The impact of education on the demographic dividend

The impact of population structure on economic growth has been studied in recent decades using different methods to estimate the so-called demographic dividend. Besides, education has been pointed out as a key factor in economic growth. We propose a decomposition of the demographic dividend, into age and education effects. We illustrate the potential of the method by illustrating its application to Mexico and Spain over the period 1970-2100. To that end, we estimate the National Transfer Accounts age profiles by schooling level and apply them to recently available population projections stratified by educational level. Our results confirm the role of population age structure in the demographic dividend, but also reveal that education attainment can be even more crucial. Moreover, we find that the way how both age and education effects finally impact on economic growth depends to a great extent on the specific consumption and labor income age profiles in each country

Effects of a High Intensity Interval Training (HIIT) in lactate and heart rate during the menstrual cycle in young skater athletes

INTRODUCTION: High intensity interval training (HIIT) effects on heart rate and lactate concentration have been widely documented in male and female athletes. However, there few reports focused to study the dynamics of these cardiac and metabolic markers during the different phases of the menstrual cycle. PURPOSE: The aim of this studywas analyze the dynamics of heart rate and lactate concentration during a HIIT protocol in the different phases of the menstrual cycle (MC) in young eumenorrheic athletes women. METHODS: Two young skater athletes (14.5±0.7 yrs.) with regular menstrual cycles were recruited. The normality of the cycle was measured with a menstrual calendar. The estimated VO2 max was assessed in an electrically braked cycle ergometer (Lode) using a graded exercise test. The HIIT protocol consisted of 12 sessions of 6 high intensity intervals at 80% VO2 max, and 6 rest intervals at 40% VO2 max. Basal and post-exercice heart rate (HR) and lactate concentrations (LC) were measured with a pulsometer (polar FT1) or test strips (Nova Biomedical), respectively. The MC was divided in six phases: Early follicular (EF), Mid follicular (MF), Late follicular (LF), Early luteal (EL), Mid luteal (ML) and Late luteal (LL), using the date since their first menstrual discharge as the start of the EF phase. RESULTS: There was a significative correlation between HR and LC (r: 0.37, p: 0.0034) throughout the 12 HIIT sessions, but this was not statistically significant in EF (r: 0.36, p: 0.21), MF (r: 0.86, p: 0.12), LF (r: 0.14, p: 0.68), ML (r: 0.04, p: 0.92) and LL (r: 0.67, p: 0.06). Interestingly, we did observe a highly significant correlation between HR and LC (r = 0.68, p = 0.0033) in the EL phase, characterized by rising progesterone levels and a transient decrease of estradiol concentrations. CONCLUSION: These preliminary results suggest that the normal fluctuation of steroid hormone levels during the menstrual cycle can affect the dynamics of HR and LC in eumenorrheic athletes

Running Economy: Reproductibility at submaximal high speed

INTRODUCTION: The running economy (RE) has been traditionally determined by measuring the steady-state consumption of oxygen at a specific speed; however few studies has been designed to evaluate the reproductibility of the RE at a high rate of maximum oxygen consumption after repeated submaximal efforts within the same session. PURPOSE: The purpose of this study was valuate if the reproductibility of running economy at submaximal high speed could be affected by two previous submaximal efforts. METHODS: In this study participated 19 subjects (mean±SD; age, 21.8±2.5 years; body mass, 71.0±10.6 and height, 175.2±8.1). During three days of assessment separately for at least 24h of recovery, subjects performed the following tests. Day 1 a maximum incremental test, to determine the intensities. Day 2 a test of running economy at 80% of VO2max. Day 3 a test of running economy at 30, 70 and 80% of VO2max separated by 5 min of recovery. t-student test was conducted to measure test-retest differences in RE the p value were set al ≤0.05. RESULTS: No significant differences were found in the Running Economy at 80% of VO2max determined in both economy tests RE 220.1± 21.6vs 219.6±20.6 (ml·kg-1·km-1), ICC; 0.92, CV; 4.4 ± 2.6. CONCLUSION: The results of the present study showed exercises sessions at 30 and 70 of VO2max performed before the submaximal exercise test (80% of VO2max) did not affected the RE during an exercise test performed at 80% of VO2max

The relationship between aerobic fitness and depression level determined with Hamilton scale in older adults

INTRODUCTION: Depression is a major public health problem associated with both morbidity and mortality throughout the world, in Mexico epidemiological reports show a prevalence of depression in older adults of 9.5% in women and 5% in men; it is widely held that regular exercise and physical activity in older subjects have a significant impact on psychological health and well-being. PURPOSE: To determine whether if higher aerobic fitness is associated with decreased symptoms of clinical depression in older adults. METHODS: Participants (n=21) included individuals raging ages from 61 to 72 years old and were not regular exercisers. The 6 minute walking test was used to determine the aerobic fitness, the total distance covered during the test was determined with pedometers; all subjects were free of unstable cardiovascular symptoms and disabilities that could interfere with performance in the sub-maximal exercise test. Indirect Peak Oxygen Consumption (VO2peak) was obtained with the equation stablished by Burr et al. (2011). Depression Symptoms were evaluated using the Hamilton Depression Scale which consisted of an interview of the subjects and scoring 17 items defined in terms of a series of categories of increasing intensity. Statistical analyses included a non-parametric Spearman correlation test to determine the association between predicted VO2peak and depression, level of significance was stablished at P≤0.05. RESULTS: Twenty one overweight (BMI 29.3±3.7 kg/m2) subjects that presented mild clinical depression symptoms were included in the study. A moderate negative correlation between predicted peak VO2 and depression was obtained, with a coefficient of r= -0.5099 (P≤0.05). A regression analysis was performed to establish the significant predictor of VO2 entering the analysis a psychological variable as a dependent factor (P value 0.0102). CONCLUSION: Based on the results, there is evidence that aerobic exercise could be a plausible and healthy strategy to avert depressive symptoms in the appearance of clinical depression in older adults

Acute Systemic Response Of BDNF, Lactate and Cortisol to Strenuous Exercise Modalities in Healthy Untrained Women

Acute bouts of intense exercise increase lactate concentration, which in turn stimulates brain-derived neurotrophic factor (BDNF) production. Cortisol released during intense exercise might inhibit BDNF synthesis. This study examined the acute effects of 2 protocols of strenuous exercise on serum BDNF. Seventeen physically-active healthy females (Age = 20.0 ± 0.9 yr., BMI = 23.0 ± 2.6 kg/m2) performed a strenuous cycle-ergometer graded exercise test (GXT) and a high-intensity interval training session (HIIT). Serum BDNF, serum cortisol, cortisol: BDNF ratio and blood lactate (BLa) were recorded at baseline and immediately following exercise. Although non-statistically significant, the HIIT session elicited a higher magnitude of change from baseline for BDNF (d = 0.17) and cortisol (d = 1.18) than after the GXT (d = -0.26, and d = 0.82, respectively). An interaction was found between GXT and HIIT trials and measurements on BLa levels, with higher post-exertion values after HIIT than after GXT (p < 0.0001, η2 = 0.650, 95%CI = 2.2, 5.2). The higher BLa levels did not raise circulating BDNF. The elevated cortisol levels may have overcome the effects of lactate on BDNF. However, the higher BLa induced by HIIT suggest that interval exercise modality on the long-term could be a feasible intervention to increase circulating peripheral BDNF, at least in untrained healthy women

Relationship between PASE score with anthropometrics and cardiovascular variables associated to obesity in an older Mexican population

INTRODUCTION: Obesity in Older Adults (OA) increases the risk to acquire non-communicable diseases such as metabolic and cardiovascular diseases. Some reports indicate that sedentary habits or low physical activity is one of the main factor that induce obesity in elderly state. PURPOSE: Determine the relationship between the level of physical activity via Physical Activity Scale for the Elderly (PASE) test, anthropometric and cardiovascular variables associated to obesity in an older Mexican population. METHODS: Fourteen OA (63.4 ± 1.78 years) from Ensenada city, Baja California were recruited. The PASE was applied individually, in each participants was determined the waist circumference (WC) and body mass index (BMI). In the same sense, the Systolic Blood Pressure (SBP) and resting Heart Rate (HR) were evaluated. Spearman correlation test was employed to determine the relationship between variables. RESULTS: The PASE score was 10.58 ± 1.52. The WC was 87.72 ± 2.15 cm. The BMI showed by the participants was 27.3 ± 0.84 kg/m2. On the other hand, the SBP was 131.07 ± 4.38 mmHg. The HR was 72.07 ± 2.50 ppm. The PASE score does not showed statistical correlation with the BMI (r=0.34; p=0.22). In the same sense, there was not significate association between PASE and WC (r=-0.06; p=0.8). The HR showed negative correlation with the PASE (r=-0.45) however, this association was not significant (p=0.1). Finally, the PASE does not correlation with the SBP (r=0.13; p=0.65). CONCLUSION: The preliminary data showed that the PASE questionnaire cannot be used to predict the variables associated to obesity in older Mexican population

Efecto de un programa de ejercicio aeróbico en la composición corporal y somatotipo de un obeso mórbido infantil

La obesidad representa un problema de salud que suele iniciarse en la infancia y la adolescencia, por un desequilibrio entre la ingesta y el gasto energético, derivando en niveles altos de grasa corporal y grados peligrosos de adiposidad relativa. Por tanto, la inactividad física es un factor de riego que favorece el sobrepeso y la obesidad. El objetivo fue diseñar y aplicar un programa de ejercicio aeróbico y evaluar su efecto en la composición corporal y somatotipo en un niño con obesidad mórbida. Se abordó como un estudio de caso, con pre-test y post-test, en un niño de 10 años, con peso corporal de 88.9 kg, estatura de 158.5 cm, un IMC clasificado de obeso mórbido, no practicante de algún deporte o actividad física regular. El programa fue de 12 semanas, 5 sesiones por semana y una duración de 30-60 min por sesión y una intensidad del 55- 70% de Fcmax. La composición corporal y el somatotipo se obtuvo por mediciones de variables antropométricas. El componente graso a través de la medición de pliegues. En los resultados destacan la diferencia en el pre-test y pos-test de los pliegues: bíceps (dif. 0.0 mm), tríceps (dif. -1.2 mm), subescapular (dif. -1.0 mm.) y suprailiaco (dif. -3.2 mm). Se encontraron pequeñas diferencias en el componente graso (dif. -1.05%) y peso graso (dif. -800 grs). Con respecto a la somaocarta, la distancia de dispersión del somatotipo no mostró valores relevantes. El efecto del programa no alcanzó niveles significativos y el sujeto aún permanece en estado de alto riesgo de saludObesity represents a health problem that usually starts in childhood and adolescence, by an imbalance between the consumption and the energy use, deriving in high levels of body fat and dangerous degrees of relative adiposity. Thus, the physical inactivity is a risk factor that favours overweight and obesity. The objective was to design and apply a program of aerobic exercises and to evaluate its effect on body composition and somatotype in a child with morbid obesity. It was addressed as a case study, with pre-test and post-test, in a 10-year-old child, with a body weight of 88.9 kg, a height of 158.5 cm, a BMI classified as morbidly obese, not practicing a sport or physical activity regularly. The program was 12 weeks, 5 sessions per week and a duration of 30-60 minutes per session and an intensity of 55-70% of Fcmax. Body composition and somatotype were obtained by measuring the anthropometric variables. The fat component through the measurement of folds. The results highlight the difference in the pre-test and post-test of the folds: biceps (diff. 0.0 mm.), triceps (diff. -1.2 mm.), subscapular (diff. -1.0 mm.) and suprailiac (diff -3.2 mm.). Small differences in the fat component (diff -1.05%) and the fat weight (diff. -800 grs.) were found. Regarding the somacarta the dispersal distance of the somatotype did not show relevant values. The effect of the program did not reach significant levels and the subject remains in a state of high health risk

Influence of anthropometry and body composition in climbing ability

INTRODUCTION: Climbing has become a popular, competitive and recreational sport. It requires, principally, skilled technique and high muscle strength. Therefore, it has been necessary to implement formal studies about the training of this discipline. Investigations have been performed some studies to demonstrate that the improvement of climbing can be explained with anthropometric and physiological variables. PURPOSE: The purpose of this study was evaluate the main variables that affect the performance of the climbing, namely, anthropometry, body composition and climbing level. METHODS: Eighteen climbers, ranged 22 - 40 years old and V2-V7 of climbing ability (according Hueco Tanks scale), were volunteered to participate. Measurements of anthropometric characteristics and body composition including height, arm spam, forearm maximum, midstylion-dactilion, lean arm mass, body mass index (BMI), skeletal muscle mass, body fat mass, visceral fat, were performed. All variables were evaluated by using a combination of a principal component analysis (PCA) with a cluster analysis. RESULTS: When the analysis was performed in both anthropometry (skeletal muscle mass, lean arm mass and forearm maximum) and body composition (BMI, body fat mass and visceral fat) groups of variables, the results showed an 86% of the variance. The anthropometry variables showed correlation with 60% of the total variance. Concretely, the higher climbing level athletes (V5-V7) showed a higher lean body mass and arm muscle mass than the lower climbing levels athletes (V0-V4). On the other hand, the last group showed higher body fat mass and visceral fat mass with respect to the V5-V7 climbing athletes. CONCLUSION: The data of the present study showed a clear tendency on the variables, both body composition and anthropometry, in terms of the climbing level. However, these results are not completely conclusive. We suggest necessary to improve the performance of the measurements in future studies

Saliva secretory IgA kinetics in obese subjects submitted to a graded exercise test

INTRODUCTION: Secretory IgA (sIgA) is predominant immunoglobulin in secretions of the mucosal immune system. It inhibit attachment and replication of pathogenic microorganism, preventing colonization by these pathogens. Therefore, sIgA is consider the first line of defense against pathogens. Previous studies have indicated a direct link between low salivary sIgA levels with of upper respiratory tract infections (UTRI) episodes in endurance sports and elite athletes. PURPOSE: Determine the effect of a maximal graded exercise test on the saliva sIgA levels in obese adult subjects. METHODS: Eleven obese male subjects (Age 31± 1.53 years) were recruited. The Body Mass Index (BMI) and, Waist Circumference (WC) were measured. Graded exercise test was performed on an electrically-braked cycle ergometer (Lode). The Heart rate (HR) was registered using a digital pulse meter (Polar FT1 model) before, immediately finished the exercise and after 30 min post- exercise test. The saliva samples were collected alongside with HR during the test. RESULTS: The WC (110.37 ± 3.89 cm) and BMI (34.73 ± 1.62 kg/m2) values confirmed the obesity state in the participants. The HR at basal was 77.09 ± 3.10 bpm, at post exercise, the HR mean was 175.45 ± 4.94 bpm (p \u3c0.0001 vs basal). Finally, at 30 post exe, the HR was 91.81 ± 3.01 bpm (P \u3c0.0001 vs post-exe). In basal state, the sIgA concentration was 94.21 ± 13.57 µm/mL. At post exe, the sIgA mean was 175.9 ± 22.45 µm/mL (p\u3c0.05 vs basal). Finally, 30’ post-exercise the sIgA level was 91.39 ± 10.40 µm/mL. However, the sIgA was not modified by the exercise. CONCLUSION: The present work demonstrates that the salivary sIgA increases temporally as a response to the graded exercise test in obese adults. Although, the changes in the sIgA concentration was not accompanied with a major sIgA secretion in the saliva

Efecto de un programa de actividad física y educación nutricional para reducir el consumo de bebidas azucaradas y desarrollo de la obesidad en escolares de Tijuana, México

Introduction: Currently, the consumption of sweetened beverages has increased and is associated with weight gain, mainly among childhood population. Therefore, the aim of the present study was to determine the effect of a physical activity program and extracurricular nutritional education on anthropometric variables and eating habits in school-age children. Material and methods: The study design was quasi-experimental pre/post with control group where a non-probabilistic convenience sampling was performed for a cohort of 35 children, separated into two groups, experimental (EG n = 21) and control (CG n = 14). The height, weight and waist circumference were assessed, and a beverage consumption frequency questionnaire was employed. The intervention program lasted 9 months with physical activity sessions of 50 minutes and 10 minutes of nutritional education with a frequency of 5 days per week. A 2x2 variance analysis was used to determine the statistical significance (p ≤ 0.05) for the effect of the intervention in both groups.Results: The participants presented an increase in the height (GE: 0.04 m, p = 0.0001; GC: 0.04 m, p = 0.0001), body mass (EG: 2.2 kg, p = 0.0001; CG: 1.1 kg, p = 0.0001) and waist circumference only was increased in the EG (2.8 cm, p = 0.02), nevertheless the BMI did not significantly change in both groups. The EG decreased sugar consumption (14.7 g/day, p = 0.05) and kilocalories (63.4 kcal, p = 0.05) from beverages, while in the CG no significant differences were found. Conclusion: It was observed that the program of physical activity and nutritional education had a positive effect on eating habits of school-aged children by reducing the consumption of sweetened beverages, as well the intake of sugar and kilocalories coming from them.Introducción: En la actualidad el consumo de bebidas azucaradas ha incrementado y se asocia con la ganancia de peso, principalmente en la población infantil. Es por esto que el objetivo del presente estudio fue determinar el efecto de un programa actividad física y educación nutricional extracurricular sobre variables antropométricas y hábitos alimentarios en niños de edad escolar. Material y métodos: El diseño del estudio fue cuasi-experimental pre/post con grupo control donde se realizó un muestreo no probabilístico por conveniencia de una cohorte de 35 niños, divididos en dos grupos, experimental  (GE n=21) y control (GC n=14). Se evaluó la estatura, el peso y la circunferencia de cintura y se aplicó un cuestionario de frecuencia de consumo de bebidas. El programa de intervención tuvo una duración de 9 meses con sesiones de actividad física de 50 minutos y 10 minutos de educación nutricional con una periodicidad de 5 días a la semana. Se utilizó un análisis de varianza 2x2 para determinar la significancia estadística (p≤0.05) por efecto de la intervención en ambos grupos.Resultados: Los sujetos presentaron un aumento de la estatura (GE: 0,04m, p=0,0001; GC: 0.04m,  p=0.0001), del peso corporal (GE: 2,2kg,  p=0.0001; GC: 1,1kg,  p=0,0001) y la circunferencia de cintura solamente incremento en el GE (2,8cm, p=0,02), sin embargo el IMC no cambio significativamente en ambos grupos. El GE disminuyó el consumo de azúcar (14,7g/día, p=0,05) y de kilocalorías (63,4kcal, p=0.05) provenientes de bebidas, mientras que en el GC no se encontraron diferencias significativas. Conclusión: Se pudo notar que el programa de actividad física y educación nutricional tuvo efecto positivo en los hábitos alimentarios de los escolares al disminuir el consumo de bebidas azucaradas, así como la ingesta de azúcar y kilocalorías proveniente de las mismas