Increases in the incremental exercise mean response time across the steady state domain: Implications for exercise testing & prescription.

We hypothesized that slowed oxygen uptake ( ) kinetics for exercise transitions to higher power outputs (PO) within the steady state (SS) domain would increase the mean response time (MRT) with increasing exercise intensity during incremental exercise. Fourteen highly trained cyclists (mean ± standard deviation []; age (39 ± 6) years [yr]; and peak = (61 ± 9) mL/kg/min performed a maximal, ramp incremental cycling test and on separate days, four 6-min bouts of cycling at 30%, 45%, 65% & 75% of their incremental peak PO (Wpeak). SS trial data were used to calculate the MRT and verified by mono-exponential and linear curve fitting.

Evaluating Airflow Sensor Methods: Precision in Indirect Calorimetry.

This study assesses the impact of three volumetric gas flow measurement methods-turbine (fT); pneumotachograph (fP), and Venturi (fV)-on predictive accuracy and precision of expired gas analysis indirect calorimetry (EGAIC) across varying exercise intensities. Six males (Age: 38 ± 8 year; Height: 178.8 ± 4.

Carbohydrate Ingestion before Exercise for Individuals with McArdle Disease: Survey Evidence of Implementation and Perception in Real-World Settings.

In individuals with McArdle disease (IWMD), the ingestion of carbohydrates before exercise has previously been shown in laboratory studies to significantly decrease the exercising symptoms of the condition and increase exercise tolerance during the early stages of exercise. As a result, carbohydrate ingestion pre-exercise is currently included in management guidelines, and often advised by medical professionals treating the condition. The aim of the current study was to determine whether positive lab-based results for the ingestion of carbohydrate before exercise in laboratory studies are being effectively translated into practice and produce perceptions of the same positive outcomes in real-world settings (RWS).

The missing hydrogen ion, Part-3: Science and the human flaws that compromise it.

The purpose of this research was to use a historical method and core principles from scientific philosophy to explain why mistakes were made in the development of the lactic acidosis construct. On a broader scope, this research explains what science is, why some scientists despite good intention, often get it wrong, and why it takes so long (decades) to correct these errors. Science is a human behaviour that consists of the identification of a problem based on the correct application of prior knowledge, the development of a method to best resolve or test the problem, completion of these methods to acquire results, and then a correct interpretation of the results.

How Much Energy Do E'Athletes Use during Gameplay? Quantifying Energy Expenditure and Heart Rate Variability Within E'Athletes.

Background: Research into esports suggests that e'athletes experience physiological stressors and demands during competition and training. The physiological demands of esports are poorly understood and need to be investigated further to inform future training guidelines, optimise performance outcomes, and manage e'athlete wellbeing. This research aimed to quantify the metabolic rate of esports gameplay and compare this outcome with heart rate variability within expert e'athletes.

Physical Activity and Self-Determination towards Exercise among Esports Athletes.

Background: Esports is competitive video gaming, performed within teams or individually, across multiple genres. Players are required to be sedentary for extended periods and require a high-level of cognitive skills for successful competitive performance. There are conflicting findings within the physical activity research in the esports industry.

The missing hydrogen ion, part-2: Where the evidence leads to.

The purpose of this manuscript was to present the evidence for why cells do not produce metabolic acids. In addition, evidence that opposes common viewpoints and arguments used to support the cellular production of lactic acid (HLa) or liver keto-acids have been provided. Organic chemistry reveals that many molecules involved in cellular energy catabolism contain functional groups classified as acids.

The missing hydrogen ion, part-1: Historical precedents vs. fundamental concepts.

The purpose of this review and commentary was to provide an historical and evidence-based account of organic acids and the biochemical and organic chemistry evidence for why cells do not produce metabolites that are acids. The scientific study of acids has a long history dating to the 16 and 17 centuries, and the definition of an acid was proposed in 1884 as a molecule that when in an aqueous solution releases a hydrogen ion (H). There are three common ionizable functional groups for molecules classified as acids: 1) the carboxyl group, 2) the phosphoryl group and 3) the amine group.

The Computational Acid-Base Chemistry of Hepatic Ketoacidosis.

Opposing evidence exists for the source of the hydrogen ions (H) during ketoacidosis. Organic and computational chemistry using dissociation constants and alpha equations for all pertinent ionizable metabolites were used to (1) document the atomic changes in the chemical reactions of ketogenesis and ketolysis and (2) identify the sources and quantify added fractional (~) H exchange (~He). All computations were performed for pH conditions spanning from 6.

Moderate continuous- and high-intensity interval training elicit comparable cardiovascular effect among middle-aged men regardless of recovery mode.

To assess the effect of active and passive intra-interval recovery modes in time-efficient high-intensity interval training (HIT) on cardiorespiratory fitness, autonomic function, and endothelial function in sedentary middle-aged men.Participants (= 62; age: 49.5 ± 5.

How to be a better scientist: Lessons from scientific philosophy, the historical development of science, and past errors within exercise physiology.

What is science? While a simple question, the answer is complex. Science is a process involving human behaviour, and due to the human influence, science is often not pursued correctly. In fact, one can argue that we still do not know what the "correct" pursuit of science should entail.

Quantifying H exchange from muscle cytosolic energy catabolism using metabolite flux and H coefficients from multiple competitive cation binding: New evidence for consideration in established theories.

The purpose of this investigation was to present calculations of fractional H exchange (~H ) from the chemical reactions of non-mitochondrial energy catabolism. Data of muscle pH and metabolite accumulation were based on published research for intense exercise to contractile failure within ~3 min, from which capacities and time profiles were modeled. Data were obtained from prior research for multiple competitive cation dissociation constants of metabolites and the chemical reactions of non-mitochondrial energy catabolism, and pH dependent calculations of ~H from specific chemical reactions.

The effects of concurrent training order on body composition and serum concentrations of follistatin, myostatin and GDF11 in sarcopenic elderly men.

Background: Due to the important role of follistatin (FLST), myostatin (MSTN) and growth differentiation factor 11 (GDF11) in muscle mass regulation; alterations in the FLST to MSTN ratio (F:M) may result in muscle mass changes in response to different concurrent training (CT) order. This study investigated the influence of 8 weeks of CT order on body composition and serum concentrations of FLST, MSTN, their ratio (F:M) and GDF11 in sarcopenic elderly men.

Methods: Thirty sarcopenic elderly men (age = 64.

Invited review: Quantifying proton exchange from chemical reactions - Implications for the biochemistry of metabolic acidosis.

Given that the chemistry of lactate production disproves the existence of a lactic acidosis, there is a need to further reveal and explain the importance of the organic and computational chemistry of pH dependent competitive cation fractional (~) proton (H) exchange (~H). An additional importance of this knowledge is that it could potentially contradict the assumption of the Stewart approach to the physico-chemical theory of acid-base balance. For example, Stewart proposed that chemical reaction and pH dependent H dissociation and association do not directly influence the pH of cellular and systemic body fluids.

Caution using data from triaxial accelerometers housed in player tracking units during running.

Usage of accelerometers within player tracking devices in sport to quantify load, vertical ground reaction force (vGRF) or energy expenditure is contrary to placement guidelines. This study aimed to determine whether trunk-mounted accelerometers were a valid and reliable method to estimate thoracic segment or centre of gravity (COG) acceleration or vGRF, and the whether the elasticised harness contributes to the overestimation of acceleration. Ten male amateur rugby players performed five linear running tasks per lower limb at three speeds, twice, each with a different player tracking unit.

Competitive cation binding computations of proton balance for reactions of the phosphagen and glycolytic energy systems within skeletal muscle.

Limited research and data has been published for the H+ coefficients for the metabolites and reactions involved in non-mitochondrial energy metabolism. The purpose of this investigation was to compute the fractional binding of H+, K+, Na+ and Mg2+ to 21 metabolites of skeletal muscle non-mitochondrial energy metabolism, resulting in 104 different metabolite-cation complexes. Fractional binding of H+ to these metabolite-cation complexes were applied to 17 reactions of skeletal muscle non-mitochondrial energy metabolism, and 8 conditions of the glycolytic pathway based on the source of substrate (glycogen vs.

Lessons from Popper for science, paradigm shifts, scientific revolutions and exercise physiology.

A connection has been made to the possible role of the central governor model (CGM) to be a paradigm shift within the exercise sciences. Unfortunately, very little evidence was presented to support this notion, and a narrow view of scientific philosophy was used to reflect on the role of the CGM in understanding exercise physiology and the pursuit of a more ideal scientific method. When contrasting the scientific philosophies of Kuhn to Popper, and applying the tenant of falsification to the research and commentary on the CGM, it is probable that the scholarship pertaining to the CGM adheres more to pseudoscience than science.

New Methods for Processing and Quantifying VO Kinetics to Steady State: VO Onset Kinetics.

Current methods of oxygen uptake (VO) kinetics data handling may be too simplistic for the complex physiology involved in the underlying physiological processes. Therefore, the aim of this study was to quantify the VO kinetics to steady state across the full range of sub-ventilatory threshold work rates, with a particular focus on the VO onset kinetics. Ten healthy, moderately trained males participated in five bouts of cycling.

Limited Effects of Endurance or Interval Training on Visceral Adipose Tissue and Systemic Inflammation in Sedentary Middle-Aged Men.

. Limited data exists for the effects of sprint-interval training (SIT) and endurance training (ET) on total body composition, abdominal visceral adipose tissue, and plasma inflammation. Moreover, whether "active" or "passive" recovery in SIT provides a differential effect on these measures remains uncertain.

Transcriptional reprogramming of metabolic pathways in critically ill patients.

Background: Critical illness causes a shift away from mitochondrial metabolism towards a greater dependence on glycolysis. This metabolic shift is thought to be associated with lactic acidosis, organ dysfunction and poor clinical outcomes. The current paradigm is that low oxygen supply causes regional hypoxia, which in turn drives such a metabolic shift.

Considerations for determining the time course of post-activation potentiation.

We sought to determine the efficacy of using a continuous time course trial to assess the temporal profile of post-activation potentiation and to determine the time course of potentiation of discrete jump squat kinetic and kinematic variables. Eight physically trained men performed jump squats before and 4, 8, and 12 min after a 5-repetition maximum back squat. Time intervals were assessed in 3 discontinuous trials (each time interval assessed in a separate trial) and in 1 continuous trial (all time intervals assessed in a single trial).