The influence of initial training status on the response of circulating insulin-like growth factor (IGF) and its binding proteins (IGFBP) to prolonged physical training was studied in young men. It was hypothesized that highly standardized training would result in more extensive changes in the circulating IGF system in untrained subjects because of lower fitness level. Seven untrained (UT) and ...

Physical activity plays a key role in the control of neuroendocrine, autonomic, and behavioral responses to physical and psychosocial stress. However, little is known about how the level of physical activity modulates stress responsiveness. Here, we test whether different levels of physical activity are associated with different adrenal, cardiovascular, and psychological responses to psychosoci...

The effect of antioxidant supplementation on exercise performance has not been clearly defined in trained or untrained individuals. The purpose of this investigation was to test the effects of quercetin-resveratrol combination on plasma anti-inflammatory response and exercise performance in untrained men. After baseline cycling performance testing, the subjects (n=8) were supplemented daily wit...

Because the maintenance of glycemia is essential during prolonged exercise, we examined the effects of endurance training, exercise intensity, and plasma lactate concentration ([lactate]) on gluconeogenesis (GNG) and hepatic glycogenolysis (GLY) in fasted men exercising at, and just below, the lactate threshold (LT), where GNG precursor lactate availability is high. Twelve healthy men (6 untrai...

The aim of this study was to investigate alterations in haemoglobin conformation and parameters related to oxidative stress in whole erythrocytes, membranes, and plasma after a single bout of exercise in a group of young untrained men. Venous blood samples from eleven healthy young untrained males (age = 22 ± 2 years, BMI = 23 ± 2.5 kg/m(2)) were taken from the antecubital vein before an increm...

PURPOSE This study examined the effects of age and training status on the pulmonary oxygen uptake (VO2p) kinetics of untrained and chronically trained young, middle-age, and older groups of men. METHODS Breath-by-breath VO2p and near-infrared spectroscopy-derived muscle deoxygenation ([HHb]) were monitored continuously in young (20-39 yr) trained (YT, n = 8) and untrained (YuT, n = 8), middle...

BACKGROUND Dietary supplements containing L-arginine are marketed to improve exercise performance, but the efficacy of such supplements is not clear. Therefore, this study examined the efficacy of acute ingestion of L-arginine alpha-ketoglutarate (AAKG) muscular strength and endurance in resistance trained and untrained men. METHODS Eight resistance trained and eight untrained healthy males i...

Background Inadequate recovery between training sessions leads to fatigue and imposes a hindrance on exercise performance. Bio-Active Peptides (BAPs) supplementation has been shown to reduce recovery time between strenuous exercise bouts and improve work capacity during subsequent bouts in athletes. However, few investigations have explored the efficacy of BAP supplementation on early performan...