BRYAN SAUNDERS
Projetos de Pesquisa
Unidades Organizacionais
LIM/17 - Laboratório de Investigação em Reumatologia, Hospital das Clínicas, Faculdade de Medicina
30 resultados
Resultados de Busca
Agora exibindo 1 - 10 de 30
conferenceObject Optimising Sodium Bicarbonate Supplementation: Are Gastro-resistant Capsules The Answer?(2018) OLIVEIRA, Luana F.; SAUNDERS, Bryan; YAMAGUCHI, Guilherme; GUALANO, Bruno; ROSCHEL, Hamilton; ARTIOLI, Guilherme G.- Skeletal muscle histidine-containing dipeptide contents are increased in freshwater turtles (C. picta bellii) with cold-acclimation(2021) DOLAN, Eimear; WARREN, Daniel E.; HARRIS, Roger C.; SALE, Craig; GUALANO, Bruno; SAUNDERS, BryanFreshwater turtles found in higher latitudes can experience extreme challenges to acid-base homeostasis while overwintering, due to a combination of cold temperatures along with the potential for environmental hypoxia. Histidine-containing dipeptides (HCDs; carnosine, anserine and balenine) may facilitate pH regulation in response to these challenges, through their role as pH buffers. We measured the HCD content of three tissues (liver, cardiac and skeletal muscle) from the anoxia-tolerant painted turtle (C. picta bellii) acclimated to either 3 or 20 degrees C. HCDs were detected in all tissues, with the highest content shown in the skeletal muscle. Turtles acclimated to 3 degrees C had more HCD in their skeletal muscle than those acclimated to 20 degrees C (carnosine = 20.8 +/- 4.5 vs 12.5 +/- 5.9 mmol. kg DM-1; ES = 1.59 (95%CI: 0.16-3.00), P = 0.013). The higher HCD content shown in the skeletal muscle of the cold-acclimated turtles suggests a role in acid-base regulation in response to physiological challenges associated with living in the cold, with the increase possibly related to the temperature sensitivity of carnosine's dissociation constant.
- Is Open-Label Placebo a New Ergogenic Aid? A Commentary on Existing Studies and Guidelines for Future Research(2020) SAITO, Tiemi; BARRETO, Gabriel; SAUNDERS, Bryan; GUALANO, BrunoThe placebo effect has been defined as a genuine psychobiological response that arises from the belief that a positive intervention has been received. However, the notion that belief in an active treatment is necessary to elicit a placebo effect has been challenged. Recent data show that placebo effects may occur even when individuals are openly informed that they are receiving an inert treatment, the so-called open-label placebo. In fact, clinical studies have shown improvements in disease symptoms in patients who underwent an open-label placebo intervention. Now, the application of open-label placebo is attracting interest among the sports science community. Open-label placebo could be a useful and ethically permitted tool to improve exercise performance when applied in combination with other legal ergogenic aids (e.g., nutritional supplements) and/or in place of illegal substances (e.g., anabolic steroids). However, independent laboratories recently investigated the effects of open-label placebo on exercise performance with contrasting results, suggesting that there is much more research required before widespread implementation of open-label placebo in the field of sport and exercise can be justified. Herein we discuss the emerging science on open-label placebo interventions from a clinical setting to sports science. Moreover, we propose a research agenda for investigations on open-label placebo in sports and exercise sciences by covering the main gaps in the field. Addressing the research agenda put forward will help to advance our understanding of this intriguing topic.
conferenceObject Chronic (24 weeks) Beta-alanine Supplementation Does Not Affect Muscle Taurine Or Blood Clinical Chemistry(2018) SAUNDERS, Bryan; FRANCHI, Mariana; OLIVEIRA, Luana F.; PAINELLI, Vitor S.; SILVA, Vinicius E.; SILVA, Rafael P.; COSTA, Luiz A. R.; SALE, Craig; HARRIS, Roger C.; ROSCHEL, Hamilton; ARTIOLI, Guilherme G.; GUALANO, Bruno- A Systematic Risk Assessment and Meta-Analysis on the Use of Oral beta-Alanine Supplementation(2019) DOLAN, Eimear; SWINTON, Paul A.; PAINELLI, Vitor de Salles; HEMINGWAY, Benedict Stephens; MAZZOLANI, Bruna; SMAIRA, Fabiana Infante; SAUNDERS, Bryan; ARTIOLI, Guilherme G.; GUALANO, Brunobeta-Alanine supplementation is one of the world's most commonly used sports supplements, and its use as a nutritional strategy in other populations is ever-increasing, due to evidence of pleiotropic ergogenic and therapeutic benefits. Despite its widespread use, there is only limited understanding of potential adverse effects. To address this, a systematic risk assessment and meta-analysis was undertaken. Four databases were searched using keywords and Medical Subject Headings. All human and animal studies that investigated an isolated, oral, beta-alanine supplementation strategy were included. Data were extracted according to 5 main outcomes, including 1) side effects reported during longitudinal trials, 2) side effects reported during acute trials, 3) effect of supplementation on circulating health-related biomarkers, 4) effect of supplementation on skeletal muscle taurine and histidine concentration, and 5) outcomes from animal trials. Quality of evidence for outcomes was ascertained using the Grading of Recommendations Assessment Development and Evaluation (GRADE) framework, and all quantitative data were meta-analyzed using multilevel models grounded in Bayesian principles. In total, 101 human and 50 animal studies were included. Paraesthesia was the only reported side effect and had an estimated OR of 8.9 [95% credible interval (CrI): 2.2, 32.6] with supplementation relative to placebo. Participants in active treatment groups experienced similar dropout rates to those receiving the placebo treatment. beta-Alanine supplementation caused a small increase in circulating alanine aminotransferase concentration (effect size, ES: 0.274, CrI: 0.04, 0.527), although mean data remained well within clinical reference ranges. Meta-analysis of human data showed no main effect of beta-alanine supplementation on skeletal muscle taurine (ES: 0.156; 95% CrI: -0.38, 0.72) or histidine (ES: -0.15; 95% CrI: -0.64, 0.33) concentration. A main effect of beta-alanine supplementation on taurine concentration was reported for murine models, but only when the daily dose was >= 3% beta-alanine in drinking water. The results of this review indicate that beta-alanine supplementation within the doses used in the available research designs, does not adversely affect those consuming it.
- Effects of -alanine and sodium bicarbonate supplementation on the estimated energy system contribution during high-intensity intermittent exercise(2019) SILVA, Rafael Pires da; OLIVEIRA, Luana Farias de; SAUNDERS, Bryan; KRATZ, Caroline de Andrade; PAINELLI, Vitor de Salles; SILVA, Vinicius da Eira; MARINS, Joao Carlos Bouzas; FRANCHINI, Emerson; GUALANO, Bruno; ARTIOLI, Guilherme GianniniThe effects of -alanine (BA) and sodium bicarbonate (SB) on energy metabolism during work-matched high-intensity exercise and cycling time-trial performance were examined in 71 male cyclists. They were randomised to receive BA+placebo (BA, n=18), placebo+SB (SB, n=17), BA+SB (BASB, n=19), or placebo+placebo (PLA, n=18). BA was supplemented for 28days (6.4gday(-1)) and SB (0.3gkg(-1)) ingested 60min before exercise on the post-supplementation trial. Dextrose and calcium carbonate were placebos for BA and SB, respectively. Before (PRE) and after (POST) supplementation, participants performed a high-intensity intermittent cycling test (HICT-110%) consisting of four 60-s bouts at 110% of their maximal power output (60-s rest between bouts). The estimated contribution of the energy systems was calculated for each bout in 39 of the participants (BA: n=9; SB: n=10; BASB: n=10, PLA: n=10). Ten minutes after HICT-110%, cycling performance was determined in a 30-kJ time-trial test in all participants. Both groups receiving SB increased estimated glycolytic contribution in the overall HICT-110%, which approached significance (SB: +23%, p=0.068 vs. PRE; BASB: +18%, p=0.059 vs. PRE). No effects of supplementation were observed for the estimated oxidative and ATP-PCr systems. Time to complete 30 kJ was not significantly changed by any of the treatments, although a trend toward significance was shown in the BASB group (p=0.06). We conclude that SB, but not BA, increases the estimated glycolytic contribution to high-intensity intermittent exercise when total work done is controlled and that BA and SB, either alone or in combination, do not improve short-duration cycling time-trial performance.
conferenceObject Beta-Alanine Did Not Improve High-Intensity Performance Throughout Simulated Road Cycling(2021) PERIM, Pedro; GOBBI, Nathan; DUARTE, Breno; OLIVEIRA, Luana Faria de; COSTA, Luiz Augusto Riani; SALE, Craig; GUALANO, Bruno; DOLAN, Eimear; SAUNDERS, BryanconferenceObject Sex, But Not Age, Associates With Whole Muscle Carnosine Content Of Trained Men And Women(2020) DOLAN, Eimear; SWINTON, Paul A.; OLIVEIRA, Luana Farias de; REZENDE, Nathalia Saffioti; MAZZOLANI, Bruna Caruso; BESTETTI, Giulia Cazetta; SMAIRA, Fabiana Infante; DUMAS, Alina; PERIM, Pedro; RIANI, Luiz; GUALANO, Bruno; SAUNDERS, Bryan- A Statistical Framework to Interpret Individual Response to Intervention : Paving the Way for Personalized Nutrition and Exercise Prescription(2018) SWINTON, Paul A.; HEMINGWAY, Ben Stephens; SAUNDERS, Bryan; GUALANO, Bruno; DOLAN, EimearThe concept of personalized nutrition and exercise prescription represents a topical and exciting progression for the discipline given the large inter-individual variability that exists in response to virtually all performance and health related interventions. Appropriate interpretation of intervention-based data from an individual or group of individuals requires practitioners and researchers to consider a range of concepts including the confounding influence of measurement error and biological variability. In addition, the means to quantify likely statistical and practical improvements are facilitated by concepts such as confidence intervals (CIs) and smallest worthwhile change (SWC). The purpose of this review is to provide accessible and applicable recommendations for practitioners and researchers that interpret, and report personalized data. To achieve this, the review is structured in three sections that progressively develop a statistical framework. Section 1 explores fundamental concepts related to measurement error and describes how typical error and CIs can be used to express uncertainty in baseline measurements. Section 2 builds upon these concepts and demonstrates how CIs can be combined with the concept of SWC to assess whether meaningful improvements occur post-intervention. Finally, section 3 introduces the concept of biological variability and discusses the subsequent challenges in identifying individual response and non-response to an intervention. Worked numerical examples and interactive Supplementary Material are incorporated to solidify concepts and assist with implementation in practice.
- Beta-alanine did not improve high-intensity performance throughout simulated road cycling(2022) PERIM, Pedro; GOBBI, Nathan; DUARTE, Breno; OLIVEIRA, Luana Farias de; COSTA, Luiz Augusto Riani; SALE, Craig; GUALANO, Bruno; DOLAN, Eimear; SAUNDERS, BryanThis study investigated the effect of beta-alanine supplementation on short-duration sprints and final 4-km simulated uphill cycling time-trial performance during a comprehensive and novel exercise protocol representative of the demands of road-race cycling, and determined if changes were related to increases in muscle carnosine content. Seventeen cyclists (age 38 +/- 9 y, height 1.76 +/- 0.07 m, body mass 71.4 +/- 8.8 kg, V?O-2max 52.4 +/- 8.3 ml center dot kg(-1)center dot min(-1)) participated in this placebo-controlled, double-blind study. Cyclists undertook a prolonged intermittent cycling protocol lasting 125 min, with a 10-s sprint every 20 min, finishing with a 4-km time-trial at 5% simulated incline. Participants completed two familiarization sessions, and two main sessions, one pre-supplementation and one post-supplementation following 28 days of 6.4 g center dot day(-1) of beta-alanine (N=11) or placebo (N=6; maltodextrin). Muscle biopsies obtained pre- and post-supplementation were analysed for muscle carnosine content. There were no main effects on sprint performance throughout the intermittent cycling test (all P>0.05). There was no group (P=0.69), time (P=0.50) or group x time interaction (P=0.26) on time-to-complete the 4-km time-trial. Time-to-completion did not change from pre- to post-supplementation for BA (-19.2 +/- 45.6 s, P=0.43) or PL (+2.8 +/- 31.6 s, P=0.99). Beta-alanine supplementation increased muscle carnosine content from pre- to post-supplementation (+9.4 +/- 4.0 mmol center dot kg(-1)dm; P<0.0001) but was not related to performance changes (r=0.320, P=0.37). Chronic beta-alanine supplementation increased muscle carnosine content but did not improve short-duration sprint performance throughout simulated road race cycling, nor 4-km uphill time-trial performance conducted at the end of this cycling test.
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