Caffeine ingestion

UNLABELLED: This study aimed to analyze the placebo effect associated with caffeine ingestion on running performance. METHODS: Thirteen recreationally trained males in long-distance running (age: 38.5 ± 11.9 years, 11.0 ± 8.8 years of running experience) performed a 6 min time trial test in each experimental condition (caffeine-informed/placebo ingested (placebo) and non-ingested (control)) separated by 7 days. The total distance covered was measured, and partial times of each 400 m were used to analyze the pacing strategy...

Background: The benefits of caffeine to physical performance have been extensively demonstrated, however, it has recently been speculated that there is an effect of the administration route on its effectiveness. Purpose: The current study investigated the effect of caffeine mouth rinse in isolation or combined with ingestion on performance in a 30-minute constant-load exercise followed by a 10-km cycling time trial. Methods: Ten physically active men performed a 30-minute constant-load exercise at 50% of the graded test Wmax, followed by a 10-km cycling time trial...

This study investigated the effects of the timing of caffeine (3 mg/kg body mass) ingestion on three-point shooting accuracy and other performance parameters during a basketball exercise simulation test (BEST). Eighteen college basketball players (mean ± SD: age = 24.4 ± 1.5 years, height = 181.7 ± 9.5 cm, body mass = 80.9 ± 13.2 kg) underwent one familiarization trial and three main conditions in a randomized order: (a) placebo (maltodextrin) and placebo, (b) caffeine and placebo, and (c) placebo and caffeine...

Despite the abundance of research investigating the efficacy of caffeine supplementation on exercise performance, the physiological and biochemical responses to caffeine supplementation during intermittent activities are less evident. This study investigated the acute effects of caffeine supplementation on measures of exercise performance, ratings of perceived exertion, and biomarkers of oxidative stress induced by an acute bout of sprint interval training. In a randomized crossover design, 12 healthy males (age: 26 ± 4 years, height: 177...

Caffeine is present in various foods and medicines and is highly accessible through various routes, regardless of age. However, most studies on caffeine have focused on the effects of high-dose caffeine ingestion based on the recommended daily amount for adults. In this study, we examined the physiological changes in the central and peripheral vessels that may occur when ingesting low-dose caffeine due to its high accessibility, with the aim of creating an environment of safe caffeine ingestion. This study included 26 healthy participants in their 20s...

Pre-exercise intake of caffeine (from ~3 to 9 mg/kg) has been demonstrated as an effective supplementation strategy to increase fat oxidation during fasted exercise. However, a pre-exercise meal can alter the potential effect of caffeine on fat oxidation during exercise as caffeine modifies postprandial glycaemic and insulinemic responses. Hypothetically, the effect of caffeine on fat oxidation may be reduced or even withdrawn during fed-state exercise. The present systematic review aimed to meta-analyse investigations on the effect of acute caffeine intake on the rate of fat oxidation during submaximal aerobic exercise performed in the fed state (last meal < 5 h before exercise)...

Vitamin B12 is an essential cofactor involved in the function of two enzymes: cytosolic methionine synthase and mitochondrial methylmalonic-CoA mutase. In our previous studies, caffeine (1,3,7-trimethylxanthine), the most popular bioactivator, was shown to reduce yolk protein (vitellogenin) and fertility in a Caenorhabditis elegans model. Based on the previous finding that methionine supplementation increases vitellogenesis in C. elegans , we investigated the role of vitamin B12 in methionine-mediated vitellogenesis during oogenesis in caffeine-ingested animals (CIA)...

This study aimed to investigate the effects of caffeine ingestion on anaerobic performance and muscle activity in young athletes. In this randomized, double-blind, and placebo-controlled study, ten highly trained male post-puberal futsal players aged 15.9 ± 1.2 years conducted two laboratory sessions. Athletes performed the Wingate test 60 min after ingestion of caffeine (CAF, 6 mg/kg body mass) or placebo (PL, dextrose) (blinded administration). Peak power, mean power, and the fatigue index were assessed...

BACKGROUND: This study aimed to determine the optimal time point, either 30 or 60 minutes, at which muscle reactivity to caffeine administration is highest. Unlike previous studies that focused on the nervous system response, we employed tensiomyography (TMG) to directly assess the effects of caffeine on muscle fibers. METHODS: TMG measurements were performed on the gastrocnemius medialis muscle of 42 male athletes who regularly consumed caffeine. Participants received a dose of 6 mg/kg body weight and TMG measurements were taken prior to caffeine intake, as well as 30 and 60 minutes afterward...

Habitual poor sleep is associated with cerebrovascular disease. Acute sleep deprivation alters the ability to match brain blood flow to metabolism (neurovascular coupling [NVC]) but it is not known how partial sleep restriction affects NVC. When rested, caffeine disrupts NVC, but its effects in the sleep-restricted state are unknown. The purpose of this study was therefore to investigate the effects of partial sleep restriction and subsequent caffeine ingestion on NVC. A total of 17 adults (mean [standard deviation] age 27 [5] years, nine females) completed three separate overnight conditions with morning supplementation: habitual sleep plus placebo (Norm_Pl), habitual sleep plus caffeine (Norm_Caf), and partial (50% habitual sleep) restriction plus caffeine (PSR_Caf)...

BACKGROUND: Caffeine (CAF) ingestion improves performance in a broad range of exercise tasks. Nevertheless, the CAF-induced, dose-dependent effect on discipline-specific performance and cognitive functions in CrossFit/High-Intensity Functional Training (HIFT) has not been sufficiently investigated. The aim of this study was to evaluate the effect of acute supplementation of three different doses of CAF and placebo (PLA) on specific performance, reaction time (RTime ), postural stability (PStab ), heart rate (HR) and perceived exertion (RPE)...

Acute caffeine intake affects brain and cardiovascular physiology, yet the concentration-effect relationships on the electroencephalogram and cardiac autonomic activity during sleep are poorly understood. To tackle this question, we simultaneously quantified the plasma caffeine concentration with ultra-high-performance liquid chromatography, as well as the electroencephalogram, heart rate and high-frequency (0.15-0.4 Hz) spectral power in heart rate variability, representing parasympathetic activity, with standard polysomnography during undisturbed human sleep...

Caffeine is an ergogenic substance that is consumed globally in many forms. The use of buccally absorbable formulations instead of gastrointestinal uptake has become increasingly popular over the years, especially when accelerated absorption with minimal gastrointestinal stress is desired. This study investigated the impact of five different formulations and administration routes of caffeine on the whole blood concentrations of caffeine, paraxanthine, and theobromine: caffeinated capsules, tablets, shots, pouches, and chewing gums...

The aim of the present study was to investigate the acute effect of caffeine or quercetin ingestion on motor unit firing patterns and muscle contractile properties before and after resistance exercise. High-density surface electromyography (HDs-EMG) during submaximal contractions and electrically elicited torque in knee extensor muscles were measured before (PRE) and 60 min after (POST1) ingestion of caffeine, quercetin glycosides, or placebo, and after resistance exercise (POST2) in ten young males. The Convolution Kernel Compensation technique was used to identify individual motor units of the vastus lateralis muscle for the recorded HDs-EMG...

PURPOSE: Cold-induced vasodilation (CIVD) is an oscillatory rise in blood flow to glabrous skin that occurs in cold-exposed extremities. Dietary flavanols increase bioavailable nitric oxide, a proposed mediator of CIVD through active vasodilation and/or withdrawal of sympathetic vascular smooth muscle tone. However, no studies have examined the effects of flavanol intake on extremity skin perfusion during cold exposure. We tested the hypothesis that acute and 8-day flavanol supplementation would augment CIVD during single-digit cold water immersion (CWI)...

Participation in a virtual reality based active shooter training drill (VR-ASD) has been shown to increase biomarkers of stress; however, the impact of caffeine consumption on this response has not been studied. Caffeine ingestion has been shown to have favorable effects on physical and cognitive performance among athletic and tactical occupations alike. This study examined the impact of caffeine ingestion on subjective and physiological markers of stress in response to a mental stress task (MST) which involved participation in a VR-ASD and cognitive challenge consisting of mental arithmetic and a Stroop challenge...

Experimental studies reveal that caffeine (trimethylxanthine) at subconvulsive doses, distinctly reduced the anticonvulsant activity of numerous antiseizure medications (ASMs) in rodents, oxcarbazepine, tiagabine and lamotrigine being the exceptions. Clinical data based on low numbers of patients support the experimental results by showing that caffeine (ingested in high quantities) may sharply increase seizure frequency, considerably reducing the quality of patients' lives. In contrast, this obviously negative activity of caffeine was not found in clinical studies involving much higher numbers of patients...

We report on a patient diagnosed with Hodgkin Lymphoma who was scheduled for [18 F]FDG PET/CT as part of routine follow-up after treatment with two cycles of chemotherapy and mediastinal external beam radiation. Although the patient was advised to fast for at least four hours, an energy drink (Red Bull ) was ingested right after radiotracer administration, which led to increased uptake in the large skeletal muscles, thereby rendering this scan as non-diagnostic. After strictly following respective dietary recommendations, the repeated scan then provided excellent image quality and revealed response to treatment...

Caffeine poisoning can cause fatal ventricular arrhythmias. In this report, we describe a case of severe caffeine poisoning with extraordinarily high blood caffeine levels. Despite developing refractory ventricular fibrillation, the patient was successfully treated with intermittent hemodialysis (IHD) under circulatory support by venoarterial extracorporeal membrane oxygenation (VA-ECMO). A 22-year-old male was transported to our hospital approximately 2.5 h after ingesting 200 highly caffeinated tablets (200 mg/tablet) (40 g caffeine total) in a suicide attempt...

INTRODUCTION/AIMS: The transcranial magnetic stimulation tests of short-interval intracortical inhibition (SICI) by both conventional amplitude measurements (A-SICI) and threshold-tracking (T-SICI) are important methods to investigate intracortical inhibitory circuits, and T-SICI has been proposed to aid the diagnosis of amyotrophic lateral sclerosis. Beverages containing caffeine are widely consumed, and caffeine has been reported to affect cortical excitability. The aim of this study was to determine whether these SICI tests are affected by caffeine...