BRYAN SAUNDERS
Projetos de Pesquisa
Unidades Organizacionais
LIM/17 - Laboratório de Investigação em Reumatologia, Hospital das Clínicas, Faculdade de Medicina
63 resultados
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Agora exibindo 1 - 10 de 63
- Effects of Sodium Bicarbonate Supplementation on Muscular Strength and Endurance: A Systematic Review and Meta-analysis(2020) GRGIC, Jozo; RODRIGUEZ, Ramon F.; GAROFOLINI, Alessandro; SAUNDERS, Bryan; BISHOP, David J.; SCHOENFELD, Brad J.; PEDISIC, ZeljkoBackground The effects of sodium bicarbonate on muscular strength and muscular endurance are commonly acknowledged as unclear due to the contrasting evidence on the topic. Objective To conduct a systematic review and meta-analysis of studies exploring the acute effects of sodium bicarbonate supplementation on muscular strength and endurance. Methods A search for studies was performed using five databases. Meta-analyses of standardized mean differences (SMDs) were performed using a random-effects model to determine the effects of sodium bicarbonate supplementation on muscular strength (assessed by changes in peak force [N], peak torque [N m], or maximum load lifted [kg]) and muscular endurance (assessed by changes in the number of repetitions performed, isokinetic total work, or time to maintain isometric force production). Subgroup meta-analyses were conducted for the muscular endurance of small vs. large muscle groups and muscular strength tested in a rested vs. fatigued state. A random-effects meta-regression analysis was used to explore possible trends in the effects of: (a) timing of sodium bicarbonate ingestion; and (b) acute increase in blood bicarbonate concentration (from baseline to pre-exercise), on muscular endurance and muscular strength. Results Thirteen studies explored the effects of sodium bicarbonate on muscular endurance and 11 on muscular strength. Sodium bicarbonate supplementation was found to be ergogenic for muscular endurance (SMD = 0.37; 95% confidence interval [CI]: 0.15, 0.59; p = 0.001). The performance-enhancing effects of sodium bicarbonate were significant for both small (SMD = 0.31; 95% CI: 0.04, 0.59; p = 0.025) and large muscle groups (SMD = 0.40; 95% CI: 0.13, 0.66; p = 0.003). Sodium bicarbonate ingestion was not found to enhance muscular strength (SMD = - 0.03; 95% CI: - 0.18, 0.12; p = 0.725). No significant effects were found regardless of whether the testing was carried out in a rested (SMD = 0.02; 95% CI: - 0.09, 0.13; p = 0.694) or fatigued (SMD = - 0.16; 95% CI: - 0.59, 0.28; p = 0.483) state. No significant linear trends in the effects of timing of sodium bicarbonate ingestion or acute increase in blood bicarbonate concentrations on muscular endurance or muscular strength were found. Conclusions Overall, sodium bicarbonate supplementation acutely improves muscular endurance of small and large muscle groups, but no significant ergogenic effect on muscular strength was found.
- Reply to Areta et al.: Time to withdraw and let the myth rest(2017) GUALANO, B.; GONCALVES, L. D. S.; PAINELLI, V. D. S.; YAMAGUCHI, G.; OLIVEIRA, L. F. de; SAUNDERS, B.; SILVA, R. P. da; MACIEL, E.; ARTIOLI, G. G.; ROSCHEL, H.
- Sodium Bicarbonate Supplementation Does Not Improve Running Anaerobic Sprint Test Performance in Semiprofessional Adolescent Soccer Players(2020) GUIMARAES, Rodrigo dos Santos; MORAIS JUNIOR, Alcides Correa de; SCHINCAGLIA, Raquel Machado; SAUNDERS, Bryan; PIMENTEL, Gustavo Duarte; MOTA, Joao FelipeErgogenic strategies have been studied to alleviate muscle fatigue and improve sports performance. Sodium bicarbonate (NaHCO3) has improved repeated sprint performance in adult team-sports players, but the effect for adolescents is unknown. The aim of the present study was to evaluate the effect of NaHCO3 supplementation on repeated sprint performance in semiprofessional adolescent soccer players. In a double-blind, placebo-controlled, crossover trial, 15 male semiprofessional adolescent soccer players (15 +/- 1 years; body fat 10.7 +/- 1.3%) ingested NaHCO3 or a placebo (sodium chloride) 90 min before performing the running anaerobic sprint test (RAST). A countermovement jump was performed before and after the RAST, and ratings of perceived exertion, blood parameters (potential hydrogen and bicarbonate concentration), and fatigue index were also evaluated. Supplementation with NaHCO3 promoted alkalosis, as demonstrated by the increase from the baseline to preexercise, compared with the placebo (potential hydrogen: +0.07 +/- 0.01 vs. -0.00 +/- 0.01, p < .001 and bicarbonate: +3.44 +/- 0.38 vs. -1.45 +/- 0.31 mmol/L, p < .001); however, this change did not translate into an improvement in RAST total time (32.12 +/- 0.30 vs. 33.31 +/- 0.41 s,p = .553); fatigue index (5.44 +/- 0.64 vs. 6.28 +/- 0.64 W/s, p = .263); ratings of perceived exertion (7.60 +/- 0.33 vs. 7.80 +/- 0.10 units, p = .525); countermovement jump pre-RAST (32.21 +/- 3.35 vs. 32.05 +/- 3.51 cm, p = .383); or countermovement jump post-RAST (31.70 +/- 0.78 vs. 32.74 +/- 1.11 cm, p = .696). Acute NaHCO3 supplementation did not reduce muscle fatigue or improve RAST performance in semiprofessional adolescent soccer players. More work assessing supplementation in this age getup is required to increase understanding in the area.
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.- Development of a Caffeine Content Table for Foods, Drinks, Medications and Supplements Typically Consumed by the Brazilian Population(2022) ROCHA, Pedro Lucas de Amorim; LIMA, Anna Luisa Caldeira; SAUNDERS, Bryan; REIS, Caio Eduardo GoncalvesBackground: The lack of a national table informing the caffeine contents in foods, drinks, dietary supplements, and medications sold in Brazil added to the noncompulsory disclosure of caffeine contents on labels of food products makes it difficult to estimate caffeine consumption in the Brazilian population. Therefore, this study aimed to develop the Brazilian Caffeine Content Table (BraCaffT). Methods: A systematic search for caffeine levels in foods, drinks, recipes, supplements, and medications was performed through a literature review, afterward collecting data from the United States Department of Agriculture Food Data Central, information from manufacturers' and websites, and the Brazilian official medication guide. Subsequently, data systematization was performed in a spreadsheet with standardized values presented in mg of caffeine per 100 g or 100 mL of food or drink and a capsule or pill for medications and some dietary supplements. Results: The BraCaffT presents 57 items, divided into 11 categories: coffees, teas and infusions, cocoa powder, chocolates, cocoa-based beverages, desserts, soft drinks, energy drinks, guarana powder, dietary supplements, and medications. Conclusions: The BraCaffT emerges as an instrument of great relevance and wide applicability in clinical contexts, in academic research, and as a database for the Brazilian population to better understand the amounts of caffeine in foods, drinks, dietary supplements, and medications consumed daily favoring a safe intake.
- 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- Reply to Zhang and Chen's Comment on ""Can I Have My Coffee and Drink It? A Systematic Review and Meta-analysis to Determine Whether Habitual Caffeine Consumption Affects the Ergogenic Effect of Caffeine""(2023) CARVALHO, Arthur; MARTICORENA, Felipe Miguel; GRECCO, Beatriz Helena; BARRETO, Gabriel; SAUNDERS, Bryan
- Extraceullular buffer choice influences acid-base responses and gastrointestinal symptoms(2021) PEACOCK, J.; SPARKS, S. A.; MIDDLEBROOK, I; HILTON, N. P.; TINNION, D.; LEACH, N.; SAUNDERS, B.; MCNAUGHTON, L. R.To compare the pharmokinetic and gastrointestinal (GI) symptom responses between an equal dose of sodium bicarbonate and sodium citrate using delayed-release capsules. Thirteen active males (age 20.5 +/- 2.1 y, height 1.82 +/- 0.1 m and body mass 76.5 +/- 9.6 kg) consumed either 0.3 g(.)kg(-1) BM sodium bicarbonate, sodium citrate or a placebo, using a double-blind, randomized crossover design. Blood bicarbonate [HCO3 (-)] concentration, pH and GI symptoms were measured pre-ingestion and every 10 min for 180 min post-consumption. [HCO3 (-)] concentration (P < 0.001) and pH (P = 0.040) were significantly higher in the sodium bicarbonate condition compared with sodium citrate condition up to 3 h post-consumption. Peak blood HCO3 (-) concentration was significantly higher with sodium bicarbonate compared with citrate (P < 0.001). Mean GI symptom scores were lower (P = 0.037) for sodium citrate (1.5 +/- 1.8 AU) than bicarbonate (2.6 +/- 3.1 AU), with considerable inter-individual variability. No GI symptoms were reported following consumption of the placebo. Both substances alter [HCO3 (-)] values significantly, with sodium bicarbonate causing significantly higher pH and [HCO3 (-)] values than the same dose of sodium citrate, but results in slightly more severe GI symptoms.