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Kristin L Jonvik, Jean Nyakayiru, Jan-Willem Van Dijk, Floris C Wardenaar, Luc J C Van Loon, Lex B Verdijk
Although beetroot juice, as a nitrate carrier, is a popular ergogenic supplement amongst athletes, nitrate is consumed through the regular diet as well. We aimed to assess the habitual dietary nitrate intake and identify the main contributing food sources in a large group of highly trained athletes. Dutch highly trained athletes (226 women and 327 men) completed 2-4 web-based 24-h dietary recalls and questionnaires within a 2-4 week period. The nitrate content of food products and food groups was determined systematically based on values found in regulatory reports and scientific literature...
October 21, 2016: International Journal of Sport Nutrition and Exercise Metabolism
Diego B Souza, Juan Del Coso, Juliano Casonatto, Marcos D Polito
PURPOSE: Caffeine-containing energy drinks (EDs) are currently used as ergogenic aids to improve physical performance in a wide variety of sport disciplines. However, the outcomes of previous investigations on this topic are inconclusive due to methodological differences, especially, in the dosage of the active ingredients and the test used to assess performance. METHODS: We performed a systematic review and meta-analysis of published studies to evaluate the effects of acute ED intake on physical performance...
October 18, 2016: European Journal of Nutrition
Cory W Baumann, Dongmin Kwak
PURPOSE: Echinacea is an herbal supplement used by endurance athletes for its performance boosting properties. It is thought that Echinacea improves the blood's oxygen carrying capacity by increasing production of erythropoietin (EPO), a glycoprotein that regulates red blood cell formation. Subsequently, these changes would lead to an overall improvement in maximal oxygen uptake (VO2max) and running economy (RE), two markers of aerobic fitness. The purpose of this review is to briefly discuss the physiological variables associated with distance running performance and how these variables are influenced by Echinacea supplementation...
September 2016: Journal of Exercise Nutrition & Biochemistry
James C Boyett, Gabrielle E W Giersch, Christopher J Womack, Michael J Saunders, Christine A Hughey, Hannah M Daley, Nicholas D Luden
This project was designed to assess the effects of time of day and training status on the benefits of caffeine supplementation for cycling performance. Twenty male subjects (Age, 25 years; Peak oxygen consumption, 57 mL·kg(-1)·min(-1)) were divided into tertiles based on training levels, with top and bottom tertiles designated as 'trained' (n = 7) and 'untrained' (n = 7). Subjects completed two familiarization trials and four experimental trials consisting of a computer-simulated 3-km cycling time trial (TT)...
October 14, 2016: Nutrients
Jason C Siegler, Paul W M Marshall, David Bishop, Greg Shaw, Simon Green
A large proportion of empirical research and reviews investigating the ergogenic potential of sodium bicarbonate (NaHCO3) supplementation have focused predominately on performance outcomes and only speculate about underlying mechanisms responsible for any benefit. The aim of this review was to critically evaluate the influence of NaHCO3 supplementation on mechanisms associated with skeletal muscle fatigue as it translates directly to exercise performance. Mechanistic links between skeletal muscle fatigue, proton accumulation (or metabolic acidosis) and NaHCO3 supplementation have been identified to provide a more targeted, evidence-based approach to direct future research, as well as provide practitioners with a contemporary perspective on the potential applications and limitations of this supplement...
December 2016: Sports Medicine—Open
Felipe D Lisbôa, Tiago Turnes, Rogério S O Cruz, João A G Raimundo, Gustavo S Pereira, Fabrizio Caputo
OBJECTIVES: The present study aimed to determine the effects of ischemic preconditioning on performance in three successive 50-m swimming trials and to measure stroke rate, stroke length and blood lactate accumulation. DESIGN: Counterbalanced, repeated-measures cross-over study. METHODS: On two separate days, eleven competitive male swimmers (20±3 years, 182±5cm, 77±5kg) performed three successive 50-m trials in a 50-m swimming pool, preceded by intermittent bilateral cuff inflation (4× 5-min of blood flow restriction+5-min of cuff deflation) at either 220 for thighs and 180mmHg for arms (ischemic preconditioning) or 20mmHg for both limbs (control-treatment)...
September 20, 2016: Journal of Science and Medicine in Sport
Katarzyna A Szcześniak, Anna Ciecierska, Piotr Ostaszewski, Tomasz Sadkowski
β-Hydroxy-β-methylbutyrate (HMB) is a popular ergogenic aid used by human athletes and as a supplement to sport horses, because of its ability to aid muscle recovery, improve performance and body composition. Recent findings suggest that HMB may stimulate satellite cells and affect expressions of genes regulating skeletal muscle cell growth. Despite the scientific data showing benefits of HMB supplementation in horses, no previous study has explained the mechanism of action of HMB in this species. The aim of this study was to reveal the molecular background of HMB action on equine skeletal muscle by investigating the transcriptomic profile changes induced by HMB in equine satellite cells in vitro...
October 2016: British Journal of Nutrition
Vitor de Salles Painelli, Antonio Herbert Lancha Junior
Sodium citrate (SCit) supplementation has been studied for several years as a strategy to reduce the muscle fatigue induced by H(+) ion accumulation within the skeletal muscle during high-intensity, short-duration exercise. Several investigations have been published on this matter, and appear to indicate that SCit is not effective as an ergogenic aid, despite its ability to increase extracellular buffering capacity. In this short report, we briefly discuss the SCit results previously published in the literature and consider them in light of new and promising findings, which appear to address issues associated with previous study designs...
September 27, 2016: British Journal of Sports Medicine
Christopher J Stevens, Lee Taylor, Ben J Dascombe
It is well established that endurance performance is negatively affected by environmental heat stress due to a complex interaction of physical, physiological and psychological alterations. Numerous scientific investigations have attempted to improve performance in the heat with pre-cooling (cooling prior to an exercise test), and as such this has become a well-established ergogenic practice for endurance athletes. However, the use of mid-cooling (cooling during an exercise test) has received considerably less research attention in comparison, despite recent evidence to suggest that the advantage gained from mid-cooling may outweigh that of pre-cooling...
September 27, 2016: Sports Medicine
Terri Susan Graham-Paulson, Thomas Andrew William Paulson, Claudio Perret, Keith Tolfrey, Philip Cordery, Victoria Louise Goosey-Tolfrey
PURPOSE: To investigate the absorption curve and acute effects of caffeine at rest in individuals with no spinal cord injury (SCI), paraplegia (PARA) and tetraplegia (TETRA). METHODS: Twenty-four healthy males (8 able-bodied (AB), 8 PARA and 8 TETRA) consumed 3 mg[BULLET OPERATOR]kg caffeine anhydrous (CAF) in a fasted state. Plasma caffeine [CAF], glucose, lactate, free-fatty acid [FFA] and catecholamine concentrations were measured during a 150 min rest period...
September 23, 2016: Medicine and Science in Sports and Exercise
Erica J Roelofs, Abbie E Smith-Ryan, Eric T Trexler, Katie R Hirsch, Meredith G Mock
The effects of pomegranate extract (PE) supplementation were evaluated on high-intensity exercise performance, blood flow, vessel diameter, oxygen saturation (SPO2), heart rate (HR), and blood pressure (BP). In a randomized, crossover design, nineteen recreationally resistance-trained participants were randomly assigned to PE (1000 mg) or placebo (PL), which were consumed 30 min prior to a repeated sprint ability (RSA) test and repetitions to fatigue (RTF) on bench and leg press. The RSA consisted of ten six-second sprints on a friction-loaded cycle ergometer with 30 s recovery...
September 20, 2016: European Journal of Sport Science
Katia Collomp, Alexandre Arlettaz, Corinne Buisson, Anne-Marie Lecoq, Cynthia Mongongu
It is generally acknowledged in the sporting world that glucocorticoid (GC) use enhances physical performance. This pharmacological class is therefore banned by the World Anti-Doping Agency (WADA) in in-competition samples after systemic but not local (defined as any route other than oral, intravenous, intramuscular or rectal) administration, which thus allows athletes to use GCs for therapeutic purposes. According to the 2016 WADA list, the urine reporting level for all GCs is set at 30ng/ml to distinguish between the authorized and banned routes of administration...
November 2016: Steroids
Claudia M Meirelles, Cristiane Matsuura
BACKGROUND: L-arginine is a semi-essential amino acid involved in nitric oxide production. As nitric oxide is an important vasodilator, L-arginine supplementation would increase blood perfusion and, subsequently, muscle performance during exercises. The aim of this study was to determine the acute effect of L-arginine supplementation on strength performance and nitric oxide levels in healthy trained individuals. METHODS: In a doubleblind, placebo-controlled, cross-over study, 12 men were randomly assigned to L-arginine or placebo supplementation...
September 13, 2016: Journal of Sports Medicine and Physical Fitness
Iker Leoz-Abaurrea, Mikel Izquierdo, Miriam Gonzalez-Izal, Roberto Aguado-Jiménez
The efficacy of the use of an upper body compression garment (UBCG) as an ergogenic aid to reduce thermoregulatory strain in older adults remains unknown. The aim of this study was to evaluate the effects of UBCG on thermoregulatory, cardiorespiratory and perceptual responses during cycling in a temperate environment (~25ºC, 66% rh) in trained older adults. Twelve cyclists aged 66±2 years performed an intermittent 1-h cycling trial at 50% of the peak power output followed by 10 min of passive recovery. Participants were provided with either commercially available UBCG or control garment in a randomized order...
September 6, 2016: Journal of Aging and Physical Activity
Jean Nyakayiru, Kristin L Jonvik, Philippe J M Pinckaers, Joan Senden, Luc J C Van Loon, Lex B Verdijk
While the majority of studies reporting ergogenic effects of dietary nitrate have used a multiday supplementation protocol, some studies suggest that a single dose of dietary nitrate prior to exercise can also improve subsequent performance. We aimed to compare the impact of acute and 6-day sodium nitrate supplementation on oxygen uptake (V̇O2) and time-trial performance in trained cyclists. Using a randomized, double blind, cross-over design, 17 male cyclists (25±4 y, V̇O2peak 65±4 mL·kg(-1)·min(-1), Wmax 411±35 W) were subjected to 3 different trials; 5 days placebo and 1 day sodium nitrate supplementation (1-DAY); 6 days sodium nitrate supplementation (6-DAY); 6 days placebo supplementation (PLA)...
September 6, 2016: International Journal of Sport Nutrition and Exercise Metabolism
Floris C Wardenaar, Ingrid Jm Ceelen, Jan-Willem Van Dijk, Roland Wj Hangelbroek, Lore Van Roy, Britte Van der Pouw, Jeanne Hm De Vries, Marco Mensink, Renger F Witkamp
The use of nutritional supplements is highly prevalent among athletes. In this cross-sectional study we assessed the prevalence of nutritional supplement use by a large group of Dutch competitive athletes in relation to dietary counselling. A total of 778 athletes (407 males and 371 females) completed a web-based questionnaire about the use of nutritional supplements. Log-binomial regression models were applied to estimate crude and adjusted prevalence ratios (PR) for the use of individual nutritional supplements in athletes receiving dietary counselling as compared to athletes not receiving dietary counselling...
September 6, 2016: International Journal of Sport Nutrition and Exercise Metabolism
Simone Porcelli, Lorenzo Pugliese, Enrico Rejc, Gaspare Pavei, Matteo Bonato, Michela Montorsi, Antonio La Torre, Letizia Rasica, Mauro Marzorati
It has been reported that nitrate supplementation can improve exercise performance. Most of the studies have used either beetroot juice or sodium nitrate as a supplement; there is lack of data on the potential ergogenic benefits of an increased dietary nitrate intake from a diet based on fruits and vegetables. Our aim was to assess whether a high-nitrate diet increases nitric oxide bioavailability and to evaluate the effects of this nutritional intervention on exercise performance. Seven healthy male subjects participated in a randomized cross-over study...
2016: Nutrients
Chris J Beedie, Philip Hurst, Damian Coleman, Abby Foad
No abstract text is available yet for this article.
May 2016: Medicine and Science in Sports and Exercise
Oliver Michael Shannon, Lauren Duckworth, Matthew John Barlow, David Woods, Jose Lara, Mario Siervo, John Paul O'Hara
Nitrate-rich beetroot juice (BRJ) increases plasma nitrite concentrations, lowers the oxygen cost (V⋅O2) of steady-state exercise and improves exercise performance in sedentary and moderately-trained, but rarely in well-trained individuals exercising at sea-level. BRJ supplementation may be more effective in a hypoxic environment, where the reduction of nitrite into nitric oxide (NO) is potentiated, such that well-trained and less well-trained individuals may derive a similar ergogenic effect. We conducted a randomised, counterbalanced, double-blind placebo controlled trial to determine the effects of BRJ on treadmill running performance in moderate normobaric hypoxia (equivalent to 2500 m altitude) in participants with a range of aerobic fitness levels...
September 30, 2016: Nitric Oxide: Biology and Chemistry
Taylor P Doyle, Rafer S Lutz, Joseph K Pellegrino, David J Sanders, Shawn M Arent
Caffeine has displayed ergogenic effects on aerobic performance. However, sports requiring precision and quick reaction may also be impacted by CNS arousal due to caffeine consumption. The purpose of this study was to assess the effects of caffeine on arousal, response time (RT), and accuracy during a simulated fencing practice. Using a randomized, within-subjects, placebo-controlled, double-blind design, Division I male and female college fencers (N = 13; 69.1 + 3.5 kg) were administered caffeine doses of 0, 1...
August 18, 2016: Journal of Strength and Conditioning Research
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