Calculating Load and Intensity Using Muscle Oxygen Saturation Data.

The study aimed to calculate training intensity and load using muscle oxygen saturation (SmO2) during two differentiated physical tasks. 29 university athletes participated in a 40-m Maximal Shuttle Run Test (MST, 10 × 40-m with 30 s recovery between sprints) and a 3000-m time trial run. Distance and time were used to calculate external load (EL). Internal load indicators were calculated based on percentage of maximum heart rate (%HRMAX) and SmO2 variables: muscle oxygen extraction (∇%SmO2) and the cardio-muscle oxygen index (CMOI) was also provided by relating ∇%SmO2 ÷ %HRMAX, and the training load were calculated as the product of speed (m/min × IL) and the efficiency index [Effindex (m/min ÷ IL)]. A student t test was applied based on Bayesian factor analysis. As expected, EL differed in the 40-m MST (331 ± 22.8) vs. 3000-m trials (222 ± 56.8) [BF10 = 6.25e+6; p = <0.001]. Likewise, IL showed higher values in 40-m MST (39.20 ± 15.44) vs. 3000-m (30.51 ± 8.67) in CMOI: [BF10 = 1.70; p = 0.039]. Training load was greater in 40-m MST (85.77 ± 27.40) vs. 3000-m (15.55 ± 6.77) [(m/min × ∇%SmO2): BF10 = 12.5; p = 0.003] and 40-m MST (129.27 ± 49.44) vs. 3000-m (70.63 ± 32.98) [(m/min × CMOI): BF10 = 169.6; p = <0.001]. Also, the Effindex was higher in 40-m MST (10.19 ± 4.17) vs. 3000-m (6.06 ± 2.21) [(m/min × ∇%SmO2): BF10 = 137.03; p = <0.001] and 40-m MST (9.69 ± 4.11) vs. 3000-m (7.55 ± 1.87) [(m/min × CMOI): BF10 = 1.86; p = 0.035]. This study demonstrates calculations of training intensity and load based on SmO2 as an internal load indicator along with speed as an external load indicator during two differentiated exercises.

Somatic Maturity and Physical Performance in Male Youth Players from a Professional Soccer Academy

SUMMARY: The aim was to analyze the relationship between somatic maturation and physical performance in male youth soccer players belonging to a professional Mexican academy. In 121 male soccer aged 11 to 16 years from a professional academy the peak height velocity (PHV), percentage of adult height (PAS), jump capacity, sprint, intermittent speed and muscle mass were estimated. ANOVA was conducted to compare performance variables among maturity somatic categories and percentiles were calculated based on maturity offset using LMS method. Furthermore, a general linear model was employed to determine the explanatory variables for performance. Post-PHV soccer players demonstrated superior physical performance across several tests compared to Pre-PHV (p<0.001) and Circa-PHV (p<0.001) players. The smoothed percentile values of performance tests, based on somatic maturation, indicated progressive performance enhancement as individuals approached PHV (-2 to 2 years from PHV) (p<0.005). PHV was associated with jump capacity (p<0.001) and intermittent speed (p=0.007) while PAS was associated with time in sprint (p=.0004). In conclusion PHV and PAS explained better performance than chronological age, body composition characteristics, injuries, or training factors.

El objetivo fue analizar la relación entre la maduración somática y el rendimiento físico en futbolistas juveniles masculinos pertenecientes a una academia profesional mexicana. Métodos. En 121 futbolistas masculinos de 11 a 16 años de una academia profesional se estimó la velocidad máxima en altura (VPH), porcentaje de altura adulta (PAS), capacidad de salto, sprint, velocidad intermitente y masa muscular. Se realizó ANOVA para comparar variables de desempeño entre categorías somáticas de madurez y se calcularon percentiles en función de la compensación de madurez utilizando el método LMS. Además, se empleó un modelo lineal general para determinar las variables explicativas del desempeño. Los jugadores de fútbol post-PHV demostraron un rendimiento físico superior en varias pruebas en comparación con los jugadores Pre-PHV (p<0,001) y Circa-PHV (p<0,001). Los valores percentiles suavizados de las pruebas de rendimiento, basados en la maduración somática, indicaron una mejora progresiva del rendimiento a medida que los individuos se acercaban al PHV (-2 a 2 años desde el PHV) (p<0,005). PHV se asoció con la capacidad de salto (p<0,001) y velocidad intermitente (p=0,007) mientras que PAS se asoció con el tiempo en sprint (p=0,0004). En conclusión PHV y PEA explicaron un mejor rendimiento que la edad cronológica, las características de composición corporal, las lesiones o los factores de entrenamiento.

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.

Control del entrenamiento con datos GPS y medidas subjetivas de fatiga y recuperación en futbolistas hondureños durante un periodo preparatorio para los Juegos Olímpicos de Tokio 2020/2021 / Training Monitoring With GPS Data and Subjective Measures of Fatigue and Recovery in Honduran Soccer Players During a Preparatory Period for Tokyo 2020/2021 Olympic Games / Monitoramento do treinamento com dados GPS e medidas subjetivas de fadiga e recuperação dos jogadores de futebol hondurenhos durante um período preparatório para os Jogos Olímpicos de Tóquio 2020/2021

Resumen: Introducción: El control de cargas de entrenamiento es importante para optimizar el rendimiento. Por lo tanto, se deben documentar metodologías que mejoren la preparación de selecciones nacionales en eventos como los juegos olímpicos. Objetivo: Determinar si los datos del GPS en combinación con medidas subjetivas de bienestar, fatiga y recuperación son apropiados para el control de las cargas durante un periodo preparatorio para los Juegos Olímpicos. Metodología: Participaron 22 jugadores profesionales sub-23 durante 5 microciclos y 27 sesiones de entrenamiento. Se recopilaron datos de carga externa a través de un sistema global de posicionamiento (GPS): Distancia total (DT), zonas de rendimiento Z0 (0-15 km/h), Z1 (15.1-18 km/h), Z2 (18.1-24 km/h), Z3 (>24.1 km/h)), velocidad máxima (Vmax (km/h)), aceleraciones (>2.5m/s2) y desaceleraciones (<2.5m/s2). También, se obtuvo la carga interna a través de medidas subjetivas de percepción del esfuerzo (RPE), calidad de la recuperación (TQR), predisposición para entrenar (RTT%) derivada de las variables de calidad del sueño, dolor muscular, niveles de energía, estado de ánimo, estrés, calidad de la alimentación y la salud. Luego se calculó la ratio subjetiva de fatiga-recuperación (F-R). Se aplicó un test ANOVA, análisis de componentes principales (ACP) y una regresión múltiple lineal. Resultados: Las variables DT (p=0.00 TE=0.22), Z0 (p= 0.00 TE=0.08), Z2 (p=0.00 TE= 0.05), Vmax (p=0.00 TE=0.42), suma de aceleración y deceleración (p=0.00 TE=0.08) y valores relativos de la carga/min (p=0.00 TE=0.17) se identificaron como variables más sensibles al cambio de la carga entre microciclos. El RTT% y ratio subjetivo F-R mostraron un tamaño del efecto moderado (p=0.04 TE=0.06 y p=0.06 TE=0.06), pero fueron sensibles al cambio entre los microciclos. El ACP extrajo 15 variables GPS y 11 variables subjetivas que explicaron el 78% de la varianza de la carga de entrenamiento. Conclusión: Utilizar datos GPS junto con medidas subjetivas implicadas en la fatiga-recuperación puede ser una buena estrategia para el control de la carga de entrenamiento en futbolistas.

Abstract: Background: Training control is essential to optimize performance. Therefore, methodologies that improve the preparation of national teams in events such as the Olympic Games should be documented. Purpose: To determine whether GPS data in combination with subjective measures of well-being, fatigue and recovery are appropriate for load monitoring during a preparatory period for the Olympic Games. Methodology: Twenty-two under-23 professional players participated during 5 micro-cycles and 27 training sessions. External load data was collected via a global positioning system (GPS): Total distance (DT), performance zones Z0 (0-15 km/h), Z1 (15.1-18 km/h), Z2 (18.1 -24 km/h), Z3 (>24.1 km/h), maximum speed (km/h), accelerations (>2.5m/s.) and decelerations (<2.5m/s.). Also, internal load was obtained through subjective measures of Rating Perceived Exertion (RPE), Total Quality Recovery (TQR), Readiness to Train (RTT%) obtained from the sleep quality, muscle pain, energy levels, mood, stress, food quality and health. The subjective rate of fatigue-recovery (F-R) was then calculated. An ANOVA test, Principal Component Analysis (PCA) and multiple linear regression were applied. Results: the variables DT (p=0.00 ES=0.22), Z0 (p= 0.00 TE=0.08), Z2 (p=0.00 ES= 0.05), maximum speed (p= 0.00 ES=0.42), sum of acceleration and deceleration (p=0.00 ES=0.08) and values relative to load/min (p=0.00 ES=0.17) were identified as variables more sensitive to load change between micro-cycles. RTT% and subjective rate F-R showed a moderate effect size (p=0.04 ES=0.06 and p=0.06 ES=0.06), but were sensitive to change between micro-cycles. PCA extracted 15 GPS variables and 11 subjective variables that explained 78% of the training load variance. Conclusion: Using GPS data together with subjective measures involved in fatigue-recovery may be a good strategy to control training load in footballers.

Resumo: Introdução: O monitoramento das cargas de treinamento é importante para otimizar o desempenho. Portanto, as metodologias devem ser documentadas para melhorar a preparação das equipes nacionais para eventos como os Jogos Olímpicos. Objetivo: Determinar se os dados GPS em combinação com medidas subjetivas de bem-estar, fadiga e recuperação são apropriados para o monitoramento da carga durante um período preparatório para os Jogos Olímpicos. Metodologia: 22 jogadores profissionais U-23 participaram durante 5 microciclos e 27 sessões de treinamento. Os dados de carga externa foram coletados através de um sistema de posicionamento global (GPS): distância total (DT), zonas de desempenho Z0 (0- 15 km/h), Z1 (15,1-18 km/h), Z2 (18,1-24 km/h), Z3 (>24,1 km/h), velocidade máxima (Vmax (km/h)), acelerações (>2,5m/ s2) e desacelerações (<2,5m/s2). Além disso, a carga interna foi obtida através de medidas subjetivas de percepção do esforço (RPE), qualidade de recuperação (TQR), predisposição para o treinamento (RTT%) derivada das variáveis de qualidade do sono, dor muscular, níveis de energia, humor, estresse, qualidade alimentar e saúde. Posteriormente a taxa subjetiva de fadiga-recuperação (F-R) foi calculada. Um teste ANOVA, análise de componentes principais (ACP) e regressão linear múltipla foram aplicados. Resultados: As variáveis DT (p=0,00 TE=0,22), Z0 (p= 0,00 TE=0,08), Z2 (p=0,00 TE= 0,05), Vmax (p=0,00 TE=0,42), soma de aceleração e desaceleração (p=0,00 TE=0,08) e valores de carga relativa/min (p=0,00 TE=0,17) foram identificadas como as variáveis mais sensíveis à mudança de carga entre microciclos. RTT% e a relação F-R subjetiva mostraram tamanho de efeito moderado (p=0,04 TE=0,06 e p=0,06 TE=0,06 TE=0,06), mas foram sensíveis à mudança entre microciclos. O ACP extraiu 15 variáveis GPS e 11 variáveis subjetivas que explicaram 78% da variância na carga de treinamento. Conclusão: O uso de dados GPS junto com medidas subjetivas envolvidas na fadiga#recuperação pode ser uma boa estratégia para o monitoramento da carga de treinamento em jogadores de futebol.

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.

Training zones through muscle oxygen saturation during a graded exercise test in cyclists and triathletes.

Use of muscle oxygen saturation (SmO2) has been validated as a performance factor during incremental exercise with portable near-infrared stereoscopy (NIRS) technology. However, there is little knowledge about the use of SmO2 to identify training zones. The objective of this study was to evaluate the metabolic zones by SmO2: maximum lipid oxidation zone (Fatmax), ventilatory thresholds (VT1 and VT2) and maximum aerobic power (MAP) during a graded exercise test (GXT). Forty trained cyclists and triathletes performed a GXT. Output power (W), heart rate (HR), oxygen consumption (VO2), energy expenditure (kcal/min) and SmO2 were measured. Data were analysed using the ANOVA test, ROC curves and multiple linear regressions. Significance was established at p ≤ 0.05. SmO2 decreases were observed from baseline (LB) to Fatmax (Δ = -16% p < 0.05), Fatmax to VT1 (Δ = -16% p < 0.05) and VT1 to VT2 (Δ = -45% p < 0.01). Furthermore, SmO2 together with weight, HR and output power have the ability to predict VO2 and energy expenditure by 89% and 90%, respectively. We conclude that VO2 and energy expenditure values can be approximated using SmO2 together with other physiological parameters and SmO2 measurements can be a complementary parameter to discriminate aerobic workload and anaerobic workload in athletes.

Monitoring Muscle Oxygen Asymmetry as a Strategy to Prevent Injuries in Footballers.

Purpose: It has been hypothesized that sports injury risk is explained by muscle metabolism. The objective was to evaluate the muscle oxygen saturation slopes (ΔSmO2 slopes) and muscle oxygenation asymmetry (MO2Asy) at rest and to study their associations with injuries during the pre-season. Methods: A total of 16 male and 10 female footballers participated in this study. Injuries were diagnosed and classified by level of severity during the pre-season. The workload was also evaluated using the rate of perceived exertion × training time, from which the accumulated loads. The SmO2 was measured at rest in the gastrocnemius muscle using the arterial occlusion method in the dominant and non-dominant legs. The repeated measures ANOVA, relative risk, and binary logistic regression were applied to assess the probability of injury with SmO2 and workload. Results: Higher MO2Asy and ΔSmO2 Slope 2 were found among footballer who suffered high-severity injuries and those who presented no injuries. In addition, an MO2Asy greater than 15% and an increase in accumulated load were variables that explained a greater probability of injury. Conclusion: This study presents the new concept of muscle oxygenation asymmetry in sports science and its possible application in injury prevention through the measurement of SmO2 at rest.

Influence of fat percentage on muscle oxygen uptake and metabolic power during repeated-sprint ability of footballers

The aim of this study was to analyse the muscle oxygen saturation (SmO2) dynamics during a repeated-sprint ability (RSA) protocol (8 sprints x 20 meters, 20 s recovery) using near-infrared spectroscopy. Twenty-five footballers were grouped according to the levels of body-fat percentage (level 1: <9%; level 2: 9.1–11.5%; and level 3: >11.6%) from the Spanish third division participated. During RSA, energy cost (EC), metabolic power (MP), speed and total time as external load were measured. Desaturation and resaturation rates and muscular oxygen extraction (▽% SmO2) of the gastrocnemius muscle, along with heart rate (HR) were used as indicators of internal load. ▽% SmO2 was identified as the most sensitive variable to detect the minimal change during RSA. Footballers with a lower fat percentage (level 1) achieved a higher ▽% SmO2 after the 4th sprint (Δ= –13; p= 0.001) and (Δ= 9.6; p= 0.017) vs level 2 and level 3, respectively. SmO2 was related to EC (r2= 0.57 p= 0.005), MP (r2= 0.61 p= 0.003), speed (r2= 0.59 p= 0.004) and total time (r2= 0.59 p= 0.004). Therefore, SmO2 was a better indicator of internal load than HR during RSA. The ▽% SmO2 can be used as a parameter to explore potential differences in footballers' RSA performance. Besides, we highlighted the relevance of measuring the body-fat percentage, since it is a variable that affects performance by disturbing ▽% SmO2, altering the ability to resist repeated high-speed bouts (sprints), a critical variable in football. (AU)

Relationship between anaerobic work capacity and critical oxygenation in athletes / Relación entre la capacidad de trabajo anaeróbico y la oxigenación crítica en deportistas / Relação entre capacidade de trabalho anaeróbico e oxigenação crítica em atletas

Objective: Anaerobic work capacity (AWC) is understood as the maximum power that the athlete can withstand over time, conditioned by high intensityeffort and it is important to interpret it for the performance improvement. In addition, the muscle oxygen saturation (SmO2) provides information onmuscle metabolism and hemodynamics. Likewise, critical oxygenation (CO) is the highest metabolic rate that results in a fully oxidative energy supplythat reaches a stable state at the substrate level. The main problem is that SmO2 generally offers a traditional laboratory interpretation withoutapplication in field tests, Therefore, the purpose of this study is to provide the use of CO as an indicator of AWC performance in high intensity exercise. Methods: Twenty-two male rugby players participated. Peak torques during an isokinetic fatigue test and muscle oxygen consumption (mVO2) and SmO2in the vastus lateralis were measured. A correlation and multiple regression analysis were applied to find an explanatory prediction model of the AWC. Results: A greater SmO2 amplitude and CO would mean less anaerobic work (r = -0.58 and r=-0.63) and less force production. In addition, CO along withweight (kg) can explain the AWC by 64% during high intensity exercise. Conclusion: The measurement of critical oxygenation is associated with the AWC, so should be considered a performance factor. These parameters couldbe included in NIRS sensors to evaluate muscle metabolism.(AU)

Objetivo: La capacidad de trabajo anaeróbico (AWC) se entiende como la potencia máxima que el deportista puede soportar a lo largo del tiempo,condicionada por un esfuerzo de alta intensidad y es importante interpretarla para la mejora del rendimiento. Además, la saturación de oxígenomuscular (SmO2) proporciona información sobre el metabolismo muscular y la hemodinámica. Asimismo, la oxigenación crítica (OC) es la tasametabólica más alta que da como resultado un suministro de energía completamente oxidativo que alcanza un estado estable a nivel de sustrato. Elprincipal problema es que SmO2 generalmente ofrece una interpretación de laboratorio tradicional sin aplicación en pruebas de campo, por lo tanto, elpropósito de este estudio es proporcionar el uso de OC como indicador del rendimiento de AWC en ejercicio de alta intensidad. Métodos: Participaron 22 jugadores masculinos de rugby. Se midieron los picos máximos después de una prueba de fatiga isocinética y el consumo deoxígeno muscular (mVO2) y SmO2 en el musculo vasto lateral. Se aplicó un análisis de correlación y regresión múltiple para encontrar un modelo depredicción explicativo del AWC. Resultados: Una mayor amplitud de SmO2 y OC supondría un menor trabajo anaeróbico (r = -0,58 y r=-0,63) y una menor producción de fuerza. Además,el CO junto con el peso (kg) pueden explicar el AWC en un 64 % durante el ejercicio de alta intensidad. Conclusión: La medición de la oxigenación crítica está asociada a la AWC, por lo que debe considerarse un factor de rendimiento. Estos parámetrospodrían incluirse en sensores NIRS para valorar el metabolismo muscular.(AU)

Objetivo: A capacidade anaeróbica de trabalho (AWC) é entendida como a potência máxima que o atleta pode suportar ao longo do tempo, condicionadapor um esforço de alta intensidade, sendo importante interpretá-la para melhorar o desempenho. Além disso, a saturação muscular de oxigênio (SmO2)fornece informações sobre o metabolismo muscular e a hemodinâmica. Da mesma forma, a oxigenação crítica (OC) é a taxa metabólica mais alta queresulta em um suprimento de energia totalmente oxidativo atingindo um estado estável no nível do substrato. O principal problema é que o SmO2geralmente oferece uma interpretação laboratorial tradicional sem aplicação em testes de campo, portanto, o objetivo deste estudo é fornecer o uso doCO como indicador de desempenho de AWC em exercícios de alta intensidade. Métodos:Participaram 22 jogadores de rugby do sexo masculino. Foram medidos os picos máximos após um teste de fadiga isocinética e o consumo deoxigênio muscular (mVO2) e SmO2 no músculo vasto lateral. Uma análise de correlação e regressão múltipla foi aplicada para encontrar um modeloexplicativo de predição do AWC. Resultados: Uma maior amplitude de SmO2 e CO implicaria em menor trabalho anaeróbio (r = -0,58 er = -0,63) e menor produção de força. Além disso, oCO junto com o peso (kg) pode explicar a AWC em 64% durante o exercício de alta intensidade. Conclusão: A medida oxigenação crítica prevê AWC, portanto, deve ser considerada um fator de desempenho. Esses parâmetros podem ser incluídos emsensores NIRS para a medição do metabolismo muscular.(AU)

Intermittent Hypoxia as a Therapeutic Tool to Improve Health Parameters in Older Adults.

Aging is associated with metabolic alterations, and with a loss of strength, muscle and bone mass. Moderate intermittent hypoxia has been proposed as a new tool to enhance health-related function. The aim of this study was to evaluate the effect of moderate intermittent hypoxia exposures on parameters related to cardiovascular and bone health in older adults. A total of 38 healthy older adults (aged 65-75 years) were divided into two groups: control group (C), and hypoxia group (H) that was subjected to an intermittent hypoxia exposure (at simulated altitude of 2500 m asl) during a 24-week period (3 days/week). Body composition, blood pressure, metabolic parameters (Cholesterol, triglycerides and glucose), C-reactive protein (CRP), vascular cell adhesion molecule-1 (VCAM-1), interleukin 8 (IL-8), interleukin 10 (IL-10), N-terminal propeptide of type I procollagen (PINP) and beta C-terminal telopeptide of collagen bone formation (b-CTX) were analyzed before and after the intervention. A repeated measures analysis of variance was performed to evaluate between-group differences. The results showed that the hypoxia group achieved after the intervention a decrease in fat mass, CRP (pro-inflammatory biomarker) and b-CTX (bone resorption biomarker), as well as an increase in PINP (bone formation biomarker). In conclusion, the intermittent hypoxia might be a useful therapeutic tool to deal with problems associated with aging, such as the increase in body fat, the loss of bone mass or low-grade inflammation.

Tent versus Mask-On Acute Effects during Repeated-Sprint Training in Normobaric Hypoxia and Normoxia.

Repeated sprint in hypoxia (RSH) is used to improve supramaximal cycling capacity, but little is known about the potential differences between different systems for creating normobaric hypoxia, such as a chamber, tent, or mask. This study aimed to compare the environmental (carbon dioxide (CO2) and wet-globe bulb temperature (WGBT)), perceptual (pain, respiratory difficulty, and rate of perceived exertion (RPE)), and external (peak and mean power output) and internal (peak heart rate (HRpeak), muscle oxygen saturation (SmO2), arterial oxygen saturation (SpO2), blood lactate and glucose) workload acute effects of an RSH session when performed inside a tent versus using a mask. Twelve well-trained cyclists (age = 29 ± 9.8 years, VO2max = 70.3 ± 5.9 mL/kg/min) participated in this single-blind, randomized, crossover trial. Participants completed four sessions of three sets of five repetitions × 10 s:20 s (180 s rest between series) of all-out in different conditions: normoxia in a tent (RSNTent) and mask-on (RSNMask), and normobaric hypoxia in a tent (RSHTent) and mask-on (RSHMask). CO2 and WGBT levels increased steadily in all conditions (p < 0.01) and were lower when using a mask (RSNMask and RSHMask) than when inside a tent (RSHTent and RSNTent) (p < 0.01). RSHTent presented lower SpO2 than the other three conditions (p < 0.05), and hypoxic conditions presented lower SpO2 than normoxic ones (p < 0.05). HRpeak, RPE, blood lactate, and blood glucose increased throughout the training, as expected. RSH could lead to acute conditions such as hypoxemia, which may be exacerbated when using a tent to simulate hypoxia compared to a mask-based system.

Muscle Oxygen Desaturation and Re-Saturation Capacity Limits in Repeated Sprint Ability Performance in Women Soccer Players: A New Physiological Interpretation.

Muscle oxygen consumption could provide information on oxidative metabolism in women soccer players. Therefore, the objective of this study was to analyze muscle oxygenation dynamics during repeated sprint ability (RSA): (8 sprint × 20 s recovery) by near-infrared spectroscopy (NIRS). The sample was made up of 38 professional women soccer players. To measure the external load, the best time, worst time, average time, individual speed, sprint decrement, and power were assessed. In connection with the internal load, the desaturation (sprint) and re-saturation (recovery) rates, as well as the oxygen extraction (∇%SmO2) in the gastrocnemius muscle and maximum heart rate (%HRmax) were measured. A repeated measures statistic was applied based on the inter-individual response of each subject from the baseline versus the other sprints, with linear regression and nonlinear regression analyses between variables. There was an increase in the SmO2: desaturation rate after four sprints (Δ = 32%), in the re-saturation rate after six sprints (Δ = 89%), and in ∇%SmO2 after four sprints (Δ = 72.1%). There was a linear association between the rates of desaturation and re-saturation relationships and the worst time (r = 0.85), and a non-linear association between ∇%SmO2 and speed (r = 0.89) and between ∇%SmO2 and the sprint decrease (r = 0.93). The progressive increase in SmO2 during RSA is a performance limitation to maintain a high speed; it depends on the capacity of fatigue resistance. Therefore, monitoring the muscle oxygenation dynamics could be a useful tool to evaluate the performance in women soccer players.

Análisis de sobrepeso y obesidad, niveles de actividad física y autoestima en escolares de San Pedro Sula, Honduras / Analysisof Overweight and Obesity, Levels of Physical Activity,and Self-Esteem in School Children of San Pedro Sula, Honduras / Análise de sobrepeso e obesidade, níveis de atividade física e autoestima em estudantes de San Pedro Sula, Honduras

Resumen El objetivo de este estudio fue analizar la prevalencia de sobrepeso, obesidad, niveles de actividad física y autoestima de la población escolar de San Pedro Sula. La muestra fue de 825 escolares con edades entre 9-13 años, los cuales fueron divididos en 416 mujeres y 409 hombres. Se realizaron mediciones del IMC (Kg/H^2), nivel de actividad física (PAQ-C) y autoestima (LAWSEQ). Se realizó un análisis factorial (ANOVA) para observar diferencias entre grupos y la correlación de Pearson para el estudio de relación de variables con intervalos de confianza del 95 %. Se encontró que el 79.8 % se encuentra en un estado de peso saludable; un 14.8 % en sobrepeso y obesidad y un 5.3 % en desnutrición, un nivel de actividad física moderado predomina en la mayoría de escolares, un nivel de autoestima bajo en 46.9 % y autoestima promedio de 50.5 %; también se mostró que el nivel de actividad física tiene correlación alta positiva con el sexo (r= 0.74 p= 0.02), siendo mayor en los escolares hombres que en las mujeres, también la actividad física tiene correlación positiva muy alta (r=0.81; p=0.001) con la autoestima. Nuestras conclusiones indican que se muestra una mayor práctica de actividad física por los escolares hombres de Honduras que por parte de las mujeres. Además, se encontró que un mayor nivel de realización de actividad física podría estar asociado a una mejor autoestima en los niños.

Abstract The objective of this study was to analyze the prevalence of overweight, obesity, physical activity levels, and self-esteem of the school children population of San Pedro Sula. The sample was 825 children aged 9-13 years, which were divided into 416 girls and 409 boys. Measurements of BMI (kg/H^2), Physical Activity level (PAQ-C) and Self-esteem (LAWSEQ) were made. A factorial analysis (ANOVA) was performed to observe differences between groups and the Pearson correlation for the study of the relationship of variables with 95% confidence intervals. It was found that 79.8% are in a healthy weight state; 14.8% in overweight and obesity, and 5.3% in malnutrition. It was also found that a moderate level of physical activity predominates in most of the children and a low self-esteem level in 46.9% and average self-esteem of 50.5%. Another finding was that the level of physical activity has a highly positive correlation with sex (r = 0.74 p = 0.02), being higher in boys than in girls; also physical activity has a very high positive correlation (r = 0.81, p = 0.001) with self-esteem. Our results indicate that children in Honduras show a greater practice of physical activity by children than that of girls. In addition, it was found that a higher level of physical activity could be associated with better self-esteem in children.

Resumo O objetivo deste estudo foi analisar a prevalência de sobrepeso, obesidade, níveis de atividade física e autoestima da população escolar de San Pedro Sula. A amostra foi de 825 escolares com idades entre 9-13 anos, divididos em 416 mulheres e 409 homens. Foram realizadas medidas de IMC (Kg/H^2), Nível de Atividade Física (PAQ-C) e Autoestima (LAWSEQ). Foi realizada análise fatorial (ANOVA) para observar as diferenças entre os grupos e a correlação de Pearson para o estudo das variáveis de relação com intervalos de confiança de 95%. Verificou-se que 79,8% estão em estado de peso saudável, 14,8% em sobrepeso e obesidade e 5,3% em desnutrição, predomina atividade física moderada na maioria dos escolares e baixa autoestima de 46,9% e autoestima média de 50.5%, também foi demonstrado que o nível de atividade física tem alta correlação positiva com o sexo (r= 0,74 p= 0,02), sendo maior em escolares do sexo masculino do que em mulheres, a atividade física também tem alta correlação positiva (r=0,81; p=0,001) com a autoestima. Nossas conclusões indicam que os estudantes do sexo masculino em Honduras são mais ativos fisicamente do que as mulheres. Além disso, verificou-se que um maior nível de atividade física poderia estar associado a uma melhor autoestima das crianças.

Asociación del sobrepeso y obesidad, consumo de oxígeno y calidad del sueño con los síntomas del intestino irritable en estudiantes universitarios de la UPNFM / Association of physical state, oxygen consumption and sleep quality with the irritable bowel symptoms in university students of the UPNFM

INTRODUCCIÓN: El interés de este estudio fue establecer posibles asociaciones con el estado físico, calidad de sueño y consumo de oxígeno máximo (VO2máx) con los síntomas de la enfermedad del síndrome de Intestino Irritables (SII) en los estudiantes universitarios. MÉTODOS: La muestra fue de n = 62 estudiantes universitarios (edad 25 ± 9 años; talla 1,63 ± 0,08 m; peso 68,6 ± 18,5 kg). Se midieron variables antropométricas, el VO2 máx mediante el test Rockport, se aplicó el cuestionario de índice de Calidad de Sueño de "Pittsburgh" (ICSP) y el "BEST-Score" 4 points. Se utilizó la prueba Anova y el coeficiente de Pearson. RESULTADO: En los síntomas del SII (%) se muestran diferencias entre sujetos normopeso vs obesidad (11,5 ± 10 vs 33,3 ± 23,1% p = 0.00). También se muestra diferencias en función del VO2 máx en ICPS: nivel 1 vs nivel 3 (26 ± 0,6 vs 13 ± 0,6% p = 0.04) y síntomas del SII (21,9 ± 10 vs 11,1 ± 17,9% p = 0.02). Los síntomas del SII obtuvieron correlación moderada con el IMC (r = 0,51; p = 0,00) y % de grasa (r = 0,60; p = 0,00), también el VO2 máx con la calidad del sueño (r = -0,52; p = 0,00). CONCLUSIÓN: Los estudiantes de la UPNFM que presentan un mayor VO2 máx muestran valores más bajos en la puntuación de síntomas del SII y podría estar asociado a conciliar mejor el sueño.

INTRODUCTION: The interest of this study was to establish possible associations with the physical state, sleep quality and maximum oxygen consumption (VO2max) with the symptoms of Irritable Bowel Syndrome (IBS) in university students. METHODS: The sample was n = 62 university students (age 25 ± 9 years, height 1.63 ± 0.08 m, weight 68.6 ± 18.5 kg). Anthropometric variables were measured, VO2max using the Rockport test, the "Pittsburgh Quality" Sleep Quality Index questionnaire (ICSP) and the "BEST-Score" 4 points were applied. The Anova test and the Pearson coefficient were used. RESULT: In the IBS symptoms (%) there are differences between subject's normal weight vs obesity (11.5 ± 10 vs 33.3 ± 23.1% p = 0.00). It also shows differences according to VO2max in ICPS: level 1 vs level 3 (26 ± 0.6 vs 13 ± 0.6% p = 0.04) and IBS symptoms (21.9 ± 10 vs 11.1 ± 17, 9% p = 0.02). The IBS symptoms showed moderate correlation with BMI (r = 0.51, p = 0.00) and of fat% (r = 0.60, p = 0.00), also the VO2max with the quality of sleep ( r = -0.52, p = 0.00). CONCLUSION: Students of UPNFM who present a higher VO2max show lower values in the symptom score of IBS and could be associated to better sleep conciliation.