Muscle Oxygen Extraction during Vascular Occlusion Test in Physically Very Active versus Inactive Healthy Men: A Comparative Study.

An increase in the delivery and use of oxygen to the musculature in physically active subjects are determinants of improving health-related aerobic capacity. Additional health benefits, such as an increase in the muscle mass and a decrease in fat mass, principally in the legs, could be achieved with weekly global physical activity levels of more than 300 min. The objective was to compare the muscle vascular and metabolic profiles of physically very active and inactive subjects. Twenty healthy men participated in the study; ten were assigned to the physically very active group (25.5 ± 4.2 years; 72.7 ± 8.1 kg; 173.7 ± 7.6 cm) and ten to the physically inactive group (30.0 ± 7.4 years; 74.9 ± 11.8 kg; 173.0 ± 6.4 cm). The level of physical activity was determined by the Global Physical Activity Questionnaire (GPAQ). A resting vascular occlusion test (5 min of an ischemic phase and 3 min of a reperfusion phase) was used, whereas a near-field infrared spectroscopy (NIRS) device was used to evaluate the muscle oxygenation in the right vastus lateralis of the quadriceps muscle. The area under the curve of the deoxyhemoglobin (HHb) during the ischemic phase and above the curve of the tissue saturation index (TSI) during the reperfusion phase were obtained to determine muscle metabolic and vascular responses, respectively. Physically very active group showed a higher absolute HHb (3331.9 ± 995.7 vs. 6182.7 ± 1632.5 mmol/s) and lower TSI (7615.0 ± 1111.9 vs. 5420.0 ± 781.4 %/s) and relative to body weight (46.3 ± 14.6 vs. 84.4 ± 27.1 mmol/s/kg and 106.0 ± 20.6 vs. 73.6 ± 13.8 %/s/kg, respectively), muscle mass (369.9 ± 122.2 vs. 707.5 ± 225.8 mmol/kg and 829.7 ± 163.4 vs. 611.9 ± 154.2 %/s/kg) and fat mass (1760.8 ± 522.9 vs. 2981.0 ± 1239.9 mmol/s/kg and 4160.0 ± 1257.3 vs. ±2638.4 ± 994.3 %/s/kg, respectively) than physically inactive subjects. A negative correlation was observed between HHb levels and TSI (r = -0.6; p < 0.05). Physically very active men (>300 min/week) present better muscle oxidative metabolism and perfusion and perform significantly more physical activity than physically inactive subjects. Extra benefits for vascular health and muscle oxidative metabolism are achieved when a subject becomes physically very active, as recommended by the World Health Organization. In addition, a higher level of physical activity determined by GPAQ is related to better vascular function and oxidative metabolism of the main locomotor musculature, i.e., the quadriceps.

Association between Fractional Oxygen Extraction from Resting Quadriceps Muscle and Body Composition in Healthy Men.

This study aimed to associate body composition with fractional oxygen extraction at rest in healthy adult men. Fourteen healthy adults (26.93 ± 2.49 years) from Chile participated. Body composition was assessed with octopole bioimpedance, and resting muscle oxygenation was evaluated in the vastus lateralis quadriceps with near-infrared spectroscopy (NIRS) during a vascular occlusion test, analyzing the muscleVO2, resaturation velocity during reactive hyperemia via the muscle saturation index (%TSI), and the area above the curve of HHb (AACrep). It was observed that the total and segmented fat mass are associated with lower reoxygenation velocities during hyperemia (p = 0.008; ß = 0.678: p = 0.002; ß = 0.751), and that the total and segmented skeletal muscle mass are associated with higher reoxygenation velocities during hyperemia (p = 0.020; ß = -0.614: p = 0.027; ß = -0.587). It was also observed that the total and segmented fat mass were associated with a higher area above the curve of HHb (AACrep) during hyperemia (p = 0.007; ß = 0.692: p = 0.037; ß = 0.564), and that total and segmented skeletal muscle mass was associated with a lower area above the curve of HHb (AACrep) during hyperemia (p = 0.007; ß = -0.703: p = 0.017; ß = -0.632). We concluded that fat mass is associated with lower resaturation rates and lower resting fractional O2 extraction levels. In contrast, skeletal muscle mass is associated with higher resaturation rates and fractional O2 extraction during reactive hyperemia. The AACrep may be relevant in the evaluation of vascular adaptations to exercise and metabolic health.

A Higher Skeletal Muscle Mass and Lower Adiposity Phenotype Is Associated with Better Cardiometabolic Control in Adults with Hip and Knee Osteoarthritis: Results from the Chilean National Health Survey 2016-2017.

OBJECTIVE: This study aimed to (1) characterize cardiometabolic factors in self-reported hip and knee osteoarthritis (OAD) across four body composition phenotypes defined by muscle mass and adiposity, and (2) associate risk factors with diabetes and hypertension (HTN). METHODS: A cross-sectional analysis of the Chilean National Health Survey 2016-17 (n = 4996) stratified participants into four groups: low skeletal muscle mass/high waist circumference (Low-SMM/High-WC), low SMM/low WC (Low-SMM/Low-WC), high SMM/high WC (High-SMM/High-WC), and high SMM/low WC (reference group). Each group was further divided into subgroups with or without diagnosed hip or knee OAD. The main outcomes were fasting plasma glucose, systolic (SBP)/diastolic (DBP) blood pressure (continuous outcomes), and other secondary factors such as cardiovascular risk (CVR). RESULTS: In the hip OAD subgroup, the Low-SMM/High-WC groups had significantly higher SBP versus the reference value (145 vs. 127 mmHg, p < 0.0001, diff +18 mmHg). In the knee OAD subgroup, the Low-SMM/High-WC groups had significantly higher SBP versus the reference value (141 vs. 134 mmHg, p < 0.0001, diff +7 mmHg). The SBP showed a significant interaction between the group and OAD diagnosis (p = 0.007 hip OAD; p < 0.0001 knee OAD). CONCLUSIONS: Hip and knee OAD associates with elevated SBP/DBP in older adults. OAD groups showed an OR above 2 for diabetes, 2.7 for HTN, 4.5 for metabolic syndrome, and over 2 for moderate-to-high cardiovascular risk. OAD interacts substantially with cardiometabolic factors, especially in low muscle mass/high adiposity phenotypes. Lifestyle optimization of physical activity and nutrition to preserve muscle mass and mitigate adiposity is essential for cardiometabolic health promotion in OAD patients.

Systemic and Pulmonary Inflammation/Oxidative Damage: Implications of General and Respiratory Muscle Training in Chronic Spinal-Cord-Injured Patients.

Chronic spinal cord injury affects several respiratory-function-related parameters, such as a decrease in respiratory volumes associated with weakness and a tendency to fibrosis of the perithoracic muscles, a predominance of vagal over sympathetic action inducing airway obstructions, and a difficulty in mobilizing secretions. Altogether, these changes result in both restrictive and obstructive patterns. Moreover, low pulmonary ventilation and reduced cardiovascular system functionality (low venous return and right stroke volume) will hinder adequate alveolar recruitment and low O2 diffusion, leading to a drop in peak physical performance. In addition to the functional effects described above, systemic and localized effects on this organ chronically increase oxidative damage and tissue inflammation. This narrative review describes both the deleterious effects of chronic spinal cord injury on the functional effects of the respiratory system as well as the role of oxidative damage/inflammation in this clinical context. In addition, the evidence for the effect of general and respiratory muscular training on the skeletal muscle as a possible preventive and treatment strategy for both functional effects and underlying tissue mechanisms is summarized.

Relación entre dimensiones antropométricas de tronco y valores de espirometría / Association between anthropometric dimensions of trunk and spirometry indices

Los objetivos del presente estudio fueron primero evaluar la asociación de dimensiones antropométricas de tórax y tronco con índices espirométricos, segundo, ajustar una ecuación de predicción con dimensiones antropométricas de tronco y tercero, comparar nuestro modelo predictivo con dos ecuaciones diagnósticas. Se evaluaron 59 estudiantes universitarios entre 20 y 40 años, de ambos sexos, sin hábito tabáquico. Las variables consideradas fueron: edad, sexo, peso, estatura, diámetro transverso de tórax, diámetro anteroposterior de tórax, perímetro de tórax, altura de tórax, altura de tronco, flujo espiratorio máximo (FEM), volumen espiratorio forzado en el primer segundo (VEF1) y capacidad vital forzada (CVF). Se utilizó el análisis de regresión múltiple para estimar los valores espirométricos en función de las variables demográficas y antropométricas. La CVF y el VEF1 tienen asociación lineal directa con el diámetro transverso de tórax, altura de tórax, perímetro de tórax y altura de tronco. Se ajustó una ecuación de regresión lineal múltiple que indicó que es posible estimar la CVF y el VEF11 en función de la altura de tronco y el perímetro de tórax para ambos sexos. Estas variables son capaces de explicar el 74 % de los valores de CVF y el 68 % de los valores de VEF1. Al comparar los valores obtenidos por nuestras ecuaciones predictivas con las ecuaciones de referencia nacional observamos que nuestros resultados son más cercanos a los de Quanjer et al. (2012) que a los de Knudson et al. (1983). La altura de tronco y el perímetro de tórax tienen asociación directa con el VEF1 y CVF y son buenos predictores del VEF1 y CVF en estudiantes universitarios. Nuestros valores estimados son más cercanos a las ecuaciones de Quanjer et al. (2012) en comparación a las estimaciones de Knudson (1983).

SUMMARY: The purposes of the present study were first to evaluate the association between anthropometric dimensions of the thorax and trunk with spirometric indices, second, to fit a prediction equation with anthropometric dimensions of the trunk, and third, to compare our predictive model with two diagnostic equations. Fifty-nine university students between 20 and 40 years old, of both sexes and non-smokers were recruited. Variables considered were age, sex, weight, height, chest transverse diameter, chest anteroposterior diameter, chest perimeter, chest height, trunk height, maximum expiratory flow (PEF), forced expiratory volume in the first second (FEV1) and forced vital capacity (FVC). Multiple regression analysis was used to estimate spirometric values based on demographic and anthropometric variables. FVC and FEV1 have a direct linear association with chest transverse diameter, chest height, chest circumference, and trunk height. A multiple linear regression equation was fitted, indicating that it is possible to estimate FVC and FEV1 as a function of trunk height and chest girth for both sexes. These variables can explain 74% of the FVC values and 68% of the FEV1 values. Comparing the values obtained by our predictive equations with the national reference equations, we observe that our results are closer to those of Quanjer et al. (2012) than to those of Knudson et al. (1983). Trunk height and chest circumference have a direct association with FEV1 and FVC and are good predictors of FEV1 and FVC in university students. Our estimated values are closer to Quanjer et al. (2012) than Knudson et al. (1983) prediction equations.

Heart Rate from Progressive Volitional Cycling Test Is Associated with Endothelial Dysfunction Outcomes in Hypertensive Chilean Adults.

BACKGROUND: A progressive volitional cycling test is useful in determining exercise prescription in populations with cardiovascular and metabolic diseases. However, little is known about the association between heart rate during this test and endothelial dysfunction (EDys) parameters in hypertensive (HTN) patients. OBJECTIVE: To investigate the association between EDys markers (flow-mediated dilation [FMD], pulse wave velocity of the brachial artery [PWVba], and carotid-intima media thickness [cIMT]) and heart rate during a cycling test in HTN adults. A secondary aim was to characterize cardiovascular, anthropometric, and body composition outcomes in this population. METHODS: This was a descriptive clinical study in which adults (men and women) were assigned to one of three groups: HTN, elevated blood pressure (Ele), or a normotensive control group (CG), and completed a progressive cycling test. The primary outcomes were FMD, PWVba, cIMT, and heart rate (HR) at 25-50 watts (HR25-50), 50-100 watts (HR50-100), and 75-150 watts (HR75-150) of the Astrand test. Secondary outcomes included body mass index (BMI), waist circumference, body fat percentage (BF%), skeletal muscle mass (SMM), resting metabolic rate (RMR), and estimated body age, as measured by a bio-impedance digital scale. RESULTS: Analyses of the associations between FMD, PWV, and HR25-50, HR50-100, and HR75-150 watts revealed no significant association in the HTN, Ele, and CG groups. However, a significant association was found between cIMT and HR75-150 watts in the HTN group (R2 47.1, ß -0.650, p = 0.038). There was also a significant trend (p = 0.047) towards increasing PWVba in the CG, Ele, and HTN groups. CONCLUSION: Heart rate during a progressive cycling test is associated with the EDys parameters cIMT in HTN patients, with particularly strong predictive capacity for vascular parameters in the second and third stages of the Astrand exercise test compared to normotensive control.

Predicting Cardiovascular Rehabilitation of Patients with Coronary Artery Disease Using Transfer Feature Learning.

Cardiovascular diseases represent the leading cause of death worldwide. Thus, cardiovascular rehabilitation programs are crucial to mitigate the deaths caused by this condition each year, mainly in patients with coronary artery disease. COVID-19 was not only a challenge in this area but also an opportunity to open remote or hybrid versions of these programs, potentially reducing the number of patients who leave rehabilitation programs due to geographical/time barriers. This paper presents a method for building a cardiovascular rehabilitation prediction model using retrospective and prospective data with different features using stacked machine learning, transfer feature learning, and the joint distribution adaptation tool to address this problem. We illustrate the method over a Chilean rehabilitation center, where the prediction performance results obtained for 10-fold cross-validation achieved error levels with an NMSE of 0.03±0.013 and an R2 of 63±19%, where the best-achieved performance was an error level with a normalized mean squared error of 0.008 and an R2 up to 92%. The results are encouraging for remote cardiovascular rehabilitation programs because these models could support the prioritization of remote patients needing more help to succeed in the current rehabilitation phase.

Effects of Inspiratory Muscle Training on Muscle Oxygenation during Vascular Occlusion Testing in Trained Healthy Adult Males.

Inspiratory muscle training (IMT) may have an additional effect on cardiovascular autonomic modulation, which could improve the metabolism and vascular function of the muscles. AIM: To determine the effects of IMT on vascular and metabolic muscle changes and their relationship to changes in physical performance. METHODS: Physically active men were randomly placed into an experimental (IMTG; n = 8) or IMT placebo group (IMTPG; n = 6). For IMT, resistance load was set at 50% and 15% of the maximum dynamic inspiratory strength (S-Index), respectively. Only the IMTG's weekly load was increased by 5%. In addition, both groups carried out the same concurrent training. Besides the S-Index, a 1.5-mile running test, spirometry, and deoxyhemoglobin (HHbAUC during occlusion) and reperfusion tissue saturation index (TSIMB and TSIMP: time from minimum to baseline and to peak, respectively) in a vascular occlusion test were measured before and after the 4-week training program. In addition, resting heart rate and blood pressure were registered. RESULTS: IMTG improved compared to IMTPG in the S-Index (Δ = 28.23 ± 26.6 cmH2O), maximal inspiratory flow (MIF: Δ = 0.91 ± 0.6 L/s), maximum oxygen uptake (Δ = 4.48 ± 1.1 mL/kg/min), 1.5-mile run time (Δ = -0.81 ± 0.2 s), TSIMB (Δ = -3.38 ± 3.1 s) and TSIMP (Δ = -5.88 ± 3.7 s) with p < 0.05. ΔVO2max correlated with S-Index (r = 0.619) and MIF (r = 0.583) with p < 0.05. Both ΔTSIMB and TSIMP correlated with ΔHHbAUC (r = 0.516 and 0.596, respectively) and with Δ1.5-mile run time (r = 0.669 and 0.686, respectively) with p < 0.05. CONCLUSION: IMT improves vascular function, which is related to additional improvements in physical performance.

Near-Infrared Spectroscopy Used to Assess Physiological Muscle Adaptations in Exercise Clinical Trials: A Systematic Review.

Using muscle oxygenation to evaluate the therapeutic effects of physical exercise in pathologies through near-infrared spectroscopy (NIRS) is of great interest. The aim of this review was to highlight the use of muscle oxygenation in exercise interventions in clinical trials and to present the technological characteristics related to the equipment used in these studies. PubMed, WOS, and Scopus databases were reviewed up to December 2021. Scientific articles that evaluated muscle oxygenation after exercise interventions in the sick adult population were selected. The PEDro scale was used to analyze the risk of bias (internal validity). The results were presented grouped in tables considering the risk of bias scores, characteristics of the devices, and the effects of exercise on muscle oxygenation. All the stages were carried out using preferred reporting items for systematic reviews and meta-analyses (PRISMA). The search strategy yielded 820 clinical studies, of which 18 met the eligibility criteria. This review detailed the characteristics of 11 NIRS devices used in clinical trials that used physical exercise as an intervention. The use of this technology made it possible to observe changes in muscle oxygenation/deoxygenation parameters such as tissue saturation, oxyhemoglobin, total hemoglobin, and deoxyhemoglobin in clinical trials of patients with chronic disease. It was concluded that NIRS is a non-invasive method that can be used in clinical studies to detect the effects of physical exercise training on muscle oxygenation, hemodynamics, and metabolism. It will be necessary to unify criteria such as the measurement site, frequency, wavelength, and variables for analysis. This will make it possible to compare different models of exercise/training in terms of time, intensity, frequency, and type to obtain more precise conclusions about their benefits for patients.

Reproducibility of Maximum Respiratory Pressure Assessment: A Systematic Review and Meta-analysis.

BACKGROUND: Accurate assessment of maximum respiratory pressure is vital when tracking disease progression and devising treatment strategies. Previous studies indicate a learning effect when undertaking maximum respiratory pressure measurements. The extent of this learning effect and methodologies undertaken to mitigate this learning effect have not been investigated systematically. RESEARCH QUESTION: What is the magnitude of improvements in maximum respiratory pressure in response to respiratory muscle warm-up protocols and repeated measures of maximum respiratory pressure in healthy individuals and clinical populations? METHODS: A comprehensive search of electronic databases was undertaken during August 2021 for studies examining the intrarater reliability of maximum inspiratory or expiratory pressure, or both, studies developing a protocol or an intervention to obtain maximum values, and studies analyzing the reliability of repeated maneuvers in a single testing session in healthy individuals and clinical populations. Included articles were analyzed critically using two appraisal tools. Standardized mean differences with 95% CIs were calculated and corrected for the sample size as a measure of the magnitude of change in maximum respiratory pressure outcomes. RESULTS: Of the 1,969 articles retrieved, 32 were included in the meta-analysis. Eighteen studies included healthy individuals and 14 studies included individuals with chronic medical conditions. The overall effect of inspiratory muscle warm-up protocols was higher (effects size [ES], 0.40; 95% CI, 0.17-0.63) in comparison with single testing session studies (ES, 0.20; 95% CI, 0.05-0.35) and studies performing repeated testing sessions of maximum respiratory pressure (ES, 0.14; 95% CI, 0.07-022). INTERPRETATION: Inspiratory muscles warm-up procedures induce higher increases in maximum inspiratory pressure in comparison with single and repeated testing sessions of maximum respiratory pressure in healthy individuals. Warm-up protocols are more effective to obtain the maximum performance of inspiratory muscles in one testing session in comparison with other methods. TRIAL REGISTRY: PROSPERO; No.: CRD42022304591; URL: https://www.crd.york.ac.uk/prospero/.

Average and Interindividual Effects to a Comprehensive Cardiovascular Rehabilitation Program.

Background: To describe the average effects and the interindividual variability after a comprehensive outpatient cardiovascular rehabilitation (CCR) program using concurrent exercise training prescribed according to cardiovascular risk stratification on cardiorespiratory fitness (CRF), anthropometric/body composition, quality of life and emotional health in patients of four cardiovascular disease profiles. Methods: CRF, anthropometric/body composition, quality of life, and emotional health were measured before and after a CCR and analyzed in heart valve surgery (HVS), heart failure with reduced ejection fraction (HFrEF), post-acute myocardial infarction (post-AMI), and in coronary artery disease (CAD) patients. Twenty, twenty-four, and thirty-two exercise sessions were prescribed according to mild, moderate, and severe baseline cardiovascular risk, respectively. In addition to concurrent exercise training, nutritional counseling, psychological support, and lifestyle education programs were performed. Results: The main outcomes by delta changes comparisons (Δ) revealed no significant differences at anthropometric/body composition as ΔBody fat decreases (HVS Δ−1.1, HFrEF Δ−1.0, post-AMI Δ−1.4, CAD Δ−1.2 kg) and ΔSkeletal muscle mass increases (HVS Δ+1.4, HFrEF Δ+0.8, post-AMI Δ+0.9, CAD Δ+0.9 kg), and CRF performance as ΔVO2peak increases (HVS Δ+4.3, HFrEF Δ+4.8, post-AMI Δ+4.1, CAD Δ+5.1 mL/kg/min) outcomes among HVS, HFrEF, post-AMI, and CAD (p > 0.05). Secondary outcomes showed significant pre-post delta changes in METs (HVS Δ+1.8, HFrEF Δ+0.7, post-AMI Δ+1.4, CAD Δ+1.4), and maximal O2pulse (HVS Δ+3.1, post-AMI Δ+2.1, CAD Δ+1.9). In addition, quality of life had a significant improvement in physical functioning (HVS Δ+17.0, HFrEF Δ+12.1, post-AMI Δ+9.8, CAD Δ+11.2), physical role (HVS Δ+28.4, HFrEF Δ+26.8, post-AMI Δ+25.6, CAD Δ+25.3), vitality (HVS Δ+18.4, HFrEF Δ+14.3, post-AMI Δ+14.2, CAD Δ+10.6) and social functioning (HVS Δ+20.4, HFrEF Δ+25.3, post-AMI Δ+20.4, CAD Δ+14.8) in all cardiovascular disease. For anxiety (HVS Δ−3.6, HFrEF Δ−2.3, post-AMI Δ−3.0, CAD Δ−3.1) and depression (HVS Δ−2.8, HFrEF Δ−3.4, post-AMI Δ−3.2, CAD Δ−2.3) significant changes were also observed. Conclusions: A CCR program that prescribes the number of exercise sessions using a cardiovascular risk stratification improves CRF, QoL, and emotional health, and the average results show a wide interindividual variability (~25% of non-responders) in this sample of four CVD profile of patients.

Características de composición corporal, ángulo de fase y agua corporal en paracaidistas chilenos de elite / Characteristics of body composition, phase angle and body water in elite Chilean skydivers

RESUMEN: Durante la práctica del paracaidismo, una deficiente composición corporal no sólo puede afectar el rendimiento deportivo, sino que, además, incrementa la probabilidad de sufrir una lesión o accidente grave. Conocer las características de sus componentes, podría ayudar a prevenirlas. El objetivo del estudio fue describir la composición corporal, ángulos de fase y agua corporal total en paracaidistas chilenos de alta competencia. Participaron del estudio 8 paracaidistas profesionales del Team Chile® (33,4 ± 4,9 años) con más de seis años de experiencia. La evaluación de las masas grasa, muscular, libre de grasa, magra y visceral, así como el ángulo de fase y el agua corporal total obtenida a través de impedancia bioeléctrica. Los deportistas presentaron un peso corporal de 76,7 ± 5,7 kg, estatura 1,72 ± 0,1 m e IMC 26,0 ± 1,9 kg/m2. La composición corporal promedio mostró un 20,6 ± 3,0 % de masa grasa, 44,9 ± 2,0 % de masa muscular y 79,4 ± 3,0 % de masa libre de grasa. El ángulo de fase promedio fue de 7,25 ± 0,33°. El agua corporal total de los participantes fue de 44,6 ± 3,2 1. Se concluye que los resultados obtenidos pueden ser utilizados por los profesionales de las ciencias del deporte como valores de referencia para el control de la composición corporal, fase angular y agua corporal en paracaidistas para optimizar el rendimiento deportivo y evitar lesiones.

SUMMARY: Unsuitable body composition in skydivers not only affect the sport performance but also could increase the probability of risk injury or severe accident; hence, to determine body composition characteristics could be helpful to prevent such events. This study aimed to describe body composition, phase angle, and total body water in highly trained Chilean skydivers. Eight Team Chile® professional skydivers (33.4 ± 4.9 years) with more than 6 years of experience participated in this study. Fat mass, muscle mass, fat-free mass, lean mass, visceral mass, phase angle, and total body water were measured by bioelectrical impedance. Skydivers had a bodyweight of 76.7±5.7 kg, a height of 1.72 ±0.1 m, and a body mass index of 26.0 ±1.9 kg/m2. Regarding body composition, they had a fat mass of 20.6 ±3.0 %, a muscle mass of 44.9 ±2.0 %, and a fat-free mass of 79.4 ±3.0 %. Phase angle and total body water were 7.25 ±0.3° and 344.6±3.2, respectively. The present findings could be useful to science sport professionals as reference values of body composition, phase angle, and total body water of highly trained skydivers to improve sports performance and avoid injuries.

Asociación entre la termografía por infrarrojo, parámetros antropométricos y gasto energético de reposo en hombres / Association between infrared thermography, anthropometry parameters and rest energy expenditure in men

RESUMEN: Es reconocido que un incremento de la grasa corporal subcutánea es capaz de alterar el patrón de liberación de calor a través de la piel. Sin embargo, la asociación con otras variables antropométricas y la influencia del gasto energético en reposo (GER), han sido escasamente abordadas. Este estudio determinó la relación de la temperatura de la piel con variables antropométricas, peso corporal y GER de hombres adultos sanos. Participaron en el estudio un total de 24 varones sanos de 33,9±8,7 años de edad, 85,8±9,7 kg de peso corporal, 172,5±6,1 cm de estatura y 28,9±3,4 kg/m2 de índice de masa corporal (IMC). Se realizaron evaluaciones antropométricas, de termografía por infrarrojo y del GER por calorimetría indirecta, con analizador de gases. La temperatura promedio de los 6-pliegues, y las individuales (toracoabdominales, supra-espinal y abdominal), tuvieron correlaciones negativas con el IMC, perímetro de cintura, índice cintura cadera, índice cintura estatura, y la sumatoria de 6 pliegues; todos con p<0,05. Además, la temperatura del pliegue supraespinal tuvo una correlación negativa con el porcentaje de masa adiposa (MA%), r=0,47(p=0,0194). La MA% y el IMC tuvieron correlaciones negativas con el GER, con r=-0,59 (p=0,002) y r=-0,53 (p=0,006), respectivamente. El promedio de temperatura de los 6-pliegues presentó una correlación positiva con el GER (r=0,44; p=0,02). La composición corporal causa una modificación en los patrones de termografía superficial local, sin afectar la relación entre el promedio de la temperatura superficial total con el GER, pudiendo éste ser un factor predictor.

SUMMARY: It is known that an increase in the subcutaneous body fat can alter the pattern of heat release through the skin. However, the relationship with other anthropometric variables and the influence of the Resting Energy Expenditure (REE) have scarcely been addressed. To determine the relationship of skin temperature with different anthropometric variables, body weight, and the REE of healthy adult males. The participants were a total of 24 healthy males of 33.9±8.7 years-old, 85.8±9.7 kg of body mass, 172.5±6.1 cm of height, and 28.9±3.4 kg/m2 of body mass index (BMI). Anthropometric, infrared thermography, and indirect calorimetry REE assessments were performed with gas analyzer. The six skinfolds average temperature, as well as the individual skinfolds (thoracoabdominal, supraspinal, and abdominal), had negative correlations with the BMI, waist circumference, waist- hip ratio, waist-to-height ratio, and the sum of the six skinfolds, all with p<0.05. In addition, the temperature of the supraspinal fold had a negative correlation with the percentage of fat mass (MA%), r=0.47 (p=0.0194). MA% and BMI had negative correlations with REE, with r=-0.59 (p=0.002) and r=-0.53 (p=0.006), respectively. The six-skinfolds average temperature presented a positive correlation with the REE (r=0.44; p=0.02). Body composition changes cause a modification in the local surface thermography patterns without affecting the relationship between the average total body surface temperature with the REE; therefore, this could act as a predictive factor.

Changes in pulmonary and plasma oxidative stress and inflammation following eccentric and concentric cycling in stable COPD patients.

PURPOSE: The purpose of this study was to compare pulmonary and plasma markers of oxidative stress and inflammation after concentric and eccentric cycling bouts in individuals with chronic obstructive pulmonary disease (COPD). METHODS: Ten patients with moderate COPD level (68.3 ± 9.1 years; forced expiratory volume in 1 s = 68.6 ± 20.4% of predicted) performed 30 min of moderate-intensity concentric (CONC-M: 50% maximum concentric cycling power output; POmax) and eccentric cycling (ECC-M: 50% POmax), and high-intensity eccentric cycling (ECC-H: 100% POmax) in a randomised order. Cardiometabolic demand was monitored during cycling. Indirect markers of muscle damage were assessed before, immediately after, 24 and 48 h after cycling (muscle strength, muscle soreness and creatine kinase activity). Plasma oxidative stress (malondialdehyde: MDA), antioxidant (glutathione peroxidase activity: GPx) and inflammatory markers (IL-6, TNF-α) were measured before and 5 min after cycling. Exhaled breath condensate (EBC) samples were collected before and 15 min after cycling and analysed for hydrogen peroxide (H2O2), nitrites (NO2-) and pH. RESULTS: Cardiometabolic demand was 40-50% lesser for ECC-M than CONC-M and ECC-H. Greater muscle damage was induced after ECC-H than ECC-M and CONC-M. MDA decreased immediately after CONC-M (- 28%), ECC-M (- 14%), and ECC-H (- 17%), while GPx remained unchanged. IL-6 increased only after ECC-H (28%), while TNF-α remained unchanged after exercise. Pulmonary H2O2, NO2- and pH remained unchanged after exercise. CONCLUSION: These results suggest that only moderate muscle damage and inflammation were induced after high-intensity eccentric cycling, which did not induce pulmonary or plasmatic increases in markers of oxidative stress. TRIAL REGISTRATION NUMBER: Trial registration number: DRKS00009755.

Inspiratory muscle training improves the swimming performance of competitive young male sprint swimmers.

BACKGROUND: Inspiratory muscle training (IMT) stimulates the strengthening of the respiratory muscles by placing a resistance to the entry of air into the lung. The objective was to observe the effect of IMT on swimming performance, and its relationship with inspiratory strength and lung function. METHODS: Fifteen male swimmers (age=15.1±1.1 years) were divided into an experimental group (EG; N.=9) and a sham control group (SCG; N.=6). Lung flows/volumes using spirometry, dynamic inspiratory strength (S-Index), maximum inspiratory flow (MIF), and swimming tests (50-m, 100-m and 200-m) were measured before and after a four-week aerobic swimming training program (R1-R2) and IMT. An initial load at 50% and 15% of S-Index was adjusted for EG and SCG respectively. Only the EG increased the initial load by 5% each week. RESULTS: The S-Index and MIF were only increased in the EG after IMT (∆S-Index=18.0±8.8 cmH2O and ∆MIF=0.7±0.33 L·min-1; P<0.05). The same occurred for FVC (∆=0.3±0.2 l), and MVV (∆=6.9±3.6 l·min-1) (P<0.05). For swimming performances, the EG swimming times decreased significantly respect to CG for 50-m (∆EG=-1.2±0.3 s vs. ∆CG=-0.1±0.2 s), 100-m (∆EG=-2.9±1 s vs. ∆CG=-0.7±0.5 s) and 200-m (∆EG=-7.3±2.8 s vs. ∆CG=-2.0±1 s) with P<0.05. Finally, the S-Index and MIF had a negative correlation with swimming performances for 50-m (S-Index, r=-0.72; MIF, r=-0.70) and 100-m (S-Index, r=-0.65; MIF, r=-0.62) with P<0.05. CONCLUSIONS: A short-period IMT increases the maximum S-Index, ventilation and MIF which positively influence the swimming performance of young swimmers.

Plyometric training improves swimming performance in recreationally-trained swimmers / O treinamento pliométrico melhora o desempenho de nadadores recreativos / El entrenamiento pliométrico mejora el desempeño de nadadores recreativos

ABSTRACT Introduction: Plyometric training significantly improves strength performance, including in aquatic sports. Objective: To compare changes in thigh girth, hamstring flexibility, squat jump height, and 200m swimming trial time induced by plyometric training in recreationally-trained swimmers. Methods: Eighteen recreationally-trained male swimmers (age=18-20 years) were randomly divided into a plyometric training group (PTG) and a control group (CG). All the swimmers completed a six-week speed swimming training plan. In the PTG only, the last ~15 min of each session was replaced with plyometric exercises. The physical characteristics and the thigh girth were measured before and after the six weeks of training. In addition, sit-and-reach flexibility and squat jump tests were conducted, as well as a 200m swimming trial. Results: Two-way ANOVA with post-hoc analysis revealed an increase in sit-and-reach flexibility (PRE: 4.5±5.3 cm; POST: 10.9±5.9 cm, p<0.01) and squat jump height (PRE: 24.9±3.7 cm; POST: 28.3±4.2 cm, p<0.01) and a decrease in 200m-swimming time (PRE: 220±26.5 sec; POST: 204±24.4 sec, p<0.01) for the PTG only. Comparing the absolute changes (post-pre) between the groups by the Student's t-test, the PTG showed a greater increase in distance reached in the sit-and-reach flexibility (PTG: 6.34±0.6 cm vs. CG: 2.4±1.2 cm, p<0.01) and squat jump height (PTG: 3.4±0.7 cm vs. CG: 0.7±0.3 cm, p<0.01) than the CG. In addition, the 200m swimming time decreased significantly more than in the CG (PTG: -15.1±2.4 sec vs. CG: -0.8±2.7 sec, p<0.01). Conclusion: Plyometric training improves jump height, flexibility, and 200m swimming performance in recreationally-trained adult swimmers. Level of Evidence II; Lesser quality RCT.

RESUMO Introdução: O treinamento pliométrico melhora significativamente o desempenho de força, inclusive em esportes aquáticos. Objetivo: Comparar alterações da circunferência da coxa, flexibilidade dos isquiotibiais, altura do salto em agachamento e tempo de prova de natação de 200 metros depois de treinamento pliométrico em nadadores recreativos. Métodos: Dezoito nadadores recreativos do sexo masculino (idade = 18 a 20 anos) foram divididos randomicamente em um grupo de treinamento pliométrico (GP) ou controle (GC). Todos realizaram um plano de treinamento de natação em velocidade por seis semanas. Somente o GP substituiu os últimos 15 minutos de cada sessão por exercícios pliométricos. As características físicas e a circunferência da coxa foram medidas antes e depois das seis semanas de treinamento. Além disso, foram testados a flexibilidade (sentar e alcançar), o salto em agachamento e a prova de natação de 200 metros. Resultados: Um teste ANOVA de duas vias com análise post hoc revelou aumento da flexibilidade (PRÉ: 4,5 ± 5,3 cm; PÓS: 10,9 ± 5,9 cm, p < 0,01) e altura do salto (PRÉ: 24,9 ± 3,7 cm; PÓS: 28,3 ± 4,2 cm, p < 0,01), assim como diminuição do tempo de natação de 200 metros (PRÉ: 220 ± 26,5 s; PÓS: 204 ± 24,4 s, p < 0,01), apenas para o GP. Ao comparar as alterações absolutas (pré-pós) entre os grupos com o teste t de Student, o GP mostrou aumento maior da distância alcançada na flexibilidade no teste sentar e alcançar (GP: 6,34 ± 0,6 cm; GC: 2,4 ± 1,2 cm, p < 0,01) e na altura do salto em agachamento (GP: 3,4±0,7 cm; GC: 0,7±0,3 cm, p <0,01) do que o GC. Além disso, o tempo de natação de 200 metros diminuiu significativamente mais do que o GC (GP: -15,1 ± 2,4 s vs. GC: -0,8±2,7 s, p <0,01). Conclusão: O treinamento pliométrico melhora a altura do salto em agachamento, a flexibilidade e o desempenho em 200 metros de natação em nadadores adultos recreativos. Nível de evidência II; ECRC de menor qualidade.

RESUMEN Introducción: El entrenamiento pliométrico mejora significativamente el desempeño de fuerza, inclusive en deportes acuáticos. Objetivo: Comparar alteraciones de la circunferencia del muslo, flexibilidad de los isquiotibiales, la altura del salto en agachamiento y tiempo de prueba de natación de 200 metros luego de entrenamiento pliométrico en nadadores recreativos. Métodos: Dieciocho nadadores recreativos del sexo masculino (edad= 18 a 20 años) fueron divididos aleatoriamente en un grupo de entrenamiento pliométrico (GP) o control (GC). Todos realizaron un plan de entrenamiento de natación en velocidad de seis semanas. Solamente el GP sustituyó los últimos 15 minutos de cada sesión con ejercicios pliométricos. Las características físicas y circunferencia de muslo se midieron antes y después de las seis semanas de entrenamiento. Además, se evaluó la flexibilidad (sentar y alcanzar), salto en agachamiento y la prueba de natación de 200 metros. Resultados: Un test ANOVA de dos vías con análisis post hoc reveló aumento de la flexibilidad (PRE: 4,5±5,3 cm; POST: 10,9±5,9 cm, p <0,01) y altura de salto (PRE: 24,9±3,7 cm; POST: 28,3±4,2 cm, p <0,01), así como disminución del tiempo de natación de 200 metros (PRE: 220±26 0,5 s POST: 204±24,4 s, p <0.01), solo para el GP. Al comparar las alteraciones absolutas (pre-post) entre los grupos con el test t de Student, el GP mostró mayor aumento de la distancia alcanzada en la flexibilidad en el test sentar y alcanzar (GP: 6,34±0,6 cm vs. GC: 2,4±1,2 cm, p <0,01) y en la altura del salto en agachamiento (GP: 3,4±0,7 cm vs. GC: 0,7±0,3 cm, p <0,01) que el GC. Además, el tiempo de natación de 200 metros disminuyó significativamente más que el GC (GP: -15,1±2,4 s vs. GC: -0,8±2,7 s, p <0,01). Conclusión: El entrenamiento pliométrico mejora la altura del salto en agachamiento, la flexibilidad y el desempeño en 200m de natación en nadadores adultos recreativos. Nivel de Evidencia II; ECRC de menor calidad.

Differences in energy expenditure, amount of physical activity and physical exertion level during a Zumba fitness class among adult women who are normal weight, overweight and obese.

BACKGROUND: One of the most popular expressions of massive group classes of aerobic physical activity is Zumba fitness. The aim of the study was to compare and relate the energy expenditure and the amount and intensity of physical effort during a Zumba fitness class in women with different Body Mass Index (BMI). METHODS: Body displacements of 61 adult women who performed a one-hour Zumba session were evaluated with triaxial accelerometers. In order to observe the effect of BMI women were divided into normal weight (N.=26), overweight (N.=21) and obese groups (N.=14). RESULTS: The average number of steps was 4533.3±1351 and the percentage of total class time of moderate to vigorous intensity (% MVPA) was 53.8±14.4%. The metabolic intensity average was 3.64±1.1 MET, with an energy expenditure by total body mass of 3.9±1.6 kcal/kg. When analyzing groups, the normal weight group had a greater number of steps (5184.2±1561.1 steps/class) compared to overweight (4244.8±1049.3 steps/class) and obese women (3756.9±685.7 steps/class) with P<0.05. Also, the normal weight group spent a lower percentage of class time at the lower levels of intensity (sedentary and lifestyle activity levels) and more time at the highest levels (vigorous and very vigorous) compared to obese women (P<0.05). Participants with a normal weight obtained a higher % MVPA (62.1±15%) compared to overweight (50.1±9.4%) and obese (44.1±11.9%) groups with P<0.05. A metabolic intensity of 4.6±1.9 MET in the normal weight group was higher compared to 3.5±1.0 MET in the overweight (P<0.05) and 3.1±1.2 MET in the obese group (P<0.05), was observed. The subjective perception of effort was 7.84±0.9 (Borg CR 10), no differences between groups. Also we observed in all participants that at higher BMI values, there were lower energy expenditure values per kilo of weight (r=-0.40; P<0.001), metabolic intensity (r=-0.39; P<0.001), step counts (r=-0.43; P<0.001) and % MVPA (r=-0.50; P<0.001). CONCLUSIONS: These results show that a higher BMI is associated with a lower intensity of effort, energy expenditure and amount of physical activity during a one-hour Zumba class, restricting to overweight and obese women to achieving the effort parameters recommended to control weight and improve cardiovascular fitness.

[ANTHROPOMETRIC CHILEAN TABLE TENNIS PLAYERS OF COMPETITIVE FEATURES]. / CARACTERÍSTICAS ANTROPOMÉTRICAS EN JUGADORES CHILENOS DE TENIS DE MESA DE NIVEL COMPETITIVO.

The aim of the study was to characterize the anthropometric profile and somatotype of a sample of 50 players table tennis competitive with an average age 21.6 (± 3.1) years belonging to the Chilean team and institutions of higher education in the region of Valparaiso. The evaluation was conducted under the protocol marking the International Society for the Advancement of Kinanthropometry (ISAK) for the measurement procedure 25 restricted profile variables described by Drinkwater, Norton and Olds. Order to determine the body composition, fat, muscle, bone, skin and tissue residual was considered, using the equations proposed by Kerr. The body shape is characterized through somatotype method proposed by Carter. The sample was divided into 4 groups; Chilean Selection, Traditional Private Universities, State Universities and Private Universities Traditional Nontraditional. Regarding body composition; the Chilean team has the highest values of muscle tissue (45.6 ± 1.7%) and the lowest values of adipose tissue (25.2 ± 1.8%), also presenting lesser value in the Σ 6 skinfolds (mm) . The results showed no significant differences between groups in the aforementioned variables. In general somatotype compared by analyzing SANOVA no significant differences between groups (p = 0.409) was observed. The results show a biotype with such a characterization of endo-mesomorph with average values (4,1-4,9-1,8). This study provides updated data biotypological reference for this sport that can be used for decision-making.

El objetivo del estudio fue caracterizar el perfil antropometrico y el somatotipo de una muestra de 50 jugadores de tenis de mesa de nivel competitivo con un promedio de edad 21,6 (± 3,1) anos pertenecientes a la seleccion chilena e instituciones de educacion superior de la region de Valparaiso. La evaluacion se realizo bajo el protocolo de marcaje de la International Society for the Advancement of Kinanthropometry (ISAK) para el procedimiento de medicion de 25 variables de perfil restringido descrito por Drinkwater1, Norton & Olds2. Con el objetivo de determinar la composicion corporal, se considero el tejido adiposo, muscular, oseo, residual y de piel, utilizando las ecuaciones propuestas por Kerr3. La forma corporal se caracterizo a traves del metodo del somatotipo propuesto por Carter4. La muestra se distribuyo en cuatro grupos: seleccion chilena, universidades privadas tradicionales, universidades estatales tradicionales y universidades privadas no tradicionales. Respecto a la composicion corporal; la seleccion chilena presenta los mayores valores de tejido muscular (45,6 ± 1,7%) y los menores valores de tejido adiposo (25,2 ± 1,8%), presentando tambien menor valor en la Σ seis pliegues (mm). Los resultados no evidenciaron diferencias significativas entre los grupos en las variables antes mencionadas. En la comparacion general del somatotipo a traves del analisis SANOVA no se aprecian diferencias significativas entre los grupos (p = 0,409). Los resultados obtenidos muestran un biotipo con una caracterizacion de tipo endo-mesomorfo con valores promedio de (4,1-4,9-1,8). Este estudio aporta datos biotipologicos actualizados de referencia para este deporte que pueden ser utilizados para la toma de decisiones.

Características antropométricas en jugadores chilenos de tenis de mesa de nivel competitivo / Anthropometric Chilean table tennis players of competitive features

El objetivo del estudio fue caracterizar el perfil antropométrico y el somatotipo de una muestra de 50 jugadores de tenis de mesa de nivel competitivo con un promedio de edad 21,6 (± 3,1) años pertenecientes a la selección chilena e instituciones de educación superior de la región de Valparaíso. La evaluación se realizó bajo el protocolo de marcaje de la International Society for the Advancement of Kinanthropometry (ISAK) para el procedimiento de medición de 25 variables de perfil restringido descrito por Drinkwater1, Norton & Olds2. Con el objetivo de determinar la composición corporal, se consideró el tejido adiposo, muscular, óseo, residual y de piel, utilizando las ecuaciones propuestas por Kerr3. La forma corporal se caracterizó a través del método del somatotipo propuesto por Carter4. La muestra se distribuyó en cuatro grupos: selección chilena, universidades privadas tradicionales, universidades estatales tradicionales y universidades privadas no tradicionales. Respecto a la composición corporal; la selección chilena presenta los mayores valores de tejido muscular (45,6 ± 1,7%) y los menores valores de tejido adiposo (25,2 ± 1,8%), presentando también menor valor en la ∑ seis pliegues (mm). Los resultados no evidenciaron diferencias significativas entre los grupos en las variables antes mencionadas. En la comparación general del somatotipo a través del análisis SANOVA no se aprecian diferencias significativas entre los grupos (p = 0,409). Los resultados obtenidos muestran un biotipo con una caracterización de tipo endo-mesomorfo con valores promedio de (4,1-4,9-1,8). Este estudio aporta datos biotipológicos actualizados de referencia para este deporte que pueden ser utilizados para la toma de decisiones (AU)

The aim of the study was to characterize the anthropometric profile and somatotype of a sample of 50 players table tennis competitive with an average age 21.6 (± 3.1) years belonging to the Chilean team and institutions of higher education in the region of Valparaiso. The evaluation was conducted under the protocol marking the International Society for the Advancement of Kinanthropometry (ISAK) for the measurement procedure 25 restricted profile variables described by Drinkwater1, Norton and Olds2. Order to determine the body composition, fat, muscle, bone, skin and tissue residual was considered, using the equations proposed by Kerr3. The body shape is characterized through somatotype method proposed by Carter4. The sample was divided into 4 groups; Chilean Selection, Traditional Private Universities, State Universities and Private Universities Traditional Nontraditional. Regarding body composition; the Chilean team has the highest values of muscle tissue (45.6 ± 1.7%) and the lowest values of adipose tissue (25.2 ± 1.8%), also presenting lesser value in the ∑ 6 skinfolds (mm). The results showed no significant differences between groups in the aforementioned variables. In general somatotype compared by analyzing SANOVA no significant differences between groups (p = 0.409) was observed. The results show a biotype with such a characterization of endo-mesomorph with average values (4,1-4,9-1,8). This study provides updated data biotypological reference for this sport that can be used for decision-making (AU)