Training methods to improve vertical jump performance.

AIM: This study aims to review the main methods used to improve vertical jump performance (VJP). METHODS: Although many training routines have been proposed, these can be grouped into four main categories: plyometric training (PT), weight training (WT), whole body vibration training (VT) and electromyostimulation training (ET). PT enhances muscular force, the rate of force development (RFD), muscular power, muscle contraction velocity, cross-sectional area (CSA), muscle stiffness allowing greater storage and release of elastic energy. WT improve muscular force, velocity, power output, and RFD during jumping on a force plate, muscle hypertrophy and neural adaptations. One of the most effective methods to improve VJP is the combination of PT with WT, which takes advantage of the enhancement of maximal dynamic force through WT and the positive effects of PT on speed and force of muscle contraction through its specific effect on type II fibers. RESULTS: Some authors have found an increase in VJP with the use of VT while other did not see such an effect. However, it remains unknown by which mechanisms VT could enhance VJP. ET has been shown to elicit muscle hypertrophy. The VJP may be improved when ET is applied concomitantly with PT or practice of sports. CONCLUSION: In summary, scientific evidence suggests that the best way to improve VJP is through the combination of PT with WT. Further research is needed to establish if better results are possible by more complex strategies.

Effect of previous exhaustive exercise on metabolism and fatigue development during intense exercise in humans.

The present study examined how metabolic response and work capacity are affected by previous exhaustive exercise. Seven subjects performed an exhaustive cycle exercise ( approximately 130%-max; EX2) after warm-up (CON) and 2 min after an exhaustive bout at a very high (VH; approximately 30 s), high (HI; approximately 3 min) or low (LO; approximately 2 h) intensity. Compared with CON, performance during EX2 was reduced (P<0.05) more in HI and LO than in VH (61+/-4% and 68+/-3% vs 35+/-4%). The muscle glycogen before EX2 was lower (P<0.05) in LO than in HI and VH, but the muscle glycogen utilization rates during EX2 were not different. Muscle glycogen concentration before EX2 was related (P<0.05) to the mean rate of muscle glycogen utilization during EX2 in HI and VH, and the mean rate of muscle lactate accumulation in LO. In HI, muscle pH before EX2 was lower (P<0.05) compared with VH and LO, but the same in HI and VH at the end of EX2. In HI, muscle pH before and after EX2 was inversely related (P<0.05) to the decrease in EX2 performance. Thus, muscle glycogen availability and low muscle pH do not per se control but appear to affect the rate of glycogenolysis/glycolysis and fatigue development during a repeated high-intensity exercise lasting 1/2-2 min.

Strength training combined with plyometric jumps in adults: sex differences in fat-bone axis adaptations.

Leptin and osteocalcin play a role in the regulation of the fat-bone axis and may be altered by exercise. To determine whether osteocalcin reduces fat mass in humans fed ad libitum and if there is a sex dimorphism in the serum osteocalcin and leptin responses to strength training, we studied 43 male (age 23.9 2.4 yr, mean +/- SD) and 23 female physical education students (age 23.2 +/- 2.7 yr). Subjects were randomly assigned to two groups: training (TG) and control (CG). TG followed a strength combined with plyometric jumps training program during 9 wk, whereas the CG did not train. Physical fitness, body composition (dual-energy X-ray absorptiometry), and serum concentrations of hormones were determined pre- and posttraining. In the whole group of subjects (pretraining), the serum concentration of osteocalcin was positively correlated (r = 0.29-0.42, P < 0.05) with whole body and regional bone mineral content, lean mass, dynamic strength, and serum-free testosterone concentration (r = 0.32). However, osteocalcin was negatively correlated with leptin concentration (r = -0.37), fat mass (r = -0.31), and the percent body fat (r = -0.44). Both sexes experienced similar relative improvements in performance, lean mass (+4-5%), and whole body (+0.78%) and lumbar spine bone mineral content (+1.2-2%) with training. Serum osteocalcin concentration was increased after training by 45 and 27% in men and women, respectively (P < 0.05). Fat mass was not altered by training. Vastus lateralis type II MHC composition at the start of the training program predicted 25% of the osteocalcin increase after training. Serum leptin concentration was reduced with training in women. In summary, while the relative effects of strength training plus plyometric jumps in performance, muscle hypertrophy, and osteogenesis are similar in men and women, serum leptin concentration is reduced only in women. The osteocalcin response to strength training is, in part, modulated by the muscle phenotype (MHC isoform composition). Despite the increase in osteocalcin, fat mass was not reduced.

Artistic versus rhythmic gymnastics: effects on bone and muscle mass in young girls.

We compared 35 prepubertal girls, 9 artistic gymnasts and 13 rhythmic gymnasts with 13 nonphysically active controls to study the effect of gymnastics on bone and muscle mass. Lean mass, bone mineral content and areal density were measured by dual energy X-ray absorptiometry, and physical fitness was also assessed. The artistic gymnasts showed a delay in pubertal development compared to the other groups (p<0.05). The artistic gymnasts had a 16 and 17 % higher aerobic power and anaerobic capacity, while the rhythmic group had a 14 % higher anaerobic capacity than the controls, respectively (all p<0.05). The artistic gymnasts had higher lean mass (p<0.05) in the whole body and the extremities than both the rhythmic gymnasts and the controls. Body fat mass was 87.5 and 61.5 % higher in the controls than in the artistic and the rhythmic gymnasts (p<0.05). The upper extremity BMD was higher (p<0.05) in the artistic group compared to the other groups. Lean mass strongly correlated with bone mineral content (r=0.84, p<0.001), and multiple regression analysis showed that total lean mass explained 64 % of the variability in whole body bone mineral content, but only 20 % in whole body bone mineral density. Therefore, recreational artistic gymnastic participation is associated with delayed pubertal development, enhanced physical fitness, muscle mass, and bone density in prepubertal girls, eliciting a higher osteogenic stimulus than rhythmic gymnastic.

Serum free testosterone, leptin and soluble leptin receptor changes in a 6-week strength-training programme.

Strength training is usually associated with a reduction in fat mass and with muscle hypertrophy. The aim of the present study was to examine whether the serum free leptin index (FLI), measured by the molar excess of soluble leptin receptor (sOB-R) over leptin, is increased by 6 weeks of strength training. Eighteen male, physical education students were randomly assigned to two groups: a strength-training (n 12) and a control group (n 6). Body composition (lean body mass and body fat) determined by dual-energy X-ray absorptiometry (DXA), muscle performance and leptin, sOB-R, total testosterone and free testosterone concentrations were determined before and after training. Fat mass was reduced by 1 kg with strength training (P<0.05). Lean body mass of trained extremities was increased by 3% (P<0.05), while the concentration of free testosterone in serum was reduced by 17% (P<0.05) after training. However, despite the reduction in fat mass and free testosterone, serum leptin concentration was not significantly affected by strength training, even after accounting for the differences in body fat. By contrast, for a given fat mass, the sOB-R was increased by 13% (P<0.05) at the end of the strength-training programme, although the molar excess of sOB-R over leptin remained unchanged. Therefore, the quantity of free leptin available to bind to the target tissues was not significantly affected by the short strength-training programme, which elicited a 7% reduction in fat mass.

Influence of extracurricular sport activities on body composition and physical fitness in boys: a 3-year longitudinal study.

OBJECTIVE: To analyse the effect of extracurricular physical activities on fat mass accumulation and physical fitness during growth in early pubertal males. DESIGN: Longitudinal study. SUBJECTS: A total of 42 male children (9.4+/-1.4 years, Tanner I-II and 12.7+/-1.5 years, Tanner III-IV, before and after the 3.3 years follow-up, respectively), randomly sampled from the population of Gran Canaria (Spain), 26 of them physically active (PA, at least 3 h per week during 3 years) and 16 non-physically active (non-PA). MEASUREMENTS: Body composition (dual-energy X-ray absorptiometry), anthropometrics (body circumferences and skinfolds) and physical fitness variables (dynamic and isometric force, anaerobic capacity and maximal aerobic power) were determined in all subjects. RESULTS: Both groups had comparable body sizes at the start and the end of the study. Body mass index increased with growth more in the PA than in the non-PA group (P<0.05). However, fat mass accumulation with growth was lower in the PA than in the non-PA (P<0.05). There was a positive relationship between the increment of total and trunkal fat mass, especially in non-active children (r2=0.93). In contrast, there was an inverse relationship between the total lean mass growth and the accumulation of total and regional fat mass (r=-0.37 to -0.41, all P<0.05). Physical fitness was maintained in the PA, while it worsened in the non-PA children. CONCLUSIONS: Without any dietary intervention, children who regularly participate in at least 3 h per week of sports activities are more protected against total and regional fat mass accumulation. They also increase their total lean and bone mass to a greater extent than children who do not participate in extracurricular sport activities. In addition, PA children maintain their physical fitness during growth, while it deteriorates in the non-PA children.

Obesidad y actividad física en niños y jóvenes: revisión bibliográfica / Obesity and physical activity in children and youth: a review

Hasta que los avances en genética permitan detectary manipular los genes implicados en el alarmanteaumento de la prevalencia de obesidad enniños y jóvenes, la única solución realista al problemade la obesidad infantil es la prevención. Intentospor mejorar a un solo nivel o en un solo escenarioel problema serán probablemente insuficientes.La solución pasa por actuar principalmentesobre los dos aspectos fundamentales del balanceenergético: la ingesta y el gasto energético. Portanto, uno de los principales objetivos es tratar demodificar las conductas de los niños, reduciendoel número de horas dedicadas a actividades sedentariasy aumentar los niveles de actividad física.Los datos presentados en esta revisión pretendencolaborar en la determinación de cuales son aquellasintervenciones más eficaces para promover undescenso de la prevalencia de obesidad en niños.Los resultados de los trabajos incluidos demuestranque añadir 3 horas a la semana de prácticadeportiva a aquellas horas que en la actualidadson obligatorias para niños prepúberes en la escuela,permite atenuar la acumulación de masagrasa durante el crecimiento, al tiempo que incrementala ganancia de masa muscular y mejora lacondición física de los niños

Until there is an advancement in gene therapy;detection and manipulation of genes involved inexcess weigh among children, it is only realistic topursue prevention activities. Multidisciplinary approachesin prevention of obesity are necessary forsuccessful outcomes.One of the principal strategies is to modify thechildren’s behaviour involves reducing sedentaryhabits and increasing PA levels. Both these behaviourchanges are part of two major components ofenergy balance: energy expenditure and food intake.Data presented in this review suggests some ofthe most effective interventions to reduce the prevalenceof obesity in children. Adding 3 hours perweek of sport activities to the compulsory physicaleducation courses in prepubertal children seems tobe effective in reducing fat mass accumulation. Italso had an effect on lean mass accretion duringgrowth and improved physical fitness

Muscular development and physical activity as major determinants of femoral bone mass acquisition during growth.

OBJECTIVES: To investigate to what extent bone mass accrual is determined by physical activity and changes in lean, fat, and total body mass during growth. METHODS: Twenty six physically active and 16 age matched control boys were followed up for three years. All subjects were prepubertal at the start of the survey (mean (SEM) age 9.4 (0.3) years). The weekly physical activity of the active boys included compulsory physical education sessions (80-90 minutes a week), three hours a week of extracurricular sports participation, and occasional sports competitions at weekends. The physical activity of the control group was limited to the compulsory physical education curriculum. Bone mineral content (BMC) and areal density (BMD), lean mass, and fat mass were measured by dual energy x ray absorptiometry. RESULTS: The effect of sports participation on femoral bone mass accrual was remarkable. Femoral BMC and BMD increased twice as much in the active group as in the controls over the three year period (p < 0.05). The greatest correlation was found between the increment in femoral bone mass and the increment in lean mass (BMC r = 0.67 and BMD r = 0.69, both p < 0.001). Multiple regression analysis revealed enhancement in lean mass as the best predictor of the increment in femoral bone BMC (R = 0.65) and BMD (R = 0.69). CONCLUSIONS: Long term sports participation during early adolescence results in greater accrual of bone mass. Enhancement of lean mass seems to be the best predictor of this bone mass accumulation. However, for a given muscle mass, a greater level of physical activity is associated with greater bone mass and density in peripubertal boys.

Enhanced bone mass and physical fitness in young female handball players.

This study evaluates the effect of physical activity on the bone content (BMC) and density (BMD) in 51 girls (14.2+/-0.4 yr). Twenty-four were placed in the handball group as they have been playing handball for at least 1 year (3.9+/-0.4). The other 27 who did not perform in any kind of regular physical activity other than that programmed during the compulsory physical education courses comprised the control group. Bone mass and areal density were measured by dual-energy X-ray absorptiometry (DXA). The maximal leg extension isometric force in the squat position with knees bent at 90 degrees and the peak force, mean power, and height jumped during vertical squat jump were assessed with a force plate. Additionally, 30-m run (running speed) and 300-m run (as an estimate of anaerobic capacity) tests were also performed. Maximal aerobic capacity was estimated using the 20-m shuttle-run tests. Compared to the controls, handballers attained better results in the physical fitness tests and had a 6% and 11% higher total body and right upper extremity lean mass (all P<0.05). The handballers showed enhanced BMC and BMD in the lumbar spine, pelvic region, and lower extremity (all P<0.05). They also showed greater BMC in the whole body and enhanced BMD in the right upper extremity and femoral neck than the control subjects (all P<0.05). As expected, total lean mass strongly correlated with total and regional BMC and BMD (r=0.79-0.91 P<0.001). Interestingly, 300-m running speed correlated with BMC and BMD variables (r=0.59-0.67 and r=0.60-0.70, respectively; all P<0.001). Multiple regression analysis showed that the 30-m running speed test, combined with the height and body mass, has also predictive value for whole-body BMC and BMD (R=0.93 and R=0.90, P<0.001). In conclusion, handball participation is associated with improved physical fitness, increased lean and bone masses, and enhanced axial and appendicular BMD in young girls. The combination of anthropometric and fitness-related variables may be used to detect girls with potentially reduced bone mass.

Leptina y ejercicio físico / Leptin and physical activity

No disponible

Leptina y composición corporal / Leptin and body composition

No disponible

Actividad física y masa ósea en niños y niñas prepúberes / Physical activity and bone mass in prepubertal children

No disponible

Fuerza dinámica durante el salto vertical y masa ósea regional en niños prepúberes / Dynamic force during vertical jump and regional bone mass in prepubescent boys

No hay muchos datos sobre los efectos que tiene la actividad deportiva extraescolar en la adquisición de fuerza y masa ósea en niños prepúberes, ni como estas dos variables se relacionan entre sí. Se midió la fuerza generada durante un salto con contramovimiento (CMJ) y además, se determinó mediante DXA el contenido (BMC) y la densidad (BMD) mineral ósea y la masa muscular (MM) de las extremidades inferiores. Las pruebas se realizaron en dos ocasiones separadas 3.25 años. Todas las variables de fuerza se incrementaron con el crecimiento (p<0.05).Como era de esperar el BMC y el BMD medio de las extremidades inferiores también aumentó con el crecimiento. Por otra parte se encontró una fuerte correlación entre variables de fuerza, la MM y masa ósea. En conclusión, realizar al menos 3 horas a la semana de actividad deportiva extraescolar no se asocia con una mejora significativa de la capacidad de salto en niños prepúberes. Por otra parte, hay una relación muy estrecha entre la masa ósea (BMC y BMD) y la masa muscular, así como con el impulso mecánico positivo durante la ejecución máxima de un salto con contramovimiento independientemente del grado de actividad física que se realice (AU)

Genetic heterogeneity of benign thyroid lesions. Static and flow cytometry, karyotyping and in situ hybridization analysis.

The present series includes 75 thyroid lesions (38 goiters, 30 adenomas, 3 follicullo-papillary encapsulated carcinomas and 4 normal thyroid) that were studied by static and flow cytometry. Four cases were also analyzed by in situ hybridization (centromeric probes for chromosomes 1 and 17) and 10 cases by G-banding cytogenetics. Results demonstrate a polymorphism and genetic instability in the thyroid tissue that may be related to the spontaneous polyploidization of their cells. The most consistent finding in cytometry was the presence of two clones associated with clinical or histological hyperactivity (46% versus 23% in non-functioning cases; chi2 distribution with a p < 0.05). Chromosomal anomalies were detected in two out of 10 cases: 46, XX, t(5,19) in 87% of cells of a diffuse hyperplastic goiter and 49, XX, +7, +17, +22 in 19% of cells of thyroiditis case. Finally, the in situ hybridization technique showed hidden trisomies of clonal origin in all of the cases studied. Evaluation of clonal trisomies by the in situ hybridization technique using the confidence interval of a binomial distribution is discussed.

Chromatin texture from hematoxylin stained thyroid lesions.

Quantitative aspects of cytology and histology should be considered in diagnostic standardisation processes. The present paper summarises the cytological differences detected in 75 thyroid lesions using a computerized textural analysis. Cells stained with progressive hematoxylin and taken from paraffin blocks were overlaid with the extracted texture. This technique was based on the lineal detection of a grey level gradient of the common logarithm of the integrated optical density (IOD) of each nucleus. Diffuse and nodular goiters (36 cases) were demonstrated to be composed of small cells containing high density texture that, on microscopical visual inspection, gave a "salt and pepper" appearance. The adenomatous goiters (2 cases) and adenomas (26 cases) were composed of low texture cells with a visual "blurry or smudgy" chromatin, while the atypical adenomas with capsular invasion (4 cases) were characterised by a "woodworm" nuclear appearance that produced the highest texture of the series. Finally, encapsulated folliculo-papillary carcinomas (3 cases) were composed of large clear nuclei with high IOD, low texture, and scattered lines that resulted in an "empty grape skin" aspect. Our findings seam to confirm the suitability of computerized textural techniques that aid in recognizing cell microscopic features objectively. The one used in the present work, based on a mathematical function of the DNA content of each individual nucleus (IOD), fulfills all microscopy detection criteria.

Translocation (5;19)(q13;q13) in a multinodular thyroid goiter.

We describe the cytogenetics of a multinodular thyroid goiter where 90% of the analyzed cells showed a diploid karyotype with a balanced translocation between chromosomes 5 and 19: 46,XX,t(5;19)(q13;q13). This translocation has been previously described in cases of thyroid adenoma. Our case is the first report of this anomaly in nodular hyperplasia. We discuss its putative role in the neoplastic transformation of thyroid lesions.

[Cognitive deterioration and dementias in an urban geriatric population]. / Deterioro cognitivo y demencias en una población geriátrica urbana.

OBJECTIVE: To find the extent of cognitive deterioration and dementias and their approximate etiology, in Pamplona's geriatric population. DESIGN: Crossover study. SITE. Pamplona's geriatric population. PATIENTS AND OTHERS PARTICIPANTS: Sample of 393 people over 64, drawn in random fashion from among the population of this age Pamplona. Ordered according to sex and age group. MAIN MEASUREMENTS AND RESULTS: The diagnostic sequence followed for the evaluation of the level of cognitive deterioration was that of Folstein's Minimental test; then the DSM-111 criteria for diagnosing dementia; and the attempt to define dementias by means of the Hachinski scale. Scores lower than 24 were observed in 24.9% of old people, reaching 82.8% in those over 84. Dementia affected 8.9% of people older than 64, and as many as 55.2% of those over 84. The aetiology of these dementias is, according to the Hachinski scale, parenchymatous in 42.8% of cases, mixed or doubtful in another 42.8% and vascular in 14.4%. Both the low educational level of those patients suffering dementia and their serious functional deterioration were notable. CONCLUSIONS: A high level of dementias exists in our elderly population. A big percentage of these are overlooked as concrete clinical phenomena, although their formal diagnosis at the Primary Care stage is relatively simple and extremely useful in order to tackle the earliest and most treatable cases.

[Voluntary acute drug poisoning in the health unit Navarra I, in 1989. Descriptive epidemiologic study]. / "Intoxicaciones medicamentosas agudas voluntarias--IMAV--en el área sanitaria Navarra I, durante 1989. Estudio epidemiológico descriptivo".

Acute voluntary medicinal intoxications (AVMI) constitute a serious social-medical problem, frequently related to other problems, such as drug addiction and psychopathies. By means of a prospective study of AVMI cases seen in 1989 by the Emergency Room of Internal Medicine in our Hospital, and for persons over the age of 13 in the Health Area Navarra I, we can conclude that there is an incidence of 70.4/100,000 inhabitants, with a relative and absolute majority of females and of residents in urban areas. One third of cases had psychopathological case histories, while another third have a prior history of drug and/or alcohol abuse. The majority of patients are under 30. The peristaltic data seem to have only a tenuous relationship to the onset of AVMI, which mainly occurs at night. In 85% of cases, we are able to determine the causing factor. Psychopharmaceuticals are present in more than 60% of autolytic cases, the highest frequency belonging to benzodiazepines. In our environment, there is a high percentage of admittances despite the fact that a positive outcome is reached in virtually all cases: only 1 exitus out of 103 cases.