Blood-Flow-Restriction-Training-Induced Hormonal Response is not Associated with Gains in Muscle Size and Strength

The aim of this study was to determine whether increases in post-exercise endocrine response to low-load resistance exercise with blood flow restriction and high-load resistance exercise would have association with increases in muscle size and strength after an 8-week training period. Twenty-nine untrained men were randomly allocated into three groups: low-load resistance exercise with (LL-BFR) or without blood flow restriction (LL), and high-load resistance exercise (HL). Participants from LL-BFR and LL groups performed leg extension exercise at 20% of one repetition maximum (1RM), four sets of 15 repetitions and the HL group performed four sets of eight repetitions at 80% 1RM. Before the first training session, growth hormone (GH), insulin-like growth factor 1 (IGF-1), testosterone, cortisol, and lactate concentration were measured at rest and 15 min after the exercise. Quadriceps CSA and 1RM knee extension were assessed at baseline and after an 8-week training period. GH increased 15 min after exercise in the LL-BFR (p = 0.032) and HL (p \u3c 0.001) groups, with GH concentration in the HL group being higher than in the LL group (p = 0.010). There was a time effect for a decrease in testosterone (p = 0.042) and an increase in cortisol (p = 0.005), while IGF-1 remained unchanged (p = 0.346). Both muscle size and strength were increased after training in LL-BFR and HL groups, however, these changes were not associated with the acute post-exercise hormone levels (p \u3e 0.05). Our data suggest that other mechanisms than the acute post-exercise increase in systemic hormones induced by LL-BFR and HL produce changes in muscle size and strength

Individual participant data meta-analysis provides no evidence of individual response variation in individuals supplementing with beta-alanine.

Currently, little is known about the extent of inter-individual 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-analysed. Changes in time to exhaustion (TTE) and muscle carnosine (MCarn) were the primary and secondary outcomes. Multi-level distributional Bayesian models were used to estimate the mean and standard deviation of BA and placebo (PLA) group change scores. The relative sizes of group standard deviations 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%CrI:1.3 to 14.3 s]) and MCarn (18.1[95%CrI:14.5 to 21.9 mmol·kgDM-1]). A large intervention response variation was identified for MCarn (σ_IR= 5.8 [95%CrI: 4.2 to 7.4 mmol·kgDM-1]); however, equivalent change score standard deviations were shown for PLA (16.1[95%CrI:13.0 to 21.3 s]) and BA (15.9[95%CrI:13.0 to 20.0 s] conditions, with the probability that standard deviation was greater in PLA being 0.64. In conclusion, the similarity in observed change score standard deviations between groups for TTE indicates the source of variation is common and therefore unrelated to BA supplementation, likely originating instead from external factors, which may include, for example, nutritional intake, sleep patterns or training status

Do whole-body vibration exercise and resistance exercise modify concentrations of salivary cortisol and immunoglobulin A?

A single bout of resistance exercise (RE) induces hormonal and immune responses, playing an important role in a long-term adaptive process. Whole-body vibration (WBV) has also been shown to affect hormonal responses. Evidence suggests that combining WBV with RE may amplify hormonal and immune responses due to the increased neuromuscular load. Therefore, the aim of this study was to evaluate salivary cortisol (Scortisol) and salivary IgA (SIgA) concentrations following a RE session combined or not with WBV. Nine university students (22.9 ± 5.1 years, 175.8 ± 5.2 cm, and 69.2 ± 7.3 kg) performed five sets of squat exercise (70% one-repetition-maximum) combined (R+V30) or not (R) with WBV at 30 Hz. Saliva samples were obtained before and after exercise. Subjects also rated their effort according to the Borg CR-10 scale (RPE). Data were analyzed by a mixed model. RPE was higher after R+V30 (8.3 ± 0.7) compared to R (6.2 ± 0.7). However, Scortisol (pre: 10.6 ± 7.6 and 11.7 ± 7.6, post: 8.3 ± 6.3 and 10.2 ± 7.2 ng/mL for R and R+V30, respectively) and SIgA concentrations (pre: 98.3 ± 22.6 and 116.1 ± 51.2, post: 116.6 ± 64.7 and 143.6 ± 80.5 µg/mL for R and R+V30, respectively) were unaffected. No significant correlations were observed between Scortisol and RPE (r = 0.45, P = 0.22; r = 0.30, P = 0.42, for R and R+V30, respectively). On the basis of these data, neither protocol modified salivary cortisol or IgA, although RPE was higher after R+V30 than R

Redução na força muscular e capacidade funcional em pacientes fisicamente inativos com lúpus eritematoso sistêmico de início juvenil, apesar de doença muito leve

ResumoObjetivoComparar a força muscular (ou seja, a força muscular dos membros superiores e inferiores) e a capacidade funcional de pacientes fisicamente inativos com lúpus eritematoso sistêmico de início juvenil (LESJ) com controles saudáveis (CTRL).MétodosEstudo transversal cuja amostra foi composta por 19 pacientes com LESJ (entre 9 e 18 anos) e 15 CTRL pareados por idade, sexo, índice de massa corporal (IMC) e nível de atividade física (avaliada através do uso de acelerômetros). A força dos membros superiores e inferiores foi avaliada pelo teste de uma repetição máxima (1‐RM). A força isométrica foi avaliada através do uso de um dinamômetro. A capacidade funcional foi avaliada pelo Timed‐stands test (TST) e Timed‐up‐and‐go test (TUG).ResultadosQuando comparados com os CTRL, os pacientes com LESJ apresentaram menor força em 1‐RM no Leg press e supino (p=0,026 e p=0,008, respectivamente) e uma tendência a menor força de preensão manual (p=0,052). Os pacientes com LESJ apresentaram menores escores no TST (p=0,036) e uma tendência a maior pontuação no TUG (p=0,070), quando comparados com o grupo CTRL.ConclusãoPacientes com LESJ, fisicamente inativos, com doença muito leve mostraram redução na força muscular e capacidade funcional quando comparados com controles saudáveis pareados por níveis de atividade física. Esses achados sugerem que pacientes com LESJ podem apresentar mais efeitos deletérios por manter um estilo de vida fisicamente inativo do que controles saudáveis. Além disso, alguns efeitos “residuais” subclínicos da doença ou do tratamento farmacológico parecem afetar pacientes com LESJ, mesmo com uma doença bem controlada.AbstractObjectiveTo compare muscle strength (i.e. lower‐ and upper‐body strength) and function between physically inactive childhood‐onset systemic lupus erythematosus patients (C‐SLE) and healthy controls (CTRL).MethodsThis was a cross‐sectional study and the sample consisted of 19 C‐SLE (age between 9 to 18 years) and 15 CTRL matched by age, sex, body mass index (BMI), and physical activity levels (assessed by accelerometry). Lower‐ and upper‐body strength was assess by the one‐repetition‐maximum (1‐RM) test. Isometric strength was assessed through a handgrip dynamometer. Muscle function was evaluated by the timed‐stands test (TST) and the timed‐up‐and‐go test (TUG).ResultsWhen compared with CTRL, C‐SLE showed lower leg‐press and bench‐press 1‐RM (p=0.026 and p=0.008, respectively), and a tendency towards lower handgrip strength (p=0.052). C‐SLE showed lower TST scores (p=0.036) and a tendency towards higher TUG scores (p=0.070) when compared with CTRL.ConclusionPhysically inactive C‐SLE patients with very mild disease showed reduced muscle strength and functionality when compared with healthy controls matched by physical activity levels. These findings suggest C‐SLE patients may greatly suffer from a physically inactive lifestyle than healthy controls do. Moreover, some sub‐clinical “residual” effect of the disease or its pharmacological treatment seems to affect C‐SLE patients even with a well‐controlled disease

Association of health vulnerability with adverse outcomes in older people with COVID-19: a prospective cohort study

OBJECTIVES: Health vulnerability is associated with a higher risk of mortality and functional decline in older people in the community. However, few studies have evaluated the role of the Vulnerable Elders Survey (VES-13) in predicting clinical outcomes of hospitalized patients. In the present study, we tested the ability of the VES-13 to predict mortality and the need for invasive mechanical ventilation in older people hospitalized with coronavirus disease 2019 (COVID-19). METHODS: This prospective cohort included 91 participants aged X60 years who were confirmed to have COVID-19. VES-13 was applied, and the demographic, clinical, and laboratory variables were collected within 72h of hospitalization. A Poisson generalized linear regression model with robust variance was used to estimate the relative risk of death and invasive mechanical ventilation. RESULTS: Of the total number of patients, 19 (21%) died and 15 (16%) required invasive mechanical ventilation. Regarding health vulnerability, 54 (59.4%) participants were classified as non-vulnerable, 30 (33%) as vulnerable, and 7 (7.6%) as extremely vulnerable. Patients classified as extremely vulnerable and male sex were strongly and independently associated with a higher relative risk of in-hospital mortality (po0.05) and need for invasive mechanical ventilation (po0.05). CONCLUSION: Elderly patients classified as extremely vulnerable had more unfavorable outcomes after hospitalization for COVID-19. These data highlight the importance of identifying health vulnerabilities in this population

The ergogenic effect of beta-alanine combined with sodium bicarbonate on high-intensity swimming performance

We investigated the effect of beta-alanine (BA) alone (study A) and in combination with sodium bicarbonate (SB) (study B) on 100- and 200-m swimming performance. In study A, 16 swimmers were assigned to receive either BA (3.2 g·day−1 for 1 week and 6.4 g·day−1 for 4 weeks) or placebo (PL; dextrose). At baseline and after 5 weeks of supplementation, 100- and 200-m races were completed. In study B, 14 were assigned to receive either BA (3.2 g·day−1 for 1 week and 6.4 g·day−1 for 3 weeks) or PL. Time trials were performed once before and twice after supplementation (with PL and SB), in a crossover fashion, providing 4 conditions: PL-PL, PL-SB, BA-PL, and BA-SB. In study A, BA supplementation improved 100- and 200-m time-trial performance by 2.1% (p = 0.029) and 2.0% (p = 0.0008), respectively. In study B, 200-m time-trial performance improved in all conditions, compared with presupplementation, except the PL-PL condition (PL-SB, +2.3%; BA-PL, +1.5%; BA-SB, +2.13% (p < 0.05)). BA-SB was not different from BA-PL (p = 0.21), but the probability of a positive effect was 78.5%. In the 100-m time-trial, only a within-group effect for SB was observed in the PL-SB (p = 0.022) and BA-SB (p = 0.051) conditions. However, 6 of 7 athletes swam faster after BA supplementation. The probability of BA having a positive effect was 65.2%; when SB was added to BA, the probability was 71.8%. BA and SB supplementation improved 100- and 200-m swimming performance. The coingestion of BA and SB induced a further nonsignificant improvement in performance

Daily leucine intake is positively associated with lower limb skeletal muscle mass and strength in the elderly.

Higher daily protein intake, with an emphasis on leucine content, is thought to mitigate age-related anabolic resistance, potentially counteracting age-related morphological and functional declines. The present study investigated potential associations between total daily leucine intake and dependent variables, including quadriceps muscle cross-sectional area (CSA) and maximum dynamic muscle strength (1-RM) in a cohort of healthy free-living older individuals of both sexes (n = 67; 34/33 men/women). Participants performed three 24-hour dietary recalls and underwent a magnetic resonance imaging exam followed by 1-RM tests. Our results demonstrate moderate associations between total daily leucine and both quadriceps CSA (r = 0.42; p = 0.004) and 1-RM (r = 0.45; p = 0.001). Furthermore, our exploratory biphasic linear regression analyses, adjusted for sex, age, and protein intake relative to body weight, revealed a plateau for daily leucine intake and muscle mass and muscle strength (around 7.6–8.0 g/day−1) in older adults. In conclusion, we demonstrated that total daily leucine intake is associated with muscle mass and strength in healthy older individuals and this association remains after controlling for multiple factors, including overall protein intake. Furthermore, our breakpoint analysis revealed non-linearities and a potential threshold for habitual leucine intake, which may help guide future research on the effects of chronic leucine intake in age-related muscle loss

Exercise training and DNA methylation profile in post-bariatric women: Results from an exploratory study

[Abstract]: Exercise training and bariatric surgery have been shown to independently modulate DNA methylation profile in clusters of genes related to metabolic and inflammatory pathways. This study aimed to investigate the effects of a 6-month exercise training program on DNA methylation profile in women who underwent bariatric surgery. In this exploratory, quasi-experimental study, we analyzed DNA methylation levels by array technology in eleven women who underwent Roux-en-Y Gastric Bypass and a 6-month, three-times-a-week, supervised exercise training program. Epigenome Wide Association Analysis showed 722 CpG sites with different methylation level equal to or greater than 5% (P < 0.01) after exercise training. Some of these CpGs sites were related to pathophysiological mechanisms of inflammation, specially Th17 cell differentiation (FDR value < 0.05 and P < 0.001). Our data showed epigenetic modification in specific CpG sites related to Th17 cell differentiation pathway in post-bariatric women following a 6-months exercise training program.This study was supported by São Paulo Research Foundation (FAPESP) (grants #2015/18669–0, #2016/05638–1, #2017/13552–2) and Coordenação de Aperfeiçoamento de Pesquisa de Pessoal de Nível Superior - CAPES (grant #88887.473556/2020–00)

Cardiac autonomic impairment and chronotropic incompetence in fibromyalgia

Abstract\ud \ud \ud \ud Introduction\ud \ud We aimed to gather knowledge on the cardiac autonomic modulation in patients with fibromyalgia (FM) in response to exercise and to investigate whether this population suffers from chronotropic incompetence (CI).\ud \ud \ud \ud Methods\ud \ud Fourteen women with FM (age: 46 ± 3 years; body mass index (BMI): 26.6 ± 1.4 kg/m2) and 14 gender-, BMI- (25.4 ± 1.3 kg/m2), and age-matched (age: 41 ± 4 years) healthy individuals (CTRL) took part in this cross-sectional study. A treadmill cardiorespiratory test was performed and heart-rate (HR) response during exercise was evaluated by the chronotropic reserve. HR recovery (deltaHRR) was defined as the difference between HR at peak exercise and at both first (deltaHRR1) and second (deltaHRR2) minutes after the exercise test.\ud \ud \ud \ud Results\ud \ud FM patients presented lower maximal oxygen consumption (VO2 max) when compared with healthy subjects (22 ± 1 versus CTRL: 32 ± 2 mL/kg/minute, respectively; P < 0.001). Additionally, FM patients presented lower chronotropic reserve (72.5 ± 5 versus CTRL: 106.1 ± 6, P < 0.001), deltaHRR1 (24.5 ± 3 versus CTRL: 32.6 ± 2, P = 0.059) and deltaHRR2 (34.3 ± 4 versus CTRL: 50.8 ± 3, P = 0.002) than their healthy peers. The prevalence of CI was 57.1% among patients with FM.\ud \ud \ud \ud Conclusions\ud \ud Patients with FM who undertook a graded exercise test may present CI and delayed HR recovery, both being indicative of cardiac autonomic impairment and higher risk of cardiovascular events and mortality.This work was supported by the Fundação de Amparo a Pesquisa do Estado de São Paulo (Grant 2009/51897-5)

β-alanine supplementation to improve exercise capacity and performance: a systematic review and meta-analysis.

Objective To conduct a systematic review and meta-Analysis of the evidence on the effects of β-Alanine supplementation on exercise capacity and performance. Design This study was designed in accordance with PRISMA guidelines. A 3-level mixed effects model was employed to model effect sizes and account for dependencies within data. Data sources 3 databases (PubMed, Google Scholar, Web of Science) were searched using a number of terms (b € β-Alanine' and b € Beta-Alanine' combined with b € supplementation', b € exercise', b € training', b € athlete', b € performance' and b € carnosine'). Eligibility criteria for selecting studies Inclusion/exclusion criteria limited articles to double-blinded, placebo-controlled studies investigating the effects of β-Alanine supplementation on an exercise measure. All healthy participant populations were considered, while supplementation protocols were restricted to chronic ingestion. Cross-over designs were excluded due to the long washout period for skeletal muscle carnosine following supplementation. A single outcome measure was extracted for each exercise protocol and converted to effect sizes for meta-Analyses. Results 40 individual studies employing 65 different exercise protocols and totalling 70 exercise measures in 1461 participants were included in the analyses. A significant overall effect size of 0.18 (95% CI 0.08 to 0.28) was shown. Meta-regression demonstrated that exercise duration significantly (p=0.004) moderated effect sizes. Subgroup analyses also identified the type of exercise as a significant (p=0.013) moderator of effect sizes within an exercise time frame of 0.5-10b €.min with greater effect sizes for exercise capacity (0.4998 (95% CI 0.246 to 0.753)) versus performance (0.1078 (95% CI b '0.201 to 0.416)). There was no moderating effect of training status (p=0.559), intermittent or continuous exercise (p=0.436) or total amount of β-Alanine ingested (p=0.438). Co-supplementation with sodium bicarbonate resulted in the largest effect size when compared with placebo (0.43 (95% CI 0.22 to 0.64)). Summary/conclusions β-Alanine had a significant overall effect while subgroup analyses revealed a number of modifying factors. These data allow individuals to make informed decisions as to the likelihood of an ergogenic effect with β-Alanine supplementation based on their chosen exercise modality