BRYAN SAUNDERS
Projetos de Pesquisa
Unidades Organizacionais
LIM/17 - Laboratório de Investigação em Reumatologia, Hospital das Clínicas, Faculdade de Medicina
10 resultados
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- 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.
- Is Bypassing the Stomach a Means to Optimize Sodium Bicarbonate Supplementation? A Case Study With a Postbariatric Surgery Individual(2018) OLIVEIRA, Luana Farias de; SAUNDERS, Bryan; ARTIOLI, Guilherme GianniniSodium bicarbonate (SB) is an ergogenic supplement shown to improve high-intensity exercise via increased blood bicarbonate buffering. Substantial amounts of the ingested bicarbonate are neutralized in the stomach. Bariatric surgery results in a small gastric pouch which dramatically reduces exposure time of any ingested food in the stomach. The aim of this study was to examine the pharmacokinetics of orally ingested SB in a postgastric bypass individual to determine the magnitude of changes in blood bicarbonate and associated side effects. We hypothesized that SB supplementation in a gastric bypass model would result in greater blood bicarbonate increases and fewer side effects than in healthy individuals due to minimal bicarbonate losses in the stomach. One postbariatric male ingested 0.3 g/kg.body mass of SB on three occasions (SB1, SB2, and SB3) and 0.3 g/kg.body mass of placebo on a further occasion. Blood bicarbonate was determined before and every 10 min following supplement ingestion for 3 hr and then every 20 min for a further 1 hr. Side effects were reported using an adapted questionnaire at identical time points. Maximal increases in blood bicarbonate with SB were +20.0, +15.2, and +12.6 mM, resulting in maximal bicarbonate concentrations of 42.8, 39.3, and 36.2 mM. Area under the curve was SB1: 8,328 mM/min; SB2: 7,747 mM/min; SB3: 7,627 mM/min, and 6,436 mM/min for placebo. Side effects with SB were scarce. Maximal bicarbonate increases were well above those shown previously, with minimal side effects, indicative of minimal neutralization of bicarbonate in the stomach. The large increases in circulating bicarbonate and minimal side effects experienced by our postgastric surgery bypass patient are indicative that minimizing neutralization of bicarbonate in the stomach, as would occur with enteric coated capsules, may optimize SB supplementation and thus warrants investigation.
- Comment on ""CYP1A2 Genotype Modifies the Effects of Caffeine Compared With Placebo on Muscle Strength in Competitive Male Athletes""(2022) BARRETO, Gabriel; ESTEVES, Gabriel P.; MARTICORENA, Felipe Miguel; SAUNDERS, Bryan
- Caffeine Mouth Rinse Does Not Improve Time to Exhaustion in Male Trained Cyclists(2021) NABUCO, Lara Lima; SAUNDERS, Bryan; SILVA, Renato Andre Sousa da; MOLINA, Guilherme Eckhardt; REIS, Caio Eduardo GoncalvesThis study investigated the effects of caffeine mouth rinse on cycling time to exhaustion (TTE) and physiological responses in trained cyclists. In a double-blinded randomized counterbalanced cross-over design, 10 recreationally trained male cyclists (mean +/- SD: 32 +/- 3 years, 72.8 +/- 5.3 kg, 1.78 +/- 0.06 m, 13.9%+/- 3.3% body fat, peak power output = 289.4 +/- 24.7 W) completed two TTE tests cycling at 75% of peak aerobic power following 24 hr of dietary and exercise standardization. Cyclists were administered 25-ml mouth rinses for 5 s containing either 85 mg of caffeine or control (water) every 5 min throughout the exercise tests. No significant improvement in TTE was shown with caffeine mouth rinse compared with control (33:24 +/- 12:47 vs. 28:08 +/- 10:18min; Cohen's dz effect size: 0.51, p =.14). Caffeinemouth rinse had no significant effect on ratings of perceived exertion (p =.31) or heart rate (p =.35) throughout the cycling TTE protocol. These data indicate that a repeated dose of caffeinated mouth rinse for 5 s does not improve cycling TTE in recreationally trained male cyclists. However, these findings should be taken with caution due to the small sample size and blinding ineffectiveness, while further well-design studies with larger samples are warranted.
- Single and Serial Carbohydrate Mouth Rinsing Do Not Improve Yo-Yo Intermittent Recovery Test Performance in Soccer Players(2022) NEHME, Rafaela; BRANCO, Flavia M. S. de; VIEIRA, Publio F.; GUIMARAES, Ana Vitoria C.; GOMES, Gederson K.; TEIXEIRA, Gabriela P.; RODRIGUES, Pedro H.; CASTRO JUNIOR, Leonardo M. de; PUGA, Guilherme M.; SAUNDERS, Bryan; OLIVEIRA, Erick P. deCarbohydrate (CHO) mouth rinsing seems to improve performance in exercises lasting 30-60 min. However, its effects on intermittent exercise are unclear. It is also unknown whether serial CHO mouth rinses can promote additional ergogenic effects when compared with a single mouth rinse. The aim of this study was to evaluate the effect of single and serial CHO mouth rinses on Yo-Yo Intermittent Recovery Test Level 1 (Yo-Yo IR1) performance in soccer players. In a randomized, crossover, double-blind, placebo-controlled design, 12 male (18.9 +/- 0.5 years) soccer players performed eight serial mouth rinses under three different conditions: placebo solution only (noncaloric juice), seven placebo mouth rinses plus a single CHO mouth rinse (8% maltodextrin), or eight CHO mouth rinses (8-CHO). Following the final mouth rinse, individuals performed the Yo-Yo IR1 test to evaluate the maximal aerobic endurance performance measured via total distance covered. There were no differences in Yo-Yo IR1 performance between sessions (p = .32; single CHO mouth rinse (8% maltodextrin): 1,198 +/- 289 m, eight CHO mouth rinses: 1,256 +/- 253 m, placebo: 1,086 +/- 284 m). In conclusion, single and serial CHO mouth rinsing did not improve performance during the Yo-Yo IR1 for soccer players. These data suggest that CHO mouth rinsing is not an effective ergogenic strategy for intermittent exercise performance irrespective of the number of rinses.
- Evening Caffeine Did Not Improve 100-m Swimming Time Trials Performed 60 Min Post-Ingestion or the Next Morning After Sleep(2022) NEWBURY, Josh W.; SAUNDERS, Bryan; GOUGH, Lewis A.The potential ergogenic benefits of caffeine (CAF) are well known within the athletic community, often leading to its use in adolescent swimming cohorts to enhance their performance. However, it has previously been reported that CAF has sleepdisturbing effects, which could be detrimental to performance over consecutive days in multiday competitions. Moreover, the effects that evening CAF ingestion has on sleep, side effects, and next- day performances are yet to be researched in trained adolescents. In a double-blind, randomized, crossover design, eight national- level swimmers (age: 18 +/- 1 years, height: 1.76 +/- 0.06 cm, body mass [BM]: 69.4 +/- 6.4 kg) ingested a capsule containing 3 mg/kg BMCAF or a placebo 60 min before an evening 100-m swimming time trial. The next morning, sleep was analyzed (Core Consensus Sleep Diary) and 100-m time trials were repeated. Side effects were analyzed via visual analog scales throughout the study. No differences were found for swimming performance (p =.911) in the evening (CAF: 59.5 +/- 7.8 s, placebo: 59.9 +/- 7.9 s, g = 0.06) or morning (CAF: 59.7 +/- 7.7 s, placebo: 60.2 +/- 7.9 s, g = 0.07). In addition, no group differences were found for any subjective side effects (e.g., anxiety: p =.468, tachycardia: p =.859, alertness: p =.959) or sleep parameters (e.g., sleep latency: p =.395, total sleep time: p =.574). These results question the use of a standardized 3 mg/ kg BM CAF ingestion strategy for 100-m swimming time trials in trained adolescents, although objective measures may be needed to confirm that CAF does not affect sleep within this cohort.
- Individual Participant Data Meta-Analysis Provides No Evidence of Intervention Response Variation in Individuals Supplementing With Beta-Alanine(2021) ESTEVES, Gabriel Perri; SWINTON, Paul; SALE, Craig; JAMES, Ruth M.; ARTIOLI, Guilherme Giannini; ROSCHEL, Hamilton; GUALANO, Bruno; SAUNDERS, Bryan; DOLAN, EimearCurrently, 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 (sigma(IR) = 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 (R) Workouts and Dietary and Supplementation Interventions to Guide Nutritional Strategies and Future Research in CrossFit (R)(2021) SOUZA, Ricardo Augusto Silva de; SILVA, Andre Guedes da; SOUZA, Magda Ferreira de; SOUZA, Liliana Kataryne Ferreira; ROSCHEL, Hamilton; SILVA, Sandro Fernandes da; SAUNDERS, BryanCrossFit (R) is a high-intensity functional training method consisting of daily workouts called ""workouts of the day."" No nutritional recommendations exist for Crosspit (R) 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 (R) and (b) the effects of nutritional strategies on CrossFit (R) performance to guide nutritional recommendations for optimal recovery, adaptations, and performance for Crosspit (R) athletes and direct future research in this emerging area. Three databases were searched for studies that investigated physiological responses to CrossFit (R) and dietary or supplementation interventions on CrossFit (R) performance. Various physiological measures revealed the intense nature of all CrossFit (R) 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 (R) 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 (R) 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 (R) athletes and is an exciting avenue for further research.
- Warm-Up Intensity Does Not Affect the Ergogenic Effect of Sodium Bicarbonate in Adult Men(2021) JONES, Rebecca L.; STELLINGWERFF, Trent; SWINTON, Paul; ARTIOLI, Guilherme Giannini; SAUNDERS, Bryan; SALE, CraigThis study determined the influence of a high- (HI) versus low-intensity (LI) cycling warm-up on blood acid-base responses and exercise capacity following ingestion of sodium bicarbonate (SB; 0.3 g/kg body mass) or a placebo (PLA; maltodextrin) 3 hr prior to warm-up. Twelve men (21 +/- 2 years, 79.2 +/- 3.6 kg body mass, and maximum power output [W-max] 318 +/- 36 W) completed a familiarization and four double-blind trials in a counterbalanced order: HI warm-up with SB, HI warm-up with PLA, LI warm-up with SB, and LI warm-up with PLA. LI warm-up was 15 min at 60% W-max, while the HI warm-up (typical of elites) featured LI followed by 2 x 30 s (3-min break) at W-max, finishing 30 min prior to a cycling capacity test at 110% W-max. Blood bicarbonate and lactate were measured throughout. SB supplementation increased blood bicarbonate (+6.4 mmol/L; 95% confidence interval, CI [5.7, 7.1]) prior to greater reductions with HI warm-up (-3.8 mmol/L; 95% CI [-5.8, -1.8]). However, during the 30-min recovery, blood bicarbonate rebounded and increased in all conditions, with concentrations similar to 5.3 mmol/L greater with SB supplementation (p <.001). Blood bicarbonate significantly declined during the cycling capacity test at 110% W-max with greater reductions following SB supplementation (-2.4 mmol/L; 95% CI [-3.8, -0.90]). Aligned with these results, SB supplementation increased total work done during the cycling capacity test at 110% W-max (+8.5 kJ; 95% CI [3.6, 13.4], similar to 19% increase) with no significant main effect of warm-up intensity (+0.0 kJ; 95% CI [-5.0, 5.0]). Collectively, the results demonstrate that SB supplementation can improve HI cycling capacity irrespective of prior warm-up intensity, likely due to blood alkalosis.
- Dietary ?-Alanine Intake Assessed by Food Records Does Not Associate With Muscle Carnosine Content in Healthy, Active, Omnivorous Men and Women(2023) REZENDE, Nathalia Saffioti; BESTETTI, Giulia Cazetta; OLIVEIRA, Luana Farias de; MAZZOLANI, Bruna Caruso; SMAIRA, Fabiana Infante; DUMAS, Alina; SWINTON, Paul; SAUNDERS, Bryan; DOLAN, Eimearbeta-Alanine (BA) is one of the most widely used sport supplements, due to its capacity to improve high-intensity exercise performance by increasing muscle carnosine (MCarn) content, and consequently, the buffering capacity of the muscle. BA is also available in a variety of animal foods, but little is currently known about the influence of dietary BA intake on MCarn. The aim of the current study was to compile a detailed summary of available data on the BA content of commonly consumed foods, and to explore whether associations could be detected between self-reported dietary BA intake and skeletal MCarn in a group of 60 healthy, active, omnivorous men and women. Dietary BA intake was assessed via 3-day food records, and MCarn content assessed by high-performance liquid chromatography. A series of univariate and multivariate linear regression models were used to explore associations between estimated dietary BA and MCarn. No evidence of associations between dietary BA intake and MCarn were identified, with effect sizes close to zero calculated from models accounting for key demographic variables (f2 <= 0.02 for all analyses). These findings suggest that capacity to increase MCarn via dietary strategies may be limited, and that supplementation may be required to induce increases of the magnitude required to improve performance.