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INTRODUCTION: Sodium bicarbonate (NaHCO3) ingestion has been found to be ergogenic in high-intensity exercise that ranges from 1 to 10 min; however, limited studies have investigated high-intensity exercise beyond this duration. PURPOSE: The present study aimed to determine the effect of NaHCO3 ingested using a carbohydrate hydrogel delivery system on 40 km time trial (TT) performance in trained male cyclists. METHODS: Fourteen trained male cyclists ingested 0.3 g kg-1 BM NaHCO3 (Maurten AB, Sweden) to determine individualised peak alkalosis, which established time of ingestion prior to exercise. Participants completed a 40 km familiarisation TT, and two 40 km experimental TTs after ingestion of either NaHCO3 or placebo in a randomised, double-blind, crossover design. RESULTS: NaHCO3 supplementation improved performance (mean improvement = 54.14 s ± 18.16 s; p = 0.002, g = 0.22) and increased blood buffering capacity prior to (HCO3- mean increase = 5.6 ± 0.2 mmol L-1, p < 0.001) and throughout exercise (f = 84.82, p < 0.001, pη2 = 0.87) compared to placebo. There were no differences in total gastrointestinal symptoms (GIS) between conditions either pre- (NaHCO3, 22 AU; Placebo, 44 AU; p = 0.088, r = 0.46) or post-exercise (NaHCO3, 76 AU; Placebo, 63 AU; p = 0.606, r = 0.14). CONCLUSION: The present study suggests that ingesting NaHCO3 mini-tablets in a carbohydrate hydrogel can enhance 40 km TT performance in trained male cyclists, with minimal GIS. This ingestion strategy could therefore be considered by cyclists looking for a performance enhancing ergogenic aid.
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PURPOSE: The use of sodium bicarbonate (SB) as a preexercise ergogenic aid has been extensively studied in short-duration high-intensity exercise. Very few studies have considered the effects of SB ingestion before prolonged high-intensity exercise. The aim of the present study was to determine the effects of a 0.3 g·kg -1 body mass dose of SB ingested before the start of a 16.1-km cycling time trial in cyclists. METHOD: Ten trained male cyclists (age, 31.1 ± 9 yr; height, 1.84 ± 0.05 m; body mass, 82.8 ± 8.5 kg; and VÌO 2peak , 60.4 ± 3.1 mL·kg -1 ·min -1 ) completed this study. Participants ingested 0.3 g·kg -1 in gelatine (SB-G) and enteric capsules (SB-E) 1 wk apart to determine individualized time-to-peak alkalosis for each ingestion form. Using a randomized crossover design, participants then performed simulated 16.1-km time trials after ingestion of SB-G, SB-E, or a placebo. RESULTS: There were significant differences in performance between the SB and placebo ingestion strategies ( f = 5.50, P = 0.014, p η2 = 0.38). Performance time was significantly improved by SB ingestion (mean improvement: 34.4 ± 42.6 s ( P = 0.031) and 40.4 ± 45.5 s ( P = 0.020) for SB-G and SB-E, respectively) compared with the placebo. Gastrointestinal symptoms were lower after SB-E compared with SB-G (36.3 ± 4.5 vs 5.6 ± 3.1 AU, P < 0.001, g = 7.09). CONCLUSIONS: This study demonstrates that increased buffering capacity after acute preexercise SB ingestion can improve endurance cycling time-trial performances. The use of SB could be considered for use in 16.1-km cycling time trials, but further work is required to establish these effects after a preexercise meal.
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Alcalose , Bicarbonato de Sódio , Adulto , Humanos , Masculino , Adulto Jovem , Ciclismo , Estudos Cross-Over , Suplementos Nutricionais , Método Duplo-Cego , Ingestão de AlimentosRESUMO
BACKGROUND: Computed tomography (CT) is an essential diagnostic tool for severe multi-trauma patients. International guidelines recommend an optimal time of 1 h from arrival. The aim of this study was to determine the time interval from arrival at the emergency department to CT for all trauma patients and the effects on in-hospital mortality and hospital length of stay. METHODS: Retrospective study of all patients who triggered a trauma call and underwent CT scanning at the Gold Coast University Hospital from January 2016 to December 2017. Exclusion criteria were scans performed at peripheral hospitals or performed more than 5 h after arrival to emergency department. RESULTS: One thousand six hundred and nineteen eligible trauma patients were admitted over the study period and underwent CT scanning. Median time to CT was found to be 43 min. CTs done within 1 h compared to those done after 1 h from emergency department arrival were found to have a higher mean injury severity score (11 ± 10 versus 9 ± 9, P = 0.003), a longer mean hospital length of stay (9 ± 21 versus 7 ± 13 days, P = 0.012) and no difference in mortality rates (2.2% versus 2.1%, P = 1.000). Age, injury severity score and intubation status were identified as independent predictors for longer hospital length of stay and higher mortality while time to CT did not. Injury severity score was shown to be an independent predictor of time to CT. CONCLUSION: Our time to CT scanning is well within the timeframe recommended by international guidelines. Early CT scanning may also improve outcomes in severely injured trauma patients.
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Traumatismo Múltiplo/diagnóstico por imagem , Traumatismo Múltiplo/mortalidade , Tomografia Computadorizada por Raios X , Adolescente , Adulto , Austrália , Criança , Pré-Escolar , Serviço Hospitalar de Emergência , Feminino , Mortalidade Hospitalar , Humanos , Lactente , Escala de Gravidade do Ferimento , Masculino , Estudos Retrospectivos , Fatores de Tempo , Centros de Traumatologia , Adulto JovemRESUMO
Graphene foams are leading contenders as frameworks for polymer thermosets, filtration/pollution control and for use as an electrode material in energy storage devices, taking advantage of graphene's high electrical conductivity and the porous structure of the foam. Here we demonstrate a simple synthesis of a macroporous 3D graphene material templated from a dextran/metal salt gel, where the metal was cobalt, nickel, copper, and iron. The gel was annealed to form a metal oxide foam prior to a methane chemical vapour deposition (CVD). Cobalt metal gels were shown to afford the highest quality material as determined by electron microscopy (SEM and TEM) and Raman spectroscopy.