Repeated Sprint Training in Hypoxia Improves Repeated Sprint Ability to Exhaustion Similarly in Active Males and Females.

Purpose: The aim of this study was to compare the physiological adaptations of males and females to repeated sprint training in hypoxia (RSH).

Methods: Active males and females completed 7 wk of repeated sprint training in normoxia (RSN; F i O 2 = 0.209, males: n = 11, females: n = 8) or RSH (F i O 2 = 0.

Effects of a 6-wk Sprint Interval Training Protocol at Different Altitudes on Circulating Extracellular Vesicles.

Purpose: This study aimed to investigate the modulation of circulating exosome-like extracellular vesicles (ELVs) after 6 wk of sprint interval training (SIT) at sea level and at 2000, 3000, and 4000 m.

Methods: Thirty trained endurance male athletes (18-35 yr) participated in a 6-wk SIT program (30-s all-out sprint, 4-min 30-s recovery; 4-9 repetitions, 2 sessions per week) at sea level ( n = 8), 2000 m (fraction of inspired oxygen (F io2 ) 0.167, n = 8), 3000 m (F io2 0.

Higher strength gain after hypoxic vs normoxic resistance training despite no changes in muscle thickness and fractional protein synthetic rate.

Acute hypoxia has previously been suggested to potentiate resistance training-induced hypertrophy by activating satellite cell-dependent myogenesis rather than an improvement in protein balance in human. Here, we tested this hypothesis after a 4-week hypoxic vs normoxic resistance training protocol. For that purpose, 19 physically active male subjects were recruited to perform 6 sets of 10 repetitions of a one-leg knee extension exercise at 80% 1-RM 3 times/week for 4 weeks in normoxia (FiO : 0.

Regulation of satellite cells by exercise in hypoxic conditions: a narrative review.

Purpose: To investigate in vivo the adaptations of satellite cell induced by exercise performed in acute or chronic hypoxic conditions and their contribution to muscle remodeling and hypertrophy.

Methods: Search terms related to exercise, hypoxia and satellite cells were entered on Embase, PubMed and Scopus. Studies were selected for their relevance in terms of regulation of satellite cells by in vivo exercise and muscle contraction in hypoxic conditions.

Effects of Sprint Interval Training at Different Altitudes on Cycling Performance at Sea-Level.

Background: Benefits of sprint interval training performed in hypoxia (SIH) compared to normoxia (SIN) have been assessed by studies mostly conducted around 3000 m of simulated altitude. The present study aims to determine whether SIH at an altitude as high as 4000 m can elicit greater adaptations than the same training at 2000 m, 3000 m or sea-level.

Methods: Thirty well-trained endurance male athletes (18-35 years old) participated in a six-week repeated sprint interval training program (30 s all-out sprint, 4 min 30 s recovery; 4-9 repetitions, 2 sessions/week) at sea-level (SL, = 8), 2000 m (FO 16.

Muscle structural, energetic and functional benefits of endurance exercise training in sickle cell disease.

Sickle cell disease (SCD) patients display skeletal muscle hypotrophy, altered oxidative capacity, exercise intolerance and poor quality of life. We previously demonstrated that moderate-intensity endurance training is beneficial for improving muscle function and quality of life of patients. The present study evaluated the effects of this moderate-intensity endurance training program on skeletal muscle structural and metabolic properties.

Simplified indices of exercise tolerance in patients with multiple sclerosis and healthy subjects: A case-control study.

Among patients with multiple sclerosis (MS), the impairment of exercise tolerance is closely related to disability. Maximal oxygen uptake (VO ) is the gold standard to assess exercise tolerance in healthy subjects (HS). Among patients with MS, the accuracy of VO measurement is often impaired because the patients are unable to reach the maximal exercise intensity due to interdependent factors linked to the disease (such as pathological fatigue, pain, lack of exercise habit, and lack of mobility).

Myoferlin Is a Yet Unknown Interactor of the Mitochondrial Dynamics' Machinery in Pancreas Cancer Cells.

Pancreas ductal adenocarcinoma is one of the deadliest cancers where surgery remains the main survival factor. Mitochondria were described to be involved in tumor aggressiveness in several cancer types including pancreas cancer. We have previously reported that myoferlin controls mitochondrial structure and function, and demonstrated that myoferlin depletion disturbs the mitochondrial dynamics culminating in a mitochondrial fission.

Does High Cardiorespiratory Fitness Confer Some Protection Against Proinflammatory Responses After Infection by SARS-CoV-2?

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) originated in China in late 2019 and has since spread rapidly to every continent in the world. This pandemic continues to cause widespread personal suffering, along with severe pressure on medical and health care providers. The symptoms of SARS-CoV-2 and the subsequent prognosis are worsened in individuals who have preexisting comorbidities prior to infection by the virus.

Anti-Inflammatory Effect of Exercise Mediated by Toll-Like Receptor Regulation in Innate Immune Cells - A Review.

Over the last three decades, the combination of a sedentary lifestyle and excessive food intake has led to a significant increase in the prevalence of obesity. The latter favors a chronic low-grade inflammatory state and an over-activation of the innate immune system, which contribute to insulin resistance and type 2 diabetes. Physical exercise is a powerful preventive tool and treatment for several diseases as it induces metabolic and immune effects that provide health benefits.

Regular Endurance Exercise Promotes Fission, Mitophagy, and Oxidative Phosphorylation in Human Skeletal Muscle Independently of Age.

This study investigated whether regular endurance exercise maintains basal mitophagy and mitochondrial function during aging. Mitochondrial proteins and total mRNA were isolated from vastus lateralis biopsies ( = 33) of young sedentary (YS), old sedentary (OS), young active (YA), and old active (OA) men. Markers for mitophagy, fission, fusion, mitogenesis, and mitochondrial metabolism were assessed using qRT-PCR, Western blot, and immunofluorescence staining.

The stiffness response of type IIa fibres after eccentric exercise-induced muscle damage is dependent on ACTN3 r577X polymorphism.

The aim of the study was to determine the effect of α-actinin-3 (ACTN3) deficiency (XX) on muscle damage induced by an eccentric exercise bout. In this purpose, 4 RR and 4 XX individuals performed an intensive eccentric knee flexion exercise on an isokinetic dynamometer. Muscle biopsies, blood and pain scores were taken before and after the exercise to determine the extent of the exercise-induced damage and the effect of the ACTN3 R577X polymorphism.

Exercise and the control of muscle mass in human.

During the course of life, muscle mass undergoes many changes in terms of quantity and quality. Skeletal muscle is a dynamic tissue able to hypertrophy or atrophy according to growth, ageing, physical activity, nutrition and health state. The purpose of the present review is to present the mechanisms by which exercise can induce changes in human skeletal muscle mass by modulating protein balance and regulating the fate of satellite cells.

Effect of environmental feedbacks on pacing strategy and affective load during a self-paced 30 min cycling time trial.

The purpose of this study was to analyze the pacing strategy and its affective consequences during self-paced cycling time trials (TT) performed at different severity of hypoxia. Eight competitive cyclists performed five 30 min self-paced TTs at their best performance in the following conditions: 1) normobaric normoxia (NN); 2) normobaric hypoxia under two simulated altitudes: 2000 m (NH) and 3500 m (NH) and 3) normobaric hypoxia but the cyclists were deceived and thought to be at sea level for 2000 m (DecNH) and 3500 m (DecNH). Power Output (PO), oxygen uptake (VO), and blood lactate concentration ([La]) were recorded to assess exercise intensity and physiological adaptations.

Impact of Very Early Physical Therapy During Septic Shock on Skeletal Muscle: A Randomized Controlled Trial.

Objectives: As the catabolic state induced by septic shock together with the physical inactivity of patients lead to the rapid loss of muscle mass and impaired function, the purpose of this study was to test whether an early physical therapy during the onset of septic shock regulates catabolic signals and preserves skeletal muscle mass.

Design: Randomized controlled trial.

Setting: Tertiary mixed ICU.

Glucocorticoid-dependent REDD1 expression reduces muscle metabolism to enable adaptation under energetic stress.

Background: Skeletal muscle atrophy is a common feature of numerous chronic pathologies and is correlated with patient mortality. The REDD1 protein is currently recognized as a negative regulator of muscle mass through inhibition of the Akt/mTORC1 signaling pathway. REDD1 expression is notably induced following glucocorticoid secretion, which is a component of energy stress responses.

Environmental hypoxia favors myoblast differentiation and fast phenotype but blunts activation of protein synthesis after resistance exercise in human skeletal muscle.

We hypothesized that a single session of resistance exercise performed in moderate hypoxic (FiO: 14%) environmental conditions would potentiate the anabolic response during the recovery period spent in normoxia. Twenty subjects performed a 1-leg knee extension session in normoxic or hypoxic conditions. Muscle biopsies were taken 15 min and 4 h after exercise in the vastus lateralis of the exercised and the nonexercised legs.

Toll like receptor expression induced by exercise in obesity and metabolic syndrome: A systematic review.

Background: Obesity and metabolic syndrome are disorders that correlate with the activation of pro-inflammatory pathways and cytokine production, to which Toll like receptors (TLR) contribute. Exercise may act as an anti-inflammatory modulator, but there is no consensus about the role of the TLR in this tuning. The present styudy aims to systematically review the current evidence on exercise-induced TLR regulation in animals and humans suffering from obesity and metabolic syndrome.

Using polyphenol derivatives to prevent muscle wasting.

Purpose Of Review: To highlight recent evidence for the ability of polyphenols and their derivatives to reduce muscle wasting in different pathological states.

Recent Findings: From January 2016 to August 2017, four articles dealt with the effects of polyphenols on muscle wasting, which were all carried out in mice. The four studies found that polyphenols reduced muscle mass loss associated with cancer cachexia, acute inflammation or sciatic nerve section.

Activating transcription factor 3 regulates chemokine expression in contracting CC myotubes and in mouse skeletal muscle after eccentric exercise.

Activating transcription factor (ATF) 3 regulates chemokine expression in various cell types and tissues. Herein, we studied this regulation in contracting muscle cells in vitro, and in skeletal muscle after muscle-damaging exercise in vivo. CC myotubes with normal or low ATF3 levels (atf3_siRNA) were electrically stimulated (EPS).

Hippo Pathway and Skeletal Muscle Mass Regulation in Mammals: A Controversial Relationship.

Skeletal muscle mass reflects a dynamic turnover between net protein synthesis and degradation. In addition, satellite cell inclusion may contribute to increase muscle mass while fiber loss results in a reduction of muscle mass. Since 2010, a few studies looked at the involvement of the newly discovered Hippo pathway in the regulation of muscle mass.

Lack of Activation of Mitophagy during Endurance Exercise in Human.

Purpose: This study aimed to determine whether fission and mitophagy are activated by acute endurance exercise in human skeletal muscle and to investigate if this activation is dependent upon the nutritional state.

Methods: Trained athletes (n = 7) cycled for 2 h at 70% V˙O2peak in a fed or fasted state. Vastus lateralis muscle biopsies were obtained at baseline, before, immediately after, and 1 h after exercise.

Urolithin B, a newly identified regulator of skeletal muscle mass.

Background: The control of muscle size is an essential feature of health. Indeed, skeletal muscle atrophy leads to reduced strength, poor quality of life, and metabolic disturbances. Consequently, strategies aiming to attenuate muscle wasting and to promote muscle growth during various (pathological) physiological states like sarcopenia, immobilization, malnutrition, or cachexia are needed to address this extensive health issue.

Activating transcription factor 3 attenuates chemokine and cytokine expression in mouse skeletal muscle after exercise and facilitates molecular adaptation to endurance training.

Activating transcription factor (ATF)3 regulates the expression of inflammation-related genes in several tissues under pathological contexts. In skeletal muscle, atf3 expression increases after exercise, but its target genes remain unknown. We aimed to identify those genes and to determine the influence of ATF3 on muscle adaptation to training.