RESUMEN
The Developmental Origins of Health and Disease hypothesis (DOHaD) proposes that growth during the prenatal period might play a critical role in health, affecting the development of diseases, such as osteoporosis. Bone health is particularly affected by human behaviors when sports participation constitutes the main manifestation of physical exercise. The aim of this study is to analyze the relationship between birth weight (BW) and bone mineral content (BMC) among adolescents, as well as to identify if sports participation and maturity can affect this relationship. The sample was composed of adolescents with ages ranging from 11 to 18 years, stratified according to normal birth weight (n = 331), low birth weight (n = 36), and macrosomia (n = 47), extracted from a wider cross-sectional study (ABCD Growth Study). BW was self-reported by the adolescent's parent. Sports participation was assessed by face-to-face interview. BMC was assessed using dual-energy X-ray absorptiometry. In the multivariate models, the relationships between BW and BMC remained non-significant, while sports participation was significantly related to BMC on lower limbs among boys (r = 0.154; p value = .001) and BMC of upper limbs among girls (r = 0.124; p value = .044). APHV was related to BMC of upper limbs among boys (r = 0.137; p value = .001). In conclusion, BMC was not affected by BW, while this phenomenon seems to be significantly affected by the positive impact of sports participation and maturation on it.
RESUMEN
Osteoporosis is a public health problem, which negatively impacts society and national health services worldwide. Altered mineralization of the skeleton can be caused by persistent vitamin D deficiency. However, the combined impact of both on bone health is still under investigation. In fact, although there is compelling evidence in the literature about the positive effect of weight-bearing sports participation on bone mineral density, its impact on bone geometry gains more attention in pediatric population. The sports modalities that we evaluated were artistic gymnastics and track and field. Nonsports group was composed of 43 adolescents. Bone density was assessed using dual-energy X-ray absorptiometry. Vitamin D concentration was assessed by blood analysis. In the crude comparison of bone outcomes, the sport group presented higher aBMD only in the trochanter (p-valueâ¯=â¯0.040). Considering the combination of the engagement in sports and vitamin D, adolescents in the sports group presented significantly higher values of aBMD in lower limbs, whole body, trochanter, shaft, and femur whole body (p-valueâ¯=â¯0.024, 0.035, 0.001, 0.019 and 0.003 respectly). In contrast, only the sport group with high vitamin D presented a higher CSA (p-valueâ¯=â¯0.015) and femur neck aBMD compared to the non-sport/low vitamin D group. Only adolescents with a combination of sports participation and higher serum concentrations of vitamin D presented better bone geometry, denoting the relevance of the combination of both factors to bone health.
Asunto(s)
Densidad Ósea , Deportes , Niño , Adolescente , Humanos , Soporte de Peso , Vitamina D , Absorciometría de Fotón , Cuello Femoral/diagnóstico por imagenRESUMEN
The objective of this study was to identify predictors of 12-mo areal bone density accrual in different body segments, lean soft tissue, and osteogenic characteristics attributed to sports participation among adolescent girls and boys. Adolescents (Girls [nâ¯=â¯64], [agedâ¯=â¯14.7]); Boys [nâ¯=â¯129], [agedâ¯=â¯14.6]) were stratified into three groups according to their engagement in different sports (Control [nâ¯=â¯68], Swimming [nâ¯=â¯25], and Weight-bearing sports [nâ¯=â¯100]). Areal bone density (aBMD [g/cm²]) and lean soft tissue (LST) [kg] were measured by dual-energy x-ray absorptiometry (DXA; Lunar DPX-NT; General Electric Healthcare, Little Chalfont, Buckinghamshire, United Kingdom). The ground reaction force (GRF) index attributed to sports participation (Sport-GRF) was created considering the GRF attributed to each sport, body weight of the adolescent, and the amount of time spent in sports participation. Osteocalcin levels (ng/mL) were estimated from a venous blood sample. Multiple regression analysis showed that after adjusting for covariates, the models involving sport-GRF, LST (Δ), and osteocalcin explained 15.8% to 76.2% of the aBMD gains. Specifically in girls, OC was only associated with lower limb aBMD accrual. In boys, however, sport ground reaction forces were positively associated with total spine aBMD accrual. Furthermore, the LST (Δ) was positively associated with aBMD accrual in all body sites (ßâ¯=â¯0.003 to 0.011) in both sexes. Increases in LST contributed significantly to gains in aBMD accrual in both sexes, being a more important predictor of changes in bone outcomes than ground reaction forces and osteocalcin.
Asunto(s)
Densidad Ósea , Osteocalcina , Deportes , Soporte de Peso , Absorciometría de Fotón , Adolescente , Peso Corporal , Femenino , Humanos , Masculino , Deportes/fisiología , NataciónRESUMEN
To analyze the impact of participation in sports with different cardiorespiratory fitness (CRF) demands on changes in metabolic and cardiovascular markers in adolescents. Longitudinal study with 12 months of follow-up (Analysis of Behaviors of Children During Growth [ABCD Growth Study]). Overall, 184 adolescents (age 15.6 ± 2.1) were classified according to sports participation: non-sport (control), low CRF sports, and high CRF sports. Metabolic outcomes were total cholesterol (TC) and its fractions, triacylglycerol (TG), glucose, insulin levels, and the insulin resistance index. Cardiovascular outcomes were arterial thickness (carotid and femoral [ultrasound]), blood pressure, and resting heart rate. Adolescents engaged in sports classified as high CRF demand presented a significant increase in HDL-c (1.2 mg/dL [95%CI: -0.5 to 3.0]) when compared to the non-sport group (-2.4 mg/dL [95%CI: -4.4 to -0.5]). Regular engagement in high CRF sports was significantly related to changes in TC (ß = -0.027 [95%CI: -0.048 to -0.005]), HDL-c (ß = 0.009 [95%CI: 0.001 to 0.019]), LDL-c (ß = -0.032 [95%CI: -0.049 to -0.016]), and glucose (ß = -0.017 [95%CI: -0.025 to -0.008]), while engagement in low CRF sports was related to changes in TG (ß = -0.065 [95%CI: -0.112 to -0.019]). No significant relationships for cardiovascular parameters were observed in the low CRF group, but one significant relationship was found between high CRF sports and changes in SBP (ß = -0.063 [95%CI: -0.117 to -0.009]). In conclusion, engagement in sports seems to be beneficial for improvements in metabolic and cardiovascular parameters in adolescents, mainly sports with higher CRF demand.
Asunto(s)
Capacidad Cardiovascular , Metaboloma , Deportes/estadística & datos numéricos , Adolescente , Brasil , Niño , Femenino , Humanos , Estudios Longitudinales , Masculino , Deportes/clasificaciónRESUMEN
OBJECTIVES: The aim of the study was to determine which anthropometric indices can best predict the presence of common cardiovascular risk factors among young adults in the rural village of Ellisras in the Limpopo Province, South Africa. METHODS: A total of 624 young adults (306 males and 318 females) aged 18 to 29 years took part in this cross-sectional study. Anthropometrics were measured according to the standard procedures. Blood pressure and blood parameters were collected and measured. The stepwise logistic regression was used to determine anthropometric indices that can predict the presence of common cardiovascular risk factors and a receiver-operating characteristic (ROC) curve was plotted to assess discrimination abilities of anthropometric indices for cardiovascular risk factors. RESULTS: The waist-to-hip ratio (WHR) in multivariable adjusted models was not found to be associated with cardiovascular risk factors compared to body mass index (BMI), waist circumference (WC), and waist-to-height ratio (WHtR). The area below the ROC curve for the abovementioned indices was above 0.62. CONCLUSIONS: The central obesity indices, WC and WHtR, are better predictors of dyslipedemia and hypercholesterolemia, whereas BMI was a better predictor of hypertension among young adults living in rural South Africa between the ages of 18 and 29 years.
Asunto(s)
Antropometría/métodos , Índice de Masa Corporal , Enfermedades Cardiovasculares/epidemiología , Dislipidemias/epidemiología , Hipercolesterolemia/epidemiología , Circunferencia de la Cintura , Relación Cintura-Estatura , Adulto , Estudios Transversales , Femenino , Humanos , Hipertensión/epidemiología , Estudios Longitudinales , Masculino , Factores de Riesgo , Sudáfrica/epidemiología , Adulto JovenRESUMEN
We analyzed the effects of 1 year of engagement in ≥ 300 min/week of organized sports on inflammatory levels and vascular structure in adolescents. The sample was composed of 89 adolescents (11.6 ± 0.7 years old [43 boys and 46 girls]), stratified according to engagement in ≥ 300 min/week of sport practice during at least 12 months of follow-up (n = 15, sport practice; n = 74, non-sport practice). Arterial thickness (carotid and femoral) was assessed by ultrasound scan, while high sensitive C-reactive protein levels were used to assess inflammatory status. Trunk fatness (densitometry scanner), biological maturation (age at peak height velocity), blood pressure, and skipping breakfast were treated as covariates. Independently of body fatness and biological maturation, the group engaged in sports presented a higher reduction in C-reactive protein (mean difference -1.559 mg/L [95%CI -2.539 to -0.579]) than the non-sport group (mean difference -0.414 mg/L [95%CI -0.846 to 0.017]) (p = 0.040). There was a significant relationship between changes in C-reactive protein and changes in femoral intima-media thickness in the non-sport group (r = 0.311 [95%CI 0.026 to 0.549]). CONCLUSION: Inflammation decreased in adolescents engaged in organized sports, independently of trunk fatness and biological maturation. Moreover, inflammation was related to arterial thickening only in adolescents not engaged in sports. What is Known: ⢠Intima media thickness is a relevant marker of cardiovascular disease in pediatric groups, being affected by obesity and inflammation. ⢠The importance of monitoring inflammatory markers from childhood is enhanced by the fact that alterations in these inflammatory markers in early life predict inflammation and alterations in carotid IMT in adulthood. What is New: ⢠Anti-inflammatory properties related to physical exercise performed at moderate intensity, on inflammation and alterations in IMT are not clear in pediatric groups. ⢠Due to the importance that sport participation has assumed as a promoter of improvements in health and quality of life, it is necessary to understand its potential benefits for cardiovascular health during human growth.
Asunto(s)
Proteína C-Reactiva/análisis , Grosor Intima-Media Carotídeo/estadística & datos numéricos , Ejercicio Físico/fisiología , Deportes/fisiología , Tejido Adiposo/fisiopatología , Adolescente , Arterias/fisiopatología , Biomarcadores/análisis , Niño , Densitometría , Femenino , Estudios de Seguimiento , Humanos , Inflamación/fisiopatología , Estilo de Vida , Estudios Longitudinales , Masculino , Factores de RiesgoRESUMEN
PURPOSE: To compare bone mineral density (BMD) gains in adolescents of both genders stratified according to different martial art styles in a 9-month follow-up study. METHODS: The longitudinal study consisted of 29 adolescents of both genders and age between 11 and 17 years stratified into a control group (not engaged in any sport) and 50 fighters (kung fu/karate, n = 29; judo, n = 21). All 79 subjects underwent anthropometric measures (weight, height, leg length, and height set) and dual-energy X-ray absorptiometry (BMD, in g/cm2) at 2 moments, baseline and 9 months later. Maturity offset (age at peak height velocity), lean soft tissue, chronological age, and resistance training were treated as covariates. RESULTS: Male judoists presented higher gains in BMD-spine [0.098 g/cm2 (95% confidence interval, 0.068-0.128)] than control group [0.040 g/cm2 (95% confidence interval, 0.011-0.069)] (post hoc test with P = .030). There was no effect of martial art on BMD gains among girls. Independently of gender, in all multivariate models, lean soft tissue constituted the most relevant covariate. CONCLUSIONS: Judo practice in adolescents affected the bone accrual significantly after 9-month follow-up compared with controls, mainly in boys.
Asunto(s)
Densidad Ósea , Artes Marciales/fisiología , Factores Sexuales , Absorciometría de Fotón , Adolescente , Antropometría , Brasil , Femenino , Estudios de Seguimiento , Humanos , Estudios Longitudinales , MasculinoRESUMEN
The objective of the present study was to investigate the effects of different sports on stress fractures among adolescents during a 9-month follow-up period. The sample was composed of 184 adolescents divided into three groups (impact sports [n = 102]; swimming [n = 35]; non-sports [n = 47]). The occurrence of stress fracture was reported by participants and coaches. As potential confounders we considered age, sex, resistance training, body composition variables and age at peak of height velocity. There were 13 adolescents who reported fractures during the 9-month period. Bone mineral density values were higher in adolescents engaged in impact sports (P-value = 0.002). Independently of confounders, the risk of stress fracture was lower in adolescents engaged in impact sports than in non-active adolescents (hazard ratio [HR] = 0.23 [95% confidence interval (CI) = 0.05 to 0.98]), while swimming practice was not associated to lower risk of fracture (HR = 0.49 [95% CI = 0.09 to 2.55]). In conclusion, the findings from this study indicate the importance of sports participation among adolescents in the reduction of stress fracture risk, especially with impact sports. More importantly, these results could be relevant for recognising adolescents in danger of not reaching their potential for peak bone mass and later an increased risk of fractures.
Asunto(s)
Traumatismos en Atletas/epidemiología , Fracturas por Estrés/epidemiología , Deportes , Adolescente , Factores de Edad , Traumatismos en Atletas/prevención & control , Estatura/fisiología , Densidad Ósea/fisiología , Brasil/epidemiología , Niño , Femenino , Fracturas por Estrés/prevención & control , Humanos , Estudios Longitudinales , Masculino , Prevalencia , Entrenamiento de Fuerza , Factores de RiesgoRESUMEN
OBJECTIVE: The aim of this study was to analyse whether changes in physical activity and body fatness are related to modifications in cardiovascular risk factors among adolescents. Material and methods A sample of 89 healthy adolescents was recruited for this study. We assessed habitual physical activity, body fat percentage, arterial thickness, blood sample, and biological maturation. Multivariate models were used to analyse the relationships between independent and dependent variables. RESULTS: Physical activity (mean difference: 429.4 steps [95% confidence interval=-427 to 1286]) and body fatness (mean difference: -0.7% [95% confidence interval=-1.6-0.2]) remained stable during the study period. Independent of changes in physical activity, for each percentage increase in body fatness, femoral intima-media thickness increased by 0.007 mm (ß=0.007 [95% confidence interval=0.001-0.013]). Longitudinal relationships were found for high-density lipoprotein-cholesterol (ß=-0.477 mg/dl [95% confidence interval=-0.805 to -0.149]) and triacylglycerol (ß=2.329 mg/dl [95% confidence interval=0.275-4.384]). CONCLUSION: Changes in body fatness are more important than the amount of physical activity on cardiovascular and metabolic risks.
Asunto(s)
Tejido Adiposo/fisiopatología , Enfermedades Cardiovasculares/epidemiología , Ejercicio Físico/fisiología , Medición de Riesgo , Tejido Adiposo/diagnóstico por imagen , Adolescente , Índice de Masa Corporal , Brasil/epidemiología , Enfermedades Cardiovasculares/diagnóstico , Enfermedades Cardiovasculares/fisiopatología , Grosor Intima-Media Carotídeo , Niño , Densitometría , Femenino , Humanos , Incidencia , Masculino , Factores de RiesgoRESUMEN
BACKGROUND: Tobacco products use is the leading cause of chronic diseases morbidity and mortality. This study explores an exposure to tobacco advertisements factors and knowledge, an association with snuff/pipe usage and cigarette smoking among Ellisras rural children aged between 11 to 18 years. METHODS: A total of 1654 subjects (854 boys and 800 girls) who were part of the Ellisras Longitudinal Study completed the questionnaire. RESULTS: A significant (p < 0.05) number of boys (11.7%) compared to girls (8.8%) received free cigarettes from the members of the community. Bill boards were successful in advertising tobacco products among the Ellisras rural boys (17% boys and 12.8% for girls, p < 0.022). Multivariate analyses found significant association between cigarette smoking (OR = 1.7 95%CI 1.1-2.7 and Model 2 OR 1.6 95%CI 1.0-2.6 adjusted for age and gender) and advertisements of tobacco products on the TV screens, videos or movies. CONCLUSIONS: Exposure to tobacco products advertisements was high among Ellisras rural children. Though tobacco products legislation exists in South Africa, efforts should be taken by the health professionals to emphasize the danger of using tobacco products even among the illiterate. Teachers and parents should refrain from advertising tobacco products at schools and at homes.
Asunto(s)
Publicidad , Conocimientos, Actitudes y Práctica en Salud , Salud Rural , Fumar , Productos de Tabaco , Adolescente , Niño , Estudios Transversales , Femenino , Humanos , Modelos Logísticos , Estudios Longitudinales , Masculino , Análisis Multivariante , Fumar/economía , Fumar/epidemiología , Fumar/psicología , Sudáfrica/epidemiología , Encuestas y Cuestionarios , Productos de Tabaco/economíaRESUMEN
In the Amsterdam Growth And Health Longitudinal Study (AGAHLS), a group of approximately 650 12- to 14-year-old boys and girls was followed in their growth, and development of their health their lifestyle including diet, physical activity and smoking. One of the main interests was the change in their aerobic fitness. From 12 to 36 years of age in total, eight repeated measurements were performed to measure peak oxygen uptake (peak VO2). In this study the data of peak VO2 are revisited and extended: We made use of all collected data as a mixed longitudinal design including cross-sectionally measured subjects as well as longitudinally measured subjects. This led to the availability of 1,194 boys and 1356 girls. With Generalized Estimating Equations (GEE) the longitudinal changes with chronological age and differences between boys and girls were analyzed. Teenage boys and girls increased their peak VO2 (ml/min) significantly (p < .001) until age 14 in girls and until age 17 in boys. However peak VO2 relative to bodyweight (peak VO2/BW) had significantly (p < .001) decreased over the whole age range from 12 to 36 in both sexes. Vigorous physical activity (VPA) also showed a decrease and was significantly (p < .001) related with lower peak VO2/BW (Beta = 0.001). This relation was stronger in boys than in girls. Because at the start of AGAHLS no fast responding metabolic instruments were available, future longitudinal studies about aerobic fitness should include also measurement of VO2 kinetics.
Asunto(s)
Conductas Relacionadas con la Salud , Consumo de Oxígeno , Aptitud Física , Adolescente , Adulto , Niño , Estudios Transversales , Prueba de Esfuerzo , Femenino , Humanos , Estudios Longitudinales , Masculino , Modelos Estadísticos , Países Bajos , Adulto JovenAsunto(s)
Ejercicio Físico/fisiología , Pediatría/historia , Adolescente , Niño , Preescolar , Historia del Siglo XX , Historia del Siglo XXI , HumanosRESUMEN
Background: Regular sport has favourable influence on the physical and mental state. Our aim was to analyse the relationship between regular sport activities, body parameters, cortisol level, perceived stress and the frequency of psychosomatic symptoms in male and female university students. Methods: Subjects were university students (N = 200). They were divided in sporting (more than 7 h week-1: 56 males (sm), 50 females (sf)) and non-sporting (less than 3 h week-1: 44 males (nsm) and 50 females (nsf)) groups. Body composition was estimated by Inbody720-analyser. Stress levels were measured by (1) free cortisol level in saliva measured by using IBL-ELISA kits and (2) questionnaires about psychosomatic symptoms and perceived stress scale. Results: There were significant subgroup' differences in body composition (fat%:sm:12.1 ± 6.0 vs. nsm:17.9 ± 6.8; sf:20.8 ± 5.5 vs. nsf:25.4 ± 5.7; muscle%:sm:50.3 ± 3.6 vs. nsm:47.6 ± 3.9; sf:43.8 ± 3.2 vs. nsf:41.7 ± 3.3), and in stress level (total scores:sm:21.0 ± 5.7 vs. nsm:23.3 ± 7.2; sf:25.5 ± 7.0 vs. nsf:28.0 ± 9.7). There were gender differences in the psychosomatic symptoms' frequency (total scores: sm: 14.6 ± 6.3 vs. sf: 20.4 ± 7.4; nsm: 14.9 ± 6.1 vs. nsf: 19.6 ± 8.2). The sporting students had larger muscle, smaller fat percentages, and lower level of stress. Basic level of salivary cortisol revealed significant relation with physical activity: sporting students had lower level of cortisol. This relation was reflected in higher percentage of students with low level of cortisol in the physically active subgroups (s/ns males: 29% vs. 15%; s/ns females: 18% vs. 5%) and in the higher percentage of female students with high level of cortisol in the non-sporting subgroup (27% vs. 11%). Conclusion: Regular sport activity is positively related with lower stress levels in university students.
Asunto(s)
Hidrocortisona , Deportes , Femenino , Humanos , Masculino , Saliva/química , Estudiantes , UniversidadesRESUMEN
BACKGROUND: The purpose of our study was to compare the physiological effects of extreme physical and psychological stress tests in male soccer players, since these two types of stress apply to athletes with high performance requirements. METHODS: A total of 63 healthy male soccer players participated in this study, all of whom underwent both of the tests. A physical stress test was carried out in an exercise physiology laboratory, where subjects completed an incremental treadmill running test to full exhaustion, and a psychological test was performed in a military tactical room, where subjects met a street offence situation. Heart rate variability (HRV) and blood pressure (BP) were recorded directly before, immediately after, and 30 min after the stress tests. RESULTS: The majority of HRV indices changed significantly in both stress protocols. Inverse, significant changes (positive for the physical test, negative for the psychological test, p < 0.001) were found when comparing the alterations of HRV indices between the tests. Significant differences were found in the changes in systolic (p = 0.003) and diastolic (p < 0.001) BP between the test protocols, and also between the baseline and post-test measurements (p < 0.001). CONCLUSION: Both HRV and BP are sensitive physiological parameters to measure the impact of extreme physical and/or psychological stress.
Asunto(s)
Carrera , Fútbol , Atletas , Prueba de Esfuerzo/métodos , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Carrera/fisiología , Fútbol/fisiologíaRESUMEN
BACKGROUND: The use of tobacco products is the major cause of chronic diseases morbidity and mortality. Most smokers start the smoking habits from childhood and adolescent stages. METHOD: This was a cross-sectional study. A total of 1654 subjects (854 boys and 800 girls), aged 11 to 18 years, who were part of the Ellisras Longitudinal Study completed the questionnaire. Association between tobacco products use and habits, attitudes and beliefs were explored in this study. Logistic regression was used to estimate the association. RESULTS: The prevalence of tobacco product use increases with increasing (4.9 to 17.1%) age among boys whereas girls do not smoke cigarette but only considerable number (1.0 to 4.1%) use home made tobacco products (pipe and snuff) among the Ellisras rural children. Parents and grand parents play a significant (about 50%) role in influencing smoking behaviour among the Ellisras rural children. Seeing actors smoking on TV shows was positively associated (p < 0.05) with smoking (OR = 2.3 95%CI (1.3-4.1 and OR = 2.3 95%CI 1.3-4.1 after adjusting for age and gender). However, women who smoke cigarette were significantly (p < 0.001) associated with success and success and wealth (OR = 2.8, 95% CI 1.5-5.2) even after adjusting for age and gender (OR = 2.9 95% CI 1.5-5.4). CONCLUSION: The usage of tobacco products was high among older boys. Girls did not smoke cigarette. This tobacco use behaviour mirrors the cultural norms and adult behaviour. The association of this tobacco used products with biological parameters will shed more light on the health of these children over time.
Asunto(s)
Tabaquismo/epidemiología , Logro , Adolescente , Niño , Estudios Transversales , Cultura , Docentes , Familia , Femenino , Amigos , Conocimientos, Actitudes y Práctica en Salud , Humanos , Modelos Logísticos , Estudios Longitudinales , Masculino , Padres , Rol , Población Rural , Distribución por Sexo , Factores Sexuales , Sudáfrica/epidemiología , Televisión , Tabaco sin HumoRESUMEN
BACKGROUND: Continuously rising performances in elite adolescent athletes requires increasing training loads. This training overload without professional monitoring, could lead to overtraining in these adolescents. METHODS: 31 elite adolescent athletes (boys: n = 19, 16 yrs; girls: n = 12, 15 yrs) participated in a field-test which contained a unified warm-up and a 200 m maximal freestyle swimming test. Saliva samples for testosterone (T) in boys, estradiol (E) in girls and cortisol (C) in both genders were collected pre-, post- and 30 min post-exercise. Lactate levels were obtained pre- and post-exercise. Brunel Mood Scale, Perceived Stress Scale and psychosomatic symptoms questionnaires were filled out post-exercise. RESULTS: Lactate levels differed between genders (boys: pre: 1.01 ± 0.26; post: 8.19 ± 3.24; girls: pre: 0.74 ± 0.23; post: 5.83 ± 2.48 mmol/L). C levels increased significantly in boys: pre- vs. post- (p = 0.009), pre- vs. 30 min post-exercise (p = 0.003). The T level (p = 0.0164) and T/C ratio (p = 0.0004) decreased after field test which draws attention to the possibility of overtraining. Maximal and resting heart rates did not differ between genders; however, heart rate recovery did (boys: 29.22 ± 7.4; girls: 40.58 ± 14.50 beats/min; p = 0.008). CONCLUSIONS: Our models can be used to explain the hormonal ratio changes (37.5-89.8%). Based on the results this method can induce hormonal response in elite adolescent athletes and can be used to notice irregularities with repeated measurements.
Asunto(s)
Prueba de Esfuerzo , Natación , Adolescente , Atletas , Femenino , Humanos , Hidrocortisona , Masculino , SalivaRESUMEN
In this review, the career of a pediatric exercise physiologist (HCGK) is given over a period of almost 50 years. His research was concentrated on the relationship of physical activity (physical education, sport, and daily physical activity) with health and fitness in teenagers in secondary schools. (1) His first experiment was an exercise test on a bicycle ergometer to measure aerobic fitness by estimating physical work capacity at a heart rate of 170 beats/minute (PWC170). (2) Secondly, a randomized control trial (RCT) was performed with an intervention of more intensive physical education (PE) with circuit interval training during three lessons per week over a period of six weeks. (3) Thereafter, a second RCT was performed with an intervention of two extra PE lessons per week over a whole school year. The results of these two RCTs appeared to be small or nonsignificant, probably because the effects were confounded by differences in maturation and the habitual physical activity of these teenagers. (4) Therefore, the scope of the research was changed into the direction of a long-term longitudinal study (the Amsterdam Growth And Health Longitudinal Study). This study included male and female teenagers that were followed over many years to get insight into the individual changes in biological factors (growth, fitness, obesity, hypercholesterolemia, and hypertension) and lifestyle parameters such as nutrition, smoking, alcohol usage, and daily physical activity. With the help of new advanced statistical methods (generalized estimating equations, random coefficient analysis, and autoregression analysis) suitable for longitudinal data, research questions regarding repeated measurements, tracking, or stability were answered. New measurement techniques such as mineral bone density by means of dual-energy X-ray absorptiometry (DEXA) showed that bone can also be influenced by short bursts of mechanical load. This changed his mind: In children and adolescents, not only can daily aerobic exercise of at least 30 to 60 minutes duration increase the aerobic power of muscles, but very short highly intensive bursts of less than one minute per day can also increase the strength of their bones.
Asunto(s)
Ejercicio Físico , Aptitud Física , Adolescente , Niño , Femenino , Humanos , Estudios Longitudinales , Masculino , Educación y Entrenamiento Físico , Instituciones AcadémicasRESUMEN
OBJECTIVE: To systematically review the literature to verify the relationship between neuromuscular fitness indicators in childhood/adolescence and bone strength variables in adulthood. DATA SOURCES: A systematic review was conducted in PUBMED, SCOPUS, SPORTDiscus, Web of Science, PsycINFO, LILACS, and SciELO, covering the entire period until March 2019. DATA SYNTHESIS: The search identified 1149 studies. After duplicity analysis and eligibility criteria, four studies were reported. In one study, baseline was childhood and, in the others, adolescence. In childhood, when adjusting the model for age and body mass index, a statistically significant relation was found for girls: standing long jump with quantitative ultrasound index (ß=0.11; p<0.05) and with speed of sound (ß=0.14; p<0.01). However, when controlling muscular performance in adulthood, the relationship was no longer significant. In adolescence, coefficients ranged from 0.16 for neuromotor battery and bone mineral density (BMD) in the lumbar region to 0.38 for hanging leg lift test and BMD of arms. The explained variance varied between 2% (bent arm hang for BMD total) and 12% (hanging leg-lift for BMD arms), therefore, a higher performance in neuromuscular fitness in adolescence was associated with better bone strength in adulthood. CONCLUSIONS: In adults, bone strength variables showed significant correlation from low to moderate magnitude with neuromuscular fitness indicators in adolescence, but not in childhood, after controlling for adult performance in neuromuscular fitness. However, there is limited evidence to support the neuromuscular fitness in early life as a determinant of bone strength in adulthood.
Asunto(s)
Huesos/fisiología , Fuerza Muscular/fisiología , Resistencia Física/fisiología , Adolescente , Factores de Edad , Índice de Masa Corporal , Densidad Ósea/fisiología , Niño , Femenino , Humanos , Masculino , Fenómenos Fisiológicos Musculoesqueléticos , Factores Sexuales , Estrés MecánicoRESUMEN
BACKGROUND: Evidence is lacking on the effects of binge alcohol consumption on metabolic syndrome in the rural South African population. The purpose of this study was to investigate the association between binge drinking and components of metabolic syndrome (MetS) amongst Ellisras rural young adults aged 21 to 31 years who are part of the Ellisras Longitudinal Study. METHODS: Logistic regression analysis was applied to a total of 624 participants (306 males and 318 females) aged 21 to 31 years who took part in the Ellisras Longitudinal Study (ELS). The model was adjusted for covariates, including smoking, age, and gender. Binge alcohol consumption was assessed using a standardised questionnaire that was validated for the Ellisras rural community. A standardised method of determining the components MetS was used after fasting blood samples were collected from all the participants. RESULTS: Binge drinking remained significantly associated with low levels of high-density lipoprotein cholesterol (HDL-C) (OR = 2.64, 95% CI = 1.23-5.65), after being adjusted for smoking, age, and gender. Other MetS components were not predicted. Instead, gender remained significantly associated with all MetS components, except triglycerides, at multivariate analysis. Age retained significance at multivariate analysis with waist girth (OR = 2.13, 95% CI = 1.37-3.34), triglycerides (OR = 2.30, 95% CI = 1.05-5.02), and the MetS composite (OR = 1.65, 95% CI = 1.12-2.41). CONCLUSION: Binge drinking was significantly associated with lower levels of HDL-C. Future studies should investigate the relationship between alcohol abuse and the components of incident MetS in this population.
Asunto(s)
Consumo Excesivo de Bebidas Alcohólicas , Síndrome Metabólico , Adulto , Anciano , Consumo de Bebidas Alcohólicas , Consumo Excesivo de Bebidas Alcohólicas/epidemiología , HDL-Colesterol , Estudios Transversales , Femenino , Humanos , Estudios Longitudinales , Masculino , Síndrome Metabólico/epidemiología , Prevalencia , Factores de Riesgo , Adulto JovenRESUMEN
BACKGROUND: Individuals grow and accumulate central patterns of body fat into the diseases they will suffer from as older adults. The need to elicit the development and tracking of central patterns of body fat from younger age into adolescent remains to be explored. METHOD: Skinfolds measurements were done according to the standard procedures in the Ellisras Longitudinal Growth and Health Study. In total, 2,225 children--550 preschool and 1,675 primary school--aged 3-10 years (birth cohorts 1993 to 1986) were enrolled at baseline in 1996 and followed through out the eight-year periodic surveys. In 2003, 1,771 children--489 preschool and 1,282 primary school--were still in the study. RESULTS: The development of triceps, biceps, suprailiac and suscapular skinfolds of Ellisras girls were significantly higher (p < 0.001 to 0.05) compared to boys over time. The tracking coefficient between the initial measurements and the subsequent measurements was higher for skinfolds (r about 0.63) than for skinfold ratios (r about 0.43). Longitudinal tracking coefficient measuring the association between the initial measurements and all the follow up measurements simultaneously was about 0.57. CONCLUSION: The accumulation of central patterns of body fat of Ellisras children starts in childhood and adolescence spurt with Ellisras girls acquiring more than boys over time. High significant tracking of skinfold thickness while the skinfold ratios show low and insignificant tracking over time. The magnitude of central patterns of body fat accumulation over time requires further investigation to clarify their association with risk factors for cardiovascular diseases.