Although it is well established that maximal O(2) uptake (Vo(2 max)) declines from adulthood to old age, the role played by alterations in skeletal muscle is unclear. Specifically, because during whole body exercise reductions in convective O(2) delivery to the working muscles from adulthood to old age compromise aerobic performance, this obscures the influence of alterations within the skeleta...

It is unclear whether preceding repetitive brief ischemia causes any improvement in the energy efficiency of intracellular calcium cycling or crossbridge cycling that may lead to cardioprotection after subsequent sustained ischemia/reperfusion, a phenomenon called ischemic preconditioning. To address this issue, left ventricular (LV) contractility (E(max)) and the relation between myocardial ox...

To further explore the limitations to maximal O(2) consumption (.VO(2 max)) in exercise-trained skeletal muscle, six cyclists performed graded knee-extensor exercise to maximum work rate (WR(max)) in hypoxia (12% O(2)), hyperoxia (100% O(2)), and hyperoxia + femoral arterial infusion of adenosine (ADO) at 80% WR(max). Arterial and venous blood sampling and thermodilution blood flow measurements...

UNLABELLED Improvements in prosthesis design have facilitated participation in competitive running for persons with lower limb loss (AMP). PURPOSE The purpose of this study was to examine the physiological responses of AMP using a run-specific prosthesis (RP) versus a traditional prosthesis (P) and cross-referenced with nonamputee controls (C) matched by training status, age, gender, and body...

VO(2) kinetics and O(2) deficit are important determinants of exercise tolerance. In "normal" conditions convective and diffusive O(2) delivery to skeletal muscle fibers do not represent important determinants of VO(2) kinetics, whose limiting factors seem mainly located within muscle fibers. Whereas a limiting role by PDH has not been confirmed, the role of inhibition of mitochondrial respirat...

Carbohydrate-protein supplementation has been found to increase the rate of training adaptation when provided postresistance exercise. The present study compared the effects of a carbohydrate and protein supplement in the form of chocolate milk (CM), isocaloric carbohydrate (CHO), and placebo on training adaptations occurring over 4.5 weeks of aerobic exercise training. Thirty-two untrained sub...

STUDY OBJECTIVES To compare the effect of montelukast and the long-acting beta(2)-agonist salmeterol on cardiopulmonary exercise economy and physical performance in adult patients with asthma during exercise. DESIGN AND PATIENTS Asthmatic patients (n = 18), aged 18 to 35 years with exercise-induced bronchoconstriction (EIB), using a double-blind, double-dummy cross-over design. Montelukast, 1...

This study investigated the repeated-sprint ability (RSA) physiological responses to a standardized, high-intensity, intermittent running test (HIT), maximal oxygen uptake (VO(2) (max)) and oxygen uptake (VO(2)) kinetics in male soccer players (professional (N = 12) and amateur (N = 11)) of different playing standards. The relationships between each of these factors and RSA performance were det...

The purpose of the study was to examine the roles of active pyruvate dehydrogenase (PDH(a)), glycogen phosphorylase (Phos), and their regulators in lactate (Lac(-)) metabolism during incremental exercise after ingestion of 0.3 g/kg of either NaHCO(3) [metabolic alkalosis (ALK)] or CaCO(3) [control (CON)]. Subjects (n = 8) were studied at rest, rest postingestion, and during constant rate cyclin...