Eccentric contractions require the lengthening of skeletal muscle during force production and result in acute and prolonged muscle injury. Because a variety of stressors, including physical exercise and injury, can result in the activation of the c-Jun NH(2)-terminal kinase (JNK) intracellular signaling cascade in skeletal muscle, we investigated the effects of eccentric exercise on the activat...

The purpose of this study was to test the hypothesis that the potentiation of concentric twitch force during work cycles is dependent upon both the speed and direction of length change. Concentric and eccentric forces were elicited by stimulating muscles during the shortening and lengthening phases, respectively, of work cycles. Work cycle frequency was varied in order to vary the speed of musc...

The purpose of this study was to estimate the efficiency of ATP utilization for concentric, eccentric, and isometric muscle action in the human tibialis anterior and extensor digitorum longus in vivo. A dynamometer was used to quantitate muscle work, or tension, while simultaneous 31P-nuclear magnetic resonance data were collected to monitor ATP, phosphocreatine, inorganic phosphate, and pH. Th...

The present study determined the effects of concentric and eccentric muscle actions on the contents of serum myostatin and follistatin-like related gene (FLRG). Eight untrained males performed one exercise bout with each leg, separated by three weeks. One bout consisted of 7 sets of 10 repetitions of eccentric muscle actions of the knee extensors at 150% of the concentric 1-RM while the other b...

The stretch-shortening cycle is one of the most interesting topics in the field of sport sciences, because the performance of human movement is enhanced by the stretch-shortening cycle (eccentric contraction). The purpose of the present study was to examine whether the influence of preactivation on the torque enhancement by stretch-shortening cycle in knee extensors. Twelve men participated in ...

Evaluation of The Acute Hormonal Responses To Concentric, Eccentric And Concentric_ Eccentric Muscle Actions in Healthy Young Men Introduction: Resistance exercise is a potent stimulus for acute increase in the concentrations of circulating hormones such as Growth Hormone (GH) and Testosterone. Conventional resistance exercise is performed using sequential concentric (CON) and eccentric (EC...

The prescription of eccentric loading is considered as a mainstay of non-operative rehabilitation programmes for mid-substance chronic Achilles tendinopathy. Such exercises have some degree of clinical utility in comparison with concentric training and are often referred to as a strengthening programme. Yet the dose parameters of the eccentric loading do not reflect an optimal strengthening pro...

BACKGROUND Long-term endurance sport practice leads to eccentric left ventricular hypertrophy (LVH). We aimed to compare the new 4-tiered classification (4TC) for LVH with the established 2-tiered classification (2TC) in a cohort of normotensive non-elite endurance athletes. METHODS Male participants of a 10-mile race were recruited and included when blood pressure (BP) was normal (<140/90 mm...

BACKGROUND Coronary remodeling plays a significant role in lumen loss in transplant allograft vasculopathy (TxCAD), but the determinants of remodeling are unknown. We assessed the relationship between remodeling and plaque topography, coronary compliance, and blood flow in TxCAD. METHODS AND RESULTS One artery in each of 27 transplant patients was investigated with simultaneous intravascular ...

The practice of incorporating augmented eccentric loading (AEL) into resistance exercise is still relatively new. Although limited, there is evidence supporting the contention that AEL may lead to both superior acute and chronic adaptations over more traditional methods. AEL involves coupled concentric and overloaded eccentric muscle actions, and attempts to optimise the muscular adaptations as...