Seven older cyclists (mean age 66.9 years) still engaged in severe endurance training (mean = 8114.3 km year-1) were examined medically, echocardiographically and they underwent a maximal stress test on a bicycle. Mean maximal values were VO2,max = 44.7 ml, Wmax = 261.4 and heart rate = 157.4 beats min-1. The heart volume/max O2-pulse ratio (mean = 46.1) and the TEDD/max O2-pulse ratio (mean = ...

Following preliminary indications that in some individuals arm exercise enhanced rather than reduced simultaneous leg endurance, ten young men and women performed three forms of intermittent work to volitional exhaustion, under duty cycles of 45 s work, 15 s rest. The protocols were as follows: (A) knee extensions at 30% maximum voluntary contraction (MVC); (B) 30% MVC knee extensions combined ...

This study compared the oxygen uptake (VO2) and running velocity at which the lactate threshold (LT), the ventilatory threshold (VT), and the maximal lactate steady state (MSSLA), and the maximal VO2 steady state (MSSVO2) occurred in 11 trained male runners (mean age = 22.4 years, range 18-28 years). Each underwent an incremental treadmill test to exhaustion. The LT was defined by a systematic,...

We hypothesized that circulating GH would increase only if a threshold of work intensity [corresponding to the anaerobic or lactate threshold (LT)] was exceeded. Ten healthy male volunteers (18-35 yr) first performed ramp-type progressive cycle-ergometer exercise to determine the LT and the maximal oxygen uptake. On subsequent mornings after an overnight fast, each subject performed bouts of 1,...

This study tested the hypothesis that the DMAX (for maximal distance) method could be applied to ratings of perceived exertion (RPE), to propose a novel method for individual detection of the lactate threshold (LT) using RPE alone during an incremental test to exhaustion. Twenty-one participants performed an incremental test on a cycle ergometer. At the end of each stage, lactate concentration ...

PURPOSE To examine the effectiveness of threshold and polarized models in the training organization of Chinese top-level sprint speed skaters using a 2-y quasi-experimental design. METHODS Two years (2004-05 and 2005-06 seasons) of the Chinese national speed-skating team's daily training load (N = 9; 5 men, 23.6 ± 1.7 y, weight 76.6 ± 4.1 kg, competitive experience 5.0 ± 0.8 y, 500-m time 35....

This case study examines the impact of low serum ferritin (sFe) on physiological assessment measures and performance in a young female 1500-m runner undertaking approximately 95-130 km/wk training. The study spans 4 race seasons and an Olympic Games. During this period, 25 venous blood samples were analyzed for sFe and hemoglobin (Hb); running economy, VO(2max), and lactate threshold were measu...

INTRODUCTION Serum lactate level may correlate with no-flow and low-flow status during cardiac arrest. Current guidelines have no recommended durations for cardiopulmonary resuscitation (CPR) before transition to the next strategy. We hypothesized that the lactate level measured during CPR could be associated with the survival probability and accordingly be useful in estimating the optimal dura...

Amyotrophic lateral sclerosis (ALS; Lou Gehrig's disease) is a progressive debilitating neurodegenerative disease with no cure. We propose a novel molecular model for the pathogenesis of ALS that involves an adenosine triphosphate (ATP)-dependent muscle neuronal lactate shuttle (MNLS) at the neuromuscular junction (NMJ) to regulate the flow of lactate from muscle to neurons and vice versa. Fail...

OBJECTIVES To examine the proportions of type 1 and type 2 muscle fibres and the degree of muscle fibre atrophy and hypertrophy in patients with chronic fatigue syndrome in relation to lactate responses to exercise, and to determine to what extent any abnormalities found might be due to inactivity. METHODS Quadriceps needle muscle biopsies were obtained from 105 patients with chronic fatigue ...