Resistance Training Volume Enhances Muscle Hypertrophy but Not Strength in Trained Men

Purpose: The purpose of this study was to evaluate muscular adaptations between low-, moderate-, and high-volume resistance training protocols in resistance-trained men. Methods: Thirty-four healthy resistance-trained men were randomly assigned to one of three experimental groups: a low-volume group performing one set per exercise per training session (n = 11), a moderate-volume group performing three sets per exercise per training session (n = 12), or a high-volume group performing five sets per exercise per training session (n = 11). Training for all routines consisted of three weekly sessions performed on nonconsecutive days for 8 wk. Muscular strength was evaluated with one repetition maximum (RM) testing for the squat and bench press. Upper-body muscle endurance was evaluated using 50% of subjects bench press 1RM performed to momentary failure. Muscle hypertrophy was evaluated using B-mode ultrasonography for the elbow flexors, elbow extensors, mid-thigh, and lateral thigh. Results: Results showed significant preintervention to postintervention increases in strength and endurance in all groups, with no significant between-group differences. Alternatively, while all groups increased muscle size in most of the measured sites from preintervention to postintervention, significant increases favoring the higher-volume conditions were seen for the elbow flexors, mid-thigh, and lateral thigh. Conclusions: Marked increases in strength and endurance can be attained by resistance-trained individuals with just three 13-min weekly sessions over an 8-wk period, and these gains are similar to that achieved with a substantially greater time commitment. Alternatively, muscle hypertrophy follows a dose–response relationship, with increasingly greater gains achieved with higher training volumes. Ke

International society of sports nutrition position stand: caffeine and exercise performance

Following critical evaluation of the available literature to date, The International Society of Sports Nutrition (ISSN) position regarding caffeine intake is as follows: 1. Supplementation with caffeine has been shown to acutely enhance various aspects of exercise performance in many but not all studies. Small to moderate benefits of caffeine use include, but are not limited to: muscular endurance, movement velocity and muscular strength, sprinting, jumping, and throwing performance, as well as a wide range of aerobic and anaerobic sport-specific actions. 2. Aerobic endurance appears to be the form of exercise with the most consistent moderate-to-large benefits from caffeine use, although the magnitude of its effects differs between individuals. 3. Caffeine has consistently been shown to improve exercise performance when consumed in doses of 3–6 mg/ kg body mass. Minimal effective doses of caffeine currently remain unclear but they may be as low as 2 mg/kg body mass. Very high doses of caffeine (e.g. 9 mg/kg) are associated with a high incidence of side-effects and do not seem to be required to elicit an ergogenic effect. 4. The most commonly used timing of caffeine supplementation is 60 min pre-exercise. Optimal timing of caffeine ingestion likely depends on the source of caffeine. For example, as compared to caffeine capsules, caffeine chewing gums may require a shorter waiting time from consumption to the start of the exercise session. 5. Caffeine appears to improve physical performance in both trained and untrained individuals. 6. Inter-individual differences in sport and exercise performance as well as adverse effects on sleep or feelings of anxiety following caffeine ingestion may be attributed to genetic variation associated with caffeine metabolism, and physical and psychological response. Other factors such as habitual caffeine intake also may play a role in between-individual response variation. 7. Caffeine has been shown to be ergogenic for cognitive function, including attention and vigilance, in most individuals. 8. Caffeine may improve cognitive and physical performance in some individuals under conditions of sleep deprivation. 9. The use of caffeine in conjunction with endurance exercise in the heat and at altitude is well supported when dosages range from 3 to 6 mg/kg and 4–6 mg/kg, respectively. 10. Alternative sources of caffeine such as caffeinated chewing gum, mouth rinses, energy gels and chews have been shown to improve performance, primarily in aerobic exercise. 11. Energy drinks and pre-workout supplements containing caffeine have been demonstrated to enhance both anaerobic and aerobic performance

Polyphenols of Traditional Apple Varieties in Interaction with Barley β-Glucan: A Study of the Adsorption Process

Apple polyphenols have been studied for various beneficial bioactivities. Especially interesting are traditional, old varieties of apples for which some initial studies have suggested significant bioactivities, but they are still not completely understood. Polyphenol bioactivities can be affected by interactions with dietary fibers such as β-glucans. The aim of this study was to investigate for the first time interactions between individual polyphenols from traditional, old apple varieties (“Božićnica” and “Batulenka”) and β-glucans by studying the adsorption process. Polyphenols were extracted from the peel and flesh of traditional apples by using an ultrasonic bath and characterized with high-performance liquid chromatography. The amounts of adsorbed (qe) and un-adsorbed (ce) polyphenols were modeled with adsorption isotherms (Langmuir, Dubinin–Radushkevich, and Hill) by using improved non-linear fitting in a novel R algorithm, developed specifically for the modeling of adsorption isotherms. Polyphenols adsorbed onto β-glucan from 9 to 203 (peel, “Božićnica”), 1 to 484 (peel, “Batulenka”), 5 to 160 (flesh, “Božićnica”), and 19 to 28 mg g−1 (flesh, “Batulenka”). The adsorption was concentration dependent (polyphenols present in higher amount adsorbed in higher amounts). Physical sorption can be suggested. Polyphenols from traditional apples adsorb onto β-glucan and should be further studied

Study of Interactions Between Individual Phenolics of Aronia with Barley Beta-Glucan

Beneficial effects of aronia phenolics are determined by their interactions with dietary fibers, such as beta-glucan. The aim of this research was to study interactions between aronia phenolics and beta-glucan by investigating the adsorption process. Phenolic compounds were extracted from aronia, analyzed using high-performance liquid chromatography, and adsorbed onto beta-glucan at pH 1.5. The adsorption data were modeled by using Langmuir, Dubinin-Radushkevich, and Hill isotherms with a novel non-linear regression developed especially for adsorption isotherms. Aronia phenolics adsorbed onto beta-glucan in amounts 31-250 mg/g (individual anthocyanins), 44-123 mg/g (individual flavonols), and 51 mg/g (neochlorogenic acid). The correlation between adsorption capacities and phenolic content was high (r2=0.94), which suggested that the adsorption might be concentration dependent. Modeling with a novel non-linear regression allowed more precise determination of adsorption isotherm parameters. Furthermore, there was a correlation between maximum adsorption capacities predicted by models and measured adsorption capacities (r2 0.76, 0.81, and 0.34 for Langmuir, Dubinin-Radushevich, Hill isotherms, respectively). The suggested bonds involved in interactions are non-covalent bonds (H bonds, Van der Waals forces). Principal component analysis showed that anthocyanins, flavonols, and phenolic acids could differently behave in the adsorption process, which could be due to differences in the chemical structures (ionic nature of anthocyanins, nonionic nature of flavonols and phenolic acids at low pH). In conclusion, aronia phenolics interacted with beta-glucan by adsorbing onto its surface, and the novel modeling developed by our team was helpful in the interpretation of this process. Interactions should be further studied due to their importance for the beneficial effects of aronia

Singly and doubly excited states in ejected electron spectra of neon at high incident electron energies

Ejected electron spectroscopy has been used to study singly and doubly excited states of neon at constant incident electron energies between 505 and 2018 eV and ejection angles from 10° to 130° with high resolution in ejected energy range from 12 to 46 eV. The full ejected electron energy range has been studied at two extreme incidence energies and three ejected angles, namely 40°, 90° and 130°. The low energy region (12 to 21.5 eV) has been investigated at 505 eV over the full angular range and at 90° at six incident energies from 505 to 2018 eV. The features in the ejected electron spectra have been attributed to the autoionisation of Ne+ (2s2p6nl) excited states and Ne (2s2p5nln′l′ and 2s22p4nln′l′) double excited autionising states. Lower energy ejected electrons arise from simultaneous excitation of s and p electrons above the second ionisation potential (62.53 eV) while higher energy ejected electrons are coming from singly and doubly excited states. The high resolution and high sensitivity allowed us to see separated singlet from triplet states at high incident energies. Comparison with previous works gives a good agreement in energy positions of measured features. At the highest ejected electron energies only the features coming from double excitation are present, but with very low intensities in the spectra due to the small cross sections and high background. New resonances are found whose classification needs new experimental and theoretical investigations

Absolute cross-sections and kinetic-energy-release distributions for electron-impact ionization and dissociation of CD3+

Absolute cross-sections have been measured for electron-impact dissociative excitation and ionization of CD3+/(CH3+) leading to formation of singly-charged fragments (CD2+, CH+, C+, H-2(+) and D+). The animated crossed-beams method is applied in the energy range from the reaction threshold up to 2.5 keV. The maximum cross-sections are found to be (14.0 +/- 1.0) x 10(-17) cm(2), (6.5 +/- 0.7) x 10(-17) cm(2), (3.3 +/- 0.3) x 10(-17) cm(2), (1.1 +/- 0.1) x 10(-17) cm(2) and (14.0 +/- 1.3) x 10(-17) cm(2) for CD2+, CH+, C+, H-2(+) and D+, respectively. Individual contributions for dissociative excitation and dissociative ionization are determined for each product as they are indispensable for plasma modelling, diagnostics and data analysis in fusion experiments. Conforming to the scheme recently used in the CD4+ study, the cross-sections are presented in analytic forms suitable for their implementation in plasma simulation codes. Kinetic-energy-release distributions are determined for each product at selected electron energies

Hypercoagulability in Cushing's syndrome: the role of specific haemostatic and fibrinolytic markers

OBJECTIVE: Hypercoagulability is a commonly described complication in patients with Cushing's syndrome. Recent clinical studies have indicated various abnormalities of coagulation and fibrinolysis parameters which may be related to that phenomenon. The aim of this study was to investigate the mechanisms underlying the hypercoagulable state in patients with Cushing's syndrome. ----- RESEARCH METHODS AND PROCEDURES: A wide range of serum markers involved in the processes of blood coagulation and fibrinolysis was measured in a group of 33 patients with Cushing's syndrome and 31 healthy controls. No participant was taking medication which could influence the result or had known diseases, except hypertension and diabetes, which could affect blood coagulation or fibrinolysis parameters. ----- RESULTS: Patients with Cushing's syndrome had higher levels of clotting factors II (P = 0.003), V (P < 0.001), VIII (P < 0.001), IX (P < 0.001), XI (P < 0.001) and XII (P = 0.019), protein C (P < 0.001), protein S (P < 0.001), C1-inhibitor (P < 0.001) and plasminogen activator inhibitor-1 (PAI-1) (P = 0.004). The activity of fibrinolytic markers, plasminogen (P < 0.001), antithrombin (P < 0.001) and antithrombin antigen (P = 0.001) was also increased in the patient group. ----- CONCLUSION: The study has demonstrated hypercoagulability in patients with Cushing's syndrome manifest as increased prothrombotic activity and compensatory activation of the fibrinolytic system. We propose the introduction of thromboprophylaxis in the preoperative and early postoperative periods, combined with a close follow-up in order to prevent possible thromboembolic events in patients with Cushing's syndrome

Low-energy electron transmission through high aspect ratio Al2O3 nanocapillaries

Electron transmission through insulating Al2O3 nanocapillaries of different diameters (40 and 270 nm) and 15 mu m length has been investigated for low-energy electrons (2-120 eV). The total intensity of transmitted current weakly depends on the incident electron energy and tilt angle defined with respect to the capillary axis. On the other hand, the intensity of elastically transmitted electrons significantly varies with the alteration of electron energy and tilt angle. In addition, we measured an energy distribution of electrons transmitted both in the straightforward direction and at large tilt angle. The measured spectra show that inelastic processes dominate and, in particular, a large amount of low-energy electrons. These low-energy electrons can be either inelastically scattered projectiles or secondary electrons emitted within the capillaries. Furthermore, a change of the tilt angle appears to influence significantly only the intensity of the elastic transmission. The present results suggest a more complex nature of low-energy electron transport through insulating nanocapillaries than proposed for positive ions. Copyright (C) EPLA, 200