Claudia Miranda-Fuentes

Summary: Obesity is a major health burden worldwide. Although bariatric surgery (BS) is recognized as an effective strategy for weight loss and comorbidities improvement, its impact on muscle strength and quality is still unclear. We aimed to examine postoperative changes in muscle strength and quality and their relationship with body mass index (BMI) changes among adults undergoing BS. To this end, we systematically searched the WoS, PubMed, EBSCO, and Scopus databases. The meta‐analyses, which included 24 articles (666 participants), showed that BS reduces absolute lower‐limb isometric strength (ES = −0.599; 95% CI = ‐0.972, −0.226; p = 0.002). Subjects who experienced a more significant reduction in BMI after BS also suffered a higher loss of absolute muscle strength. Similarly, absolute handgrip strength showed a significant decrease (ES = −0.376; 95% CI = −0.630, −0.121; p = 0.004). We found insufficient studies investigating medium‐ and long‐term changes in muscle strength and/or quality after BS. This study provides moderate‐quality evidence that BS‐induced weight loss can reduce the strength of appendicular muscles in the short term, which should be addressed in management these subjects. More high‐quality studies are needed to evaluate the impact of BS on muscle strength and the different domains of muscle quality in the medium and long term (registered on PROSPERO CRD42022332581).

The purpose of this study was to determine the reference values of the velocity of execution of the five Sit-to-Stand in older adults through a systematic review of the literature. Three databases were reviewed: Medline (PubMed), Scopus and Web of Science, with the deadline of March 2021. The search terms were: "sit to stand" OR "stand to sit" OR "chair rise" OR "chair rising" AND "kinematic" OR "velocity". The experimental studies were evaluated using the Quality Assessment of Diagnostic Accuracy Assessment (QUADAS) scale by independent reviewers. A total of seven studies were included. The velocity of execution in older adults (n=85) that presented neurological health conditions was between 0.33 m/s and 0.38 m/s. In the healthy (n=246) ones it was between 0.27 m/s and 0.94 m/s. Between 60 to 70 years (n=157) it was from 0.31 m/s and 1.59 m/s, and from 70 to 80 years (n=225) it was from 0.27 m/s and 1.04 m/s. The execution velocity of five Sit-to-Stand in older adults ranges from a minimum of 0.27 m/s to a maximum of 1.59 m/s for the complete stop-and-sit cycle. These antecedents may be useful to predict or detect functional alterations and disability. Resumen.El propósito de este estudio fue determinar los valores de referencia de la prueba sentado-de pie de cinco repeticiones en adultos mayores a través de una revisión sistemática de la literatura. Se revisaron tres bases de datos: Medline (PubMed), Scopus y Web of Science con fecha límite Marzo del 2021. Los términos de búsqueda fueron: "sit to stand" OR "stand to sit" OR "chair rise" OR "chair rising" AND "kinematic" OR "velocity". Los estudios experimentales se evaluaron por revisores independientes mediante la escala “Quality Assessment of Diagnostic Accuracy Assessment (QUADAS)”. Se incluyó un total de siete estudios. La velocidad de ejecución en adultos mayores que presentaban condiciones de salud neurológica (n=85) estuvo entre 0.33 m/s y 0.38 m/s. En sujetos sanos (n=246) estuvo entre 0.27 m/s y 0.94 m/s. En sujetos entre 60 a 70 años (n=157) fue de 0.31 m/s y 1.59 m/s, y de 70 a 80 años (n=225) fue de 0.27 m/s y 1.04 m/s. La velocidad de ejecución de la prueba sentado-de pie de cinco repeticiones en adultos mayores varía desde un mínimo de 0.27 m/s hasta un máximo de 1.59 m/s para el ciclo completo de parar y sentarse. Estos antecedentes pueden ser útiles para predecir o detectar alteraciones funcionales y discapacidad.

Summary: Although bariatric surgery (BS) is recognized as an effective strategy for body weight loss, its impact on cardiorespiratory fitness (CRF) is still unclear. We aimed to examine postoperative changes in CRF (VO_2max/peak) and its relationship with weight loss among adults undergoing BS. We systematically searched the WoS, PubMed, MEDLINE, and Scopus databases. Observational and intervention studies were selected reporting the presurgery and postsurgery CRF, measured by breath‐by‐breath VO₂ or its estimation. Eleven articles (312 patients) revealed that BS leads to a reduction in absolute VO_2max/peak in the short term (effect size, ES = −0.539; 95%CI = −0.708, −0.369; p < 0.001), and those patients who suffered a more significant decrease in BMI after BS also had a greater loss of absolute VO_2max/peak. However, VO_2max/peak relative to body weight increased after surgery (ES = 0.658; 95%CI = 0.473, 0.842; p < 0.001). An insufficient number of studies were found investigating medium and long‐term changes in CRF after BS. This study provides moderate‐quality evidence that the weight loss induced by BS can reduce CRF in the short term, which represents a therapeutic target to optimize BS outcomes. More high‐quality studies are needed to evaluate the impact of BS on VO_2max/peak in the short, medium, and long term including normalized values for fat‐free mass.

Background: The purpose of this study was to determine the reliability for the strength and movement velocity of the concentric phase from the five Sit-to-Stand (5STS), using three incremental loads measured by a functional electromechanical dynamometer (FEMD) in healthy young adults. Methods: The average and peak strength and velocity values of sixteen healthy adults (mean ± standard deviation (SD): age = 22.81 ± 2.13 years) were recorded at 5, 10 and 15 kg. To evaluate the reliability of FEMD, the intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were obtained. Results: Reliability was high for the 10 kg (CV range: 3.70–4.18%, ICC range: 0.95–0.98) and 15 kg conditions (CV range: 1.64–3.02%, ICC: 0.99) at average and peak strength, and reliability was high for the 5 kg (CV range: 1.71–2.84%, ICC range: 0.96–0.99), 10 kg (CV range: 0.74–1.84%, ICC range: 0.99–1.00) and 15 kg conditions (CV range: 0.79–3.11%, ICC range: 0.99–1.00) at average and peak velocity. Conclusions: The findings of this study demonstrate that FEMD is a reliable instrument to measure the average and peak strength and velocity values during the five STS in healthy young adults.

Background: This study aimed to report, through a systematic review of the literature, the baseline and final reference values obtained by near-infrared spectroscopy (NIRS) of muscle oxygen saturation (SmO₂) during resistance training in healthy adults. Methods: Original research studies were searched from four databases (Scopus, PubMed, WOS, and SportDiscus). Subsequently, three independent reviewers screened the titles and abstracts, followed by full-text reviews to assess the studies’ eligibility. Results: Four studies met the inclusion criteria, data were extracted and methodological quality was assessed using the Downs and Black scale. Muscle oxygen saturation (% SmO2) during reported muscle strength exercises showed a decreasing trend after a muscle strength protocol; that is, before the protocol (range = 68.07–77.9%) and after (range = 9.50–46.09%). Conclusions: The trend of the SmO₂ variables is to decrease after a muscle strength protocol. Studies are lacking that allow expanding the use of these devices during this type of training.

Background: The objective of this study was to establish the reliability of the Humon Hex near-infrared reflectance spectroscopy (NIRS) in determining muscle oxygen saturation (SmO₂) and hemoglobin concentration (Hgb) at rest and during isometric and dynamic strength exercises using a functional electromechanical dynamometer (FEMD). Methods: The SmO₂ and Hgb values of sixteen healthy adults (mean ± standard deviation (SD): Age = 36.1 ± 6.4 years) were recorded at rest and during isometry (8 s), dynamic strength I (initial load of 40% of the average isometric load, with 2 kg increments until muscle failure) and dynamic strength II (same as I, but with an initial load of 40% of the maximum isometric load) activity. To evaluate the reliability in the determination of SmO₂ and Hgb of this device, intraclass correlation coefficient (ICC), standard error of measurement (SEM) and coefficient of variation (CV) were obtained. Results: The main results obtained are SmO₂ at rest (CV = 5.76%, SEM = 3.81, ICC = 0.90), isometric strength (CV = 3.03%, SEM = 2.08, ICC = 0.92), dynamic strength I (CV = 10.6, SEM = 7.17, ICC = 0.22) and dynamic strength II (CV = 9.69, SEM = 6.75, ICC = 0.32); Hgb at rest (CV = 1.97%, SEM = 0.24, ICC = 0.65), isometric strength (CV = 0.98%, SEM = 0.12, ICC = 0.96), dynamic strength I (CV = 3.25, SEM = 0.40, ICC = 0.54) and dynamic strength II (CV = 2.74, SEM = 0.34, ICC = 0.65). Conclusions: The study shows that Humon Hex is a reliable device to obtain SmO₂ and Hgb data in healthy adult subjects at rest and during isometric strength, providing precision for measurements made with this device.

Purpose Obesity has been associated with reduced vagal function and increased sympathetic activity. Cardiac autonomic dysfunction has emerged as a major risk factor in the development of cardiovascular disease. Cardiac autonomic function (CAF) can be assessed by heart rate variability (HRV), an independent predictor of mortality based on changes in time intervals between adjacent heartbeats (RR). Bariatric surgery is considered the most effective treatment for obesity and its comorbidities, with sleeve gastrectomy (SG) being the most frequent bariatric procedure. There are few studies on HRV changes in women with obesity after SG. The aim of this study was to evaluate the short-term impact of SG on CAF and its relationship with weight loss. Materials and Methods An observational cohort study was conducted. Twenty-three female patients were assessed before SG and at 1 and 3 months after surgery. CAF was evaluated by analyzing HRV from 5-min records of RR intervals while the subject was supine. HRV was analyzed in time and frequency domains and with a nonlinear method. Results Patients (36.0 ± 11.1 years old, BMI 35.1 ± 3.4 kg/m²) presented higher HRV values, on average, in all domains both at 1 and 3 months after SG (p < 0.05). In addition, all anthropometric parameters improved (p < 0.001) although there was no relationship between HRV improvements and anthropometric changes. Conclusion SG seems to be effective at reducing excess weight and improving HRV at the short term, and these changes are detectable as early as the first month after surgery. HRV assessment appears as a promising low-cost tool that deserves further research.

La condición física es un conjunto de atributos físicos determinante de la capacidad de realizar un trabajo pudiendo o no estar relacionado con la salud^10,11; la capacidad cardiorrespiratoria (CCR) es un componente de esta condición utilizado como indicador de salud y de expectativa de vida, siendo objetivada a través del consumo de oxígeno máximo (VO₂ max)^12–14; corresponde a la mayor cantidad de oxígeno que una persona puede consumir, transportar y utilizar en una inspiración durante la realización de un ejercicio dinámico^15,16. Para evaluar esta variable se necesita de las máximas capacidades cardiorrespiratorias del sujeto^17,18, situación que puede resultar riesgosa en algunos casos¹⁹. En pacientes con obesidad, estas evaluaciones generalmente son submáximas y se utiliza el término consumo de oxígeno peak (VO₂ peak) para denominar la cantidad de oxígeno consumido en el momento de la detención de la prueba^15,20–22, el cual se expresa en valores absolutos (L/min) o relativos al peso corporal (ml/kg/min)²³. Uno de los aspectos poco descritos del VO₂ es su cinética, la cual consiste en la respuesta dinámica del VO₂ al comienzo de un ejercicio de carga constante durante 6 a 10 minutos, aproximadamente^24–26. Para poder describir el comportamiento de la cinética del VO₂ a carga subumbral, se utiliza la expresión matemática: VO₂ = BL + A(1- e^-(t-TD/τ)), donde VO2 = consumo de oxígeno en función del tiempo; BL = consumo de oxígeno inicial o de base; A = ganancia total del consumo de oxígeno; e = base del logaritmo natural, t = tiempo; τ = tau; TD = tiempo de retraso que precede al incremento en el VO₂ muscular²⁷.