Impact of exercise and fasting on mitochondrial regulators in human muscle.

Objectives: To investigate the impact of acute energetic stress (acute HIIE and fasting) on , , , , and in human skeletal muscle.

Methods: The current study performed secondary analyses using muscle biopsy samples from two previously published studies: study 1) leg muscle biopsies from nine men and eight women were obtained pre and 3 h following acute high-intensity interval cycling exercise (HIIE); study 2) leg muscle biopsies were obtained from nine men pre-, during, and post-an 8 h fast with or without 2 h of arm ergometer exercise. RT-PCR was performed on samples from each study to determine the mRNA expression of , , , , and .

PERM1-An Emerging Transcriptional Regulator of Mitochondrial Biogenesis: A Systematic Review.

Background/objectives: This systematic review aims to explore the role of PERM1 across different organisms, tissues, and cellular functions, with a particular focus on its involvement in regulating skeletal muscle mitochondrial biogenesis.

Methods: This systematic review follows The PRISMA 2020 Statement. We used the Covidence systematic review software for abstract/title screening, full-text review, and data extraction.

Do Surrogate Markers of Cardiorespiratory Fitness Predict Individual Changes in VO? A Randomized Controlled Trial.

The purpose of the current study was to test the hypothesis that individual response classification for surrogate markers of cardiorespiratory fitness (CRF) will agree with response classification for VO. Surrogate markers of CRF were time to fatigue on treadmill test (TTF), time trial performance (3kTT), resting heart rate (RHR), submaximal heart rate (SubmaxHR), and submaximal ratings of perceived exertion (SubmaxRPE). Twenty-five participants were randomized into a high-intensity interval training (HIIT: = 14) group or non-exercise control group (CTL: = 11).

Physiological and perceptual response to critical power anchored HIIT: a sex comparison study.

Purpose: The aim of this study was to test the hypothesis that using threshold-based high intensity interval training (HIIT) prescribed at an intensity above critical power (CP) in males and females matched for maximal oxygen uptake ( Omax) (mL/kg lean mass/min) will yield no sex differences in time to fatigue.

Methods: Thirteen males (mean ± SD: 22.0 ± 2.

Standard Deviation of Individual Response for VO Following Exercise Interventions: A Systematic Review and Meta-analysis.

Background: Although numerous attempts to demonstrate inter-individual differences in trainability across various outcomes have been unsuccessful, the investigation of maximal oxygen consumption (VO) trainability warrants further study.

Objective: Our objective was to conduct the first systematic review and meta-analysis to evaluate inter-individual differences in VO trainability across aerobic exercise training protocols utilizing non-exercising comparator groups.

Methods: We conducted a literature search across three databases: EMBASE, PubMed and SCOPUS.

Differential changes in appetite hormones post-prandially based on menstrual cycle phase and oral contraceptive use: A preliminary study.

This was a preliminary study that examined whether appetite regulation is altered during the menstrual cycle or with oral contraceptives. Ten naturally cycling females (NON-USERS) and nine tri-phasic oral contraceptive using females (USERS) completed experimental sessions during each menstrual phase (follicular phase: FP; ovulatory phase: OP; luteal phase: LP). Appetite perceptions and blood samples were obtained fasted, 30, 60, and 90 min post-prandial to measure acylated ghrelin, active glucagon-like peptide-1 (GLP-1), and total peptide tyrosine tyrosine (PYY).

Risk of bias in exercise science: A systematic review of 340 studies.

Risk of bias can contribute to irreproducible science and mislead decision making. Analyses of smaller subsections of the exercise science literature suggest many exercise science studies have unclear or high risk of bias. The current review (osf.

Increasing aerobic exercise intensity fails to consistently improve the glycemic response in people living with prediabetes or type 2 diabetes mellitus: the INTENSITY trial.

Some individuals with prediabetes or type 2 diabetes mellitus (T2DM) who engage in exercise will not experience the anticipated improvements in glycemic control, referred to as non-responders. Increasing exercise intensity may improve the proportion of individuals who become responders. The objectives were to () identify responders and non-responders based on changes in glycated hemoglobin (HbA1c) in individuals with prediabetes or T2DM following 16 weeks of aerobic exercise; () investigate if increasing exercise intensity enhances the responders' status for individuals not previously responding favourably to the intervention.

AMPK and PGC- following maximal and supramaximal exercise in men and women: a randomized cross-over study.

We tested the hypothesis that AMPK activation and peroxisome proliferator gamma coactivator 1 alpha (PGC-1) expression are not augmented as exercise intensity (power output) increases from maximal to supramaximal intensities and conducted an exploratory analysis comparing AMPK activation and PGC-1α expression in males and females. Seventeen ( = 9 males;  = 8 females) recreationally active, healthy, young individuals volunteered to participate in the current study. Participants completed work matched interval exercise at 100% (Max) and 133% (Supra) of peak work rate (WRpeak).

CARM1 drives mitophagy and autophagy flux during fasting-induced skeletal muscle atrophy.

CARM1 (coactivator associated arginine methyltransferase 1) has recently emerged as a powerful regulator of skeletal muscle biology. However, the molecular mechanisms by which the methyltransferase remodels muscle remain to be fully understood. In this study, skeletal muscle-specific knockout (mKO) mice exhibited lower muscle mass with dysregulated macroautophagic/autophagic and atrophic signaling, including depressed AMP-activated protein kinase (AMPK) site-specific phosphorylation of ULK1 (unc-51 like autophagy activating kinase 1; Ser555) and FOXO3 (forkhead box O3; Ser588), as well as MTOR (mechanistic target of rapamycin kinase)-induced inhibition of ULK1 (Ser757), along with AKT/protein kinase B site-specific suppression of FOXO1 (Ser256) and FOXO3 (Ser253).

Including supramaximal verification reduced uncertainty in VO response rate.

Many reports describe using a supramaximal verification phase-exercising at a power output higher than the highest power output recorded during an incremental cardiopulmonary test-to validate VO. The impact of verification phases on estimating the proportion of individuals who increased VO in response to high-intensity interval training (HIIT) remains an underexplored area in the individual response literature. This analysis investigated the influence of same-day and separate-day verification phases during repeated measurements (incremental tests-INCR1 and INCR2; incremental tests + supramaximal verification phases-INCR1+ and INCR2+) of VO on typical error (TE) and the proportion of individuals classified as responders (i.

No acute hyperglycemia induced impairment in brachial artery flow-mediated dilation before or after aerobic exercise training in young recreationally active males.

There is some evidence that transient endothelial dysfunction induced by acute hyperglycemia may be attenuated by a single bout of aerobic exercise. However, the impact of aerobic exercise training on acute hyperglycemia-induced endothelial dysfunction has not been explored. The purpose of this study was to determine the impact of aerobic exercise training on the endothelial function response to acute hyperglycemia.

Exploring interindividual differences in fasting and postprandial insulin sensitivity adaptations in response to sprint interval exercise training.

Previous studies have concluded that wide variance in changes in insulin sensitivity markers following exercise training demonstrates heterogeneity in individual trainability. However, these studies frequently don't account for technical, biological, and random within-subject measurement error. We used the standard deviation of individual responses (SD) to determine whether interindividual variability in trainability exists for fasting and postprandial insulin sensitivity outcomes following low-volume sprint interval training (SIT).

Change in Central Cardiovascular Function in Response to Intense Interval Training: A Systematic Review and Meta-analysis.

Introduction: High-intensity interval training and sprint interval training significantly increase maximal oxygen uptake (V̇O 2max ), which enhances endurance performance and health status. Whether this response is due to increases in central cardiovascular function (cardiac output (CO) and blood volume) or peripheral factors is unknown.

Purpose: This study aimed to conduct a systematic review and meta-analysis to assess the effects of high-intensity interval training and sprint interval training (referred to as intense interval training) on changes in central cardiovascular function.

Interindividual Differences in Trainability and Moderators of Cardiorespiratory Fitness, Waist Circumference, and Body Mass Responses: A Large-Scale Individual Participant Data Meta-analysis.

Although many studies have assumed variability reflects variance caused by exercise training, few studies have examined whether interindividual differences in trainability are present following exercise training. The present individual participant data (IPD) meta-analysis sought to: (1) investigate the presence of interindividual differences in trainability for cardiorespiratory fitness (CRF), waist circumference, and body mass; and (2) examine the influence of exercise training and potential moderators on the probability that an individual will experience clinically important differences. The IPD meta-analysis combined data from 1879 participants from eight previously published randomized controlled trials.

Impacts of altered exercise volume, intensity, and duration on the activation of AMPK and CaMKII and increases in PGC-1α mRNA.

The purpose of this review is to explore and discuss the impacts of augmented training volume, intensity, and duration on the phosphorylation/activation of key signaling protein - AMPK, CaMKII and PGC-1α - involved in the initiation of mitochondrial biogenesis. Specifically, we explore the impacts of augmented exercise protocols on AMP/ADP and Ca signaling and changes in post exercise PGC - 1α gene expression. Although AMP/ADP concentrations appear to increase with increasing intensity and during extended durations of higher intensity exercise AMPK activation results are varied with some results supporting and intensity/duration effect and others not.

Subcutaneous adipose tissue sclerostin is reduced and Wnt signaling is enhanced following 4-weeks of sprint interval training in young men with obesity.

Sclerostin is a Wnt/β-catenin antagonist, mainly secreted by osteocytes, and most known for its role in reducing bone formation. Studies in rodents suggest sclerostin can also regulate adipose tissue mass and metabolism, representing bone-adipose tissue crosstalk. Exercise training has been shown to reduce plasma sclerostin levels; but the effects of exercise on sclerostin and Wnt/β-catenin signaling specifically within adipose tissue has yet to be examined.

A Systematic Review Examining the Approaches Used to Estimate Interindividual Differences in Trainability and Classify Individual Responses to Exercise Training.

Many reports describe statistical approaches for estimating interindividual differences in trainability and classifying individuals as "responders" or "non-responders." The extent to which studies in the exercise training literature have adopted these statistical approaches remains unclear. This systematic review primarily sought to determine the extent to which studies in the exercise training literature have adopted sound statistical approaches for examining individual responses to exercise training.

Intramuscular hematoma of the vastus lateralis following percutaneous skeletal muscle microbiopsy: a case report.

Recently, percutaneous microbiopsy needles have been used as a less invasive alternative to the Bergstrom needle for obtaining human skeletal muscle biopsy to assess changes in protein content, gene expression, and enzymatic activities. Unlike the Bergstrom muscle biopsy procedure, potential complications associated with microbiopsies of human skeletal muscle have not been documented. Therefore, the present case report follows a young male's recovery from a muscle biopsy-induced hemorrhage/hematoma of the right vastus lateralis with the specific aims of (1) informing future participants, researchers, and clinicians on expected time course of recovery and (2) informing methods to minimize future participant adverse event risk during and after the percutaneous microbiopsy procedure.

Directions for Exercise Treatment Response Heterogeneity and Individual Response Research.

Treatment response heterogeneity and individual responses following exercise training are topics of interest for personalized medicine. Proposed methods to determine the contribution of exercise to the magnitude of treatment response heterogeneity and categorizing participants have expanded and evolved. Setting clear research objectives and having a comprehensive understanding of the strengths and weaknesses of the available methods are vital to ensure the correct study design and analytical approach are used.

Examining interindividual differences in select muscle and whole-body adaptations to continuous endurance training.

New Findings: What is the central question of the study? Do interindividual differences in trainability exist for morphological and molecular skeletal muscle responses to aerobic exercise training? What is the main finding and its importance? Interindividual differences in trainability were present for some, but not all, morphological and molecular outcomes included in our study. Our findings suggest that it is inappropriate, and perhaps erroneous, to assume that variability in observed responses reflects interindividual differences in trainability in skeletal muscle responses to aerobic exercise training.

Abstract: Studies have interpreted a wide range of morphological and molecular changes in human skeletal muscle as evidence of interindividual differences in trainability.

Genome wide association study of response to interval and continuous exercise training: the Predict-HIIT study.

Background: Low cardiorespiratory fitness (V̇O) is highly associated with chronic disease and mortality from all causes. Whilst exercise training is recommended in health guidelines to improve V̇O, there is considerable inter-individual variability in the V̇O response to the same dose of exercise. Understanding how genetic factors contribute to V̇O training response may improve personalisation of exercise programs.

Molecular regulation of skeletal muscle mitochondrial biogenesis following blood flow-restricted aerobic exercise: a call to action.

Blood flow-restricted (BFR) exercise can induce training adaptations comparable to those observed following training in free flow conditions. However, little is known about the acute responses within skeletal muscle following BFR aerobic exercise (AE). Moreover, although preliminary evidence suggests chronic BFR AE may augment certain training adaptations in skeletal muscle mitochondria more than non-BFR AE, the underlying mechanisms are poorly understood.

Can non-responders be 'rescued' by increasing exercise intensity? A quasi-experimental trial of individual responses among humans living with pre-diabetes or type 2 diabetes mellitus in Canada.

Introduction: Exercise is recommended to improve glycaemic control. Yet, individual changes in glycaemic control following exercise can vary greatly, meaning while some significantly improve others, coined 'non-responders', do not. Increasing the intensity of exercise may 'rescue' non-responders and help generate a response to training.