BRYAN SAUNDERS
Projetos de Pesquisa
Unidades Organizacionais
LIM/17 - Laboratório de Investigação em Reumatologia, Hospital das Clínicas, Faculdade de Medicina
15 resultados
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- Directions for Future Studies to Determine Dietary Nitrate Efficacy in Female Athletes(2023) CARVALHO, Arthur; DUARTE, Breno; ELLIOTT-SALE, Kirsty Jayne; SAUNDERS, Bryan
- 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
- Effects of caffeine chewing gum supplementation on exercise performance: A systematic review and meta-analysis(2023) BARRETO, G.; LOUREIRO, L. M. R.; REIS, C. E. G.; SAUNDERS, B.The aim of this systematic review with meta-analysis was to determine the effect of caffeine gum (Caff-gum) on exercise performance-related outcomes. Several databases were searched for studies assessing the effect of Caff-gum in placebo-controlled protocols involving healthy adults. Random-effects meta-analyses using standardized mean differences (SMD) were performed to determine the effect of Caff-gum on exercise outcomes with several sub-analyses (training status, exercise type, timing and dose) for potential modifying factors. 14 studies were included, totalling 200 participants. There was a significant overall effect of Caff-gum compared to placebo (SMD = 0.21, 95%CI: 0.10-0.32; p = 0.001). Subgroup analysis showed improved performance for trained (SMD = 0.23, 95%CI: 0.08-0.37; p = 0.004), but not for untrained (SMD = 0.14, 95%CI: -0.02-0.29; p = 0.07) individuals. Caff-gum improved both endurance (SMD = 0.27, 95%CI: 0.12-0.42; p = 0.002) and strength/power (SMD = 0.20, 95%CI: 0.03-0.37; p = 0.03) performance outcomes. Caff-gum was ergogenic when consumed within 15 min prior to initiating exercise (SMD = 0.27, 95%CI: 0.07-0.4; p = 0.01), but not when provided >15 min prior (SMD = -0.48, 95%CI = -1.7-0.82; p = 0.25). There was no significant effect of Caff-gum with doses <3 mg/kg body mass (BM) (SMD = 0.20, 95%CI: -0.03-0.43; p = 0.07), but there was a significant effect when the dose was >= 3 mg/kg BM (SMD = 0.22, 95%CI: 0.07-0.37; p = 0.01). Caff-gum supplementation may be an effective ergogenic strategy for trained athletes involved in both endurance and strength/power exercise, using a recommended dose of >= 3 mg/kg BM consumed within 15 min of initiating exercise.
- The interplay between bicarbonate kinetics and gastrointestinal upset on ergogenic potential after sodium bicarbonate intake: a randomized double-blind placebo-controlled trial(2023) DURKALEC-MICHALSKI, Krzysztof; NOWACZYK, Paulina M.; KAMINSKA, Joanna; SAUNDERS, Bryan; LONIEWSKI, Igor; CZUBASZEK, Dominika; STEFFL, Michal; PODGORSKI, TomaszThis double-blind placebo-controlled cross-over study utilized comprehensive monitoring of blood bicarbonate (HCO3 over bar ) kinetics and evaluation of gastrointestinal (GI) upset to determine their impact on an ergogenic potential of sodium bicarbonate (SB) co-ingested with carbohydrate (CHO). Nineteen CrossFit athletes performed 6 bouts of 15 s Wingate Anaerobic Test (WAnT) 90 min post-ingestion of 0.4 g center dot kg(-1) body mass (BM) of SB (SB + CHO treatment) or PLA (PLA + CHO treatment) with 15 g CHO. Blood HCO3 over bar concentration was evaluated at baseline, 30-, 60-, 75- and 90 min post-ingestion, in between WAnT bouts, and 3 and 45 min post-exercise, while GI upset at 120 min after protocol started. Control (no supplementation; CTRL) procedures were also performed. An effective elevation of extra-cellular buffering capacity was observed 60-90 min post-ingestion of SB + CHO. At mean peak blood HCO3 over bar , or at start of exercise an increase > 6 mmol center dot L-1 in HCO3 over bar was noted in 84% and 52.6% participants, respectively. SB + CHO did not prevent performance decrements in WAnT bouts. There were no significant relationships between changes in blood HCO3 over bar and WAnTs' performance. Total GI was significantly higher in SB + CHO compared to CTRL, and stomach problems in SB + CHO compared to CTRL and PLA + CHO. There were inverse associations between peak- (p = 0.031; r = - 0.495), average- (p = 0.002; r = - 0.674) and minimum power (p = 0.008; r = - 0.585) and total GI upset, as well as average power and severe GI distress (p = 0.042; r = - 0.471) at SB + CHO. The implemented dose of SB + CHO was effective in improving buffering capacity, but did not prevent decrements in WAnTs' performance. GI side effects were crucial in affecting the ergogenic potential of SB and thus must be insightfully monitored in future studies.
- A cloth facemask increased ratings of perceived exertion and reduced affect, without affecting sprint or muscular performance(2023) DANTAS, Matheus; BARBOZA-NETO, Rui; GUARDIEIRO, Natalia Mendes; PINTO, Ana Lucia de Sa; GUALANO, Bruno; SAUNDERS, BryanWe determined the effects of wearing a cloth facemask on exercise performance and subjective responses during training of track and field athletes. Track and field athletes (n = 10, sprinters and long jumpers) performed two training sessions with and without a three-layered antiviral cloth facemask. The training session simulated the specific demands of the sport, consisting of five 30-m sprints, interspersed with passive 4-min intervals. Countermovement jump performance was assessed pre- and post-sprints, and ratings of perceived exertion (RPE) and affect were collected throughout. There was no evidence of condition*time interactions for sprint time (P = 0.21) or acceleration (P = 0.47). There was weak evidence of a condition effect on RPE (P = 0.05), though no condition*time interaction (P = 0.35). There was moderate evidence of a condition*time interaction for affect (P = 0.02), with lower ratings following sprints 3, 4 and 5 when using the mask. These findings suggest that wearing a mask may negatively impact subjective feelings of training without necessarily harming sprint performance.
- Performing moderate to severe activity is safe and tolerable for healthy youth while wearing a cloth facemask(2023) MARTICORENA, Felipe Miguel; BARRETO, Gabriel Castanho; GUARDIEIRO, Natalia Mendes; ESTEVES, Gabriel Perri; OLIVEIRA, Tamires Nunes; OLIVEIRA, Luana Farias de; PINTO, Ana Lucia de Sa; RIANI, Luiz; PRADO, Danilo Mendes; SAUNDERS, Bryan; GUALANO, BrunoObjectiveTo investigate if a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in healthy young individuals. MethodsNine participants (sex, female/male: 6/3; age: 13 +/- 1 years; VO2peak: 44.5 +/- 5.5 mL/kg/min) underwent a progressive square-wave test at four intensities: (1) 80% of ventilatory anaerobic threshold (VAT), (2) VAT, and (3) 40% between VAT and _VO2peak wearing a triple-layered cloth facemask or not. Participants then completed a final stage to exhaustion at a running speed equivalent to the maximum achieved during the cardio-respiratory exercise test (Peak). Physiological, metabolic, and perceptual measures were measured. ResultsMask did not affect spirometry (forced vital capacity, peak expiratory flow, forced expiratory volume; all p >= 0.27), respiratory (inspiratory capacity, end-expiratory volume [EELV] to functional vital capacity ratio, EELV, respiratory frequency [Rf], tidal volume [VT], Rf/VT, end tidal carbo dioxide pressure, ventilatory equivalent to carbon dioxide ratio; all p >= 0.196), hemodynamic (heart rate, systolic and diastolic blood pressure; all p > 0.41), ratings of perceived exertion (p = 0.04) or metabolic measures (lactate; p = 0.78) at rest or at any exercise intensity. ConclusionsThis study shows that performing moderate to severe activity is safe and tolerable for healthy youth while wearing a cloth facemask.
- Spit It Out: Is Caffeine Mouth Rinse an Effective Ergogenic Aid? A Systematic Review and Meta-Analysis(2023) NABUCO, Lara Lima; MENDES, Guilherme Falcao; BARRETO, Gabriel; SAUNDERS, Bryan; REIS, Caio Eduardo GoncalvesThe effects of caffeine mouth rinse (Caff-MR) on sports performance have been evaluated by recent studies presenting contrasting results. Therefore, this systematic review aimed to summarize the evidence regarding the effects of Caff-MR on sports performance. According to Preferred Reporting Items for Systematic Reviews and Meta-Analyses recommendations, the search through PubMed, Web of Science, and Scopus databases was performed until December 2021. A random-effects meta-analysis of standardized mean differences was performed to assess the overall effect of Caff-MR on sports performance-related outcomes. Sixteen studies met the inclusion criteria (207 participants). The meta-analysis showed no significant overall effect of Caff-MR on sports performance (p = 0.09). Moreover, no effects were shown on maximal heart rate or ratings of perceived exertion. The risk of bias for the included studies assessed using the risk of bias in randomized trials Cochrane tool presented 87.5% (n = 14) of the studies as medium and 12.5% (n = 2) as high scores. These data do not support using Caff-MR for sports performance, although more consistent and well-controlled studies are warranted. Large heterogeneity in study designs precludes making practical recommendations for exercise performance. More research is warranted to elucidate the potential of Caff-MR, specifically focusing on determining the optimal dose.
- A Cloth Facemask Causes No Major Respiratory or Cardiovascular Perturbations During Moderate to Heavy Exercise(2023) GUARDIEIRO, Natalia Mendes; BARRETO, Gabriel; MARTICORENA, Felipe Miguel; OLIVEIRA, Tamires Nunes; OLIVEIRA, Luana Farias de; PINTO, Ana Lucia de Sa; PRADO, Danilo Marcelo Leite do; SAUNDERS, Bryan; GUALANO, BrunoPurpose: Investigate whether a cloth facemask could affect physiological and perceptual responses to exercise at distinct exercise intensities in untrained individuals. Methods: Healthy participants (n = 35; 17 men, age 30 [4] y, and 18 women, age 28 [5] y) underwent a progressive square wave test at 4 intensities: (1) 80% of ventilatory anaerobic threshold; (2) ventilatory anaerobic threshold; (3) respiratory compensation point; and (4) exercise peak (Peak) to exhaustion, 5-minute stages, with or without a triple-layered cloth facemask (Mask or No-Mask). Several physiological and perceptual measures were analyzed. Results: Mask reduced inspiratory capacity at all exercise intensities (P < .0001). Mask reduced respiratory frequency (P = .001) at Peak (-8.3 breaths-min-1; 95% confidence interval [CI], -5.8 to -10.8), respiratory compensation point (-6.9 breaths-min-1; 95% CI, - 4.6 to -9.2), and ventilatory anaerobic threshold (-6.5 breaths-min-1; 95% CI, -4.1 to -8.8), but not at Baseline or 80% of ventilatory anaerobic threshold. Mask reduced tidal volume (P < .0001) only at respiratory compensation point (-0.5 L; 95% CI, - 0.3 to -0.6) and Peak (-0.8 L; 95% CI, -0.6 to -0.9). Shallow breathing index was increased with Mask only at Peak (11.3; 95% CI, 7.5 to 15.1). Mask did not change HR, lactate, ratings of perceived exertion, blood pressure, or oxygen saturation. Conclusions: A cloth facemask reduced time to exhaustion but had no major impact on cardiorespiratory parameters and had a slight but clinically meaningless impact on respiratory variables at higher intensities. Moderate to heavy activity is safe and tolerable for healthy individuals while wearing a cloth facemask. ClinicalTrials.gov: NCT04887714.
- DO YOU HAVE TO LIE TO INDUCE PLACEBO EFFECTS?: The use of open label placebos in sport and exercise(2023) SAUNDERS, B.; MARTICORENA, F. M.; GUALANO, B.The use of deceptive placebo in practice is inherently fraught with ethical constraints and trust issues, meaning that alternative methods must be employed in practice. This has led to the development of an alternative approach through which placebo effects might be generated, namely open-label placebo (also called “honest placebo”). This method consists of openly informing the individual that they are receiving an inert intervention (i.e., a placebo). While there is a growing body of evidence demonstrating the efficacy of this method in clinical practice, data in sport and exercise remain scarce. In this chapter, we discuss the use of open-label placebo as a potential ergogenic intervention in the context of exercise and sports, we propose theoretical mechanisms through which they work, and we place an emphasis on practical applications and research gaps in this emerging area of research. © 2024 selection and editorial matter, Philip Hurst and Chris Beedie; individual chapters, the contributors.
- Carbohydrates and Endurance Exercise: A Narrative Review of a Food First Approach(2023) NADERI, Alireza; GOBBI, Nathan; ALI, Ajmol; BERJISIAN, Erfan; HAMIDVAND, Amin; FORBES, Scott C.; KOOZEHCHIAN, Majid S.; KARAYIGIT, Raci; SAUNDERS, BryanCarbohydrate (CHO) supplements such as bars, gels, drinks and powders have become ubiquitous as effective evidence-based CHO sources that improve endurance exercise performance. However, athletes are increasingly turning to more cost-effective 'food-first' approaches for CHO ingestion to improve exercise performance. Mixed CHO foods including cooked lentils, oats, honey, raisins, rice, and potatoes are all effective pre-exercise CHO food sources. Caution is advised when selecting some of these foods as a primary CHO source, as some athletes may be prone to gastrointestinal discomfort-especially regarding those foods where the quantities required for recommended CHO intake may be voluminous (e.g., potatoes). Palatability may be another barrier to the ingestion of some of these CHO-rich foods. Although most of these CHO-rich foods appear effective for exercise performance or recovery when consumed pre- and post-exercise, not all are viable to ingest during exercise due to difficulties in the quantities required, transport, and/or gastrointestinal discomfort. Raisins, bananas and honey may be particularly useful CHO foods for consumption during exercise, as they are easily transportable. Athletes should trial CHO food sources before, during and/or following training before implementation during competition.