Evidence shows an association between muscular strength (MS) and health among young people, however low muscular strength cut points for the detection of high metabolic risk in Latin-American populations are scarce. The aim of this study was twofold: to explore potential age- and sex-specific thresholds of MS, for optimal cardiometabolic risk categorization among Colombian children and adolescents; and to investigate whether cardiometabolic risk differed by MS group by applying the receiver operating characteristic curve (ROC) cut point. MS was estimated by using a handle dynamometer on 1,950 children and adolescents from Colombia, using MS relative to weight (handgrip strength/body mass). A metabolic risk score was computed from the following components: waist circumference, triglycerides, HDL-c, glucose, and systolic and diastolic blood pressure. ROC analysis showed a significant discriminatory accuracy of MS in identifying the low/high metabolic risk in children and adolescents and in both genders. In children, the handgrip strength/body mass levels for a low metabolic risk were 0.359 and 0.376 in girls and boys, respectively. In adolescents, these points were 0.440 and 0.447 in girls and boys, respectively. In conclusion, the results suggest an MS level relative to weight for having a low metabolic risk, which could be used to identify youths at risk.

The purpose of this study was to compare the neurotrophic factor response following one session of high-intensity exercise, resistance training or both in a cohort of physically inactive overweight adults aged 18–30 years old. A randomized, parallel-group clinical trial of 51 men (23.6 ± 3.5 years; 83.5 ± 7.8 kg; 28.0 ± 1.9 kg/m²) who are physically inactive (i.e., < 150 min of moderate-intensity exercise per week or IPAQ score of 6 months) and are either abdominally obese (waist circumference ≥90 cm) or have a body mass index, BMI ≥25 and ≤ 30 kg/m² were randomized to the following four exercise protocols: high-intensity exercise (4 × 4 min intervals at 85–95% maximum heart rate [HRmax] interspersed with 4 min of recovery at 75–85% HRmax) (n = 14), resistance training (12–15 repetitions per set, at 50–70% of one repetition maximum with 60 s of recovery) (n = 12), combined high-intensity and resistance exercise (n = 13), or non-exercising control (n = 12). The plasma levels of neurotrophin-3 (NT-3), neurotrophin-4 (also known as neurotrophin 4/5; NT-4 or NT-4/5), and brain-derived neurotrophic factor (BDNF) were determined before (pre-exercise) and 1-min post-exercise for each protocol session. Resistance training induced significant increases in NT-3 (+39.6 ng/mL [95% CI, 2.5–76.6; p = 0.004], and NT-4/5 (+1.3 ng/mL [95% CI, 0.3–2.3; p = 0.014]), respectively. Additionally, combined training results in favorable effects on BDNF (+22.0, 95% CI, 2.6–41.5; p = 0.029) and NT-3 (+32.9 ng/mL [95% CI, 12.3–53.4; p = 0.004]), respectively. The regression analysis revealed a significant positive relationship between changes in BDNF levels and changes in NT-4/5 levels from baseline to immediate post-exercise in the combined training group (R² = 0.345, p = 0.034) but not the other intervention groups. The findings indicate that acute resistance training and combined exercise increase neurotrophic factors in physically inactive overweight adults. Further studies are required to determine the biological importance of changes in neurotrophic responses in overweight men and chronic effects of these exercise protocols. Trial Registration: ClinicalTrials.gov, NCT02915913 (Date: September 22, 2016).

Ramírez-Vélez, R, Morales, O, Peña-Ibagon, JC, Palacios-López, A, Prieto-Benavides, DH, Vivas, A, Correa-Bautista, JE, Lobelo, F, Alonso-Martínez, AM, and Izquierdo, M. Normative reference values for handgrip strength in Colombian schoolchildren: the FUPRECOL study. J Strength Cond Res 31(1): 217–226, 2017—The primary aim of this study was to generate normative handgrip (HG) strength data for 10 to 17.9 year olds. The secondary aim was to determine the relative proportion of Colombian children and adolescents that fall into established Health Benefit Zones (HBZ). This cross-sectional study enrolled 7,268 schoolchildren (boys n = 3,129 and girls n = 4,139, age 12.7 [2.4] years). Handgrip was measured using a hand dynamometer with an adjustable grip. Five HBZs (Needs Improvement, Fair, Good, Very Good, and Excellent) have been established that correspond to combined HG. Centile smoothed curves, percentile, and tables for the third, 10th, 25th, 50th, 75th, 90th, and 97th percentile were calculated using Cole's LMS method. Handgrip peaked in the sample at 22.2 (8.9) kg in boys and 18.5 (5.5) kg in girls. The increase in HG was greater for boys than for girls, but the peak HG was lower in girls than in boys. The HBZ data indicated that a higher overall percentage of boys than girls at each age group fell into the “Needs Improvement” zone, with differences particularly pronounced during adolescence. Our results provide, for the first time, sex- and age-specific HG reference standards for Colombian schoolchildren aged 9–17.9 years.

Los objetivos del presente estudio fueron i) analizar y comparar el autoconcepto físico en estudiantes universitarios considerando posibles diferencias entre sexos y asociaciones con el estrato socioeconómico y la edad, y ii) generar perfiles de los estudiantes utilizando algoritmos de aprendizaje automático no supervisado. Un total de 230 estudiantes colombianos entre los 18 y 38 años pertenecientes a programas académicos de Educación Física (n = 118) y Psicología (n = 112) participaron en este estudio transversal. Se aplicó el cuestionario de autoconcepto físico (PSQ). Se hallaron diferencias significativas entre hombres y mujeres. No se encontraron diferencias en el autoconcepto físico entre los hombres de los programas académicos; sin embargo, los valores de las mujeres fueron significativamente diferentes entre los dos programas (p< .05). Se evidenció una asociación inversa baja entre el autoconcepto físico y el estrato socioeconómico y la edad. Luego del análisis de agrupación jerárquica sobre componentes principales, se identificaron dos perfiles estadísticamente diferentes con tamaño del efecto grande para el autoconcepto físico y todos sus dominios (Perfil 1 [n = 138] versus Perfil 2 [n = 92]; p< .05; η2< .45). Aunque el autoconcepto físico contribuyó en mayor medida al componente principal, con valores mayores para el perfil 2, el ≈73% de las mujeres (n = 101) se agruparon en el perfil 1 y hubo una mayor cantidad de estudiantes de Psicología (85/112) que de Educación Física (27/118) en el perfil 2. Los resultados muestran comportamientos diferentes del autoconcepto físico entre hombres y mujeres de los dos programas académicos. Los perfiles generados podrían ayudar a universidades, orientadores y profesores a planear intervenciones dentro de las instituciones para favorecer el desarrollo del autoconcepto físico a la vez que se evalúan otras asociaciones potenciales. Palabras clave: Autoconcepto físico, universitarios, educación física, psicología, aprendizaje automático no supervisado The aims of this study were i) to analyze and compare the physical self-concept in university students considering possible differences between sexes and associations with socioeconomic status and age, and ii) to generate student profiles using unsupervised machine learning algorithms. A total of 230 Colombian students between 18 and 38 years of age from the Physical Education (n = 118) and Psychology (n = 112) majors participated in this cross-sectional study. The physical self-concept questionnaire (PSQ) was applied. Significant differences were found between men and women. No differences were found in physical self-concept among men in the academic programs; however, women's values were significantly different between the two programs (p< .05). A low inverse association was evident between physical self-concept and socioeconomic stratum and age. Following hierarchical clustering analysis on principal components, two statistically different profiles with large effect sizes were identified (Profile 1 [n = 138] versus Profile 2 [n = 92]; p< .05; η2< .45). Although physical self-concept contributed most to the principal component, with higher values for profile 2, ≈73% of females (n = 101) were clustered in profile 1 and there were a greater number of Psychology (85/112) than Physical Education (27/118) students in profile 2. The results show different behaviors of physical self-concept between men and women in the two academic programs, so the profiles generated could help universities, counselors and professors to plan interventions within the institutions to favor its development while evaluating other potential associations. Keywords: Physical self-concept, college students, physical education, psychology, unsupervised machine learning

ResumenObjetivoExaminar si el consumo de bebidas azucaradas se relaciona con alteraciones en el perfil lipídico-metabólico y con marcadores de adiposidad en una muestra de estudiantes universitarios de Colombia.MétodosEstudio transversal en 280 voluntarios (73,9% varones) de 3 universidades de Colombia. El consumo de bebidas azucaradas se obtuvo mediante un cuestionario de frecuencia de ingesta en los últimos 7 días (BEVQ-15) en los dominios: bebidas azucaradas carbonatadas y refrescos de jugo. Se identificó la cantidad y la frecuencia de consumo (nunca, una vez, 2-3 veces y +4 veces/sem). Se obtuvieron datos bioquímicos de glucosa, colesterol total, triglicéridos, c-HDL, c-LDL, índice arterial e índice de Castelli. Se calculó el índice lipídico-metabólico según las concentraciones de triglicéridos, c-LDL, c-HDL y glucosa. La circunferencia de cintura, el índice de masa corporal, el índice de adiposidad corporal y el porcentaje de grasa corporal por impedancia bioeléctrica se usaron como marcadores de adiposidad.ResultadosEn el grupo de varones, los participantes que acusaron mayor consumo de bebidas azucaradas (+4 veces/sem) presentaron mayores valores de circunferencia de cintura, porcentaje de grasa corporal, colesterol total, triglicéridos, c-LDL, así como en los índices de Castelli y arterial (p=NS). En mujeres se observó esta relación en el índice de masa corporal, la circunferencia de cintura, el porcentaje de grasa corporal, los triglicéridos y el c-LDL (p tendencia4 times per week). Data for biomarkers included total cholesterol, triglycerides, c-HDL, c-LDL, arterial index and Castelli index. Lipid-metabolic index was calculated through serum concentrations of triglycerides, c-HDL, c-LDL and glucose. Waist circumference, body mass index and fat mass percentage were evaluated via bioelectrical impedance and used as markers of adiposity.ResultsMale reported higher sugar-sweetened beverages consumption (>4 times/wk) and elicited higher values of fat mass, waist circumference, total cholesterol, triglycerides, c-LDL and Castelli and arterial indices (P=NS). These relationships were also observed among women for body mass index, waist circumference, fat mass, triglycerides and c-LDL (P<.05). Furthermore, higher sugar-sweetened beverages consumption categories were negatively associated with lipid-metabolic index (P<.05) after adjustments by sex, age and body mass index.ConclusionA higher sugar-sweetened beverages consumption was associated with a major lipid-metabolic profile and also with higher concentrations of adiposity markers among university students from Colombia