Educational Strategies for Teaching Metabolic Profiles Across Three Endurance Training Zones.

This article explores an innovative educational approach using a metabolic board designed to enhance understanding of muscle metabolism across three endurance training zones: Z1 (light intensity), Z2 (moderate intensity), and Z3 (intense/severe intensity). The aerobic threshold marks the transition from light to moderate domains, and the anaerobic threshold separates moderate from intense domains, with both thresholds adapting to training. Exercises within each training zone elicit specific adaptive responses through distinct signaling pathways, but the metabolic profile induced remains relatively constant across these intensity domains.

Subcellular fractionation of frozen skeletal muscle samples.

Cell fractionation can be used to determine the localization and trafficking of proteins between cellular compartments such as the cytosol, mitochondria, and nuclei. Subcellular fractionation is usually performed immediately after tissue dissection because freezing may fragment cell membranes and induce organellar cross-contamination. Mitochondria are especially sensitive to freezing/thawing and mechanical homogenization.

Mountain Ultramarathon Induces Early Increases of Muscle Damage, Inflammation, and Risk for Acute Renal Injury.

This study aimed to investigate changes in muscle damage during the course of a 217-km mountain ultramarathon (MUM). In an integrative perspective, inflammatory response and renal function were also studied. Six male ultra-runners were tested four times: pre-race, at 84 km, at 177 km, and immediately after the race.

Glycemic Control and Muscle Damage in 3 Athletes With Type 1 Diabetes During a Successful Performance in a Relay Ultramarathon: A Case Report.

Ultramarathon races are fairly demanding and impose substantial physiological stress on healthy athletes. These competitions may thus be considerably more challenging for individuals with diabetes. This case study aims to describe glycemic control, muscle damage, inflammation, and renal function in 3 athletes with type 1 diabetes during a successful performance in a relay ultramarathon.

Hematological and biochemical markers of iron status in a male, young, physically active population.

The aim of this study was to establish reference intervals (RIs) for the hemogram and iron status biomarkers in a physically active population. The study population included male volunteers (n = 150) with an average age of 19 ± 1 years who had participated in a regular and controlled exercise program for four months. Blood samples were collected to determine hematological parameters using a Sysmex XE-5000 analyzer (Sysmex, Kobe, Japan).

Exhaustive exercise with different rest periods changes the collagen content and MMP-2 activation on the calcaneal tendon.

Tendons adapt to different mechanical stimuli through a remodeling process involving metalloproteinases (MMPs) and collagen synthesis. The purpose of this study was to investigate the activities of MMP-2 and MMP-9 and the collagen content in tendons after exhaustive acute exercise sessions over the course of 1, 3, or 6 days, with 1-hr or 3-hr rest periods between each session. Wistar rats were grouped into control (C), trained with 1-hr (groups 1d1h, 3d1h, and 6d1h) and trained with 3-hr (groups 1d3h, 3d3h and 6d3h) groups with rest periods between the treadmill running sessions, for 1, 3, and 6 days.

Time course of muscle damage and inflammatory responses to resistance training with eccentric overload in trained individuals.

The purpose of this study was to observe the time course of muscle damage and inflammatory responses following an eccentric overload resistance-training (EO) program. 3 females (23.8 ± 2.

Interaction between overtraining and the interindividual variability may (not) trigger muscle oxidative stress and cardiomyocyte apoptosis in rats.

Severe endurance training (overtraining) may cause underperformance related to muscle oxidative stress and cardiomyocyte alterations. Currently, such relationship has not been empirically established. In this study, Wistar rats (n = 19) underwent eight weeks of daily exercise sessions followed by three overtraining weeks in which the daily frequency of exercise sessions increased.

Proteomic profiling of skeletal muscle in an animal model of overtraining.

Excessive training (i.e. overtraining, OT) may result in underperformance, which can be characterized by the time needed to re-establish performance (i.

Reference intervals for saliva analytes collected by a standardized method in a physically active population.

Objectives: Our aims were to test a liquid-based saliva collection system for total antioxidant status (TAS), uric acid (UA), total protein concentration (TP) and salivary alpha-amylase (SAA) activity; to determine if these analytes in serum and saliva are correlated in a physically active population and to establish reference intervals for these parameters.

Design And Methods: Participants in this study were 115 physically active males (18-20 years old). Saliva samples were collected using the Saliva Collection System (Greiner Bio-One) immediately before obtaining blood.

Time course of strength and power recovery after resistance training with different movement velocities.

The purpose of this study was to evaluate the time course of strength and power recovery after a single bout of strength training designed with fast and slow contraction velocities. Nineteen male subjects were randomly divided into 2 groups: the slow-velocity contraction (SV) group and the fast velocity contraction (FV) group. Resistance training protocols consisted of 5 sets of 12 repetition maximum (5 × 12RM) with 50 seconds of rest between sets and 2 minutes between exercises.

Reproducibility of an incremental treadmill VO(2)max test with gas exchange analysis for runners.

The evaluation of performance through the application of adequate physical tests during a sportive season may be a useful tool to evaluate training adaptations and determine training intensities. For runners, treadmill incremental VO(2)max tests with gas exchange analysis have been widely used to determine maximal and submaximal parameters such as the ventilatory threshold (VT) and respiratory compensation point (RCP) running speed. However, these tests often differ in methodological characteristics (e.

Reference change values of blood analytes from physically active subjects.

The analysis of blood constituents allows the detection of various physiological or pathological states when their values are increased or decreased in relation to a well-defined reference group or to themselves if monitored longitudinally. In the latter case, it is important to know the reference change value (RCV) or critical difference, which defines the percentage change that should be exceeded-given the analytical and biological variations inherent to a particular test, in that there is a significant difference between the two consecutive measurements. Our objective was to calculate the biological variation, analytical variation and RCV of the biochemical and hematological parameters in subjects undergoing 4 months of regular aerobic training.

Is lactate production related to muscular fatigue? A pedagogical proposition using empirical facts.

The cause-effect relationship between lactic acid, acidosis, and muscle fatigue has been established in the literature. However, current experiments contradict this premise. Here, we describe an experiment developed by first-year university students planned to answer the following questions: 1) Which metabolic pathways of energy metabolism are responsible for meeting the high ATP demand during high-intensity intermittent exercise? 2) Which metabolic pathways are active during the pause, and how do they influence phosphocreatine synthesis? and 3) Is lactate production related to muscular fatigue? Along with these questions, students received a list of materials available for the experiment.

Understanding the glycemic index and glycemic load and their practical applications.

We have introduced the study of synthesis pathways using two experiments: 1-the determination of the glycemic index (GI) of some foods and the effects of fiber and fat on the GI; 2-the determination of blood glucose levels after the ingestion of meals with high and low glycemic loads (GL). After a practice assembly, when the foods and meals that were eaten by the students were tallied, the students were divided into groups. At the next class, three members of each group, who had fasted for 8 hr, ingested 50 g of carbohydrate in food or a meal.

Development and characterization of an overtraining animal model.

Purpose: Development of an endurance training-overtraining protocol for Wistar rats that includes increased workload and is characterized by analyses of performance and biomarkers.

Methods: The running protocol lasted 11 wk: 8 wk of daily exercise sessions followed by 3 wk of increasing training frequency (two, three, and four times), with decreasing recovery time between sessions (4, 3, and 2 h) to cause an imbalance between overload and recovery. The performance tests were made before training (T1) and after the 4th (T2), 8th (T3), 9th (T4), 10th (T5), and 11th (T6) training weeks.

Vitamin C and e supplementation effects in professional soccer players under regular training.

Exercise training is known to induce an increase in free radical production potentially leading to enhanced muscle injury. Vitamins C and E are well known antioxidants that may prevent muscle cell damage. The purpose of this study was to determine the effects of these supplemental antioxidant vitamins on markers of oxidative stress, muscle damage and performance of elite soccer players.

The upper values of plasma creatine kinase of professional soccer players during the Brazilian National Championship.

The current schedule of the Brazilian Soccer Championship may not give players enough recovery time between games. This could increase the chances of muscle damage and impaired performance. We hypothesized that plasma creatine kinase (CK) activity could be a reliable indirect marker of muscle overload in soccer players, so we sought to identify the reference values for upper limits of CK activity during a real-life elite competition.

Determination of the anaerobic threshold and maximal lactate steady state speed in equines using the lactate minimum speed protocol.

Maximal blood lactate steady state concentration (MLSS) and anaerobic threshold (AT) have been shown to accurately predict long distance events performance and training loads, as well, in human athletes. Horse endurance races can take up to 160 km and, in practice, coaches use the 4 mM blood lactate concentration, a human based fixed concentration to establish AT, to predict training loads to horse athletes, what can lead to misleading training loads. The lactate minimum speed (LMS) protocol that consists in an initial elevation in blood lactate level by a high intensity bout of exercise and then establishes an individual equilibrium between lactate production and catabolism during progressive submaximal efforts, has been proposed as a nonfixed lactate concentration, to measure individual AT and at the same time predicts MLSS for human long distance runners and basketball players as well.

Electrocatalytic determination of reduced glutathione in human erythrocytes.

The determination of reduced glutathione (GSH) in human erythrocytes using a simple, fast and sensitive method employing a glassy carbon electrode modified with cobalt tetrasulfonated phthalocyanine (CoTSPc) immobilized in poly(L: -lysine) (PLL) film was investigated. This modified electrode showed very efficient electrocatalytic activity for anodic oxidation of GSH, decreasing substantially the anodic overpotentials for 0.2 V versus Ag/AgCl.

Adequacies of skin puncture for evaluating biochemical and hematological blood parameters in athletes.

Objective: The authors tested the effect of blood sampling (skin versus venous puncture) on some biochemical and hematological blood parameters in athletes to answer whether skin puncture could be used as a substitute for venous puncture.

Design: Comparative study of 2 methods of blood samples collection.

Setting: The blood was collected in the same athletes at 3 different moments of the preparatory training phase.