Interactions of Chronic Stress Exposure and Stress Appraisal on Vascular Endothelial Function Among Young Adults.

We investigated the associations of ongoing, chronic stress exposure and stress appraisal on vascular endothelial function (VEF) in young adults. In 72 healthy young adults (74% female; age = 25±1 y), we assessed chronic stress exposure and appraisal with a measure that quantified chronic stress exposure and chronic stress appraisal related to 8 specific stressors over the last year. Participants completed the perceived stress scale (PSS) as a measure of global, proximal stress appraisal.

Habitual preexercise caffeine supplementation prevents exercise training-induced attenuation of exercising systolic blood pressure and double product.

We examined the effect of habitual preexercise caffeine supplementation on training-induced adaptations to exercising systolic blood pressure (SBP), diastolic blood pressure (DBP), pulse pressure (PP), heart rate (HR), and double product (DP). Young women (means ± SD; 24 ± 7 yr) were randomized to a caffeine (120 mg) supplement (CAF; = 17) or placebo (PLA; = 16) group, completed 6 wk of high-intensity exercise training on three nonconsecutive days per week, and supplemented with CAF or PLA 30-60 min before exercise or else upon waking. Before (PRE) and after (POST) the intervention, SBP, DBP, and HR were measured and PP and DP were calculated, at rest and during fixed-power exercise at 50 and 75 W.

Acute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization.

Purpose: We conducted a randomized, double-blind, placebo-controlled crossover trial in young adults to examine the dose-dependent (600 mg versus 1200 mg), acute effects of consumption of an tea extract (GLE) on mood, cognitive and motor-cognitive performance, as well as its acute cardiovascular effects.

Methods: Twenty-five adults (mean ± SD, age = 28 ± 7 y; 9 M/16 F) completed familiarization and then three randomly ordered experimental visits where they consumed either 600 mg (GLE) or 1200 mg (GLE) GLE or placebo (PLA). Following supplement consumption, participants completed a mood state survey, assessments of perceived jitteriness, energy, and focus, and neurocognitive and motor-cognitive testing.

Acute effects of commercial energy drink consumption on exercise performance and cardiovascular safety: a randomized, double-blind, placebo-controlled, crossover trial.

The aim of this study was to examine the acute effects of a non-caloric energy drink (C4E) compared to a traditional sugar-containing energy drink (MED) and non-caloric placebo (PLA) on exercise performance and cardiovascular safety. Thirty healthy, physically active males (25 ± 4 y) completed three experimental visits under semi-fasted conditions (5-10 h) and in randomized order, during which they consumed C4E, MED, or PLA matched for volume, appearance, taste, and mouthfeel. One hour after drink consumption, participants completed a maximal, graded exercise test (GXT) with measurement of pulmonary gases, an isometric leg extension fatigue test (ISO), and had their cardiac electrical activity (ECG), leg blood flow (LBF), and blood pressure (BP) measured throughout the visit.

Novel Energy Drink Improves Cognitive Function and Mood, without Influencing Myocardial Oxygen Demand or Ventricular Repolarization in Adult Gamers: A Randomized, Double-Blind, Placebo-Controlled, Crossover Trial.

Objectives: To examine the efficacy of acute consumption of a novel energy drink (C4S) versus placebo for improving cognitive and gaming performance and mood. Secondarily, we examined the cardiovascular safety profile of acute C4S consumption.

Methods: Forty-five healthy, young adult video gamers completed two experimental visits in randomized order where they consumed either C4S or a placebo and then completed a validated battery of neurocognitive tests, played five video games, and completed a mood state survey.