Water-Based Exercise in Patients With Nonspecific Chronic Low-Back Pain: A Systematic Review With Meta-Analysis.

ABSTRACT: Babiloni-Lopez, C, Fritz, N, Ramirez-Campillo, R, and Colado, JC. Water-based exercise in patients with nonspecific chronic low-back pain: a systematic review with meta-analysis. J Strength Cond Res 38(1): 206-219, 2024-This study aimed to systematically review and synthesize evidence (i.e., active [land-based training] and nonactive controls [e.g., receiving usual care]) regarding the effects of water-based training on patients with nonspecific chronic low-back pain (NSCLBP). Web of Science (WOS), PubMed (MEDLINE), EMBASE, EBSCO (SPORTDiscus; CINAHL), and PEDro were searched, with no date restrictions, until October 2021. The included studies satisfied the following criteria: (a) NSCLBP (≥12 weeks) patients, (b) water-based intervention, (c) control group (land-based trained; nonactive group), and (d) outcomes related to pain, disability, quality of life, or flexibility. The main outcome analyzed in the meta-analysis was pain intensity. Secondary outcomes included disability, body mass index, and flexibility. The random-effects model was used, and effect size (ES) values are presented with 95% confidence intervals (CIs). The impact of heterogeneity was assessed (I2 statistic), with values of <25%, 25-75%, and >75% representing low, moderate, and high levels, respectively. Alpha was set at p < 0.05. In conclusion, 15 studies (n = 524) were meta-analyzed. After intervention, pain intensity was reduced compared with nonactive controls (ES = -3.61; p < 0.001) and a similar reduction was noted when compared with land-based trained group (ES = -0.14; p = 0.359). Greater decrease in disability (ES = 2.15; p < 0.001) and greater increase in sit-and-reach (i.e., flexibility; ES = -2.44; p < 0.001) were noted after intervention compared with the nonactive group. In conclusion, water-based exercise therapy reduces pain intensity, disability, and increases flexibility in NSCLBP compared with nonactive subjects and was equally effective compared with land-based exercise to reduce pain. Favorable effects may be expected at ≤8 weeks. However, due to several methodological issues (e.g., high heterogeneity), for the improvement of most outcomes, we are unable to provide other than a weak recommendation in favor of intervention compared with control treatment.

Anthropometric Characteristics, Handgrip Strength, and Upper Limb Asymmetries in Highly Trained Chilean Shot Put Para-Athletes / Características Antropométricas, Fuerza de Prensión Manual y Asimetrías de Miembros Superiores en Para-Atletas Chilenos de Lanzamiento de Bala Altamente Entrenados

SUMMARY: Anthropometric characteristics, including body size, shape, and composition, can have a significant impact on sports performance due to their influence on various physiological and biomechanical factors. However, limited research has been conducted on the anthropometric characteristics of highly trained throwing para-athletes. The purpose of this study was to describe the anthropometric characteristics, handgrip strength, and upper limb bilateral asymmetries of highly trained Chilean shot put para-throwers. Five male Chilean shot put para-athletes (average age of 38.8 ± 7.7 years) were assessed for their anthropometric characteristics, including skinfold thickness at six anatomical sites, girth at five sites, and bone breadth at two sites. Handgrip strength and bilateral asymmetries were also measured. The body mass and height of the athletes were found to be 90.5 ± 5.1 kg and 179.1 ± 8.9 cm, respectively. The athletes were found to have an endo-mesomorph somatotype (4.4-6.9-1.0) with high levels of fat mass (25.7 ± 2.8 %) and skeletal muscle mass (39.1 ± 3.7 %). The handgrip strength of the athletes was found to be 66.4 ± 6.7 kg with a bilateral asymmetry of 6.5 ± 6.2 %, with the dominant hand showing greater strength. The results indicate that the shot put para-athletes have a somatotype characterized by increased muscularity and body fat, along with a considerable stature. Although handgrip strength was found to be high, the athletes showed bilateral asymmetry, which requires further investigation to determine the cause and implications.

Las características antropométricas, incluido el tamaño, forma y composición del cuerpo, pueden tener un impacto significativo en el rendimiento deportivo debido a su influencia en diversos factores fisiológicos y biomecánicos. Sin embargo, las investigaciones sobre las características antropométricas para-atletas de lanzamiento altamente entrenados son limitadas. El propósito de este estudio fue describir las características antropométricas, la fuerza de prensión manual y las asimetrías bilaterales de miembros superiores de paralanzadores chilenos altamente entrenados en lanzamiento de la bala. Se evaluaron las características antropométricas de cinco atletas masculinos chilenos de lanzamiento de bala (edad promedio de 38,8 ± 7,7 años), incluido el grosor de los pliegues cutáneos en seis sitios anatómicos, la circunferencia en cinco sitios y la anchura de los huesos en dos sitios. También se midieron la fuerza de prensión manual y las asimetrías bilaterales. Se encontró que la masa corporal y la altura de los atletas eran 90,5 ± 5,1 kg y 179,1 ± 8,9 cm, respectivamente. Los atletas tenían un somatotipo endo-mesomorfo (4.4-6.9-1.0) con altos niveles de masa grasa (25.7 ± 2.8 %) y masa muscular esquelética (39.1 ± 3.7 %). Se encontró además que la fuerza de prensión manual de los atletas era de 66,4 ± 6,7 kg con una asimetría bilateral de 6,5 ± 6,2 %, mostrando mayor fuerza la mano dominante. Los resultados indican que los atletas de lanzamiento de bala tienen un somatotipo caracterizado por una mayor musculatura y grasa corporal, junto con una estatura considerable. Aunque se encontró que la fuerza de agarre era alta, los atletas mostraron asimetría bilateral, lo que requiere de más investigaciones para determinar las causa e implicaciones.

Cardiorespiratory optimal point as a submaximal evaluation tool in endurance athletes: An exploratory study.

Introduction: The cardiorespiratory optimal point (COP) represents the lowest minute ventilation to oxygen consumption ratio (VE/VO2) and can be estimated during a CPET at submaximal intensity when an exercise test until volitional fatigue is not always advisable (i.e., a conflict zone where you cannot be confident of the security because near-competition, off-season, among other). COP's physiological components have not been wholly described yet. Therefore, this study seeks to identify the determinants of COP in highly trained athletes and its influence on maximum and sub-maximum variables during CPET through principal c omponent analysis (PCA) (explains the dataset's variance). Methods: Female (n = 9; age, 17.4 ± 3.1 y; maximal VO2 [VO2max]), 46.2 ± 5.9 mL/kg/min) and male (n = 24; age, 19.7 ± 4.0 y; VO2max, 56.1 ± 7.6 mL/kg/min) athletes performed a CPET to determine the COP, ventilatory threshold 1 (VT1) and 2 (VT2), and VO2max. The PCA was used to determine the relationship between variables and COP, explaining their variance. Results: Our data revealed that females and males displayed different COP values. Indeed, males showed a significant diminished COP compared to the female group (22.6 ± 2.9 vs. 27.2 ±3.4 VE/VO2, respectively); nevertheless, COP was allocated before VT1 in both groups. Discussion: PC analysis revealed that the COP variance was mainly explained (75.6%) by PC1 (expired CO2 at VO2max) and PC2 (VE at VT2), possibly influencing cardiorespiratory efficiency at VO2max and VT2. Our data suggest that COP could be used as a submaximal index to monitor and assess cardiorespiratory system efficiency in endurance athletes. The COP could be particularly useful during the offseason and competitive periods and the return to the sports continuum.

Lifestyle and cardiometabolic risk factors in the ethnic and non-ethnic population > 15 years of age: results from the National Chilean Health Survey 2016-2017.

Introduction: Background: lifestyle and cardiometabolic risk factors information is scarce regarding youth and adults of Latin-American ethnics. Objective: the primary aim was to describe the lifestyle and cardiometabolic risk factors for arterial hypertension (HTN) and diabetes in ethnic Latin-American groups (Mapuche and Aymara) and other non-ethnics > 15 years of age in the Chilean population. A secondary aim was to determine the association between physical activity 'intensity' with HTN and diabetes markers. Material and methods: a representative sample from the National Chilean Health Survey 2016-2017, included Mapuche (EG-Map; women n = 166, men n = 300; total n = 466), Aymara (EG-Aym; women n = 96, men n = 55; total n = 151), and a non-ethnic population group (No-EG; women n = 2057, men n = 3445; total n = 5502). The main outcomes were; systolic blood pressure (SBP), diastolic blood pressure (DBP), fasting plasma glucose (GL), and secondary outcomes were other anthropometric, lipid profile, and lifestyle parameters. Results: GL was significantly associated with nutrition (0.9 %, p < 0.0001), tobacco and alcohol habits (0.6 %, p < 0.0001). SBP was significantly associated with nutrition (whole-grains 0.04, p = 0.001; water consumption 0.07, p < 0.0001), sleep hygiene (week 0.04, p = 0.030; on weekends -0.04, p = 0.026), and alcohol consumption (-0.06, p < 0.0001). Conclusion: in conclusion, lifestyle differences among Mapuche and Aymara ethnic groups in comparison with non-ethnic Chilean peers > 15 years are significantly associated with blood pressure and glycemia.

Introducción: Antecedentes: la información sobre estilos de vida y factores de riesgo cardiometabólico es escasa en jóvenes y adultos de etnia latinoamericana. Objetivo: el objetivo principal fue describir el estilo de vida y los factores de riesgo cardiometabólico para la hipertensión arterial (HTA) y la diabetes en grupos étnicos latinoamericanos (Mapuche y Aymara) y otros no étnicos > 15 años de la población chilena. Un objetivo secundario fue determinar la asociación de la "intensidad" de la actividad física con la HTA y los marcadores de diabetes. Material y métodos: muestra representativa de la Encuesta Nacional de Salud de Chile 2016-2017, compuesta por mapuches (EG-Map; mujeres n = 166, hombres n = 300; total n = 466), aymaras (EG-Aym; mujeres n = 96, hombres n = 55; total n = 151) y un grupo poblacional no étnico (No-GE; mujeres n = 2057, hombres n = 3445; total n = 5502). Las principales evaluaciones fueron la presión arterial sistólica (PAS), la presión arterial diastólica (PAD) y la glucosa plasmática en ayunas (GL), y los resultados secundarios fueron otros parámetros antropométricos, del perfil lipídico y del estilo de vida. Resultados: la GL se asoció significativamente a los hábitos nutricionales (0,9 %, p < 0,0001) y los hábitos de tabaco y alcohol (0,6 %, p < 0,0001). La PAS se asoció significativamente con la nutrición (cereales integrales 0,04, p = 0,001; consumo de agua 0,07, p < 0,0001), higiene del sueño (semana 0,04, p = 0,030; fines de semana -0,04, p = 0,026) y consumo de alcohol (- 0,06, p < 0,0001). Conclusión: en conclusión, las diferencias de estilo de vida entre las etnias mapuche y aymara en comparación con sus pares chilenos no étnicos mayores de 15 años se asocian significativamente con la presión arterial y la glucemia.

Twelve weeks of treadmill exercise training with green tea extract reduces myocardial oxidative stress and alleviates cardiomyocyte apoptosis in aging rat: The emerging role of BNIP3 and HIF-1α/IGFBP3 pathway.

In this study, we consider the effect of treadmill exercise training, green tea extract, and combination of exercise training with green tea extract, in aging rat cardiac myocytes apoptosis markers (i.e., HIF-1α, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, Bax/Bcl-2 ratio, and hematoxylin and eosin). Twenty-four rats (male, Wistar) were divided into four groups: (I) control (n = 6), (II) green tea extract (n = 6), (III) exercise (n = 6), and (IV) exercise + green tea extract (n = 6). Exercise groups performed 12 weeks of running on a rodent treadmill at 17-27 m.min-1 (60-75% vo2peak) for 5 days per week. Green tea extract involved 300 mg.kg-1 , 5 days per week for 12 weeks. After being euthanized, the blood and heart were collected for glutathione peroxidase (GPx) activity, malondialdehyde (MDA), HIF-1α, BNIP3, insulin-like growth factor-binding protein-3 (IGFBP3), Bax, Bcl-2, caspase-3, Bax/Bcl-2 ratio, and hematoxylin and eosin level measurements. Compared to control, the ANOVA demonstrated significant effects of green tea extract (F = 14.646 to 32.453, p = .009 to .001, η = 0.295 to 0.715) and exercise training (F = 9.213 to 133.828, p = .007 to .001, η = 0.315 to η = 0.870) on HIF-1a, BNIP3, Bax, IGFBP3, Bcl-2, caspase-3, MDA, GPx, and Bax/Bcl-2 ratio. However, the combination of green tea extract and exercise had no effect on the aforementioned apoptosis markers when compared to isolated green tea extract or isolated exercise (F = 0.002 to 4.068, p = .057 to .968, and η = 0.001 to 0.169). PRACTICAL APPLICATIONS: Isolated exercise training and green tea extract may provide a cardioprotective effect on aging-induced apoptosis through the downregulation of HIF-1α, BNIP3, and IGFBP3 in the heart muscle. However, further research is needed to clarify the effects of combining exercise and green tea.

Web-based exercise interventions for patients with depressive and anxiety disorders: a systematic review of randomized controlled trials

Objective: The number of people suffering from depression and/or anxiety has increased steadily due to the coronavirus disease 2019 (COVID-19) pandemic. In this context, web-based exercise interventions have emerged as a potential treatment strategy. The objective of this study was to synthetize evidence from randomized controlled trials regarding the effects of web-based exercise interventions on patients with depressive and/or anxiety disorders. Methods: Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines were followed. Six databases were searched (Cochrane Library, EBSCO, PubMed, SciELO, Scopus, and Web of Science), and eligible articles were identified according to a PICOS inclusion-exclusion approach (participants with depressive or anxiety disorders; web-based exercise interventions; active or passive control group; assessment of changes in depressive or anxiety disorders; randomized design). Primary outcomes were depressive and/or anxiety symptoms. The quality of evidence was assessed with Grading of Recommendations Assessment, Development, and Evaluation. Results: Of 7,846 search results, three studies met the inclusion criteria (172 participants between 18 and 65 years of age, 95.9% women). The web-based exercise interventions lasted 8-12 weeks and involved endurance training, yoga, or combined endurance and strength training. The comparators involved non-exercise controls or active controls. Compliance rates were low. Web-based exercise interventions were not superior to controls regarding anxiety symptoms, and only one study found benefits for depressive symptoms (p ≤ 0.05). The quality of the cumulative evidence was low. Conclusion: The available data regarding the effects of web-based exercise interventions on depression and/or anxiety symptoms is scarce, the risk of bias is high, and the quality of the cumulative results is low. Currently, no clear recommendations can be provided. Registration number: PROSPERO CRD42021225938.

Dynamic circadian fluctuations of glycemia in patients with type 2 diabetes mellitus

BACKGROUND: Diabetes mellitus (DM) has glucose variability that is of such relevance that the appearance of vascular complications in patients with DM has been attributed to hyperglycemic and dysglycemic events. It is known that T1D patients mainly have glycemic variability with a specific oscillatory pattern with specific circadian characteristics for each patient. However, it has not yet been determined whether an oscillation pattern represents the variability of glycemic in T2D. This is why our objective is to determine the characteristics of glycemic oscillations in T2D and generate a robust predictive model. RESULTS: Showed that glycosylated hemoglobin, glycemia, and body mass index were all higher in patients with T2D than in controls (all p < 0.05). In addition, time in hyperglycemia and euglycemia was markedly higher and lower in the T2D group (p < 0.05), without significant differences for time in hypoglycemia. Standard deviation, coefficient of variation, and total power of glycemia were significantly higher in the T2D group than Control group (all p < 0.05). The oscillatory patterns were significantly different between groups (p = 0.032): the control group was mainly distributed at 2-3 and 6 days, whereas the T2D group showed a more homogeneous distribution across 2-3-to-6 days. CONCLUSIONS: The predictive model of glycemia showed that it is possible to accurately predict hyper- and hypo-glycemia events. Thus, T2D patients exhibit specific oscillatory patterns of glycemic control, which are possible to predict. These findings may help to improve the treatment of DM by considering the individual oscillatory patterns of patients.

Entrenamiento con sobrecarga, duración de la repetición e hipertrofia: una revisión de la literatura / Resistance training, repetition duration and hypertrophy: a literature review

RESUMEN En el contexto del entrenamiento con sobrecargas, la duración de la repetición (tempo) hace referencia al tiempo total que dura una sola repetición dentro de una serie de un ejercicio, siendo el resultado de la suma entre la fase concéntrica, isométrica y excéntrica del levantamiento (o viceversa, dependiendo del ejercicio). Ha existido controversia los últimos años respecto a la duración de la repetición (y sus fases) y su impacto en la hipertrofia. El objetivo de esta revisión fue analizar los efectos de programas de entrenamiento donde se hayan comparado distintos tempos de levantamiento y su impacto en la hipertrofia. Se realizó una búsqueda de literatura en la base de datos electrónica Pubmed, con los siguientes criterios de inclusión: i) programas de entrenamiento que induzcan fallo volitivo, ii) que los estudios se hayan realizado bajo acciones dinámicas y con ≥4 semanas de intervención y iii) que los sujetos de estudio sean mayores de 18 años hasta mediana edad. De un total de 473 estudios, cuatro fueron incluidos, donde participaron 113 sujetos (79 hombres y 34 mujeres) y los tempos utilizados variaron entre 1.5 y 90 segundos, con menores tempos asociados a mayor efecto hipertrófico. Un tiempo entre 2 y 6 segundos sería efectivo para inducir adaptaciones hipertróficas.

ABSTRACT In overload training the duration of the repetition (tempo) refers to the total time that a single repetition lasts within a set, the result being the sum between the concentric, isometric and eccentric phases of the lift (or vice versa depending on the exercise). There has been controversy in recent years regarding the duration of the repetition (and its phases) and its impact on muscle hypertrophy. The objective of this review was to analyze the effects of training programs and compare the different lifting tempos and their impact on hypertrophy. A literature search was carried out in the Pubmed electronic database, with the following inclusion criteria: i) training programs that induce volitional failure, ii) studies had been carried out under dynamic actions and with ≥4 weeks of intervention, and iii) study subjects are older than 18 years old to middle age. Of a total of 473 studies, four were included, where, 113 subjects (79 men and 34 women) participated and the tempos varied between 1.5 and 90 seconds, with lower tempos associated with a greater hypertrophic effect. A tempo between 2 and 6 seconds would be effective in inducing hypertrophic adaptations.

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.

Effect of warm-up on hand grip strength in sedentary overweight women / Efecto del calentamiento en la fuerza de agarre de mano en mujeres sedentarias con sobrepeso

Abstract Introduction: In recent years, handgrip strength assessment has gained special relevance in health. However, a standardized application protocol that includes warm-up procedures is required to measure it. Objective: To compare the acute effects of four warm-up strategies on maximal handgrip strength (MHS) in sedentary overweight women. Materials and methods: Single-blind, randomized, crossover study in which MHS was measured in 12 overweight women under the following conditions: i) no warm-up (control condition), ii) static stretching warm-up, iii) strength-based warm-up (i.e., resistance band exercise), and iv) isometric squeezing-ball warm-up for the forearm muscles. A Jamar dynamometer was used for the measurements, which were taken on four different days, at 48-hour rest intervals; three measurements were made per hand. Results: MHS mean values were 23.8 and 24.9 kg without warm-up, 20.3 and 21.4 kg after stretching warm-up, 20.9 and 22.9 kg after strength-based warm-up, and 22.0 and 23.0 kg after squeezing-ball warm-up for non-dominant and dominant hand, respectively. No significant differences (p>0.05; one-way ANOVA) were observed between protocols, nor were there differences in MHS in relation to nutritional status, lean mass, or fat mass. Conclusion: Warm-up is not required to measure MHS in overweight sedentary women when three measurements are made.

Resumen Introducción. En los últimos años se ha dado una mayor importancia a la medición de la fuerza máxima de agarre de mano, sin embargo para hacer esta medición se requiere un protocolo estandarizado de aplicación, incluyendo procedimientos de calentamiento. Objetivo. Comparar los efectos agudos de cuatro tipos de calentamiento en la fuerza máxima de agarre de mano de mujeres sedentarias con sobrepeso. Materiales y métodos. Estudio ciego, aleatorizado y cruzado en el que se midió la fuerza máxima de agarre de mano de 12 mujeres con sobrepeso bajo las siguientes condiciones: i) sin calentamiento (condición de control), ii) con calentamiento de estiramiento estático, iii) con calentamiento basado en la fuerza (p. ej., ejercicios con banda elástica) y iv) con calentamiento con bola terapéutica de compresión para los músculos del antebrazo. Para las mediciones se utilizó un dinamómetro Jamar y estas se realizaron en cuatro días diferentes y en intervalos de 48 horas de descanso; además, se hicieron tres intentos de medición por mano. Resultados. Los valores promedio de fuerza máxima de agarre para la mano no dominante y dominante fueron 23.8kg y 24.9kg sin calentamiento, 20.3kg y 21.4kg con estiramiento, 20.9kg y 22.9kg con banda elástica y 22.0kg y 23.0kg con bola terapéutica, respectivamente. No hubo diferencias significativas (p>0.05; ANOVA de una vía) entre los protocolos, ni diferencias en la fuerza máxima de agarre de mano en relación con estado nutricional, masa magra o masa grasa. Conclusión. No se requiere una sesión de calentamiento para medir la fuerza máxima de agarre de mano en mujeres sedentarias con sobrepeso cuando se realizan tres intentos de medición.

Changes in anthropometric parameters and physical fitness in older adults after participating in a 16-week physical activity program / Cambios en los parámetros antropométricos y la condición física en adultos mayores luego de participar en un programa de actividad física de 16 semanas

Abstract Introduction: Physical activity is important for achieving healthy aging. Objective: To analyze changes in anthropometric parameters and physical fitness among Chilean older adults after participating in a 16-week physical activity program and to evaluate whether there were differences in relation to their baseline nutritional status or not. Materials and methods: Pre-experimental quantitative study. The study population consisted of 176 older adults (155 women and 21 men) distributed in three groups: normal weight (n = 56), overweight (n=67) and obese (n = 53). The following variables were evaluated: body mass index (BMI), waist circumference (WC), waist-to-height ratio (WHR) and physical fitness. Results: Significant decreases between pre- and post-measurements were found for WC (p<0.001), BMI (p=0.015), and WHR (p<0.001). Improvements were observed in the following tests: chair stand (p<0.001), arm curl (p<0.001), 2-min step (p<0.001), chair sit-&-reach (p=0.018) and back scratch (p=0.014). Regarding BMI, significant changes were observed between normal weight vs. overweight participants (p=0.001) and between normal weight vs. obese participants (p=0.001). Conclusion: Older adult participants that regularly attended the physical activity program were able to reduce their WC, BMI and WHR, and also improved their physical-functional performance on the chair stand, arm curl, 2-min step, chair sit-&-reach and back scratch tests. In addition, anthropometric parameters and physical fitness also improved regardless of their baseline nutritional status.

Resumen Introducción. La actividad física es de gran importancia para lograr un envejecimiento saludable. Objetivos. Estudiar los cambios en los parámetros antropométricos y la condición física de adultos mayores (AM) chilenos después de 16 semanas de participación en un programa de actividad física, y evaluar las diferencias en relación con su estado nutricional inicial. Materiales y métodos. Estudio pre-experimental cuantitativo. Población: 176 AM (155 mujeres y 21 hombres) distribuidos en 3 grupos: normopesos (n = 56), sobrepesos (n=67) y obesos (n = 53). Se evaluaron las siguientes variables: índice de masa corporal (IMC), perímetro de cintura (PC), índice cintura-estatura (ICE) y condición física. Resultados. Se observaron reducciones significativas en PC (p<0.001), IMC (p=0.015) e ICE (p<0.001), y mejoras en las siguientes pruebas: sentarse y levantarse de una silla (p<0.001), flexiones del codo (p<0.001), dos minutos de marcha (p<0.001), flexión del tronco en silla (p=0.018) y juntar las manos tras la espalda (p=0.014). Se encontraron diferencias significativas respecto al IMC entre participantes normopesos y sobrepesos (p=0.001), y entre normopesos y obesos (p=0.001). Conclusión. Los AM que participaron regularmente en el programa de actividad física lograron reducir su PC, IMC e ICE y mejorar su rendimiento físico-funcional en las pruebas de sentarse y levantarse de una silla, flexiones de codo, dos minutos de marcha, y flexibilidad del tren inferior y superior. Además, sus parámetros antropométricos y su condición física mejoraron independientemente de su estado nutricional inicial.

Validation of a novel equation to predict lower-limb muscle mass in young soccer players: a brief communication / Validación de una nueva ecuación para predecir la masa muscular de los miembros inferiores en jugadores jóvenes de fútbol: una comunicación breve

Lower-limbs appendicular muscle mass is a key body composition trait related to health and performance. Considering the relevance of lower-limbs appendicular muscle mass in soccer players, the assessment and monitoring of this variable with a low-cost tool would be of great value in order to improve performance through training and nutritional interventions. This study aimed to develop a multiple regression model in order to validate, through dual-energy X-ray absorptiometry, a novel equation to predict lower-limbs appendicular muscle mass in young soccer players using anthropometric variables. Forty-two soccer players of the Chilean National Team (age, 17.1±1.3 years; body mass, 70.0±6.8 kg; height, 175.0±6.6 cm) underwent anthropometrically and body composition assessments. Forward stepwise linear regression was used to develop the equation to estimate the lower-limb appendicular muscle mass. The estimated results were compared with measurements by dual-energy X-ray absorptiometry. The best predictor model to estimate lower-limbs appendicular muscle mass was (kg): (-21.268 + (0.087*height) - (0.853*middle thigh circumference) - (0.329*middle thigh skinfold) + (1.136*corrected middle thigh circumference) + (0.306*calf circumference)) (R2= 0.83). The lower-limbs appendicular muscle mass estimated by the equation and measured by DXA were similar (14.71±1.72 kg vs 14.76±1.89 kg, respectively), and have a good concordance according to Bland-Altman method (mean difference: 0.049 kg; 95 % IC: -1.481 to 1.578 kg) and Lin's concordance correlation coefficient (0.91; 95 % CI: 0.85 - 0.96) methods. In conclusion, the predictive equation is a valid, easy to calculate, and a low-cost tool to predict lower-limbs appendicular muscle mass in young soccer players.

La masa muscular de los miembros inferiores es un factor antropométrico clave relacionado a la salud y el rendimiento deportivo. Considerando la relevancia de este factor en jugadores de fútbol, la medición y monitoreo de esta variable a través de herramientas prácticas de bajo costo puede ser de gran utilidad para lograr objetivos relacionados a mejorar el rendimiento a través del entrenamiento e intervenciones nutricionales. El objetivo de este estudio fue desarrollar un modelo de regresión lineal con el objetivo de validar una nueva ecuación predictiva de la masa muscular de miembros inferiores en jugadores jóvenes de fútbol. Cuarenta y dos jugadores jóvenes de fútbol pertenecientes a la Selección Nacional Chilena (17,1±1,3 años; 70,0±6,8 kg; 175,0±6,6 cm) fueron sometidos a evaluaciones antropométricas y de composición corporal. La regresión lineal de pasos hacia adelante fue utilizada para desarrollar la ecuación para estimar la masa muscular de miembros inferiores. Los resultados estimados fueron comparados con medición de absorciometría de rayos X de doble energía (DEXA). El mejor modelo predictor de masa muscular de miembros inferiores (kg) fue: (-21,268 + (0,087*talla) - (0,853*circunferencia de muslo medio) - (0,329*pliegue de muslo medio) + (1,136*circunferencia de muslo medio corregida) + (0,306*circunferencia de pantorrilla)) (R2= 0,83). La masa muscular estimada por la ecuación y la medida por DEXA fue similar (14,71±1,72 kg vs 14,76±1,89 kg, respectivamente), y tuvo una buena concordancia acorde al método Bland-Altman (diferencia promedio: 0,049 kg; 95 % IC: -1,481 to 1,578 kg) y el coeficiente de correlación de concordancia de Lin (0,91; 95 % CI: 0,85 - 0,96). En conclusión, la ecuación predictiva desarrollada en este estudio es una herramienta válida, fácil de calcular y de bajo costo que permite estimar la masa muscular de miembros inferiores en futbolistas jóvenes.

Relationship between anthropometric nutritional status and functional capacity in older adults living in the community / Relación entre estado nutricional antropométrico y condición física funcional en adultos mayores independientes

ABSTRACT Background: The functional fitness of older people may be associated with their nutritional status. Aim: To assess the association between of anthropometric measures with functional fitness in older people. Material and Methods: Cross-sectional study conducted in 75 participants aged 65 to 89 years. Body mass index (BMI), waist-to-height ratio (WHtR), fat mass (FM) and skeletal muscle mass index (SMI) were calculated from anthropometric measures. The functional fitness was determined using the Senior Fitness Test battery. Results: BMI and FM indicated obesity, and WHtR indicated cardiometabolic risk in 49%, 55% and 83% of participants, respectively. SMI indicated a low muscle mass in 91% of females. Performance standards of chair stand, arm curl, 2-min step test and 8-foot up-and-go tests were met in 1%, 8%, 1% and 89% of participants, respectively. Significant negative correlations were found between 2-min step test and BMI, WHtR and FM (r = −0.26, −0.31 and −0.48 respectively). Back scratch had a negative correlation with BMI (r = −0.23) and SMI (rho = −0.28). Significant positive correlations were found between 8-foot up-and-go, WHtR (rho = 0.28) and FM (rho = 0.23), and between 2-min step test and SMI (rho = 0.28). The coefficient of determination (R2) between 2-min step test with BMI, WHtR and FM were 0.05, 0.08 and 0.22, respectively, while the R2 between back scratch and BMI was 0.04. Multiple regression models indicated that FM affected the 2-min step test independently of BMI and WHtR (adjusted R2 = 0.22), however age and sex negatively influenced these associations. Conclusions: Functional fitness of older adults is influenced by nutritional anthropometric measures, particularly BMI, WHtR and FM for aerobic capacity, and BMI for upper limb flexibility.

Introducción: El estado nutricional y la condición física funcional (CFF) pueden estar relacionados en adultos mayores. Objetivo: Analizar la influencia de medidas antropométricas nutricionales sobre CFF. Material y Método: Estudio transversal realizado en 75 adultos de 65 a 89 años. Las variables antropométricas fueron índice de masa corporal (IMC), razón cintura-talla (RCT), masa adiposa (MA) e índice de masa muscular esquelética (IMME). La evaluación de CFF se efectuó con la batería Senior Fitness Test. Resultados: El IMC y MA indicaron obesidad, y RCT indicó riesgo cardiometabólico en 49%, 55% y 83% de los participantes, respectivamente. IMME indicó una baja masa muscular en 91% de las mujeres. El estándar de rendimiento para las pruebas sentarse-levantarse, flexión-codo, paso-2-minutos y levantarse-caminar-sentarse se logró en 1%, 8%, 1% y 89% de los participantes, respectivamente. Se encontraron correlaciones significativas negativas entre paso-2-minutos con IMC, RCT y MA (r = −0.26,-0.31 y-0.48 respectivamente. La misma asociación se observó entre juntar-manos-espalda con IMC (r = −0.23) e IMME (rho = −0.28). Se encontraron correlaciones significativas positivas entre levantarse-caminar-sentarse con RCT (rho=0.28) y MA (rho = 0.23), y entre paso-2-minutos con IMME (rho = 0.28). Los R2 entre paso-2-minutos e IMC, RCT y MA fueron 0.05, 0.08 y 0.22, respectivamente, mientras que el R2 entre juntar-manos-espalda e IMC fue 0.04. Los modelos de regresión múltiple indicaron que MA afectó la prueba paso-2-minutos independientemente de IMC y RCT (R2 ajustado = 0.22), aunque la edad y sexo afectaron negativamente estas asociaciones. Conclusiones: La CFF de adultos mayores es influenciada por alteraciones evidenciadas por medidas antropométricas nutricionales, particularmente IMC, RCT y MA sobre la capacidad aeróbica, e IMC sobre la flexibilidad de extremidad superior.

Basal Serum Cortisol and Testosterone/Cortisol Ratio Are Related to Rate of Na+ Lost During Exercise in Elite Soccer Players.

During exercise, the human body maintains optimal body temperature through thermoregulatory sweating, which implies the loss of water, sodium (Na+), and other electrolytes. Sweat rate and sweat Na+ concentration show high interindividual variability, even in individuals exercising under similar conditions. Testosterone and cortisol may regulate sweat Na+ loss by modifying the expression/activity of the cystic fibrosis transmembrane conductance regulator. This has not been tested. As a first approximation, the authors aimed to determine whether basal serum concentrations of testosterone or cortisol, or the testosterone/cortisol ratio relate to sweat Na+ loss during exercise. A total of 22 male elite soccer players participated in the study. Testosterone and cortisol were measured in blood samples before exercise (basal). Sweat samples were collected during a training session, and sweat Na+ concentration was determined. The basal serum concentrations of testosterone and cortisol and their ratio were (mean [SD]) 13.6 (3.3) pg/ml, 228.9 (41.4) ng/ml, and 0.06 (0.02), respectively. During exercise, the rate of Na+ loss was related to cortisol (r = .43; p < .05) and to the testosterone/cortisol ratio (r = -.46; p < .01), independently of the sweating rate. The results suggest that cortisol and the testosterone/cortisol ratio may influence Na+ loss during exercise. It is unknown whether this regulation depends on the cystic fibrosis transmembrane conductance regulator.

Caracterización de los estilos de vida en dueñas de casa chilenas: análisis de la Encuesta Nacional de Salud 2009-2010 / Lifestyles of Chilean housewives: analysis of the 2009-2010 Chilean Health Survey

Background: Housewives represent a important proportion of the Chilean population. However, there is limited evidence about their lifestyles. Aim: To characterize lifestyles and determine the level of compliance with healthy lifestyles guidelines of housewives in Chile. Material and Methods: Housewives from the 2009-2010 National Health Survey were included. The variables studied included levels of physical activity (PA), sedentary behavior, diet, hours of sleep and smoking. Compliance with healthy lifestyle behaviors was evaluated through logistic regression, granting a value of 1 for compliance and 0 for non-compliance. A healthy lifestyle was defined as meeting at least four healthy behaviors. Results: Housewives aged > 55 years had a higher BMI and waist circumference compared to those aged < 40 years. Housewives were also more likely to report moderate alcohol consumption and were more likely to meet a healthier lifestyle score (Odds ratio = 1.52 [95% confidence intervals: 1.09 to 2.11], p = 0.013). No significant age trends were observed for other lifestyle behaviors. Conclusions: Housewives had high levels of central obesity, excess body weight and high levels of salt intake but low alcohol intake. Their healthy lifestyles behaviors increased along with increasing age.

Post-activation Potentiation: Effects of Different Conditioning Intensities on Measures of Physical Fitness in Male Young Professional Soccer Players.

The aim of this study was to compare the effects of different warm-up conditioning intensities on the physical fitness (i.e., post-activation potentiation -PAP), of professional male field soccer players. Athletes (n = 10; age: 21.6 ± 3.2 years) completed a control warm-up and warm-ups aimed to induce PAP, in random and counterbalanced order. After control and experimental warm-up sessions participants completed a triple hop test with the dominant (H3Jd) and a non-dominant (H3Jnd) leg, a squat jump (SJ), a countermovement jump (CMJ), a change of direction ability (COD) test, a repeated sprint with a COD (RSCOD) test and a linear 30-m sprint test (S-30). The control warm-up (WU) protocol was designed according to athlete's regular warm-up practice. The experimental warm-ups included the same exercises as the WU, with addition of one set of half-back squats for 10 repetitions at 60%, 5 repetitions at 80%, and 1 repetition at 100% of 1RM (60%-1RM, 80%-1RM and 100%-1RM, respectively.) Threshold values for Cohen's effect sizes (ES) were calculated and used for group's comparison. Likely to most likely improvements were shown in H3Jd (ES = 0.52), H3Jnd (ES = 0.51), COD (ES = 0.38), fasted sprint (RSCODb) (ES = 0.58) and the total time of all sprints (RSCODt) (ES = 0.99) only after the 80%-1RM protocol in comparison to the WU. Conversely, 100%-1RM and 60%-1RM protocols, compared to WU, induced possibly to most likely poorer performance in all jumps, COD and RSCODb (ES = -0.07 to -1.03 and ES = -0.48 to -0.91, respectively). Possibly to most likely improvements were shown in all jumps, COD, RSCODb and RSCODt after the 80%-1RM warm-up protocol in comparison to the 100%-1RM and 60%-1RM warm-up protocols (ES = 0.35 to 2.15 and ES = 0.61 to 1.46, respectively). A moderate warm-up intensity (i.e., 80%-1RM back squat) may induce greater PAP, including improvements in jumping, repeated and non-repeated change of direction speed in male soccer players.

Influencia de la edad sobre el cumplimiento de las recomendaciones de actividad física: Resultados de la Encuesta Nacional de Salud en Chile 2009-2010 / Adherence to physical activity recommendations across age categories: Findings from the 2009-2010 Chilean National Health Survey

RESUMEN A pesar de que la actividad física (AF) es un factor protector contra las enfermedades crónicas no transmisibles, un gran porcentaje de la población no cumple los niveles mínimos recomendados. El objetivo fue investigar como varían los niveles de práctica de AF entre los diferentes grupos etarios en la población chilena. Se incluyeron 5.133 participantes de la Encuesta Nacional de Salud 2009-2010. La AF fue determinada utilizando el cuestionario GPAQ. La inactividad física fue definida como <600 MET/min/semana de AF moderada a vigorosa. La asociación entre AF y edad fue investigada por sexo mediante regresión logística. Las mujeres presentaron una mayor probabilidad de ser físicamente inactivas en comparación a los hombres (p<0,0001). Al analizar la prevalencia de inactividad física por sexo y grupo etario, esta cambió ligeramente entre los 20 a 59 años, pero a partir de los 60 se observó un incremento importante en la prevalencia llegando a 63% y 56% para mujeres y hombres >80 años, respectivamente. Los resultados obtenidos confirman la necesidad de seguir fomentando la práctica regular de AF física a través de todo el ciclo vital, pero en especial sobre los 60 años, ya que este grupo presenta una mayor probabilidad de ser físicamente inactivo.

ABSTRACT Although physical activity (PA) is a protective factor against non-communicable diseases, there is an important proportion of the population who do not meet PA guidelines. Our aim was to investigate how adherence to PA guidelines varies across different age groups in the Chilean population. 5,133 participants from the 2009-2010 Chilean Health Survey were included in this study. PA was measured using the Global Physical Activity Questionnaire (GPAQ). Physical inactivity was defined as <600 MET/min/week of moderate to vigorous intensity PA. Logistic regression was used to investigate the association of PA with age. The main finding of this shows that women were more likely to be inactive than men (p<0.0001). Physical inactivity prevalence varied slightly between 20 and 59 years. However, among those individuals aged >60 years the prevalence increased markedly, reaching 63% and 56% for women and men aged >80 years, respectively. These findings confirm the necessity of promoting PA across the lifespan, but more importantly, these results suggest that more promotion and opportunities for engaging in PA should be created especially for older adults, who are more likely to be physically inactive.

Effectiveness of HIIT compared to moderate continuous training in improving vascular parameters in inactive adults.

BACKGROUND: Strong evidence shows that physical inactivity increases the risk of many adverse health conditions, including major non-communicable diseases, such as cardiovascular disease (CVD), metabolic syndrome, and breast and colon cancers, and shortens life expectancy. We aimed to determine the effects of moderate (MCT)- versus high-intensity interval training (HIT) on vascular function parameters in physically inactive adults. We hypothesized that individualized HIT prescription would improve the vascular function parameters more than the MCT in a greater proportion of individuals. METHODS: Twenty-one inactive adults were randomly allocated to receive either MCT group (60-75% of their heart rate reserve, [HRR] or HIT group (4 min at 85-95% of peak HRR), 3 days a week for 12 weeks. Vascular function (brachial artery flow-mediated dilation, FMD [%], normalized brachial artery flow-mediated dilation, FMDn [%], aortic pulse wave velocity, PWV [m·s- 1], AIx, augmentation index: aortic and brachial [%]), were measured at baseline and over 12 weeks of training. In order for a participant to be considered a responder to improvements in vascular function parameters (FMDn and PWV), the typical error was calculated in a favorable direction. RESULTS: FMD changed by - 1.0% (SE 2.1, d = 0.388) in the MCT group, and + 1.8% (SE 1.8, d = 0.699) in the HIT group (no significant difference between groups: 2.9% [95% CI, - 3.0 to 8.8]. PWV changed by + 0.1 m·s- 1 (SE 0.2, d = 0.087) in the MCT group but decreased by - 0.4 m·s- 1 in the HIT group (SE 0.2, d = 0.497), with significant difference between groups: - 0.4 [95% CI, - 0.2 to - 0.7]. There was not a significant difference in the prevalence of no-responder for FMD (%) between the MCT and HIT groups (66% versus 36%, P = 0.157). Regarding PWV (m·s- 1), an analysis showed that the prevalence of no-responder was 77% (7 cases) in the MCT group and 45% (5 cases) in the HIT group (P = 0.114). CONCLUSIONS: Under the conditions of the present study, both groups experienced changed in vascular function parameters. Compared to MCT group, HIT is more efficacious for improving FMD and decreasing PWV, in physically inactive adults. TRIAL REGISTRATION: ClinicalTrials.gov NCT02738385 registered on 23 March 2016.