The Relationship between Socioeconomic Status, Family Income, and Measures of Muscular and Cardiorespiratory Fitness in Colombian Schoolchildren

Objective To determine the associations between socioeconomic status (SES) and physical fitness in a sample of Colombian youth. Study design Prueba SER is cross-sectional survey of schoolchildren in Bogota, Colombia. Mass, stature, muscular fitness (standing long-jump, handgrip), and cardiorespiratory fitness (20-m shuttle run) were measured in 52 187 schoolchildren 14-16 years of age. Area-level SES was categorized from 1 (very low) to 4 (high) and parent-reported family income was categorized as low, middle, or high. Results Converting measures into z scores showed stature, muscular, and cardiorespiratory fitness were significantly (z = 0.3-0.7) below European values. Children in the mid- and high SES groups jumped significantly further than groups with very low SES. Differences were independent of sex but became nonsignificant when adjusted for anthropometric differences. Participants in the mid-SES and high-SES groups had better handgrip scores when adjusted for body dimension. There were, however, no significant between-group differences in cardiorespiratory fitness, which was strongly clustered by school and significantly greater in students from private schools. Conclusions Area-level SES is associated with measures of muscular fitness in Colombian schoolchildren. These associations were largely explained by the large differences in body dimensions observed between SES groups. When area-level SES is considered, there was no evidence that family income influenced fitness. The clustering of outcomes reaffirms the potential importance of schools and area-level factors in promoting fitness through opportunities for physical activity. Interventions implemented in schools, can improve academic attainment; a factor likely to be important in promoting the social mobility of children from poorer families

Desarrollo de la fuerza muscular en niños como estrategia para disminuir el riesgo de enfermedad cardiometabólica

Los factores de riesgo para las enfermedades cardiometabólicas (ECM) como la obesidad, la resistencia a la insulina y el síndrome metabólico tienen su inicio en la infancia. Existe evidencia de que la adiposidad infantil se relaciona con factores de riesgo para presentar enfermedad cardiovascular en la vida adulta, principalmente en la población hispana, en la cual se ha observado mayor vulnerabilidad para desarrollar enfermedades crónicas no transmisibles. Las altas tasas de morbimortalidad secundaria a enfermedades cardiovasculares en países de medianos y bajos ingresos económicos como Colombia, demanda profundizar en el estudio de los mecanismos que relacionan las bases biológicas y epigenéticas de la programación fetal y el riesgo de presentar ECM. Nosotros hemos publicado evidencias de que nuestra población tiene una alta sensibilidad para presentar inflamación de bajo grado y resistencia a la insulina a menores niveles de adiposidad visceral, asociada a una menor fuerza de empuñadura, la cual es un marcador del contenido de masa muscular. Proponemos que mejorar la condición física, sobre todo la capacidad aeróbica y la fuerza muscular, es una intervención efectiva para disminuir el riesgo de desarrollar enfermedad cardiovascular en niños y adolescentes colombianos, al disminuir la masa grasa, los marcadores de inflamación crónica de bajo grado y mejorar la cantidad y calidad de la masa muscular. Abstract Risk factors for cardiometabolic diseases such as obesity, insulin resistance, and metabolic syndrome arise during childhood. There is evidence that adiposity in children is associated with risk factors for cardiovascular disease later in life, particularly among the Hispanic population, where vulnerability for the development of chronic non-communicable diseases is greater. The high mortality and morbidity rates of cardiovascular disease in middle-and low-income countries such as Colombia, makes it necessary to delve deeper into the mechanisms related to the biological and epigenetic basis of fetal programming, and the risk to develop cardiometabolic diseases. Based in our published studies, we have evidence that our population is highly prone to having chronic low- grade inflammation and insulin resistance at lower levels of visceral adiposity, associated with a weaker handgrip, a muscle mass marker. Therefore, we propose that improving physical condition, more particularly aerobic capacity and muscle strength, is an effective intervention to decrease the risk of cardiovascular disease in Colombian children and adolescents, through a decrease in the fat mass, chronic low- grade inflammation markers, and an improvement in both the quality and amount of muscle mass

Fitness Changes in Adolescent Girls Following In-School Combined Aerobic and Resistance Exercise: Interaction With Birthweight.

Purpose: To assess the efficacy of a supervised in-school combined resistance and aerobic training program in adolescent girls and investigate whether responses differ according to birthweight. Methods: Participants (girls aged 13–17 y) were randomized either to an intervention replacing physical education (PE) classes with 2 × 60-minute training sessions per week (n = 58) or to a control group that continued to attend 2 × 60 minutes per week of curriculum PE (n = 41). We measured muscular fitness (handgrip, standing long jump, and sit-ups), cardiorespiratory fitness (20-m shuttle run), skinfolds, and lean body mass preintervention and postintervention and determined effect size (Hedge’s g) differences between changes in these measures. We also compared changes within lower (<3000 g) and normal birthweight intervention and PE control subgroups. Results: The intervention group showed greater improvements in all the fitness measures and lean body mass (g = 0.22–0.48) and lower skinfold increases (g = 0.41) than PE controls. Within the intervention group, improvements in all fitness measures were larger in lower birthweight (g = 0.53–0.94) than in normal birthweight girls (g = 0.02–0.39). Conclusion: Replacing curriculum PE with supervised training improved muscular and cardiorespiratory fitness and body composition outcomes in adolescent females. Our findings suggest an enhanced adaptive response to training in participants with lower birthweight which warrants further investigation

The Impact of the FIFA 11+Training Program on Injury Prevention in Football Players : A Systematic Review

Peer reviewe

Inflammation and Hypertension: Are There Regional Differences?

Hypertension is a chronic disease with global prevalence and incidence rapidly increasing in low and medium income countries. The surveillance of cardiovascular risk factors, such as hypertension, is a global health priority in order to estimate the burden and trends, to appropriately direct resources, and to measure the effect of interventions. We propose here that the adoption of Western lifestyles in low and middle incomes countries has dramatically increased the prevalence of abdominal obesity, which is the main source of proinflammatory cytokines, and that the vascular systemic inflammation produced by adipose tissue contributes to the development of hypertension. The concentration of proinflammatory cytokines is higher in the Latin American population than that reported in developed countries, suggesting a higher susceptibility to develop systemic low-degree inflammation at a given level of abdominal obesity. These particularities are important to be considered when planning resources for health care programs. Moreover, studying these singularities may provide a better understanding of the causes of the burden of cardiovascular risk factors and the remarkable variability in the prevalence of these medical conditions within and between countries

The Impact of the FIFA 11+Training Program on Injury Prevention in Football Players : A Systematic Review

Peer reviewe

Concordance between the indirect V̇O2max value estimated through the distance in Yo-Yo intermittent recovery test level 1 and the direct measurement during a treadmill protocol test in elite youth soccer players

The main aim of this study was to evaluate the concordance between the indirect V̇O2max value estimated by the distance achieved in the Yo-Yo intermittent recovery test level 1 (YYIR1) and the direct measurement during a treadmill protocol test (TP) in elite youth soccer players. Methods: Fourteen elite under 20 year’s old soccer players from a first division soccer club were evaluated. Test were performed one week apart. In both tests V̇O2, was measured with an ambulatory gas exchange measurement. YYIR1 estimated V̇O2max was calculated using the equation described by Bangsbo et al. (2008) and in TP was calculated using American College of Sport Medicine equation. Results: Lin´s concordance correlation coefficient between direct V̇O2max in TP and estimated V̇O2max in YYIR1=0.271 (poor concordance). Conclusions: The poor concordance between direct and indirect V̇O2max measurements in TP and YYIR1, indicated that in an elite population both test, are not good indirect predictors of V̇O2max, reached in those tests using current predictive equations. The YYIR1 is well established as a performance-relevant test in elite players, but our data suggests that due to its poor concordance with imprecise estimation of V̇O2max, which should be measured directly if this variable is of specific interest

The SIMAC study: A randomized controlled trial to compare the effects of resistance training and aerobic training on the fitness and body composition of Colombian adolescents.

The aim of this study was to evaluate the impact on muscle strength, aerobic fitness and body composition, of replacing the physical education (PE) class of Colombian adolescents with resistance or aerobic training. 120 tanner stage 3 adolescents attending a state school were randomized to resistance training, aerobic training, or a control group who continued to attend a weekly 2- hour PE class for 16 weeks. The resistance training and aerobic training groups participated in twice weekly supervised after-school exercise sessions of < 1 hour instead of their PE class. Sum of skinfolds, lean body mass (bioelectrical impedance analysis), muscular strength (6 repetition maximum (RM)) bench press, lateral pulldown and leg press) and estimated cardiorespiratory fitness (multistage 20 meter shuttle run) were assessed at pre and post intervention. Complete data were available for n = 40 of the resistance training group, n = 40 of the aerobic training group and n = 30 PE (controls). Resistance training attenuated increases in sum of skinfolds compared with controls (d = 0.27, [0.09-0.36]). We found no significant effect on lean body mass. Resistance training produced a positive effect on muscle strength compared with both controls (d = 0.66 [.49-.86]) and aerobic training (d = 0.55[0.28-0.67]). There was a positive effect of resistance training on cardiorespiratory fitness compared with controls (d = 0.04 [-0.10-0.12]) but not compared with aerobic training (d = 0.24 [0.10-0.36]). Replacing a 2-hour PE class with two 1 hour resistance training sessions attenuated gains in subcutaneous adiposity, and enhanced muscle strength and aerobic fitness development in Colombian youth, based on a median attendance of approximately 1 session a week. Further research to assess whether adequate stimuli for the development of muscular fitness exists within current physical education provision is warranted

Correction for Johansson et al., An open challenge to advance probabilistic forecasting for dengue epidemics.

Correction for “An open challenge to advance probabilistic forecasting for dengue epidemics,” by Michael A. Johansson, Karyn M. Apfeldorf, Scott Dobson, Jason Devita, Anna L. Buczak, Benjamin Baugher, Linda J. Moniz, Thomas Bagley, Steven M. Babin, Erhan Guven, Teresa K. Yamana, Jeffrey Shaman, Terry Moschou, Nick Lothian, Aaron Lane, Grant Osborne, Gao Jiang, Logan C. Brooks, David C. Farrow, Sangwon Hyun, Ryan J. Tibshirani, Roni Rosenfeld, Justin Lessler, Nicholas G. Reich, Derek A. T. Cummings, Stephen A. Lauer, Sean M. Moore, Hannah E. Clapham, Rachel Lowe, Trevor C. Bailey, Markel García-Díez, Marilia Sá Carvalho, Xavier Rodó, Tridip Sardar, Richard Paul, Evan L. Ray, Krzysztof Sakrejda, Alexandria C. Brown, Xi Meng, Osonde Osoba, Raffaele Vardavas, David Manheim, Melinda Moore, Dhananjai M. Rao, Travis C. Porco, Sarah Ackley, Fengchen Liu, Lee Worden, Matteo Convertino, Yang Liu, Abraham Reddy, Eloy Ortiz, Jorge Rivero, Humberto Brito, Alicia Juarrero, Leah R. Johnson, Robert B. Gramacy, Jeremy M. Cohen, Erin A. Mordecai, Courtney C. Murdock, Jason R. Rohr, Sadie J. Ryan, Anna M. Stewart-Ibarra, Daniel P. Weikel, Antarpreet Jutla, Rakibul Khan, Marissa Poultney, Rita R. Colwell, Brenda Rivera-García, Christopher M. Barker, Jesse E. Bell, Matthew Biggerstaff, David Swerdlow, Luis Mier-y-Teran-Romero, Brett M. Forshey, Juli Trtanj, Jason Asher, Matt Clay, Harold S. Margolis, Andrew M. Hebbeler, Dylan George, and Jean-Paul Chretien, which was first published November 11, 2019; 10.1073/pnas.1909865116. The authors note that the affiliation for Xavier Rodó should instead appear as Catalan Institution for Research and Advanced Studies (ICREA) and Climate and Health Program, Barcelona Institute for Global Health (ISGlobal). The corrected author and affiliation lines appear below. The online version has been corrected

Robust estimation of bacterial cell count from optical density

Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals &lt;1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data