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https://www.readbyqxmd.com/read/28723815/effect-of-energy-drink-consumption-on-power-and-velocity-of-selected-sport-performance-activities
#1
Bert H Jacobson, Garrett M Hester, Ty B Palmer, Kathryn Williams, Zachary K Pope, John H Sellers, Eric C Conchola, Conrad Woolsey, Carlos Estrada
Energy drinks comprise a multibillion dollar market focused on younger, active and competitive individuals. Marketing includes claims of improved alertness and performance. The purpose of this study was to assess power (W) and velocity (m·s) of a simulated, isolated forehand stroke (FHS) and a counter movement vertical jump (CVJ) before and after ingestion of a commercially available energy shot (ES) or a placebo (PL). Healthy college-aged male and female (N=36) volunteers were randomly placed in the ES or PL...
July 17, 2017: Journal of Strength and Conditioning Research
https://www.readbyqxmd.com/read/28696284/caffeine-induces-gastric-acid-secretion-via-bitter-taste-signaling-in-gastric-parietal-cells
#2
Kathrin Ingrid Liszt, Jakob Peter Ley, Barbara Lieder, Maik Behrens, Verena Stöger, Angelika Reiner, Christina Maria Hochkogler, Elke Köck, Alessandro Marchiori, Joachim Hans, Sabine Widder, Gerhard Krammer, Gareth John Sanger, Mark Manuel Somoza, Wolfgang Meyerhof, Veronika Somoza
Caffeine, generally known as a stimulant of gastric acid secretion (GAS), is a bitter-tasting compound that activates several taste type 2 bitter receptors (TAS2Rs). TAS2Rs are expressed in the mouth and in several extraoral sites, e.g., in the gastrointestinal tract, in which their functional role still needs to be clarified. We hypothesized that caffeine evokes effects on GAS by activation of oral and gastric TAS2Rs and demonstrate that caffeine, when administered encapsulated, stimulates GAS, whereas oral administration of a caffeine solution delays GAS in healthy human subjects...
July 10, 2017: Proceedings of the National Academy of Sciences of the United States of America
https://www.readbyqxmd.com/read/28694153/caffeinated-energy-drink-intake-modulates-motor-circuits-at-rest-before-and-after-a-movement
#3
Carmen Concerto, Carmenrita Infortuna, Eileen Chusid, Diego Coira, Jacqueline Babayev, Rowan Metwaly, Hesam Naenifard, Eugenio Aguglia, Fortunato Battaglia
Energy drinks are thought to improve certain aspects of athletic and cognitive performances. Moreover, less is understood about physiological mechanisms that might underlie these effects. The aim of this study was to examine the influence of sugar-free energy drink (SFED) ingestion on corticomotor excitability and plasticity. Fourteen college students consumed a commercially available SFED or a "dummy" drink. By using Transcranial magnetic Stimulation (TMS) we investigated resting motor threshold (RMT), motor evoked potential (MEP) amplitude and cortical silent period (CSP)...
July 8, 2017: Physiology & Behavior
https://www.readbyqxmd.com/read/28644716/the-effects-of-acute-carbohydrate-and-caffeine-feeding-strategies-on-cycling-efficiency
#4
Matthew Cole, James G Hopker, Jonathan D Wiles, Damian A Coleman
To assess the effect of carbohydrate and caffeine on gross efficiency (GE), 14 cyclists (V̇O2max 57.6 ± 6.3 ml.kg(-1.)min(-1)) completed 4 × 2-hour tests at a submaximal exercise intensity (60% Maximal Minute Power). Using a randomized, counter-balanced crossover design, participants consumed a standardised diet in the 3-days preceding each test and subsequently ingested either caffeine (CAF), carbohydrate (CHO), caffeine+carbohydrate (CAF+CHO) or water (W) during exercise whilst GE and plasma glucose were assessed at regular intervals (~30 mins)...
June 23, 2017: Journal of Sports Sciences
https://www.readbyqxmd.com/read/28638217/diet-in-irritable-bowel-syndrome-what-to-recommend-not-what-to-forbid-to-patients
#5
REVIEW
Anamaria Cozma-Petruţ, Felicia Loghin, Doina Miere, Dan Lucian Dumitraşcu
A substantial proportion of patients with irritable bowel syndrome (IBS) associate their symptoms with the ingestion of specific foods. Therefore, in recent years, scientific research has increasingly focused on the role of diet in IBS and dietary management is now considered an important tool in IBS treatment. This article reviews the main dietary approaches in IBS emphasizing evidence from experimental and observational studies and summarizing the main diet and lifestyle recommendations provided by dietary guidelines and scientific literature...
June 7, 2017: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/28631923/influence-of-ingesting-a-flavonoid-rich-supplement-on-the-metabolome-and-concentration-of-urine-phenolics-in-overweight-obese-women
#6
David C Nieman, Sivapriya Ramamoorthy, Colin D Kay, Courtney L Goodman, Christopher R Capps, Zack L Shue, Nicole Heyl, Mary H Grace, Mary A Lila
This study evaluated the effect of ingesting a flavonoid-rich supplement (329 mg/d) on total urine phenolics and shifts in plasma metabolites in overweight/obese female adults using untargeted metabolomics procedures. Participants (N = 103, 18-65 y, BMI ≥ 25 kg/m(2)) were randomized to flavonoid (F) or placebo (P) groups for 12 weeks with blood and 24 h urine samples collected prestudy and after 4 and 12 weeks in a parallel design. Supplements were prepared as chewable tablets and included vitamin C, wild bilberry fruit extract, green tea leaf extract, quercetin, caffeine, and omega 3 fatty acids...
June 30, 2017: Journal of Proteome Research
https://www.readbyqxmd.com/read/28625890/acute-effects-of-coffee-on-skin-blood-flow-and-microvascular-function
#7
Erik Tesselaar, Dzeneta Nezirevic Dernroth, Simon Farnebo
OBJECTIVE: Studies on the acute effects of coffee on the microcirculation have shown contradicting results. This study aimed to investigate if intake of caffeine-containing coffee changes blood flow and microvascular reactivity in the skin. METHODS: We measured acute changes in cutaneous vascular conductance (CVC) in the forearm and the tip of the finger, the microvascular response to transdermal iontophoresis of acetylcholine (ACh) and sodium nitroprusside (SNP) and post-occlusive reactive hyperemia (PORH) in the skin, after intake of caffeinated or decaffeinated coffee...
June 15, 2017: Microvascular Research
https://www.readbyqxmd.com/read/28617848/effect-of-caffeine-ingestion-on-anaerobic-capacity-quantified-by-different-methods
#8
Lucyana Arcoverde, Rodrigo Silveira, Fabiano Tomazini, André Sansonio, Romulo Bertuzzi, Adriano Eduardo Lima-Silva, Victor Amorim Andrade-Souza
We investigated whether caffeine ingestion before submaximal exercise bouts would affect supramaximal oxygen demand and maximal accumulated oxygen deficit (MAOD), and if caffeine-induced improvement on the anaerobic capacity (AC) could be detected by different methods. Nine men took part in several submaximal and supramaximal exercise bouts one hour after ingesting caffeine (5 mg·kg-1) or placebo. The AC was estimated by MAOD, alternative MAOD, critical power, and gross efficiency methods. Caffeine had no effect on exercise endurance during the supramaximal bout (caffeine: 131...
2017: PloS One
https://www.readbyqxmd.com/read/28603504/the-safety-of-ingested-caffeine-a-comprehensive-review
#9
REVIEW
Jennifer L Temple, Christophe Bernard, Steven E Lipshultz, Jason D Czachor, Joslyn A Westphal, Miriam A Mestre
Caffeine is the most widely consumed psychoactive drug in the world. Natural sources of caffeine include coffee, tea, and chocolate. Synthetic caffeine is also added to products to promote arousal, alertness, energy, and elevated mood. Over the past decade, the introduction of new caffeine-containing food products, as well as changes in consumption patterns of the more traditional sources of caffeine, has increased scrutiny by health authorities and regulatory bodies about the overall consumption of caffeine and its potential cumulative effects on behavior and physiology...
2017: Frontiers in Psychiatry
https://www.readbyqxmd.com/read/28576568/early-life-exposure-to-caffeine-affects-the-construction-and-activity-of-cortical-networks-in-mice
#10
Walid Fazeli, Stefania Zappettini, Stephan Lawrence Marguet, Jasper Grendel, Monique Esclapez, Christophe Bernard, Dirk Isbrandt
The consumption of psychoactive drugs during pregnancy can have deleterious effects on newborns. It remains unclear whether early-life exposure to caffeine, the most widely consumed psychoactive substance, alters brain development. We hypothesized that maternal caffeine ingestion during pregnancy and the early postnatal period in mice affects the construction and activity of cortical networks in offspring. To test this hypothesis, we focused on primary visual cortex (V1) as a model neocortical region. In a study design mimicking the daily consumption of approximately three cups of coffee during pregnancy in humans, caffeine was added to the drinking water of female mice and their offspring were compared to control offspring...
May 30, 2017: Experimental Neurology
https://www.readbyqxmd.com/read/28566632/anti-stress-effect-of-green-tea-with-lowered-caffeine-on-humans-a-pilot-study
#11
Keiko Unno, Hiroshi Yamada, Kazuaki Iguchi, Hitoshi Ishida, Yasunori Iwao, Akio Morita, Yoriyuki Nakamura
Theanine, an amino acid in tea, has significant anti-stress effects on animals and humans. However, the effect of theanine was blocked by caffeine and gallate-type catechins, which are the main components in tea. We examined the anti-stress effect of green tea with lowered caffeine, low-caffeine green tea, on humans. The study design was a single-blind group comparison and participants (n=20) were randomly assigned to low-caffeine or placebo tea groups. These teas (≥500 mL/d), which were eluted with room temperature water, were taken from 1 week prior to pharmacy practice and continued for 10 d in the practice period...
2017: Biological & Pharmaceutical Bulletin
https://www.readbyqxmd.com/read/28561231/large-intra-subject-variability-in-caffeine-pharmacokinetics-randomized-cross-over-study-of-single-caffeine-product
#12
Muhammad M Hammami, Syed N Alvi
Background Average bioequivalence has been criticized for not adequately addressing individual variations. Importance of subjects' blinding in bioequivalence studies has not been well studied. We explored the extent of intra-subject pharmacokinetic variability and effect of drug-ingestion unawareness in subjects taking single caffeine product. Methods A single-dose randomized cross-over design was used to compare pharmacokinetics of 200 mg caffeine, described as caffeine (overt) or as placebo (covert). Maximum concentration (Cmax), Cmax first time (Tmax), area-under-the-concentration-time-curve, to last measured concentration (AUCT), extrapolated to infinity (AUCI), or to Tmax of overt caffeine (AUCOverttmax), and Cmax/AUCI were calculated blindly using standard non-compartmental method...
May 23, 2017: Drug Research
https://www.readbyqxmd.com/read/28537195/caffeine-ingestion-acutely-enhances-muscular-strength-and-power-but-not-muscular-endurance-in-resistance-trained-men
#13
Jozo Grgic, Pavle Mikulic
The goal of this randomized, double-blind, cross-over study was to assess the acute effects of caffeine ingestion on muscular strength and power, muscular endurance, rate of perceived exertion (RPE), and pain perception (PP) in resistance-trained men. Seventeen volunteers (mean ± SD: age = 26 ± 6 years, stature = 182 ± 9 cm, body mass = 84 ± 9 kg, resistance training experience = 7 ± 3 years) consumed placebo or 6 mg kg(-1) of anhydrous caffeine 1 h before testing...
May 24, 2017: European Journal of Sport Science
https://www.readbyqxmd.com/read/28536868/caffeine-increases-the-velocity-of-rapid-eye-movements-in-unfatigued-humans
#14
Charlotte J W Connell, Benjamin Thompson, Jason Turuwhenua, Robert F Hess, Nicholas Gant
BACKGROUND: Caffeine is a widely used dietary stimulant that can reverse the effects of fatigue on cognitive, motor and oculomotor function. However, few studies have examined the effect of caffeine on the oculomotor system when homeostasis has not been disrupted by physical fatigue. This study examined the influence of a moderate dose of caffeine on oculomotor control and visual perception in participants who were not fatigued. METHODS: Within a placebo-controlled crossover design, 13 healthy adults ingested caffeine (5 mg·kg(-1) body mass) and were tested over 3 h...
August 2017: Psychopharmacology
https://www.readbyqxmd.com/read/28536463/tea-induced-improvement-of-endothelial-function-in-humans-no-role-for-epigallocatechin-gallate-egcg
#15
Mario Lorenz, Franziska Rauhut, Christine Hofer, Stefanie Gwosc, Eda Müller, Damaris Praeger, Benno F Zimmermann, Klaus-Dieter Wernecke, Gert Baumann, Karl Stangl, Verena Stangl
Consumption of tea is inversely associated with cardiovascular diseases. However, the active compound(s) responsible for the protective effects of tea are unknown. Although many favorable cardiovascular effects in vitro are mediated by epigallocatechin gallate (EGCG), its contribution to the beneficial effects of tea in vivo remains unresolved. In a randomised crossover study, a single dose of 200 mg EGCG was applied in three different formulas (as green tea beverage, green tea extract (GTE), and isolated EGCG) to 50 healthy men...
May 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28535819/does-the-placebo-effect-modulate-drug-bioavailability-randomized-cross-over-studies-of-three-drugs
#16
Muhammad M Hammami, Ahmed Yusuf, Faduma S Shire, Rajaa Hussein, Reem Al-Swayeh
BACKGROUND: Medication effect is the sum of its drug, placebo, and drug*placebo interaction effects. It is conceivable that the interaction effect involves modulating drug bioavailability; it was previously observed that being aware of caffeine ingestion may prolong caffeine plasma half-life. This study was set to evaluate such concept using different drugs. METHODS: Balanced single-dose, two-period, two-group, cross-over design was used to compare the pharmacokinetics of oral cephalexin, ibuprofen, and paracetamol, each described by its name (overt) or as placebo (covert)...
May 23, 2017: Journal of Negative Results in Biomedicine
https://www.readbyqxmd.com/read/28503530/caffeine-supplementation-affects-the-immunometabolic-response-to-concurrent-training
#17
Fabrício Eduardo Rossi, Valéria Leme Gonçalves Panissa, Paula Aulves Monteiro, José Gerosa-Neto, Érico Chagas Caperuto, Jason Michael Cholewa, Alessandro Moura Zagatto, Fábio Santos Lira
The aim of the present study was to investigate the effects of caffeine (CAF) and carbohydrate (CHO) intake on strength performance and its metabolic and inflammatory responses during concurrent training. Seven active males ingested a double-placebo (P), CAF (capsule 5 mg/kg) or CHO (20% maltodextrin solution) supplementation before strength exercise. Participants performed three randomized sessions of 5,000-m high-intensity intermittent aerobic exercise at maximal intensity followed by strength exercise, performing after the P, CHO, and CAF intake...
April 2017: Journal of Exercise Rehabilitation
https://www.readbyqxmd.com/read/28495846/dispelling-the-myth-that-habitual-caffeine-consumption-influences-the-performance-response-to-acute-caffeine-supplementation
#18
Lívia de Souza Gonçalves, Vitor de Salles Painelli, Guilherme Yamaguchi, Luana Farias de Oliveira, Bryan Saunders, Rafael Pires da Silva, Erika Maciel, Guilherme Giannini Artioli, Hamilton Roschel, Bruno Gualano
OBJECTIVE: To investigate the influence of habitual caffeine intake on exercise performance to acute caffeine supplementation. METHODS: A double-blind, crossover, counterbalanced study was performed. Forty endurance-trained cyclists were allocated into tertiles according to their daily caffeine intake: low (58 ± 29 mg(.)d(-1)), moderate (143 ± 25 mg(.)d(-1)), and high consumers (351 ± 139 mg(.)d(-1)). Participants completed three trials in which they performed simulated cycling time-trials in the fastest time possible following ingestion of: caffeine (CAF: 6 mg(...
May 11, 2017: Journal of Applied Physiology
https://www.readbyqxmd.com/read/28488924/effects-of-caffeine-on-countermovement-jump-performance-variables-in-elite-male-volleyball-players
#19
Hermann Zbinden-Foncea, Isabel Rada, Jesus Gomez, Marco Kokaly, Trent Stellingwerff, Louise Deldicque, Luis Peñailillo
PURPOSE: To examine the effects of a moderate dose of caffeine in elite male volleyball players on countermovement jump (CMJ) performance, as well as temporal concentric and eccentric phase effects. METHODS: Ten elite male volleyball players took part in two experimental days via a randomized cross-over trial 1 week apart in which they ingested either 5 mg/kg of caffeine or a placebo in double-blind fashion. Heart rate and blood pressure parameters were measured at rest and 60 min post-ingestion...
May 10, 2017: International Journal of Sports Physiology and Performance
https://www.readbyqxmd.com/read/28479951/acute-effects-of-24-h-sleep-deprivation-on-salivary-cortisol-and-testosterone-concentrations-and-testosterone-to-cortisol-ratio-following-supplementation-with-caffeine-or-placebo
#20
Ciaran Mc Donald, Joss Moore, Alan McIntyre, Kevin Carmody, Bernard Donne
Caffeine has become a popular ergogenic aid amongst athletes and usage to improve athletic performance has been well documented. The effect of caffeine on anabolic and catabolic hormones in a sleep-deprived s tate has had little investigation to date. The purpose of the current study was to investigate the potential of caffeine to offset the effects, if any, of short-term sleep deprivation and exercise on an athlete's testosterone and cortisol concentrations via salivary technique. Eleven competitive male athletes volunteered to be part of this prospective double-blinded study...
2017: International Journal of Exercise Science
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