Physiology of sedentary behavior.

Sedentary behaviors (SB) are characterized by low energy expenditure while in a sitting or reclining posture. Evidence relevant to understanding the physiology of SB can be derived from studies employing several experimental models: bed rest, immobilization, reduced step count, and reducing/interrupting prolonged SB. We examine the relevant physiological evidence relating to body weight and energy balance, intermediary metabolism, cardiovascular and respiratory systems, the musculoskeletal system, the central nervous system, and immunity and inflammatory responses. Excessive and prolonged SB can lead to insulin resistance, vascular dysfunction, shift in substrate use toward carbohydrate oxidation, shift in muscle fiber from oxidative to glycolytic type, reduced cardiorespiratory fitness, loss of muscle mass and strength and bone mass, and increased total body fat mass and visceral fat depot, blood lipid concentrations, and inflammation. Despite marked differences across individual studies, longer term interventions aimed at reducing/interrupting SB have resulted in small, albeit marginally clinically meaningful, benefits on body weight, waist circumference, percent body fat, fasting glucose, insulin, HbA1c and HDL concentrations, systolic blood pressure, and vascular function in adults and older adults. There is more limited evidence for other health-related outcomes and physiological systems and for children and adolescents. Future research should focus on the investigation of molecular and cellular mechanisms underpinning adaptations to increasing and reducing/interrupting SB and the necessary changes in SB and physical activity to impact physiological systems and overall health in diverse population groups.

Cardiorespiratory abnormalities in ICU survivors of COVID-19 with postacute sequelae of SARS-CoV-2 infection are unrelated to invasive mechanical ventilation.

Postacute sequelae of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection (PASC) often leads to exertional intolerance and reduced exercise capacity, particularly in individuals previously admitted to an intensive care unit (ICU). However, the impact of invasive mechanical ventilation (IMV) on PASC-associated cardiorespiratory abnormalities during exercise remains poorly understood. This single-center, cross-sectional study aimed to gather knowledge on this topic. Fifty-two patients with PASC recruited ∼6 mo after ICU discharge were clustered based on their need for IMV (PASC + IMV, n = 27) or noninvasive support therapy (PASC + NIS, n = 25). Patients underwent pulmonary function and cardiopulmonary exercise testing (CPX) and were compared with a reference group (CONTROL, n = 19) comprising individuals of both sexes with similar age, comorbidities, and physical activity levels but without a history of COVID-19 illness. Individuals with PASC, irrespective of support therapy, presented with higher rates of cardiorespiratory abnormalities than CONTROL, especially dysfunctional breathing patterns, dynamic hyperinflation, reduced oxygen uptake and oxygen pulse, and blunted heart rate recovery (all P < 0.05). Only the rate of abnormal oxygen pulse was greater among PASC + IMV group than PASC + NIS group (P = 0.05). Mean estimates for all CPX variables were comparable between PASC + IMV and PASC + NIS groups (all P > 0.05). These findings indicate significant involvement of both central and peripheral factors, leading to exertional intolerance in individuals with PASC previously admitted to the ICU, regardless of their need for IMV.NEW & NOTEWORTHY We found cardiorespiratory abnormalities in ICU survivors of severe-to-critical COVID-19 with PASC to be independent of IMV need. Overall, both group of patients experienced dysfunctional breathing patterns, dynamic hyperinflation, lower oxygen uptake and oxygen pulse, and blunted heart rate responses to CPX. PASC seems to impact exertional tolerance and exercise capacity due to ventilatory inefficiency, impaired aerobic metabolism, and potential systolic and autonomic dysfunction, all of these irrespective of support therapy during ICU stay.

Association between ultra-processed food and flavonoid intakes in a nationally representative sample of the US population.

Consumption of ultra-processed food (UPF) has been associated with several chronic diseases and poor diet quality. It is reasonable to speculate that the consumption of UPF negatively associates with flavonoid dietary intake; however, this assumption has not been previously examined. The present study aims to assess association between the dietary contribution of UPF and flavonoid intake in the US population aged 0 years and above. We performed a cross-sectional analysis of dietary data collected by 24-h recalls from 7640 participants participating in the National Health and Nutrition Examination Survey 2017-2018. Foods were classified according to the Nova classification system. The updated US Department of Agriculture (USDA) Database for the Flavonoid Content of Selected Foods (Release 3.3) database was used to estimate total and six classes of flavonoid intakes. Flavonoid intakes were compared across quintiles of dietary contribution of UPF (% of total energy intake) using linear regression models. The total and five out of six class flavonoid intakes decreased between 50 and 70 % across extreme quintiles of the dietary contribution of UPF (Pfor linear trend < 0·001); only isoflavones increased by over 260 %. Our findings suggest that consumption of UPF is associated with lower total and five of six class flavonoid intakes and with higher isoflavone intakes, supporting previous evidence of the negative impact of UPF consumption on the overall quality of the diet and health outcomes.

Trehalose Improved 20-min Cycling Time-Trial Performance After 100-min Cycling in Amateur Cyclists.

Carbohydrate (CHO) supplementation during endurance exercise can improve performance. However, it is unclear whether low glycemic index (GI) CHO leads to differential ergogenic and metabolic effects compared with a standard high GI CHO. This study investigated the ergogenic and metabolic effects of CHO supplementation with distinct GIs, namely, (a) trehalose (30 g/hr), (b) isomaltulose (30 g/hr), (c) maltodextrin (60 g/hr), and (d) placebo (water). In this double-blind, crossover, counterbalanced, placebo-controlled study, 13 male cyclists cycled a total of 100 min at varied exercise intensity (i.e., 10-min stages at 1.5, 2.0, and 2.5 W/kg; repeated three times plus two 5-min stages at 1.0 W/kg before and after the protocol), followed by a 20-min time trial on four separated occasions. Blood glucose and lactate (every 20 min), heart rate, and ratings of perceived exertion were collected throughout, and muscle biopsies were taken before and immediately after exercise. The results showed that trehalose improved time-trial performance compared with placebo (total work done 302 ± 39 vs. 287 ± 48 kJ; p = .01), with no other differences between sessions (all p ≥ .07). Throughout the 100-min protocol, blood glucose was higher with maltodextrin compared with the other supplements at all time points (all p < .05). Heart rate, ratings of perceived exertion, muscle glycogen content, blood glucose, and lactate were not different between conditions when considering the 20-min time trial (all p > .05). Trehalose supplementation throughout endurance exercise improved cycling performance and appears to be an appropriate CHO source for exercise tasks up to 2 hr. No ergogenic superiority between the different types of CHO was established.

Exercise modifies hypothalamic connectivity and brain functional networks in women after bariatric surgery: a randomized clinical trial.

BACKGROUND: Obesity is a disease that may involve disrupted connectivity of brain networks. Bariatric surgery is an effective treatment for obesity, and the positive effects on obesity-related conditions may be enhanced by exercise. Herein, we aimed to investigate the possible synergistic effects of Roux-en-Y Gastric Bypass (RYGB) and exercise training on brain functional networks. METHODS: Thirty women eligible for bariatric surgery were randomly assigned to a Roux-en-Y gastric bypass (RYGB: n = 15, age = 41.0 ± 7.3 years) or RYGB plus Exercise Training (RYGB + ET: n = 15, age = 41.9 ± 7.2 years). Clinical, laboratory, and brain functional connectivity parameters were assessed at baseline, and 3 (POST3) and 9 months (POST9) after surgery. The 6-month, three-times-a-week, exercise intervention (resistance plus aerobic exercise) was initiated 3 months post-surgery (for RYGB + ET). RESULTS: Exercise superimposed on bariatric surgery (RYGB + ET) increased connectivity between hypothalamus and sensorial regions (seed-to-voxel analyses of hypothalamic connectivity), and decreased default mode network (DMN) and posterior salience (pSAL) network connectivity (ROI-to-ROI analyses of brain networks connectivity) when compared to RYGB alone (all p-FDR < 0.05). Increases in basal ganglia (BG) network connectivity were only observed in the exercised training group (within-group analyses). CONCLUSION: Exercise training is an important component in the management of post-bariatric patients and may improve the hypothalamic connectivity and brain functional networks that are involved in controlling food intake. TRIAL REGISTRATION: Clinicaltrial.gov: NCT02441361.

Quality of life, fatigue, sleep quality, and mental health in systemic lupus erythematosus patients with a high cardiovascular risk profile.

Systemic lupus erythematosus (SLE) patients report worse health-related quality of life (HRQL), fatigue, anxiety, depression, and sleep quality, when compared to the general population and other chronic diseases. Furthermore, cardiometabolic diseases are highly prevalent in SLE and are also associated with these parameters. Thus, it is plausible to suggest that SLE patients with a high cardiovascular risk may report worse results for these parameters. The aim of the study is to describe HRQL, fatigue, anxiety and depression symptoms, and sleep quality in a sample of SLE patients with a high cardiovascular risk profile (i.e., BMI between 25 and 40 kg/m2 and/or dyslipidemia, hypertension, or diabetes). This was a cross-sectional study where patients were assessed for (i) demographic, anthropometric, and disease-related parameters, (ii) HRQL, (iii) fatigue, (iv) anxiety and depression symptoms, and (v) sleep quality. One-hundred patients completed the study; however, only 87 patients were assessed for sleep quality data. Patients averaged 41.7 ± 9 years, and most patients were classified as overweight/obese (87%). SF-36 scores for physical and mental components summary were 51.3 ± 9.6 and 54.2 ± 15.6, respectively, with "bodily pain" and "role emotional" presenting the lower scores. The total SLEQOL score was 105.1 ± 42.0, with lower scores reported for "self-image" and "mood." Fatigue score was 30.8 ± 8.9, and 78% and 93% reported severe symptoms of anxiety and depression, respectively. The average sleep effectiveness was 82.9 ± 6.6%. Sleep latency, total time in bed (TTiB), and total sleep time (TST) were 8.4 ± 8.9, 495.8 ± 79.7, and 409.7 ± 69.9 min, respectively. Patients reported an average of 17.8 ± 6.2 WE, with 4.5 ± 1.5 min duration and a WASO of 77.7 ± 36.6 min. Despite similar HRQL, fatigue, and sleep quality parameters to those reported by other SLE populations, SLE patients with a high cardiovascular risk had a higher prevalence of depression and anxiety. Understanding SLE patients' quality of life and psychological symptoms is of utmost importance to improve disease management. The findings of this study highlight the need for more intensive and global care regarding mental health when considering a high cardiovascular risk in SLE.

A randomized controlled trial of an intervention promoting physical activity and healthy eating recommendations in systemic lupus erythematosus: the protocol study "Living Well with Lupus".

There is a paucity of studies assessing multidisciplinary interventions focused on tackling physical inactivity/sedentary behavior and poor dietary habits in SLE. The Living well with Lupus (LWWL) is a randomized controlled trial to investigate whether a six-month lifestyle change intervention will improve cardiometabolic risk factors (primary outcome) among systemic lupus erythematosus (SLE) patients with low disease activity (SLEDAI score ≤ 4) and with high cardiovascular risk. As secondary goals, we will evaluate: (1) the intervention's safety, efficacy, and feasibility in promoting lifestyle changes, and (2) the effects of the intervention on secondary outcomes (i.e., clinical parameters, functional capacity, fatigue, psychological aspects, sleep quality and health-related quality of life). Patients will be randomly allocated to either a control (i.e., standard care) or a lifestyle intervention group using a simple randomization (1:1 ratio, blocks of 20). Mixed Model analyses will be conducted for comparing groups following an intention-to-treat approach. A per protocol analysis will also be conducted. This study has the potential to generate new, clinically relevant data able to refine the multidisciplinary management of SLE patients. Protocol version number: NCT04431167 (first version).

Effects of a 16-week home-based exercise training programme on health-related quality of life, functional capacity, and persistent symptoms in survivors of severe/critical COVID-19: a randomised controlled trial.

BACKGROUND: Long-lasting effects of COVID-19 may include cardiovascular, respiratory, skeletal muscle, metabolic, psychological disorders and persistent symptoms that can impair health-related quality of life (HRQoL). We investigated the effects of a home-based exercise training (HBET) programme on HRQoL and health-related outcomes in survivors of severe/critical COVID-19. METHODS: This was a single-centre, single-blinded, parallel-group, randomised controlled trial. Fifty survivors of severe/critical COVID-19 (5±1 months after intensive care unit discharge) were randomly allocated (1:1) to either a 3 times a week (~60-80 min/session), semi-supervised, individualised, HBET programme or standard of care (CONTROL). Changes in HRQoL were evaluated through the 36-Item Short-Form Health Survey, and physical component summary was predetermined as the primary outcome. Secondary outcomes included cardiorespiratory fitness, pulmonary function, functional capacity, body composition and persistent symptoms. Assessments were performed at baseline and after 16 weeks of intervention. Statistical analysis followed intention-to-treat principles. RESULTS: After the intervention, HBET showed greater HRQoL score than CONTROL in the physical component summary (estimated mean difference, EMD: 16.8 points; 95% CI 5.8 to 27.9; effect size, ES: 0.74), physical functioning (EMD: 22.5 points, 95% CI 6.1 to 42.9, ES: 0.83), general health (EMD: 17.4 points, 95% CI 1.8 to 33.1, ES: 0.73) and vitality (EMD: 15.1 points, 95% CI 0.2 to 30.1, ES: 0.49) domains. 30-second sit-to-stand (EMD: 2.38 reps, 95% CI 0.01 to 4.76, ES: 0.86), and muscle weakness and myalgia were also improved in HBET compared with CONTROL (p<0.05). No significant differences were seen in the remaining variables. There were no adverse events. CONCLUSION: HBET is an effective and safe intervention to improve physical domains of HRQoL, functional capacity and persistent symptoms in survivors of severe/critical COVID-19. TRIAL REGISTRATION NUMBER: NCT04615052.

Oxygen uptake kinetics and chronotropic responses to exercise are impaired in survivors of severe COVID-19.

The post-acute phase of coronavirus disease 2019 (COVID-19) is often marked by several persistent symptoms and exertional intolerance, which compromise survivors' exercise capacity. This was a cross-sectional study aiming to investigate the impact of COVID-19 on oxygen uptake (V̇o2) kinetics and cardiopulmonary function in survivors of severe COVID-19 about 3-6 mo after intensive care unit (ICU) hospitalization. Thirty-five COVID-19 survivors previously admitted to ICU (5 ± 1 mo after hospital discharge) and 18 controls matched for sex, age, comorbidities, and physical activity level with no prior history of SARS-CoV-2 infection were recruited. Subjects were submitted to a maximum-graded cardiopulmonary exercise test (CPX) with an initial 3-min period of a constant, moderate-intensity walk (i.e., below ventilatory threshold, VT). V̇o2 kinetics was remarkably impaired in COVID-19 survivors as evidenced at the on-transient by an 85% (P = 0.008) and 28% (P = 0.001) greater oxygen deficit and mean response time (MRT), respectively. Furthermore, COVID-19 survivors showed an 11% longer (P = 0.046) half-time of recovery of V̇o2 (T1/2V̇o2) at the off-transient. CPX also revealed cardiopulmonary impairments following COVID-19. Peak oxygen uptake (V̇o2peak), percent-predicted V̇o2peak, and V̇o2 at the ventilatory threshold (V̇o2VT) were reduced by 17%, 17%, and 12% in COVID-19 survivors, respectively (all P < 0.05). None of the ventilatory parameters differed between groups (all P > 0.05). In addition, COVID-19 survivors also presented with blunted chronotropic responses (i.e., chronotropic index, maximum heart rate, and heart rate recovery; all P < 0.05). These findings suggest that COVID-19 negatively affects central (chronotropic) and peripheral (metabolic) factors that impair the rate at which V̇o2 is adjusted to changes in energy demands.NEW & NOTEWORTHY Our findings provide novel data regarding the impact of COVID-19 on submaximal and maximal cardiopulmonary responses to exercise. We showed that V̇o2 kinetics is significantly impaired at both the onset (on-transient) and the recovery phase (off-transient) of exercise in these patients. Furthermore, our results suggest that survivors of severe COVID-19 may have a higher metabolic demand at a walking pace. These findings may partly explain the exertional intolerance frequently observed following COVID-19.

Carotid intima-media thickness and flow-mediated dilation do not predict acute in-hospital outcomes in patients hospitalized with COVID-19.

Studies have suggested a potential role of endothelial dysfunction and atherosclerosis in the pathophysiology of COVID-19. Herein, we tested whether brachial flow-mediated dilation (FMD) and carotid intima-media thickness (cIMT) measured upon hospital admission are associated with acute in-hospital outcomes in patients hospitalized with COVID-19. A total of 211 patients hospitalized with COVID-19 were submitted to assessments of FMD and mean and maximum cIMT (cIMTmean and cIMTmax) within the first 72 h of hospital admission. Study primary outcome was a composite of intensive care unit admission, mechanical ventilation, or death during the hospitalization. These outcomes were also considered independently. Thrombotic events were included as a secondary outcome. Odds ratios (ORs) and confidence intervals (CIs) were calculated using unadjusted and adjusted multivariable logistic regression models. Eighty-eight (42%) participants demonstrated at least one of the composite outcomes. cIMTmean and cIMTmax were predictors of mortality and thrombotic events in the univariate analysis (cIMTmean and mortality: unadjusted OR 12.71 [95% CI 1.71-94.48]; P = 0.014; cIMTmean and thrombotic events: unadjusted OR 11.94 [95% CI 1.64-86.79]; P = 0.015; cIMTmax and mortality: unadjusted OR 8.47 [95% CI 1.41-51.05]; P = 0.021; cIMTmax and thrombotic events: unadjusted OR 12.19 [95% CI 2.03-73.09]; P = 0.007). However, these associations were no longer present after adjustment for potential confounders (P > 0.05). In addition, FMD% was not associated with any outcome. In conclusion, cIMT and FMD are not independent predictors of clinical outcomes in patients hospitalized with COVID-19. These results suggest that subclinical atherosclerosis and endothelial dysfunction may not be the main drivers of COVID-19 complications in patients hospitalized with COVID-19.NEW & NOTEWORTHY Studies have suggested a role of endothelial dysfunction and atherosclerosis in COVID-19 pathophysiology. In this prospective cohort study, we assessed the prognostic value of carotid intima-media thickness (IMT) and flow-mediated dilation (FMD) in patients with COVID-19. Carotid IMT and FMD were not independent predictors of major outcomes. These results suggest that other risk factors may be the main drivers of clinical outcomes in patients with COVID-19.

Association between physical activity and immunogenicity of an inactivated virus vaccine against SARS-CoV-2 in patients with autoimmune rheumatic diseases.

OBJECTIVES: To investigate whether physical activity is associated with enhanced immunogenicity of a SARS-CoV-2 inactivated vaccine (Coronavac) in patients with autoimmune rheumatic diseases (ARD) (n = 898) and in non-ARD (n = 197) individuals without pre-existing immunogenicity to SARS-CoV-2. METHODS: This was a prospective cohort study within an open-label, single-arm, phase 4 vaccination trial. Immunogenicity was assessed after vaccination by measuring seroconversion rates of total anti-SARS-CoV-2 S1/S2 IgG (SC), geometric mean titers of anti-S1/S2 IgG (GMT), factor-increase in GMT (FI-GMT), frequency of neutralizing antibody (NAb), and median neutralizing activity. Physical activity (active being defined as ≥ 150 min/week) and sedentary behavior (>8h/day) were assessed by questionnaire. RESULTS: Physically active ARD patients (n = 494) were younger and less frequently used prednisone/biologics than inactive patients (n = 404). After controlling for covariates, active patients exhibited greater SC (OR: 1.4 [95%CI: 1.1-2.0]), GMT (32% [95%CI: 8.8-60) and FI-GMT (33% [95%CI: 9.6-63%]) vs. inactive. Cluster analysis (physical activity/sedentary status) revealed greater GMT (43.0% [95% CI: 11.0-84.0%) and FI-GMT (48.0% [95%CI: 14.0-92.0%]) in active/non-sedentary vs. inactive/sedentary ARD patients. A dose-response was observed, with greater benefits for the group of patients performing ≥ 350 min/week of physical activity (OR: 1.6 [95%CI: 1.1-2.4]; 41% [95%CI: 10-80%]; 35% [95%CI: 4.3-74], for SC, GMT, and FI-GMT, respectively) vs. the least active group (≤30 min/week). Greater SC (OR: 9.9 [95%CI: 1.1-89.0]) and GMT (26% [95%CI: 2.2-56.0%]) were observed in active vs. inactive non-ARD. CONCLUSIONS: A physically active lifestyle may enhance SARS-CoV-2 vaccine immunogenicity, a finding of particular clinical relevance for immunocompromised patients. TRIAL REGISTRATION: Clinicaltrials.gov #NCT04754698.

A home-based exercise program during COVID-19 pandemic: Perceptions and acceptability of juvenile systemic lupus erythematosus and juvenile idiopathic arthritis adolescents.

OBJECTIVES: To investigate the perceptions and acceptability of a home-based exercise intervention in systemic lupus erythematosus (JSLE) and juvenile idiopathic arthritis (JIA) adolescent patients during the COVID-19 pandemic, and to explore the effects of the intervention on health-related quality of life (HRQoL), sleep quality, and mental health conditions parameters. METHODS: This was a randomized controlled trial of a 12-week, home-based exercise training program conducted between October and December 2020. During this period, social distancing measures were in place in Brazil to contain the spread of COVID-19. Adolescent patients diagnosed with JSLE and JIA participated in the study. Health-related qualitative and quantitative data were collected before and after the follow-up. RESULTS: 21 JSLE patients and 30 JIA patients were analyzed. Six themes emerged from patients' feedback: 1) Suitability of the home-based format; 2) Appropriate trainer supervision, 3) Motivators and facilitators for the program; 4) Barriers to the program; 5) Health benefits; 6) Patients' suggestions to improve the program. Overall, data indicated that the intervention showed good acceptability and elicited improvements in the perceived HRQoL and fatigue in JIA and JSLE patients during the pandemic. However, further quantitative analyses with validated HRQoL, sleep quality, and mental health conditions instruments did not capture these benefits (p>0.05). CONCLUSION: Our main findings based on in-depth qualitative assessments suggest that a home-based exercise training program was suitable and well-accepted by adolescents with JSLE and JIA during the COVID-19 pandemic. Nonetheless, adherence was not high, particularly among JIA patients, suggesting that facilitators and barriers identified in the current study should be explored to improve the quality of new home-based exercise programs implementation, particularly in a future emerging crisis.

Physical activity and antibody persistence 6 months after the second dose of CoronaVac in immunocompromised patients.

This prospective cohort study within an open-label, single-arm, phase 4 vaccination trial (clinicaltrials.gov #NCT04754698) aimed to investigate the association between physical activity and persistent anti-SARS-CoV-2 antibodies 6 months after two-dose schedule of CoronaVac in autoimmune rheumatic diseases (ARD) patients (n = 748). Persistent immunogenicity 6 months after the full-course vaccination was assessed using seroconversion rates of total anti-SARS-CoV-2 S1/S2 IgG, geometric mean titers of anti-S1/S2 IgG (GMT), and frequency of positive neutralizing antibodies (NAb). Physical activity was assessed trough questionnaire. Adjusted point estimates from logistic regression models indicated that physically active patients had greater odds of seroconversion rates (OR: 1.5 [95%CI: 1.1 to 2.1]) and NAb positivity (OR: 1.5 [95%CI: 1.0 to 2.1]), and approximately 43% greater GMT (42.8% [95%CI: 11.9 to 82.2]) than inactive ones. In conclusion, among immunocompromised patients, being physically active was associated with an increment in antibody persistence through 6 months after a full-course of an inactivated SARS-CoV-2 vaccine.

Session Rating of Perceived Exertion as an Efficient Tool for Individualized Resistance Training Progression.

ABSTRACT: Gomes, RL, Lixandrão, ME, Ugrinowitsch, C, Moreira, A, Tricoli, V, and Roschel, H. Session rating of perceived exertion as an efficient tool for individualized resistance training progression. J Strength Cond Res 36(4): 971-976, 2022-The present study aimed to investigate the effects of an individualized resistance training (RT) progression model based on the session rating of perceived exertion (RPE) on gains in muscle mass and strength when compared with a conventional predetermined progression method (PP). Twenty previously trained young male subjects were randomly allocated to 1 of the 2 groups: RPE (n = 10) or PP (n = 10). Muscle cross-sectional area (CSA) and maximum dynamic strength were assessed at baseline and after 6 weeks. The RPE-based progression model resulted in a lower number of high-intensity sessions compared with the PP-based model. Despite this, both groups showed significant and similar increases in CSA (p < 0.0001; RPE = 6.55 ± 5.27% and PP = 9.65 ± 3.63%) and strength (p < 0.0001; RPE = 9.68 ± 4.57% and PP = 9.28 ± 4.01%) after the intervention period. No significant between-group difference was observed for total training volume (RPE = 45,366.00 ± 10,190.00 kg and PP = 47,779.00 ± 5,685.00 kg; p = 0.52). Our results showed that an RT progression model based on session-to-session physiological response assessments resulted in fewer high-intensity training sessions while allowing for similar gains in muscle strength and mass. Thus, trainees are encouraged to adopt session RPE as a potential tool to control workload progression throughout a training period and allowing the optimization of training stimulus on an individual basis.

Increased sympathetic and haemodynamic responses to exercise and muscle metaboreflex activation in post-menopausal women with rheumatoid arthritis.

KEY POINTS: Rheumatoid arthritis (RA) patients present exacerbated blood pressure responses to exercise, but little is known regarding the underlying mechanisms involved.  This study assessed autonomic and haemodynamic responses to exercise and to the isolated activation of muscle metaboreflex in post-menopausal women with RA.  Participants with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These responses were associated with multiple pro- and anti-inflammatory cytokines and with pain.  The results of the present study support the suggestion that an abnormal reflex control of circulation is an important mechanism underlying the exacerbated cardiovascular response to exercise and increased cardiovascular risk in RA. ABSTRACT: Studies have reported abnormal cardiovascular responses to exercise in rheumatoid arthritis (RA) patients, but little is known regarding the underlying mechanisms involved. This study assessed haemodynamic and sympathetic responses to exercise and to the isolated activation of muscle metaboreflex in women diagnosed with RA. Thirty-three post-menopausal women diagnosed with RA and 10 matched controls (CON) participated in this study. Mean arterial pressure (MAP), heart rate (HR) and muscle sympathetic nerve activity (MSNA frequency and incidence) were measured during a protocol of isometric knee extension exercise (3 min, 30% of maximal voluntary contraction), followed by post-exercise ischaemia (PEI). Participants with RA showed greater increases in MAP and MSNA during exercise and PEI than CON (ΔMAPexercise  = 16 ± 11 vs. 9 ± 6 mmHg, P = 0.03; ΔMAPPEI  = 15 ± 10 vs. 5 ± 5 mmHg, P = 0.001; ΔMSNAexercise  = 17 ± 14 vs. 7 ± 9 bursts min-1 , P = 0.04; ΔMSNAPEI  = 14 ± 10 vs. 6 ± 4 bursts min-1 , P = 0.04). Autonomic responses to exercise showed significant (P < 0.05) association with pro- (i.e. IFN-γ, IL-8, MCP-1 and TNFα) and anti-inflammatory (i.e. IL-1ra and IL-10) cytokines and with pain. In conclusion, post-menopausal women with RA showed augmented pressor and sympathetic responses to exercise and to the activation of muscle metaboreflex. These findings provide mechanistic insights that may explain the abnormal cardiovascular responses to exercise in RA.

Acute cardiometabolic effects of brief active breaks in sitting for patients with rheumatoid arthritis.

Exercise is a treatment in rheumatoid arthritis, but participation in moderate-to-vigorous exercise is challenging for some patients. Light-intensity breaks in sitting could be a promising alternative. We compared the acute effects of active breaks in sitting with those of moderate-to-vigorous exercise on cardiometabolic risk markers in patients with rheumatoid arthritis. In a crossover fashion, 15 women with rheumatoid arthritis underwent three 8-h experimental conditions: prolonged sitting (SIT), 30-min bout of moderate-to-vigorous exercise followed by prolonged sitting (EX), and 3-min bouts of light-intensity walking every 30 min of sitting (BR). Postprandial glucose, insulin, c-peptide, triglycerides, cytokines, lipid classes/subclasses (lipidomics), and blood pressure responses were assessed. Muscle biopsies were collected following each session to assess targeted proteins/genes. Glucose [-28% in area under the curve (AUC), P = 0.036], insulin (-28% in AUC, P = 0.016), and c-peptide (-27% in AUC, P = 0.006) postprandial responses were attenuated in BR versus SIT, whereas only c-peptide was lower in EX versus SIT (-20% in AUC, P = 0.002). IL-1ß decreased during BR, but increased during EX and SIT (P = 0.027 and P = 0.085, respectively). IL-1ra was increased during EX versus BR (P = 0.002). TNF-α concentrations decreased during BR versus EX (P = 0.022). EX, but not BR, reduced systolic blood pressure (P = 0.013). Lipidomic analysis showed that 7 of 36 lipid classes/subclasses were significantly different between conditions, with greater changes being observed in EX. No differences were observed for protein/gene expression. Brief active breaks in sitting can offset markers of cardiometabolic disturbance, which may be particularly useful for patients who may find it difficult to adhere to exercise.NEW & NOTEWORTHY Exercise is a treatment in rheumatoid arthritis but is challenging for some patients. Light-intensity breaks in sitting could be a promising alternative. Our findings show beneficial, but differential, cardiometabolic effects of active breaks in sitting and exercise in patients with rheumatoid arthritis. Breaks in sitting mainly improved glycemic and inflammatory markers, whereas exercise improved lipidomic and hypotensive responses. Breaks in sitting show promise in offsetting aspects of cardiometabolic disturbance associated with prolonged sitting in rheumatoid arthritis.

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.

Exercise Is Key to Sustaining Metabolic Gains After Bariatric Surgery.

The extent to which the benefits of bariatric surgery may be maintained by lifestyle changes after surgery is unclear. Our hypothesis is that exercise may sustain some metabolic benefits and counteract some of the adverse effects of surgery. In this review, we present findings supporting the proposition that exercise is key to improving overall health in patients after bariatric surgery.

Individual Participant Data Meta-Analysis Provides No Evidence of Intervention Response Variation in Individuals Supplementing With Beta-Alanine.

Currently, little is known about the extent of interindividual variability in response to beta-alanine (BA) supplementation, nor what proportion of said variability can be attributed to external factors or to the intervention itself (intervention response). To investigate this, individual participant data on the effect of BA supplementation on a high-intensity cycling capacity test (CCT110%) were meta-analyzed. Changes in time to exhaustion (TTE) and muscle carnosine were the primary and secondary outcomes. Multilevel distributional Bayesian models were used to estimate the mean and SD of BA and placebo group change scores. The relative sizes of group SDs were used to infer whether observed variation in change scores were due to intervention or non-intervention-related effects. Six eligible studies were identified, and individual data were obtained from four of these. Analyses showed a group effect of BA supplementation on TTE (7.7, 95% credible interval [CrI] [1.3, 14.3] s) and muscle carnosine (18.1, 95% CrI [14.5, 21.9] mmol/kg DM). A large intervention response variation was identified for muscle carnosine (σIR = 5.8, 95% CrI [4.2, 7.4] mmol/kg DM) while equivalent change score SDs were shown for TTE in both the placebo (16.1, 95% CrI [13.0, 21.3] s) and BA (15.9, 95% CrI [13.0, 20.0] s) conditions, with the probability that SD was greater in placebo being 0.64. In conclusion, the similarity in observed change score SDs between groups for TTE indicates the source of variation is common to both groups, and therefore unrelated to the supplement itself, likely originating instead from external factors such as nutritional intake, sleep patterns, or training status.

A Systematic Review of CrossFit® Workouts and Dietary and Supplementation Interventions to Guide Nutritional Strategies and Future Research in CrossFit®.

CrossFit® is a high-intensity functional training method consisting of daily workouts called "workouts of the day." No nutritional recommendations exist for CrossFit® that are supported by scientific evidence regarding the energetic demands of this type of activity or dietary and supplement interventions. This systematic review performed in accordance with PRISMA guidelines aimed to identify studies that determined (a) the physiological and metabolic demands of CrossFit® and (b) the effects of nutritional strategies on CrossFit® performance to guide nutritional recommendations for optimal recovery, adaptations, and performance for CrossFit® athletes and direct future research in this emerging area. Three databases were searched for studies that investigated physiological responses to CrossFit® and dietary or supplementation interventions on CrossFit® performance. Various physiological measures revealed the intense nature of all CrossFit® workouts of the day, reflected in substantial muscle fatigue and damage. Dietary and supplementation studies provided an unclear insight into effective strategies to improve performance and enhance adaptations and recovery due to methodological shortcomings across studies. This systematic review showed that CrossFit® is a high-intensity sport with fairly homogenous anaerobic and aerobic characteristics, resulting in substantial metabolic stress, leading to metabolite accumulation (e.g., lactate and hydrogen ions) and increased markers of muscle damage and muscle fatigue. Limited interventional data exist on dietary and supplementation strategies to optimize CrossFit® performance, and most are moderate to very low quality with some critical methodological limitations, precluding solid conclusions on their efficacy. High-quality work is needed to confirm the ideal dietary and supplemental strategies for optimal performance and recovery for CrossFit® athletes and is an exciting avenue for further research.