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Caffeine ingestion

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https://www.readbyqxmd.com/read/28420550/effect-of-a-moderate-caffeine-dose-on-endurance-cycle-performance-and-thermoregulation-during-prolonged-exercise-in-the-heat
#1
Ross E Beaumont, Lewis J James
OBJECTIVES: This study investigated the influence of a moderate caffeine dose on endurance cycle performance and thermoregulation during prolonged exercise in high ambient temperature. DESIGN: Double-blind cross-over study. METHODS: Eight healthy, recreationally active males (mean±SD; age: 22±1 years; body mass: 71.1±8.5kg; VO2peak: 55.9±5.8mLkg(-1)min(-1); Wmax: 318±37W) completed one VO2peak test, one familiarisation trial and two experimental trials...
March 31, 2017: Journal of Science and Medicine in Sport
https://www.readbyqxmd.com/read/28349034/repeated-sprint-ability-is-not-enhanced-by-caffeine-arginine-and-branched-chain-amino-acids-in-moderately-trained-soccer-players
#2
Andrea Ermolao, Tobia Zanotto, Nicolò Carraro, Tommaso Fornasier, Marco Zaccaria, Daniel Neunhaeuserer, Marco Bergamin
The aim was to investigate the effect of a dietary supplementation on the repeated sprint ability (RSA) performance in recreationally trained team sports athletes. Twelve young men underwent a RSA exercise protocol in five trials, in which participants ingested carbohydrates (CHO) plus caffeine (Caf), CHO plus arginine (Arg), CHO plus branched-chain amino acids (BCAA), CHO plus Caf, Arg, and BCAA (ALL), and CHO only. Heart rate, oxygen saturation, hematic lactate, ratings of perceived exertion, average sprint time, total time, best sprint time, peak power, and average power were taken...
February 2017: Journal of Exercise Rehabilitation
https://www.readbyqxmd.com/read/28344456/caffeine-ingestion-improves-repeated-freestyle-sprints-in-elite-male-swimmers
#3
Paul S R Goods, Grant Landers, Sacha Fulton
The purpose of this investigation was to determine the efficacy of a moderate dose of caffeine to improve repeat-sprint performance in elite freestyle sprinters. Nine highly trained male swimmers performed 6 x 75 m freestyle sprints on two occasions 1-h after consuming either 3 mg·kg(-1) caffeine (CAF), or placebo, in a cross-over manner. Capillary blood samples for the analysis of blood lactate concentration and pH were collected after the 1(st), 3(rd), and 5(th) sprint, while heart rate and perceived exertion (RPE) were collected after every sprint...
March 2017: Journal of Sports Science & Medicine
https://www.readbyqxmd.com/read/28338362/the-effects-of-caffeine-taurine-or-caffeine-taurine-co-ingestion-on-repeat-sprint-cycling-performance-and-physiological-responses
#4
Rory Warnock, Owen Jeffries, Stephen Patterson, Mark Waldron
PURPOSE: This study investigated the effects of caffeine (C), taurine (T), caffeine and taurine co-ingestion (C+T) or placebo (P) on repeated Wingate cycling performance and associated physiological responses. METHODS: Seven male team sports players participated in a randomised, single-blind, cross-over study, where they completed three Wingate tests, each separated by 2-min, an hour after ingesting: C (5 mg/kg BM), T (50 mg/kg BM), C+T (5 mg/kg BM + 50 mg/kg BM) or P (5 mg/kg BM) in a gelatine capsule...
March 24, 2017: International Journal of Sports Physiology and Performance
https://www.readbyqxmd.com/read/28334840/review-of-caffeine-related-fatalities-along-with-postmortem-blood-concentrations-in-51-poisoning-deaths
#5
Alan Wayne Jones
Publications reporting concentrations of caffeine in postmortem blood were reviewed if the cause of death was attributed to overdosing (poisoning) with drugs. Age and gender of the deceased, the manner of death (accident, suicide or undetermined) and types of co-ingested drugs were evaluated in relation to the concentrations of caffeine in blood (N = 51). The mean age (±SD) of the victims was 39 ± 17.8 years (range 18-84 years) and most were female (N = 31 or 61%). The difference in mean age of males (42 ± 17...
April 1, 2017: Journal of Analytical Toxicology
https://www.readbyqxmd.com/read/28323164/mapping-the-pharmacological-modulation-of-brain-oxygen-metabolism-the-effects-of-caffeine-on-absolute-cmro2-measured-using-dual-calibrated-fmri
#6
Alberto Merola, Michael A Germuska, Esther Ah Warnert, Lewys Richmond, Daniel Helme, Sharmila Khot, Kevin Murphy, Peter J Rogers, Judith E Hall, Richard G Wise
This study aims to map the acute effects of caffeine ingestion on grey matter oxygen metabolism and haemodynamics with a novel MRI method. Sixteen healthy caffeine consumers (8 males, age = 24.7±5.1) were recruited to this randomised, double-blind, placebo-controlled study. Each participant was scanned on two days before and after the delivery of an oral caffeine (250mg) or placebo capsule. Our measurements were obtained with a newly proposed estimation approach applied to data from a dual calibration fMRI experiment that uses hypercapnia and hyperoxia to modulate brain blood flow and oxygenation...
March 17, 2017: NeuroImage
https://www.readbyqxmd.com/read/28298151/effect-of-exclusion-of-frequently-consumed-dietary-triggers-in-a-cohort-of-children-with-chronic-primary-headache
#7
Sepideh Taheri
BACKGROUND: Although dietary factors are known to trigger headaches, the relationship between food and headache in children remains unclear. This prospective, observational case series aimed to evaluate the effect of exclusion of frequently-consumed foods in a cohort of children with headache. METHODS: One hundred and fifteen children aged 3-15 (mean 10.5) years with primary headache were followed in a paediatric outpatient clinic. Patients who frequently consumed foods or food additives known to trigger headaches were advised to exclude them for six weeks and to return for follow-up with headache and food diary...
March 2017: Nutrition and Health
https://www.readbyqxmd.com/read/28287486/cyp1a2-genotype-variations-do-not-modify-the-benefits-and-drawbacks-of-caffeine-during-exercise-a-pilot-study
#8
Juan J Salinero, Beatriz Lara, Diana Ruiz-Vicente, Francisco Areces, Carlos Puente-Torres, César Gallo-Salazar, Teodoro Pascual, Juan Del Coso
Previous investigations have determined that some individuals have minimal or even ergolytic performance effects after caffeine ingestion. The aim of this study was to analyze the influence of the genetic variations of the CYP1A2 gene on the performance enhancement effects of ingesting a moderate dose of caffeine. In a double-blind randomized experimental design, 21 healthy active participants (29.3 ± 7.7 years) ingested 3 mg of caffeine per kg of body mass or a placebo in testing sessions separated by one week...
March 11, 2017: Nutrients
https://www.readbyqxmd.com/read/28275131/tea-catechin-and-caffeine-activate-brown-adipose-tissue-and-increase-cold-induced-thermogenic-capacity-in-humans
#9
Takeshi Yoneshiro, Mami Matsushita, Masanobu Hibi, Hiroshi Tone, Masao Takeshita, Koichi Yasunaga, Yoshihisa Katsuragi, Toshimitsu Kameya, Hiroki Sugie, Masayuki Saito
Background: The thermogenic effects of green tea catechin have been repeatedly reported, but their mechanisms are poorly understood.Objective: The aim of this study was to investigate the acute and chronic effects of catechin on brown adipose tissue (BAT), a site specialized for nonshivering thermogenesis, in humans.Design: Fifteen healthy male volunteers underwent fluorodeoxyglucose-positron emission tomography to assess BAT activity. To examine the acute catechin effect, whole-body energy expenditure (EE) after a single oral ingestion of a beverage containing 615 mg catechin and 77 mg caffeine (catechin beverage) was measured...
March 8, 2017: American Journal of Clinical Nutrition
https://www.readbyqxmd.com/read/28271601/phytochemical-compounds-in-sport-nutrition-synephrine-and-hydroxycitric-acid-hca-as-examples-for-evaluation-of-possible-health-risks
#10
REVIEW
Nadiya Bakhiya, Rainer Ziegenhagen, Karen I Hirsch-Ernst, Birgit Dusemund, Klaus Richter, Katharina Schultrich, Sophie Pevny, Bernd Schäfer, Alfonso Lampen
Numerous food supplements contain phytochemical compounds as active ingredients. Though such supplements are often perceived by consumers as being risk-free, the safety of many of them is currently uncertain. The present review provides two examples for risk assessment for phytochemical ingredients which are used in certain supplements marketed for sportspeople - synephrine (extracted from fruits of Citrus aurantium) and hydroxycitric acid (HCA, isolated from fruits of Garcinia cambogia). Animal and human studies as well as case reports provide evidence for cardiovascular effects due to ingestion of high synephrine doses, especially in combination with caffeine and physical exertion...
March 8, 2017: Molecular Nutrition & Food Research
https://www.readbyqxmd.com/read/28196026/caffeine-inhibits-fluid-secretion-by-interlobular-ducts-from-guinea-pig-pancreas
#11
Yuka Mochimaru, Akiko Yamamoto, Miyuki Nakakuki, Makoto Yamaguchi, Ituka Taniguchi, Hiroshi Ishiguro
OBJECTIVES: Caffeine is contained in coffee, tea, and numerous beverages and foods. We examined the direct effects of caffeine on the physiological function of pancreatic duct cells by using interlobular duct segments isolated from guinea pig pancreas. METHODS: The rate of fluid secretion was continuously measured by monitoring the luminal volume of isolated duct segments. Changes in intracellular Ca concentration ([Ca]i) were estimated by microfluorometry in ducts loaded with Fura-2...
April 2017: Pancreas
https://www.readbyqxmd.com/read/28150478/effects-of-silk-peptides-administration-on-fat-utilization-over-a-whole-day-in-mice
#12
Jisu Kim, Jonghoon Park, Bokyung Kim, Chi-Ho Lee, Kiwon Lim, Heajung Suh
Purpose: The aim of the present narrative review was to consider the evidence on the timing, optimal dose and intake duration of the main dietary supplements β-alanine, nitrate, caffeine, creatine, sodium bicarbonate, carbohydrate and protein. Methods: This review article will focuses on timing, optimal dose and intake duration of main dietary supplements for consuming. Results: This paper reviewed the evidence to determine the optimal time, efficacy doses and intake duration for sports supplements verified by scientific evidence that report a performance enhancing effect in both situation of laboratory and training settings...
December 31, 2016: Journal of Exercise Nutrition & Biochemistry
https://www.readbyqxmd.com/read/28150472/timing-optimal-dose-and-intake-duration-of-dietary-supplements-with-evidence-based-use-in-sports-nutrition
#13
REVIEW
Alireza Naderi, Erick P Oliveira, Tim N Ziegenfuss, MarkE T Willems
Purpose: The aim of the present narrative review was to consider the evidence on the timing, optimal dose and intake duration of the main dietary supplements β-alanine, nitrate, caffeine, creatine, sodium bicarbonate, carbohydrate and protein. Methods: This review article will focuses on timing, optimal dose and intake duration of main dietary supplements for consuming. Results: This paper reviewed the evidence to determine the optimal time, efficacy doses and intake duration for sports supplements verified by scientific evidence that report a performance enhancing effect in both situation of laboratory and training settings...
December 31, 2016: Journal of Exercise Nutrition & Biochemistry
https://www.readbyqxmd.com/read/28096758/effects-of-acute-ingestion-of-a-pre-workout-dietary-supplement-with-and-without-p-synephrine-on-resting-energy-expenditure-cognitive-function-and-exercise-performance
#14
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Elfego Galvan, Ryan Dalton, Dillon Walker, Christopher Rasmussen, Peter S Murano, Mike Greenwood, Richard B Kreider
BACKGROUND: The purpose of this study was to examine the effects of acute ingestion of a pre-workout dietary supplement (PWS) with and without p-synephrine (S) on perceptions of readiness to perform, cognitive function, exercise performance, and markers of safety. METHODS: In a randomized, double-blind, and counterbalanced manner; 25 healthy and recreationally active male and female participants ingested a flavored maltodextrin placebo (PLA), a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg) with 2 g of maltodextrin and flavoring; or, the PWS with Citrus aurantium (PWS + S) extract standardized for 30% p-synephrine (20 mg)...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28096757/effects-of-ingesting-a-pre-workout-dietary-supplement-with-and-without-synephrine-for-8%C3%A2-weeks-on-training-adaptations-in-resistance-trained-males
#15
Y Peter Jung, Conrad P Earnest, Majid Koozehchian, Minye Cho, Nick Barringer, Dillon Walker, Christopher Rasmussen, Mike Greenwood, Peter S Murano, Richard B Kreider
BACKGROUND: The purpose of this study was to examine whether ingesting a pre-workout dietary supplement (PWS) with and without synephrine (S) during training affects training responses in resistance-trained males. METHODS: Resistance-trained males (N = 80) were randomly assigned to supplement their diet in a double-blind manner with either a flavored placebo (PLA); a PWS containing beta-alanine (3 g), creatine nitrate as a salt (2 g), arginine alpha-ketoglutarate (2 g), N-Acetyl-L-Tyrosine (300 mg), caffeine (284 mg), Mucuna pruiriens extract standardized for 15% L-Dopa (15 mg), Vitamin C as Ascorbic Acid (500 mg), niacin (60 mg), folate as folic acid (50 mg), and Vitamin B12 as Methylcobalamin (70 mg); or, the PWS supplement with Citrus aurantium extract containing 20 mg of synephrine (PWS + S) once per day for 8-weeks during training...
2017: Journal of the International Society of Sports Nutrition
https://www.readbyqxmd.com/read/28054436/low-dose-of-caffeine-enhances-the-efficacy-of-antidepressants-in-major-depressive-disorder-and-the-underlying-neural-substrates
#16
Qing-Shan Liu, Ran Deng, Yuyan Fan, Keqin Li, Fanggang Meng, Xueli Li, Rui Liu
SCOPE: Caffeine is one of the most frequently used psychoactive substances ingested mainly via beverage or food products. Major depressive disorder is a serious and devastating psychiatric disorder. Emerging evidence indicates that caffeine enhances the antidepressant-like activity of common antidepressant drugs in rodents. However, whether joint administration of low dose of caffeine enhances the antidepressant actions in depressed patients remains unclear. METHODS AND RESULTS: A total of 95 male inpatients were assigned to three groups and were asked to take either caffeine (60, 120mg) or placebo (soymilk powder) daily for 4 weeks on the basis of their current antidepressant medications...
January 5, 2017: Molecular Nutrition & Food Research
https://www.readbyqxmd.com/read/28053881/effect-of-novel-dietary-supplement-on-metabolism-in%C3%A2-vitro-and-in%C3%A2-vivo
#17
Roger A Vaughan, Ailish C White, Jason R Beam, Nicholas P Gannon, Randi Garcia-Smith, Roy M Salgado, Marco Bisoffi, Kristina A Trujillo, Carole A Conn, Christine M Mermier
Obesity is an increasingly prevalent and preventable morbidity with multiple behavioral, surgical and pharmacological interventions currently available. Commercial dietary supplements are often advertised to stimulate metabolism and cause rapid weight and/or fat loss, although few well-controlled studies have demonstrated such effects. We describe a commercially available dietary supplement (purportedly containing caffeine, catechins, and other metabolic stimulators) on resting metabolic rate in humans, and on metabolism, mitochondrial content, and related gene expression in vitro...
January 2017: Journal of Traditional and Complementary Medicine
https://www.readbyqxmd.com/read/28050917/acute-caffeine-ingestion-on-performance-in-young-judo-athletes
#18
Camilla Astley, Diego Souza, Marcos Polito
PURPOSE: To compare the acute effect of caffeine ingestion on performance in young judo athletes. METHODS: In a randomized double-blind design, eighteen judo athletes (16.1 ± 1.4 yrs.) were evaluated on three nonconsecutive days. On the first day, the special judo fitness test (SJFT) was used as a control session. On the second day, the sample was randomly divided into two equal groups. One group received 4 mg.kg(-1) of caffeine (capsule) and the other group received a placebo...
January 4, 2017: Pediatric Exercise Science
https://www.readbyqxmd.com/read/28031026/acute-caffeine-ingestion-reduces-insulin-sensitivity-in-healthy-subjects-a-systematic-review-and-meta-analysis
#19
REVIEW
Xiuqin Shi, Wenhua Xue, Shuhong Liang, Jie Zhao, Xiaojian Zhang
BACKGROUND: According to previous meta-analyses, coffee consumption reduces the risk of type 2 diabetes mellitus. However, the underlying mechanism remains unknown. Whether caffeine, the key ingredient in coffee, has a beneficial effect on the glycemic homeostasis and the anti-diabetic effect is particularly controversial. The aim of this study was to summarize the effect of acute caffeine ingestion on insulin sensitivity in healthy men. METHODS: A comprehensive literature search for papers published before April 2016 was conducted in EMBASE, PubMed, and Cochrane Library databases...
December 28, 2016: Nutrition Journal
https://www.readbyqxmd.com/read/28011360/effects-of-peppermint-tea-consumption-on-the-activities-of-cyp1a2-cyp2a6-xanthine-oxidase-n-acetyltranferase-2-and-udp-glucuronosyltransferases-1a1-1a6-in-healthy-volunteers
#20
Elias Begas, Athanasia Tsioutsiouliti, Evangelos Kouvaras, Serkos A Haroutounian, Konstantinos M Kasiotis, Dimitrios Kouretas, Eftihia Asprodini
Peppermint leaves are widely used for the symptomatic treatment of digestive disorders. Previous studies have shown significant effects of its natural products on human enzyme activity; however, there is no study available concerning the effects of peppermint tea on metabolizing enzymes in humans. Aim of the present study was to investigate the effect of peppermint tea on CYP1A2, CYP2A6, Xanthine Oxidase (XO), N-acetyltranferase-2 (NAT2) and UDP-glucuronosyltransferases-1A1/1A6 (UGT1A1/1A6) activities in healthy subjects...
February 2017: Food and Chemical Toxicology
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