Apelin as a Potential Regulator of Peak Athletic Performance.

Apelin, as a cardiokine/myokine, is emerging as an important regulator of cardiac and skeletal muscle homeostasis. Loss of apelin signaling results in premature cardiac aging and sarcopenia. However, the contribution of apelin to peak athletic performance remains largely elusive.

Exercise-related hemoconcentration and hemodilution in hydrated and dehydrated athletes: An observational study of the Hungarian canoeists.

Hemoconcentration during exercise is a well-known phenomenon, however, the extent to which dehydration is involved is unclear. In our study, the effect of dehydration on exercise-induced hemoconcentration was examined in 12 elite Hungarian kayak-canoe athletes. The changes of blood markers were examined during acute maximal workload in hydrated and dehydrated states.

Adrenal, Gonadal and Peripherally Steroid Changes in Response to Extreme Physical Stress for Characterizing Load Capacity in Athletes.

Athletes are often exposed to extreme physical stress during training or competitions. The consequent activation of the hypothalamus-hypophysis-adrenal (HPA) axis results in intensified steroid hormone production in the adrenal cortex. We determined the impact of an acute extreme physical stress on adrenal and gonadal steroidogenesis in healthy male professional athletes ( = 40).

High-Resolution Dynamics of Hemodilution After Exercise-Related Hemoconcentration.

Purpose: Hemoconcentration during acute intense exercise is intensively investigated, while the rearrangement of hematological parameters during the recovery period is less understood. The aim of our study was to understand the mechanisms of hemodilution after short-term dynamic exercise.

Methods: Twelve euhydrated male kayak athletes and 6 untrained controls were examined on a spiroergometer.

Comparison of the Cardiovascular Effects of Extreme Psychological and Physical Stress Tests in Male Soccer Players.

Background: The purpose of our study was to compare the physiological effects of extreme physical and psychological stress tests in male soccer players, since these two types of stress apply to athletes with high performance requirements.

Methods: A total of 63 healthy male soccer players participated in this study, all of whom underwent both of the tests. A physical stress test was carried out in an exercise physiology laboratory, where subjects completed an incremental treadmill running test to full exhaustion, and a psychological test was performed in a military tactical room, where subjects met a street offence situation.

Characteristics of the athlete's heart in aged hypertensive and normotensive subjects.

Background: Both hypertension and age-related impairment of the cardiac condition are known to be improved by regular physical training. As relatively few studies have been reported about the older, hypertensive patients, the aim of this study was to establish cardiac benefits of active lifestyle in these subjects.

Methods: Two-dimensionally guided M-mode, Doppler- and tissue Doppler echocardiography was performed in 199 normo- and hypertensive, active and sedentary older (age >60 years) men (N.

Reaction Kinetics Modeling of eHsp70 Induced by Norepinephrine in Response to Exercise Stress.

Exercise elicits a systemic adaptation reaction, involving both neuroendocrine and cellular/paracrine stress responses, exemplified by the sympathoadrenergic activity and the release of cellular Hsp70 into the circulation. Regular sports training is known to result in increased fitness. In this study, we characterized the plasma norepinephrine and Hsp70 levels and modeled their relationship in response to exercise stress by bicycle ergometer in 12 trained judoka athletes and in 10 healthy controls.

Metabolic and catecholamine response to sympathetic stimulation in early-treated adult male patients with phenylketonuria.

Purpose: Defective function of phenylalanine hydroxylase in phenylketonuria (PKU) results in the accumulation of phenylalanine (Phe) and the reduction of tyrosine (Tyr) in the blood, interfering in the normal development and function of organs and tissues in the body. Tyr is the precursor of catecholamines, secreted in response to stress by the adrenal medulla and paraganglia. The aim of this study was to evaluate plasma catecholamine and amino acid response to an escalating series of sympathetic stress tests in PKU patients.

Osteocalcin gene polymorphism and bone density in Hungarian athletes.

Osteoporosis, a public health problem, is mainly determined on the basis of bone mineral density (BMD). The rs1800247 polymorphism of the osteocalcin gene is associated with BMD. The results of one recent Polish study led us to the examination of a possible connection between polymorphism and bone ultrasound parameters in the Hungarian population, including elite athletes.

Hormonal Neuroendocrine and Vasoconstrictor Peptide Responses of Ball Game and Cyclic Sport Elite Athletes by Treadmill Test.

Objective: Our objective was to evaluate complex hormonal response in ball game and cyclic sport elite athletes through an incremental treadmill test, since, so far, variables in experimental procedures have often hampered comparisons of data.

Methods: We determined anthropometric data, heart rate, maximal oxygen uptake, workload, plasma levels of lactate, adrenaline, noradrenaline, dopamine, cortisol, angiontensinogen and endothelin in control (n = 6), soccer (n = 8), handball (n = 12), kayaking (n = 9) and triathlon (n = 9) groups based on a Bruce protocol through a maximal exercise type of spiroergometric test.

Results: We obtained significant increases for adrenaline, 2.

Energy-sensing factors coactivator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and AMP-activated protein kinase control expression of inflammatory mediators in liver: induction of interleukin 1 receptor antagonist.

Obesity and insulin resistance are associated with chronic, low grade inflammation. Moreover, regulation of energy metabolism and immunity are highly integrated. We hypothesized that energy-sensitive coactivator peroxisome proliferator-activated receptor γ coactivator 1-α (PGC-1α) and AMP-activated protein kinase (AMPK) may modulate inflammatory gene expression in liver.

Increased short-term variability of the QT interval in professional soccer players: possible implications for arrhythmia prediction.

Background: Sudden cardiac death in competitive athletes is rare but it is significantly more frequent than in the normal population. The exact cause is seldom established and is mostly attributed to ventricular fibrillation. Myocardial hypertrophy and slow heart rate, both characteristic changes in top athletes in response to physical conditioning, could be associated with increased propensity for ventricular arrhythmias.