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

Post-exercise hypotension (PEH) has been assessed by three calculation approaches: I = (post-exercise − pre-exercise), II = (post-exercise − post-control), and III = [(post-exercise − pre-exercise) − (post-control − pre-control)]. This study checked whether these calculation approaches influence PEH and its determinants. For that, 30 subjects underwent two exercise (cycling, 45 min, 50% VO2 peak) and two control (seated rest, 45 min) sessions. Systolic (SBP) and diastolic (DBP) blood pressures, cardiac output (CO), systemic vascular resistance (SVR), heart rate (HR), and stroke volume (SV) were measured pre- and post-interventions in each session. The mean value for each moment in each type of session was calculated, and responses to exercise were analyzed with each approach (I, II, and III) to evaluate the occurrence of PEH and its determinants. Systolic PEH was significant when calculated by all approaches (I = −5 ± 1, II = −11 ± 2, and III = −11 ± 2 mmHg, p < 0.05), while diastolic PEH was only significant when calculated by approaches II and III (−6 ± 1 and −6 ± 1 mmHg, respectively, p < 0.05). CO decreased significantly after the exercise when calculated by approach I, but remained unchanged with approaches II and III, while SVR increased significantly with approach I, but decreased significantly with approaches II and III. HR was unchanged after the exercise with approach I, but increased significantly with approaches II and III, while SV decreased significantly with all approaches. Thus, PEH and its hemodynamic determinants are influenced by the calculation approach, which should be considered when designing, analyzing, and comparing PEH studies

Consistency of hemodynamic and autonomic mechanisms underlying post-exercise hypotension

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

Effects of exercise induced muscle damage on cardiovascular responses to isometric muscle contractions and post-exercise circulatory occlusion

Purpose: The aim of the present study was to investigate whether exercise-induced muscle damage (EIMD) influences cardiovascular responses to isometric exercise and post-exercise circulatory occlusion (PECO). We hypothesized that EIMD would increase muscle afferent sensitivity and, accordingly, increase blood pressure responses to exercise and PECO. Methods: Eleven male and nine female participants performed unilateral isometric knee extension at 30% of maximal voluntary contraction (MVC) for 3-min. A thigh cuff was rapidly inflated to 250 mmHg for two min PECO, followed by 3 min recovery. Heart rate and blood pressure were monitored beat-by-beat, with stroke volume and cardiac output estimated from the Modelflow algorithm. Measurements were taken before and 48 h after completing eccentric knee-extension contractions to induce muscle damage (EIMD). Results: EIMD caused 21% decrease in MVC (baseline: 634.6 ± 229.3 N, 48 h: 504.0 ± 160 N), and a 17-fold increase in perceived soreness using a visual-analogue scale (0–100 mm; VASSQ) (both p < 0.001). CV responses to exercise and PECO were not different between pre and post EIMD. However, mean arterial pressure (MAP) was higher during the recovery phase after EIMD (p < 0.05). Significant associations were found between increases in MAP during exercise and VASSQ, Rate of Perceived Exertion (RPE) and Pain after EIMD only (all p < 0.05). Conclusion: The MAP correlations with muscle soreness, RPE and Pain during contractions of damaged muscles suggests that higher afferent activity was associated with higher MAP responses to exercise

Time of day affects heart rate recovery and variability after maximal exercise in pre-hypertensive men

Heart rate (HR) recovery (HRR) and variability (HRV) after exercise are non-invasive tools used to assess cardiac autonomic regulation and cardiovascular prognosis. Autonomic recovery is slower after evening than morning exercise in healthy individuals, but this influence is unknown in subjects with autonomic dysfunction, although it may affect prognostic evaluation. This study compared post-exercise HRR and HRV after maximal morning and evening exercise in pre-hypertensive men. Ten volunteers randomly underwent two maximal exercise tests conducted in the morning (8-10 a.m.) and evening (6-8 p.m.). HRR60s (HR reduction at 60 s of recovery - prognostic index), T30 (short-term time-constant of HRR - parasympathetic reactivation marker), rMSSD30s (square root of the mean of the sum of the squares of differences between adjacent R-R intervals on subsequent 30 s segments - parasympathetic reactivation marker), and HRRτ (time constant of the first order exponential fitting of HRR - marker of sympathetic withdraw and parasympathetic reactivation) were measured. Paired t-test and two-way ANOVA were used. HRR60s and HRRτ were similar after exercise in the morning and evening (27 ± 7 vs. 29 ± 7 bpm, p = 0.111, and 79 ± 14 vs. 96 ± 29 s, p = 0.119, respectively). T30 was significantly greater after evening exercise (405 ± 215 vs. 295 ± 119 s, p = 0.002) and rMSSD30s was lower in the evening (main factor session, p = 0.009). In conclusion, in pre-hypertensive men, the prognostic index of HRR, HRR60s, is not affected by the time of day when exercise is conducted. However, post-exercise parasympathetic reactivation, evaluated by T30 and rMSSD30s, is blunted after evening exercise

Efficacy of home-based physical activity interventions in patients with autoimmune rheumatic diseases: A systematic review and meta-analysis

Introduction: Physical activity (PA) has been receiving increasing interest in recent years as an adjuvant therapy for autoimmune rheumatic disease (ARDs), but there is scarce information about the efficacy of home-based PA for patients with ARDs. Objective: To perform a systematic review and meta-analysis on the efficacy of home-based physical activity (PA) interventions in improving health-related quality of life, functional capacity, pain, and disease activity in patients with ARDs. Methods: Searches were performed in PubMed, Web of Science, Scopus, Cochrane, CINAHL database and Sport Discus. Trials were considered eligible if they included a home-based physical activity intervention. The population included adults with autoimmune rheumatic diseases (e.g., rheumatoid arthritis, systemic lupus erythematosus, idiopathic inflammatory myopathies, systemic sclerosis and ankylosing spondylitis), comparisons included non-physical activity control or centre-based interventions (i.e., interventions performed on a specialized exercise centre) and the outcomes were quality of life, pain, functional capacity, disease activity and inflammation. Results: Home-based physical activity improved quality of life (p<0.01; g = 0.69; IC95%, 0.61 to 1.07) and functional capacity (p = 0.04; g = - 0.51; IC95%, -0.86; -0.16), and reduced disease activity (p = 0.03; g = - 0.60; IC95%, -1.16; -0.04) and pain (p = 0.01; g = -1.62; IC95%, -2.94 to -0.31) compared to the non-physical activity control condition. Additionally, home-based physical activity interventions were as effective as centre-based interventions for all investigated outcomes. Conclusion: Home-based PA is an efficacious strategy to improve disease control and aleviate symptoms in ARD

Recommendations in Post-exercise Hypotension: Concerns, Best Practices and Interpretation

Post-exercise hypotension (PEH) is a clinically relevant phenomenon that has been widely investigated. However, the characteristics of study designs, such as familiarization to blood pressure measurements, duration of PEH assessments or strategies to analyze PEH present discrepancies across studies. Thus identifying key points to standardize across PEH studies is necessary to help researchers to build stronger study designs, to facilitate comparisons across studies, and to avoid misinterpretations of results. The goal of this narrative review of methods used in PEH studies was therefore to gather and find possible influencers in the characteristics of study design and strategies to analyze blood pressure. Data found in this review suggest that PEH studies should have at least two familiarization screening visits, and should assess blood pressure for at least 20 min, but preferably for 120 min, during recovery from exercise. Another important aspect is the strategy to analyze PEH, which may lead to different interpretations. This information should guide a priori study design decisions

Effects of physical activity on vascular function in autoimmune rheumatic diseases: A systematic review and meta-analysis

Objectives: To summarize existing evidence and quantify the effects of physical activity on vascular function and structure in autoimmune rheumatic diseases (ARDs). Methods: Databases were searched (through March 2020) for clinical trials evaluating the effects of physical activity interventions on markers of micro- and macrovascular function and macrovascular structure in ARDs. Studies were combined using random effects meta-analysis, which was conducted using Hedges' g. Meta-analyses were performed on each of the following outcomes: microvascular function [i.e. skin blood flow or vascular conductance responses to acetylcholine (ACh) or sodium nitropusside (SNP) administration]; macrovascular function [i.e. brachial flow-mediated dilation (FMD%) or brachial responses to glyceryl trinitrate (GTN%); and macrovascular structure [i.e. aortic pulse wave velocity (PWV)]. Results: Ten studies (11 trials) with a total of 355 participants were included in this review. Physical activity promoted significant improvements in microvascular [skin blood flow responses to ACh, g = 0.92 (95% CI 0.42, 1.42)] and macrovascular function [FMD%, g = 0.94 (95% CI 0.56, 1.02); GTN%, g = 0.53 (95% CI 0.09, 0.98)]. Conversely, there was no evidence for beneficial effects of physical activity on macrovascular structure [PWV, g = -0.41 (95% CI -1.13, 0.32)]. Conclusions: Overall, the available clinical trials demonstrated a beneficial effect of physical activity on markers of micro- and macrovascular function but not on macrovascular structure in patients with ARDs. The broad beneficial impact of physical activity across the vasculature identified in this review support its role as an effective non-pharmacological management strategy for patients with ARDs

Maintenance of Physical Activity Behavior by Individuals with Prediabetes and Diabetes during the COVID-19 Pandemic after Completing an Exercise Intervention in Brazil

This cross-sectional study evaluated the perception of individuals with prediabetes/diabetes about their living conditions during the COVID-19 pandemic to identify the facilitators, barriers, and reasons to remain physically active at home and adhere to recommended exercise. It included individuals with prediabetes/diabetes who had completed an exercise intervention, which started on-site and moved to a remote home-based regime due to the COVID-19 pandemic and were advised to keep exercising at home. The outcomes were assessed by a bespoke questionnaire that was developed by the research team, the Brazilian Portuguese adapted version of the Exercise Adherence Rating scale, and the Motives for Physical Activity Measure-Revised scale. Of 15 participants (8 female, 58 ± 11 years), most reported positive perceptions about their living conditions and few difficulties maintaining some physical activity at home. However, only 53.8% of them adhered to the recommended exercise. Time flexibility, no need for commuting, and a sense of autonomy were the main facilitators of home exercise, while a lack of adequate space was the main barrier. The descending order of median scores that were obtained in each reason for physical activity was fitness, enjoyment, competence, social, and appearance. Individuals with prediabetes/diabetes maintained some physical activity during the pandemic, mainly motivated by health concerns

Anatomical characterisation of the kidneys of Didelphis aurita (Didelphimorphia: Didelphidae)

Background: Didelphis aurita is a marsupial with wide distribution in the South American continent and highly adapted to urban centres. The objective of this study was to describe the measurements and skeletopy of the kidneys and renal vascularisation of this species.Materials and methods: With this aim, 29 cadavers (14 males and 15 females) of D. aurita collected on highways were analysed. The rostrum-sacral length of specimens, kidney measurements (length, width and thickness) and the length of the renal vessels were measured and the renal skeletopy registered.Results: In the right kidney, average length, width, thickness and ellipsoid volume were 28.6 ± 5.0 mm, 15.6 ± 2.9 mm, 12.8 ± 3.0 mm and 3.3 ± 2.4 cm3, respectively; in the left kidney, 31.0 ± 3.8 mm, 14.5 ± 3.6 mm, 12.6 ± 2.6 mm and 3.2 ± 2.2 cm3, respectively. There was no significant difference in the comparison of averages of renal dimensions between sexes and between antimeres. The right renal artery (13.2 ± 2.6 mm) was significantly longer (p &lt; 0.01) than the left renal artery (10.7 ± 2.3 mm). In contrast, the left renal vein (13.9 ± 3.5 mm) was longer (p &lt; 0.01) than the right renal vein (7.0 ± 2.3 mm). The skeletopy of the right kidney predominated between T13–L1 in 58.6% of the cases and the skeletopy of the left kidney between L1–L3 in 41.4%. The average length of the kidneys corresponded to 6% to 8% of the rostrum-sacral length of the specimens.Conclusions: The data of the present study characterised the measurements and topography of kidneys and renal vessels in D. aurita and can support the interpretation of clinical, experimental and pathological findings in this species

Reproducibility of heart rate recovery in patients with intermittent claudication

Background: Postexercise heart rate recovery (HRR) is a non-invasive tool for cardiac autonomic function assessment. Reproducibility of HRR has been established in healthy subjects; however, no study has evaluated this reproducibility in clinical populations who may present autonomic dysfunction. Patients with peripheral artery disease and intermittent claudication (IC) often present altered cardiac autonomic function and HRR could be an interesting tool for evaluating autonomic responses to interventions in this population. Therefore, the reproducibility of HRR should be determined in this specific population. Objective: To determine the reproducibility of HRR indices in patients with IC. Methods: Nineteen men with IC underwent two repeated maximal treadmill tests. Raw HR and relative HRR (difference to exercise peak) indices measured at 30, 60, 120, 180, 240 and 300s of recovery were evaluated. The presence of systematic bias was assessed by comparing test and retest mean values via paired t-test. Reliability was assessed by intraclass correlation coefficient (ICC), and agreement by typical error (TE), coefficient of variation (CV) and minimal detectable difference (MDD). Results: There were no significant differences between the test and retest values of all raw HR and relative HRR indices (P ≥ 0·05), except for HR120s (P = 0·032). All indices exhibited excellent reliability (ICC ≥ 0·78). Raw HR and relative HRR indices showed TEs ≤ 6·4 bpm and MDDs ≤ 17·8 bpm. In addition, all indices showed CVs ≤ 13·2%, except HRR30s (CV = 45·6%). Conclusions: The current results demonstrated that most HRR indices were highly reproducible with no systematic error, excellent reliability and good agreement in patients with IC following maximal graded exercise