and after (137 ± 13 mmHg vs. 115 ± 5 mmHg, p<0.05) the resistance training session. Similarly, DBP also decreased significantly when the values from the last session were compared with the first session, when measured at rest (83 ± 14 mmHg vs 73 ± 9 mmHg, p<0.05). Low volume and high effort resistance training seems to be a feasible non-pharmacological strategy to help controlling blood pressure in hypertensive patients within a hospital.

Practical Recommendations Relevant to the Use of Resistance Training for COVID-19 Survivors

The novel coronavirus disease (COVID-19) has emerged at the end of 2019 and caused a global pandemic. The disease predominantly affects the respiratory system; however, there is evidence that it is a multisystem disease that also impacts the cardiovascular system. Although the long-term consequences of COVID-19 are not well-known, evidence from similar diseases alerts for the possibility of long-term impaired physical function and reduced quality of life, especially in those requiring critical care. Therefore, rehabilitation strategies are needed to improve outcomes in COVID-19 survivors. Among the possible strategies, resistance training (RT) might be particularly interesting, since it has been shown to increase functional capacity both in acute and chronic respiratory conditions and in cardiac patients. The present article aims to propose evidence-based and practical suggestions for RT prescription for people who have been diagnosed with COVID-19 with a special focus on immune, respiratory, and cardiovascular systems. Based on the current literature, we present RT as a possible safe and feasible activity that can be time-efficient and easy to be implemented in different settings.

Strength Training Reduces Cardiac and Renal Oxidative Stress in Rats with Renovascular Hypertension

Fundamento

O treino de força tem efeitos benéficos em doenças renais, além de ajudar a melhorar a defesa antioxidante em animais saudáveis.

Objetivo

Verificar se o treino de força reduz o dano oxidativo ao coração e rim contralateral para cirurgia de indução de hipertensão renovascular, bem como avaliar as alterações na atividade das enzimas antioxidantes endógenas superóxido dismutase (SOD), catalase (CAT) e glutationa peroxidase (GPx).

Métodos

Dezoito ratos machos foram divididos em três grupos (n=6/grupo): placebo, hipertenso e hipertenso treinado. Os animais foram induzidos a hipertensão renovascular através da ligação da artéria renal esquerda. O treino de força foi iniciado quatro semanas após a indução da hipertensão renovascular, teve 12 semanas de duração e foi realizada a 70% de 1RM. Depois do período de treino, os animais foram submetidos a eutanásia e o rim esquerdo e o coração foram retirados para realizar a quantificação de peróxidos de hidrogênio, malondialdeído e grupos sulfidrílicos, que são marcadores de danos oxidativos. Além disso, foram medidas as atividades das enzimas antioxidantes superóxido dismutase, catalase e glutationa peroxidase. O nível de significância adotado foi de 5% (p < 0,05).

Resultados

Depois do treino de força, houve redução de danos oxidativos a lipídios e proteínas, como pode-se observar pela redução de peróxidos de hidrogênio e níveis sulfidrílicos totais, respectivamente. Além disso, houve um aumento nas atividades das enzimas antioxidantes superóxido dismutase, catalase e glutationa peroxidase.

Conclusão

O treino de força tem o potencial de reduzir danos oxidativos, aumentando a atividades de enzimas antioxidantes. (Arq Bras Cardiol. 2021; 116(1):4-11)

Use of low volume, high effort resistance training to manage blood pressure in hypertensive patients inside a public hospital: a proof of concept study

Physical exercise has been shown to have an important role in the prevention and treatment of arterial hypertension. However, the general exercise recommendations are time consuming, which might be detrimental to exercise adoption. Based on this, minimal doses of exercise have been suggested as an alternative approach and this report investigates the feasibility and effects of low volume and high effort resistance training for hypertensive patients in a hospital setting. This is a pilot non-randomized prospective study where 15 sedentary hypertensive patients (11 women and 4 men) performed 24 resistance training sessions over 12 weeks at a public hospital. The resistance training sessions consisted of two sets of four exercises, with a rest interval of two minutes between sets. Systolic blood pressure (SBP) and diastolic blood pressure (DBP) were measured 10 minutes before and 10 minutes after each training. No injuries or intercurrence were reported during the study. SBP decreased significantly when compared the first and last sessions, when the measures were performed at rest (152 ± 16 mmHg vs. 122 ± 9 mmHg vs, p<0.05), and after (137 ± 13 mmHg vs. 115 ± 5 mmHg, p<0.05) the resistance training session. Similarly, DBP also decreased significantly when the values from the last session were compared with the first session, when measured at rest (83 ± 14 mmHg vs 73 ± 9 mmHg, p<0.05). Low volume and high effort resistance training seems to be a feasible non-pharmacological strategy to help controlling blood pressure in hypertensive patients within a hospital.

Novel Resistance Training Approach to Monitoring the Volume in Older Adults: The Role of Movement Velocity

We analyzed the effects of velocity-monitored resistance training (RT) with a velocity loss of 20% on strength and functional capacity in institutionalized older adults. Thirty-nine participants (78.8 ± 6.7 years) were divided into a control group (CG; n = 20) or an RT group (n = 19). Over 10 weeks, the RT group performed two sessions per week, and the mean velocity of each repetition was monitored in the leg-press and chest-press exercises at 40-65% of one-repetition maximum (1RM). The set ended when the participants reached a velocity loss of 20%. The CG maintained their daily routine. At pre- and post-test, both groups were assessed in the 1RM leg-press, 1RM chest-press, handgrip strength, medicine ball throw (MBT), walking speed, and sit-to-stand (STS). At baseline, we did not find significant differences between groups. After 10 weeks, we observed significant differences (p < 0.001-0.01) between groups in the 1RM leg-press, 1RM chest-press, MBT-1 kg, and STS. The RT group performed a total number of repetitions of 437.6 ± 66.1 in the leg-press and 296.4 ± 78.9 in the chest-press. Our results demonstrate that velocity loss effectively prescribes the volume in older adults and that a threshold of 20% improves strength-related variables in this population.

Plasma Homocysteine and Autonomic Nervous Dysfunction: Association and Clinical Relevance in OSAS

Objective

Elevated plasma homocysteine (Hcy) is an independent risk factor for cardiovascular diseases, but the precise mechanism of Hcy in cardiovascular disease remains elusive. This study is aimed at evaluating the association between Hcy levels and autonomic nervous system and at investigating their clinical relevance in obstructive sleep apnea syndrome (OSAS).

Methods

A total of 191 subjects with OSAS were enrolled for this cross-sectional study. Heart rate variability (HRV) represents the status of the autonomic nervous system and is a well-known index that allows studying the autonomic modulation. HRV and polysomnography parameters were collected based on Holter monitors and polysomnography system. The software computed all the basic HRV parameters including SDANN, SDNN and pNN50. Correlation analyses between Hcy and HRV parameters and echocardiographic parameters were performed.

Results

Compared with the mild-moderate OSAS group, the prevalence of male and smoking and Hcy levels were considerably higher in the severe OSAS group (P = 0.01, P = 0.02, and P = 0.01, respectively). Also, there were significant linear relationships between Hcy quartiles with the proportion of severe OSAS (P = 0.01 for the trend). Interesting, there is a negative linear correlation between SDANN and Hcy quartiles (P = 0.02 for the trend). Spearman's correlation analysis showed a significant negative correlation between SDANN and Hcy levels (r = -0.17, P = 0.02). Interestingly, the relationship of it remains significant after adjustment for clinical covariates (r = -0.15, P = 0.04). However, echocardiographic parameters were not significantly correlated with Hcy or HRV parameters (all P > 0.05).

Conclusions

Elevated plasma Hcy level is linearly correlated with cardiac autonomic nervous function disorders in patients with OSAS.

High and low-load resistance training produce similar effects on bone mineral density of middle-aged and older people: A systematic review with meta-analysis of randomized clinical trials

PURPOSE

To compare the effects of high-load (≥ 70 of 1RM) and low-load (< 70 of 1RM) resistance training (RT) on femoral neck and lumbar spine bone mineral density (BMD) in middle-aged and older people.

DESIGN

Systematic review with meta-analysis.

DATA SOURCE

English language searches of the electronic databases PubMed/Medline, Scopus and Web of Science.

INCLUSION CRITERIA

(i) older or middle-aged (≥ 45 years old) participants of both sexes with or without comorbidities, (ii) studies that compared high-load (≥70% 1 RM) versus low-load (<70% 1RM) RT, (iii) studies that examined femoral neck or lumbar spine BMD.

RESULTS

From 1052 studies found, six were included in qualitative and quantitative analysis. The meta-analysis revealed no difference between groups for femoral neck (weighted mean difference [MD] and 95% confidence interval (CI) = 0.00 g/cm² [95% CI, -0.01 to 0.01]; P = 0.63) and lumbar spine (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.12) BDM. There was a substantial heterogeneity for femoral neck (I² = 47%; P = 0.07) and lumbar spine (I² = 59%; P = 0.02). Subgroup analysis revealed a significant effect of high-load RT on femoral neck BMD when participants presented normal BMD values (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.04) and on interventions lasting up to 6 months (MD = 0.01 g/cm² [95% CI, -0.00 to 0.02]; P = 0.03).

CONCLUSION

Both high- and low-load RT have similar effects on femoral neck and lumbar spine BMD in aging people.

Improvements in health parameters of a diabetic and hypertensive patient with only 40 minutes of exercise per week: a case study

Purpose: The present study aimed to report the effects of 15 weeks of a minimal dose resistance training on blood glucose levels, blood pressure, heart rate, physical capacity, and quality of life of a 67 old woman with type 2 diabetes mellitus, cardiopathy and hypertension.Method: The Patient was sedentary with a family history of heart failure and coronary artery disease. She suffered a heart attack in 2013 and was submitted to six cardiac catheterizations and one angioplasty between the 2015 and 2017. On April 2017, she was initially untrained in resistance training and was followed for 15 weeks with the performance of 31 resistance training sessions. Resistance training followed a minimal dose approach with 4 exercises performed with 2 sets to muscle failure, twice a week.Results: After follow up, the Patient presented a reduction in blood glucose, systolic and diastolic blood pressure, and heart rate at rest. There were also improvements on body mass index, cardiorespiratory fitness and quality of life. These results were accompanied by a reduction in the amount of antihypertensive and anti-diabetic medications.Conclusions: These results suggest that only 40 min of resistance training per week might help to improve general health and quality of life in a patient with hypertension and type 2 diabetes mellitus.Implications for RehabilitationMinimal dose resistance training improved health parameters in a diabetic and hypertensive patient.Resistance training promoted a reduction in the drugs used to control blood pressure and blood glucose levels.