VO2 Steady State at and Just Above Maximum Lactate Steady State Intensity.

Over recent decades the association between metabolic and gas exchange parameters during exercise has become evident. Different "thresholds" (such as lactate thresholds, critical power, EMG thresholds) and intensity domains appear to be linked to an upper limit of oxygen uptake steady state (V̇O). The aim of this study was to investigate whether MLSS is associated with the upper limit for a V̇O.

Association Between the 25-Hydroxyvitamin D Status and Physical Performance in Healthy Recreational Athletes.

Molecular and clinical studies have linked vitamin D (vitD) deficiency to several aspects of muscle performance. For this retrospective cross-sectional study data from 297 male (M) and 284 female (F) healthy recreational athletes were used to evaluate the prevalence of vitD deficiency in athletes living in Austria and to determine whether serum 25-hydroxyvitamin D (25(OH)D) correlates with maximal (P) and submaximal physical performance (P) measured on a treadmill ergometer. The data were controlled for age, season, weekly training hours (WTH), body mass index (BMI) and smoking status.

Physiological Demands of Simulated Off-Road Cycling Competition.

The purpose of the study was to measure the demands of off-road cycling via portable spirometry, leg-power output (PO), heart rate (HR) and blood lactate (BLa) concentration. Twenty-four male competitive cyclists (age: 29±7.2 yrs, height: 1.

Blood lactate concentration at the maximal lactate steady state is not dependent on endurance capacity in healthy recreationally trained individuals.

The aim of the study was to investigate the independent relationship between maximal lactate steady state (MLSS), blood lactate concentration [La] and exercise performance as reported frequently. Sixty-two subjects with a wide range of endurance performance (MLSS power output 199 ± 55 W; range: 100-302 W) were tested on an electronically braked cycle ergometer. One-min incremental exercise tests were conducted to determine maximal variables as well as the respiratory compensation point (RCP) and the second lactate turn point (LTP2).

A single nucleotide polymorphism associates with the response of muscle ATP synthesis to long-term exercise training in relatives of type 2 diabetic humans.

Objective: Myocellular ATP synthesis (fATP) associates with insulin sensitivity in first-degree relatives of subjects with type 2 diabetes. Short-term endurance training can modify their fATP and insulin sensitivity. This study examines the effects of moderate long-term exercise using endurance or resistance training in this cohort.

Short-term exercise training does not stimulate skeletal muscle ATP synthesis in relatives of humans with type 2 diabetes.

Objective: We tested the hypothesis that short-term exercise training improves hereditary insulin resistance by stimulating ATP synthesis and investigated associations with gene polymorphisms.

Research Design And Methods: We studied 24 nonobese first-degree relatives of type 2 diabetic patients and 12 control subjects at rest and 48 h after three bouts of exercise. In addition to measurements of oxygen uptake and insulin sensitivity (oral glucose tolerance test), ectopic lipids and mitochondrial ATP synthesis were assessed using(1)H and(31)P magnetic resonance spectroscopy, respectively.

Impaired mitochondrial function and insulin resistance of skeletal muscle in mitochondrial diabetes.

Objective: Impaired muscular mitochondrial function is related to common insulin resistance in type 2 diabetes. Mitochondrial diseases frequently lead to diabetes, which is mostly attributed to defective beta-cell mitochondria and secretion.

Research Design And Methods: We assessed muscular mitochondrial function and lipid deposition in liver (hepatocellular lipids [HCLs]) and muscle (intramyocellular lipids [IMCLs]) using (31)P/(1)H magnetic resonance spectroscopy and insulin sensitivity and endogenous glucose production (EGP) using hyperinsulinemic-euglycemic clamps combined with isotopic tracer dilution in one female patient suffering from MELAS (myopathy, encephalopathy, lactic acidosis, and stroke-like episodes) syndrome and in six control subjects.

Reduced basal ATP synthetic flux of skeletal muscle in patients with previous acromegaly.

Background: Impaired mitochondrial function and ectopic lipid deposition in skeletal muscle and liver have been linked to decreased insulin sensitivity. As growth hormone (GH) excess can reduce insulin sensitivity, we examined the impact of previous acromegaly (AM) on glucose metabolism, lipid storage and muscular ATP turnover.

Participants And Methods: Seven AM (4f/3 m, age: 46+/-4 years, BMI: 28+/-1 kg/m(2)) and healthy volunteers (CON: 3f/4 m, 43+/-4 years, 26+/-2 kg/m(2)) matched for age and body mass underwent oral glucose testing for assessment of insulin sensitivity (OGIS) and ss-cell function (adaptation index, ADAP).

Menstrual cycle: no effect on exercise cardiorespiratory variables or blood lactate concentration.

Purpose: Numerous investigations have reported changes in metabolic and cardiorespiratory responses associated with the menstrual cycle. We examined whether variables commonly used in exercise testing are influenced by menstrual cycle phases.

Methods: Nineteen eumenorrheic women performed two incremental tests to voluntary exhaustion on a cycle ergometer during two different phases of the menstrual cycle: the follicular phase (FP) and the luteal phase (LP).

Beta1-adrenoceptor mediated origin of the heart rate performance curve deflection.

Purpose: The deflection of the HR performance curve (HRPC) has been described as an objective marker of submaximal exercise performance. HR response to incremental cycle ergometer exercise is shown to be neither linear nor uniform and a physiological explanation of the deflection phenomenon is lacking. We hypothesized that differences in the beta1-adrenoceptor site are the source of these differences.

Effect of high-volume and -intensity endurance training in heart transplant recipients.

Background: A recommended component of heart transplant recipients (HTR) is endurance-oriented exercise therapy. However, the trainability of HTR after transplantation is vague. We examined the effect of high-volume and -intensity exercise training on exercise performance in HTR, compared with HTR undergoing regular rehabilitation training, and sedentary healthy subjects (SHS).

Changes in blood lactate and respiratory gas exchange measures in sports with discontinuous load profiles.

This study compares two different sport events (orienteering = OTC; tennis = TEC) with discontinuous load profiles and different activity/recovery patterns by means of blood lactate (LA), heart rate (HR), and respiratory gas exchange measures (RGME) determined via a portable respiratory system. During the TEC, 20 tennis-ranked male subjects [age: 26.0 (3.

Respiratory gas exchange and lactate measures during competitive orienteering.

Purpose: In the past, orienteering sports analyses were based on heart rate (HR) and lactate (LA) measures. This study assessed additional respiratory gas exchange measures (RGEM) to provide further information regarding the physiological requirements of orienteering competitions (OTC).

Methods: Eleven elite male athletes performed simulated OTC.

Accuracy of neuro-fuzzy logic and regression calculations in determining maximal lactate steady-state power output from incremental tests in humans.

The aim of this study was to employ neuro-fuzzy logic and regression calculations to determine the accuracy of prediction of the power output ( P) of the maximal lactate steady-state (MLSS) on a cycle ergometer calculated from the results of incremental tests. A group of 17 male and 17 female sports students underwent two incremental tests (a 1 min test T(1): initial exercise intensity 0.2 W x kg(-1) increasing 0.