Glycaemic Effects of a 156-km Ultra-trail Race in Athletes: An Observational Field Study.

Background: Ultra-trail running races pose appreciable physiological challenges, particularly for glucose metabolism. Previous studies that yielded divergent results only measured glycaemia at isolated times.

Objectives: We aimed to explore the impact of an ultra-endurance race on continuously measured glycaemia and to understand potential physiological mechanisms, as well as the consequences for performance and behavioural alertness.

In Amateur Athletes With Type 1 Diabetes, a 9-Day Period of Cycling at Moderate-to-Vigorous Intensity Unexpectedly Increased the Time Spent in Hyperglycemia, Which Was Associated With Impairment in Heart Rate Variability.

Objective: In type 1 diabetes, autonomic dysfunction may occur early as a decrease in heart rate variability (HRV). In populations without diabetes, the positive effects of exercise training on HRV are well-documented. However, exercise in individuals with type 1 diabetes, particularly if strenuous and prolonged, can lead to sharp glycemic variations, which can negatively impact HRV.

Cannabidiol in sport: Ergogenic or else?

In the sports domain, cannabis is prohibited by the World Anti-Doping Agency (WADA) across all sports in competition since 2004. The few studies on physical exercise and cannabis focused on the main compound i.e.

Beetroot Juice Does Not Enhance Supramaximal Intermittent Exercise Performance in Elite Endurance Athletes.

Nitrate (NO)-rich beetroot juice (BR) is recognized as an ergogenic supplement that improves exercise tolerance during submaximal to maximal intensity exercise in recreational and competitive athletes. A recent study has investigated the effectiveness of BR on exercise performance during supramaximal intensity intermittent exercise (SIE) in Olympic-level track cyclists, but studies conducted in elite endurance athletes are scarce. The present study aimed to determine whether BR supplementation enhances the tolerance to SIE in elite endurance athletes.

Active Versus Passive Recovery in High-Intensity Intermittent Exercises in Children: An Exploratory Study.

This study aimed to compare the effect of active recovery (AR) versus passive recovery (PR) on time to exhaustion and time spent at high percentages of peak oxygen uptake ( ) during short, high-intensity intermittent exercises in children. Twelve children (9.5 [0.

Plasma asymmetric dimethylarginine concentrations are not related to differences in maximal oxygen uptake in endurance trained and untrained men.

New Findings: What is the central question of this study? Is there an association of plasma concentration of asymmetric dimethylarginine, which is related to exercise capacity in patients with cardiovascular diseases, with oxygen delivery and subsequently exercise capacity in healthy subjects in the absence of the potentially confounding influence of inflammation and oxidative stress? What is the main finding and its importance? Plasma asymmetric dimethylarginine concentrations are not related to exercise capacity in healthy subjects, while O delivery in the working skeletal muscle during the maximal graded-exercise test is not associated with any of the l-arginine analogues. ADMA alone does not play a crucial role in local muscle perfusion and in maintaining exercise capacity.

Abstract: Asymmetric dimethylarginine (ADMA) is an endogenous inhibitor of nitric oxide (NO) synthesis that could limit oxygen (O ) delivery in the working skeletal muscles by altering endothelium-dependent vasodilatation.

Longitudinal Follow-Up of Physical Activity During School Recess: Impact of Playground Markings.

To promote physical activity (PA) among children, few studies have reported long-term effects of playground marking during school recess. The aim of this study was to investigate the impact of a playground design on children's recess PA across 12 months and to evaluate the influence of covariates on the intervention effects with accelerometry data. Two hundred and eighty-three children (aged 6-11 years) were selected from 3 elementary schools.

Cardiorespiratory Responses to Continuous and Intermittent Exercises in Children.

The aim of the study was to characterize aerobic responses to high intensity intermittent (HIIE) and continuous (CE) exercises in prepubertal children. 26 children aged 8 to 11-year-old took part in a preliminary session to determine peakVO and Maximal Aerobic Velocity (MAV). In 5 subsequent experimental visits, the participants completed 2 CE and 3 HIIE sessions in a randomized order.

Exercise training and high-fat diet elicit endocannabinoid system modifications in the rat hypothalamus and hippocampus.

The purpose of the present study was to examine the effect of chronic exercise on the hypothalamus and hippocampus levels of the endocannabinoids (eCBs) anandamide (AEA) and 2-arachidonoylglycerol (2-AG) and of two AEA congeners and on the expression of genes coding for CB1, CB2 receptors (Cnr1 and Cnr2, respectively), and the enzymes responsible for eCB biosynthesis and degradation, in rats fed with a standard or high-fat diet. Male Wistar rats (n = 28) were placed on a 12-week high-fat (HFD) or standard diet period, followed by 12 weeks of exercise training for half of each group. Tissue levels of eCBs and related lipids were measured by liquid chromatography mass spectrometry, and expression of genes coding for CB1 and CB2 receptors and eCB metabolic enzymes was measured by quantitative real-time polymerase chain reaction (qPCR).

Effects of chronic exercise on the endocannabinoid system in Wistar rats with high-fat diet-induced obesity.

The endocannabinoid system is dysregulated during obesity in tissues involved in the control of food intake and energy metabolism. We examined the effect of chronic exercise on the tissue levels of endocannabinoids (eCBs) and on the expression of genes coding for cannabinoid receptor 1 (CB1) and cannabinoid receptor 2 (CB2) (Cnr1 and Cnr2, respectively) in the subcutaneous (SAT) and visceral adipose tissues and in the soleus and extensor digitorim longus (EDL) muscles, in rats fed with standard or high-fat diet. Twenty-eight male Wistar rats were placed on high-fat diet or standard diet (HFD and Ctl groups, respectively) during 12 weeks whereafter half of each group was submitted to an exercise training period of 12 weeks (HFD + training and Ctl + training).

Effect of dietary nitrate supplementation on tolerance to supramaximal intensity intermittent exercise.

Dietary nitrate (NO3(-)) supplementation has been shown to increase exercise tolerance and improve oxidative efficiency during aerobic exercise in healthy subjects. We tested the hypothesis that a 3-day supplementation in beetroot juice (BJ) rich in NO3(-) would improve the tolerance to supramaximal intensity intermittent exercise consisting of 15-s exercise periods at 170% of the maximal aerobic power interspersed with 30-s passive recovery periods. The number of repetitions completed before reaching volitional exhaustion was significantly higher in the BJ than in the placebo condition (26.

Swimmers can train in hypoxia at sea level through voluntary hypoventilation.

This study used an innovative technique of pulse oximetry to investigate whether swimmers can train under hypoxic conditions through voluntary hypoventilation (VH). Ten trained subjects performed a front crawl swimming series with normal breathing (NB), VH at high (VHhigh) and low pulmonary volume (VHlow). Arterial oxygen saturation was continuously measured via pulse oximetry (SpO2) with a waterproofed forehead sensor.

Continuous vs. interval aerobic training in 8- to 11-year-old children.

The aim of the present study was to show if the use of continuous-running training vs. intermittent-running training has comparable or distinct impact on aerobic fitness in children. At first, children were matched according to their chronological age, their biological age (secondary sexual stages), and their physical activity or training status.

Effect of high intensity intermittent training on heart rate variability in prepubescent children.

The purpose of this study was to observe the effect of high intermittent exercise training on children's heart rate variability (HRV). Thirty-eight children (age 9.6 +/- 1.

Is aerobic endurance a determinant of cardiac autonomic regulation?

The aim of this study was to determine if subjects matched for VO2max but with differing aerobic endurance displayed similar heart rate variability (HRV) at rest and heart rate recovery (HRR) after maximal exercise. We hypothesized that the higher the aerobic endurance, the higher the HRV and the faster the HRR. Twenty-eight well trained middle- and long-distance runners (24 men and 4 women) performed a maximal continuous graded exercise test for the determination of maximal oxygen consumption (VO2max), ventilatory threshold (VT), peak treadmill velocity (PTV) and HRR, as well as a test to measure the autonomic regulation of heart rate during supine rest, using HRV analysis.

Prediction of one-hour running performance using constant duration tests.

Critical velocity (CV) represents, theoretically, the highest velocity that can be sustained without fatigue. The aim of this study was to compare CV computed from 5 mathematical models in order to determine which CV estimate is better correlated with 1-hour performance and which model provides the most accurate prediction of performance. Twelve trained middle- and long-distance male runners (29 +/- 5 years) performed 3 randomly ordered constant duration tests (6, 9, and 12 minutes), a maximal running velocity test for the estimation of CV, and a 1-hour track test (actual performance).

Validity of the polar S810 heart rate monitor to measure R-R intervals at rest.

Purpose: This study was conducted to compare R-R intervals and the subsequent analysis of heart rate variability (HRV) obtained from the Polar S810 heart rate monitor (HRM) (Polar Electro Oy) with an electrocardiogram (ECG) (Physiotrace, Estaris, Lille, France) during an orthostatic test.

Methods: A total of 18 healthy men (age: 27.1 +/- 1.