Assessment of Cardiorespiratory and Metabolic Contributions in an Extreme Intensity CrossFit® Benchmark Workout

Our purpose was to characterize the oxygen uptake kinetics (VO 2), energy systems contributions and total energy expenditure during a CrossFit ® benchmark workout performed in the extreme intensity domain. Fourteen highly trained male CrossFitters, aged 28.3 ± 5.4 years, with height 177.8 ± 9.4 cm, body mass 87.9 ± 10.5 kg and 5.6 ± 1.8 years of training experience, performed the Isabel workout at maximal exertion. Cardiorespiratory variables were measured at baseline, during exercise and the recovery period, with blood lactate and glucose concentrations, including the ratings of perceived exertion, measured pre- and post-workout. The Isabel workout was 117 ± 10 s in duration and the VO 2 peak was 47.2 ± 4.7 mL·kg -1·min -1, the primary component amplitude was 42.0 ± 6.0 mL·kg -1·min -1, the time delay was 4.3 ± 2.2 s and the time constant was 14.2 ± 6.0 s. The accumulated VO 2 (0.6 ± 0.1 vs. 4.8 ± 1.0 L·min -1) value post-workout increased substantially when compared to baseline. Oxidative phosphorylation (40%), glycolytic (45%) and phosphagen (15%) pathways contributed to the 245 ± 25 kJ total energy expenditure. Despite the short ~2 min duration of the Isabel workout, the oxygen-dependent and oxygen-independent metabolism energy contributions to the total metabolic energy release were similar. The CrossFit ® Isabel requires maximal effort and the pattern of physiological demands identifies this as a highly intensive and effective workout for developing fitness and conditioning for sports. </p

Somatic and neurobehavioral development of offspring of rats treated with primaquine antimalarial during pregnancy

Made available in DSpace on 2018-01-26T16:16:00Z (GMT). No. of bitstreams: 2 license.txt: 1748 bytes, checksum: 8a4605be74aa9ea9d79846c1fba20a33 (MD5) klaus_magno.pdf: 735681 bytes, checksum: b1e7fd596c56f7ccc6034e69b6a696eb (MD5) Previous issue date: 2017Fundação Oswaldo Cruz. Escola Nacional de Saúde Pública Sergio Arouca. Rio de Janeiro, RJ, Brasil.A primaquina é o único fármaco que promove a cura radical da doença causada por P. vivax e possivelmente também por P. ovale, porém possui diversos problemas em se utilizar a primaquina durante a gravidez, pois é um fármaco capaz de penetrar a placenta, e por não se conhecer o estado de enzima glicose-6-fosfato desidrogenase (G6DP) do feto, a metabolização do fármaco no feto pode ser deficitária. No entanto não tem se pesquisado que problemas essa terapia pode causar a uma gravidez e a prole, o ineditismo do trabalho contribui para o campo de estudo por elucidar os desafios que tal terapia enfrentaria. Nesse estudo foi visto que a primaquina não é capaz de ser transmitida para a prole através da amamentação, e que não afetou os parâmetros de desenvolvimento e crescimento dos jovens expostos intra-utero ao fármaco, mas teve efeito na sobrevida dos filhotes e no comportamento no teste de campo aberto (open-field).Primaquine is the only drug that promotes the radical cure of the disease caused by p. Vivax and possibly also by p. Ovale, but has several problems in using primaquine during pregnancy, since it is a drug capable of penetrating the placenta, and by not knowing the state of the enzyme glucose 6-phosphate dehydrogenase (g6dp) of the fetus, the fetus in drug metabolism may be deficient. However, it has not been investigated what problems this therapy can cause to a pregnancy and the offspring, the novelty of the work contributes to the field of study to elucidate the challenges that such therapy would face. In this study, primaquine was not able to be transmitted to the offspring through breastfeeding, and did not affect the developmental and growth parameters of the intra-uterus exposed to the drug, but had an effect on the survival of the pups and behavior in the open-field test

How to Work with Electromyography Decomposition in Practical Classes of Exercise Physiology and Biomechanics

Concepts about motor unit recruitment are important learning contents in exercise physiology and biomechanics classes that are usually taught theoretically. In the last few years, great advances have occurred in the decomposition of surface electromyography, allowing the learning of theoretical contents in an experimental way. In this tutorial paper, we have described the decomposition of surface electromyography methodological aspects and examples to teach motor unit recruitment concepts in exercise physiology and biomechanics practical lessons. This work has the aim to facilitate physiology and biomechanics academics to introduce this technique in practical classes

How to Work with Electromyography Decomposition in Practical Classes of Exercise Physiology and Biomechanics

Concepts about motor unit recruitment are important learning contents in exercise physiology and biomechanics classes that are usually taught theoretically. In the last few years, great advances have occurred in the decomposition of surface electromyography, allowing the learning of theoretical contents in an experimental way. In this tutorial paper, we have described the decomposition of surface electromyography methodological aspects and examples to teach motor unit recruitment concepts in exercise physiology and biomechanics practical lessons. This work has the aim to facilitate physiology and biomechanics academics to introduce this technique in practical classes

Effect of the Fran CrossFit Workout on Oxygen Uptake Kinetics, Energetics, and Postexercise Muscle Function in Trained CrossFitters

PURPOSE: Fran is one of the most popular CrossFit benchmark workouts used to control CrossFitters' improvements. Detailed physiological characterization of Fran is needed for a more specific evaluation of CrossFitters' training performance improvements. The aim of the study was to analyze the oxygen uptake (V˙O2) kinetics and characterize the energy system contributions and the degree of postexercise fatigue of the unbroken Fran.METHODS: Twenty trained CrossFitters performed Fran at maximal exertion. V˙O2 and heart-rate kinetics were assessed at baseline and during and post-Fran. Blood lactate and glucose concentrations and muscular fatigue were measured at baseline and in the recovery period.RESULTS: A marked increase in V˙O2 kinetics was observed at the beginning of Fran, remaining elevated until the end (V˙O2peak: 49.2 [3.7] mL·kg-1·min-1, V˙O2 amplitude: 35.8 [5.2] mL·kg-1·min-1, time delay: 4.7 [2.5] s and time constant: 23.7 [11.1] s; mean [SD]). Aerobic, anaerobic lactic, and alactic pathways accounted for 62% (4%), 26% (4%), and 12% (2%) of energy contribution. Reduction in muscle function in jumping ability (jump height: 8% [6%], peak force: 6% [4%], and maximum velocity: 4% [2%]) and plank prone test (46% [20%]) was observed in the recovery period.CONCLUSIONS: The Fran unbroken workout is a high-intensity effort associated with an elevated metabolic response. This pattern of energy response highlights the primary contribution of aerobic energy metabolism, even during short and very intense CrossFit workouts, and that recovery can take &gt;24 hours due to cumulative fatigue.</p

Electromyographic effects of elbow joint flexors and extensors during induced muscle pain.

SampleThirteen volunteers, all males (mean age 27±5 years, 178±11 cm, and 78 ±17 kg) participated in the experiment.Apparatus and movementTwo minutes of continuous horizontal elbow flexion/extension movements (115º range) aiming at a 22º-wide target positioned at each end of the arc of motion were performed on a manipulandum. The average number of movements (flexion and extension of the elbow joint) performed was 95,23 ± 14.24. A load of 10 kg was added to the manipulandum to increase the mechanical strength of the task to be performed. Volunteers were seated comfortably with the dominant arm in semi-prone position, strapped at an adjustable support and fixed at 45º of shoulder horizontal flexion in 90º of abduction. Shoulder angles were defined relative to the coronal plane with 0º corresponding to the arm aligned with this plane. The forearm was strapped to a light manipulandum positioned horizontally aligned with the arm support (Fig. 1). The elbow joint was positioned just above the fulcrum of the manipulandum so that only horizontal movements were permitted. The volunteers were instructed to grasp a handle and to do the movements as fast and as accurately as possible. Visual feedback of the elbow position, the target width, and the range of motion were shown to the volunteer on a computer screen. Verbal encouragement was provided in order to obtain the maximum possible speed of the cyclic contractions.Experimental muscle painAn infusion of 1.5 ml of sterile hypertonic saline (5.8%) was injected intramuscularly into the biceps brachialis muscle (lateral head) at a rate of 90 ml/h, using a disposable stainless needle (27 g, 40 mm) connected via a tube (IVAC, G30303) to an infusion pump (ALARIS medical systems, Asena, UK). Pain intensity was assessed using a 10-cm electronic visual analogue scale (VAS), where 0 cm represented "no pain" and 10 cm represented "intolerable pain." The VAS signal was continuously recorded. Participants were allowed to adjust the values using their non-exercising hand and were instructed to focus on the VAS during breaks between individual trials. Mean VAS scores obtained during and between the trials were calculated.General proceduresThe volunteers attended the laboratory in two sessions, separated by at least one week. In each session, two minutes of flexion and extension movements were performed in three conditions, namely, pre-infusion, immediately after infusion of hypertonic (or isotonic) saline solution and 30 minutes after the pain, eventually caused by the infusion, was vanished.Pain assessmentTo assess pain perception, a 10-centimeter electronic visual analog scale (VAS) was used. On the scale, 0 cm represented "no pain" and 10 cm indicated "intolerable pain." Subjects could continuously adjust the VAS score using their hand not involved in the exercise to reflect their pain intensity throughout the experiment. They were instructed to focus on the VAS during rest periods between trials. The mean VAS scores during both exercise and rest periods were then calculated. The angular position of flexion and extension of the elbow joint, as well as the electromyographic activity of the muscles analyzed were synchronously acquired.Kinematic and EMG recordingsElectromyography signal (EMG) of biceps brachii (long head), triceps brachii (lateral head), trapezius, and brachioradialis muscle were recorded. The EMG intensity of each muscle was normalized by the respective peak (average of two trials) of maximal voluntary isometric contraction recorded before the first set of trials. An electrogoniometer (Biometrics SG110, Ladysmith, Vt.) was used to measure elbow angular position. A pair of surface electrodes (Medicotest 72001-k, ØLstykke, Denmark) was placed in the direction of the muscle fibers (2 cm apart) on shaved, abraded cleaned skin. On biceps brachii (long head) the electrodes were placed on the line between the medial acromion and the fossa cubit at 1/3 from the fossa cubit. For the triceps brachii (lateral head) the electrodes were placed at 50 % on the line between the posterior crista of the acromion and the olecranon at 2 finger widths lateral to the line. For upper trapezius the electrodes were placed at 50% on the line from the acromion to the spine on vertebra C7. On the brachioradialis belly, the electrodes were placed in the distal part of the upper arm where the muscle becomes superficial, lateral to the line between acromion and cubital fossa. All the electrode placements were done according to SENIAM recommendation. The EMG signals were bandpass filtered (second order, 20–500 Hz), amplified (1,000–10,000 times; CounterPoint MK2, Dantec, Skovlunde, Denmark) and sampled at 2 kHz. Pain intensity (VAS), electrogoniometer, and electromyographic signals were acquired in parallel by an analog/digital converter and stored on a personal computer.The dataThe data are stored in a .csv format that can be read using excel software. The data set comprises files with the sEMG signal from thirteen volunteers plus one file named “EMG_pain_info” in .txt format. The data files are separated in columns by comma. The files are organized by columns in the following structure: Visual analog scale, electronic goniometer biceps brachii, trapezius, triceps brachii, brachioradialis. These files are named as S01BBHa, where the S01 stands for subject 01, and BB stands for biceps brachialis (the muscle where pain was induced), H or I stands for hypertonic or isotonic saline solution, and “a, b and c” stands for the epoch of the protocol, being a the epoch pre infusion, b the epoch immediately after infusion, and c is the epoch containing data acquired immediately after the pain has completely vanished. Altogether 7279 contractions data, of 13 subjects in three different conditions and three epochs. The EMG_pain_info file contains details about the data collection, and anthropometric data of subjects evaluated in the study.</p

Effects of once-weekly exenatide on cardiovascular outcomes in type 2 diabetes

BACKGROUND: The cardiovascular effects of adding once-weekly treatment with exenatide to usual care in patients with type 2 diabetes are unknown. METHODS: We randomly assigned patients with type 2 diabetes, with or without previous cardiovascular disease, to receive subcutaneous injections of extended-release exenatide at a dose of 2 mg or matching placebo once weekly. The primary composite outcome was the first occurrence of death from cardiovascular causes, nonfatal myocardial infarction, or nonfatal stroke. The coprimary hypotheses were that exenatide, administered once weekly, would be noninferior to placebo with respect to safety and superior to placebo with respect to efficacy. RESULTS: In all, 14,752 patients (of whom 10,782 [73.1%] had previous cardiovascular disease) were followed for a median of 3.2 years (interquartile range, 2.2 to 4.4). A primary composite outcome event occurred in 839 of 7356 patients (11.4%; 3.7 events per 100 person-years) in the exenatide group and in 905 of 7396 patients (12.2%; 4.0 events per 100 person-years) in the placebo group (hazard ratio, 0.91; 95% confidence interval [CI], 0.83 to 1.00), with the intention-to-treat analysis indicating that exenatide, administered once weekly, was noninferior to placebo with respect to safety (P<0.001 for noninferiority) but was not superior to placebo with respect to efficacy (P=0.06 for superiority). The rates of death from cardiovascular causes, fatal or nonfatal myocardial infarction, fatal or nonfatal stroke, hospitalization for heart failure, and hospitalization for acute coronary syndrome, and the incidence of acute pancreatitis, pancreatic cancer, medullary thyroid carcinoma, and serious adverse events did not differ significantly between the two groups. CONCLUSIONS: Among patients with type 2 diabetes with or without previous cardiovascular disease, the incidence of major adverse cardiovascular events did not differ significantly between patients who received exenatide and those who received placebo