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1.
The purpose of the study was to determine the specificity of the development and training of coordination skills (CSs) in 11- to 19-year-old soccer players (n = 600). Tests for soccer players’ CSs and technical skills and one- and two-year training experiments on targeted development of CSs were used. It was found that the period from 11 to 13 years of age was the most favorable for the development of CSs in soccer players, and the period from 14 to 16 years of age was the next most favorable. The use of special coordination training aimed at development of individual CSs led to a greater improvement, with the CS and technical skill parameters of athletes from the experimental groups being significantly higher (by 2.5–38.3 and 3.6–12.2%, respectively) than those of athletes from the control groups developing CSs by the traditional method using dexterity exercises.  相似文献   

2.
50 sedentary males and 128 sports persons (volleyball=82, soccer=46) of 20-24 years were selected from West Bengal, India, to evaluate and compare their anthropometry and body composition. Skinfolds, girth measurements, body fat percentage (%fat), and endomorphy were significantly higher among sedentary individuals, but lean body mass (LBM) and mesomorphy were significantly (p<0.001) higher among the sports persons. Soccer and volleyball players were found to be ectomorphic mesomorph, whereas sedentary subjects were endomorphic mesomorph. The soccer and volleyball players had higher %fat with lower body height and body mass than their overseas counterparts. %fat exhibited a significant correlation with body mass index (BMI) and thus prediction equations for %fat from BMI were computed in each group. The present data will serve as a reference standard for the anthropometry and body composition of Indian soccer and volleyball players and the prediction norms for %fat will help to provide a first-hand impression of body composition in the studied population.  相似文献   

3.
In the present study, we attempted to clarify the effects of lifestyle and body compositions on basal metabolism and to clarify the effects of physical training on thermoregulatory responses to cold. Basal metabolism, body compositions, and questionnaires regarding lifestyle were evaluated in 37 students. From multiple linear regression analysis, sex, muscle weight, fat intake, and diurnal temperature were selected as significant explanatory variables. In a second experiment, rectal and the skin temperature at 7 different points as well as the oxygen uptake of eight males were measured at 10 degrees C for 90 min before and after training. The decline in rectal temperature that was observed before training was not observed after training. In addition, rectal temperature was significantly higher at post-training than at pre-training. These results suggest that some lifestyle factors affect cold tolerance; in particular, daily activity might improve our ability to control heat radiation and basal heat production.  相似文献   

4.
In the course of an intense weightlifting training of young athletes the change characteristics of the first phase was an increase in lean body mass, while in the second phase it was the improvement of motor abilities. Obviously, the improvement of weightlifting performance took place at a pace matching motor conduction development. The influence to be drawn concerning training methodology is that at least a half or one whole year of conditioning is necessary to create the somatic and functional preconditions of a possibly correct execution of the weightlifting technique. This finding warns against encouraging to take in competitions at an early age as well as against employing great weights in training, because both of these are likely to severely disturb outlined healthy sequence of morphological and functional development.  相似文献   

5.
The number of sedentary young adults has dramatically increased in past decades, and sedentary lifestyles are adopted at an increasingly earlier age. Little is known about barriers or predictors to (re)initiate regular physical activity in this group. The purpose of the study is to (a) identify subgroups in nonathletes differing in their amenability to physical exercise, (b) to analyze them for differences in barriers and intention to exercise, and (c) compare importance of sports during youth in nonathletes to trained peers. Using a health and fitness questionnaire 589 nonathletes were queried in the cross-sectional survey and compared with 270 trained peers. Athletic abstainers (A), lower (L), and higher (H) motivated nonathletes were separated based on previous engagement in sports. Of the nonathletes, 54.7% reported only 1 barrier to exercise. Although this feature was most prominent in H (71.5%), the other groups showed significantly more barriers and a broader distribution. Similar characteristics but minor differences were observed for perceived importance of sports during youth. The most significant differences between athletes and nonathletes emerged enquiring the attitude and activity of the parents. The majority of nonathletes (72.8%) indicate their intention to exercise in the future. Their intention differed significantly in H (88.1%), L (76.1%), and A (59.1%). However, there are good reasons to doubt that most of those intending nonathletes will actually become physically active. Even in the analyzed narrow age range of men different motivated groups of nonathletes were found. Because of the differences in receptiveness and approachability health promotion policies may not only consider the often recommended tailored interventions but also carefully designed incentive programs.  相似文献   

6.
We investigated the relationship between IGF-I, gender, height, weight, body composition and birth size in 260 healthy 7- and 8-year-old children (139 females). All children were born term at Nepean Hospital, Western Sydney. Body composition was measured using dual energy X-ray absorptiometry. IGF-I levels were determined by radioimmunoassay. Girls had higher IGF-I levels than boys (20.2 +/- 6.5 nmol/l compared to 15.9 +/- 6.1 nmol/l, p < 0.001) but there was no correlation between age and IGF-I. IGF-I was positively correlated with height SDS (R(2) = 0.12), weight SDS (R(2) = 0.19), BMI SDS (R(2) = 0.18), total body fat (%) (R(2) = 0.14), and fat-free tissue/cm (R(2) = 0.03). After adjusting for gender and current weight, IGF-I-levels were inversely related to birth size - children with the lowest birth size and heaviest current weight had the highest IGF-I levels. This correlation between birth weight and IGF-I supports the hypothesis that the IGF-I axis is altered in babies who are small for gestational age.  相似文献   

7.
The aim of the study was to investigate the relationships between specific anthropometric (9 skinfolds, 13 girths, 8 lengths and 8 breadths), body composition (body fat %, fat free mass [FFM], fat mass [FM]) parameters and bone mineral parameters (bone mineral density [BMD], bone mineral content [BMC) in young rhythmic gymnasts and same age controls. Eighty nine 7-8-year-old girls participated in this study and were divided to the rhythmic gymnast's (n = 46) and control (n = 43) groups. Body composition was determined by dual energy X-ray absorptiometry (FFM, FM, body fat %, BMD and BMC). Body fat % and FM were lower and BMD and BMC values at lumbar spine (L2-L4) and femoral neck were higher in rhythmic gymnasts compared with controls. All measured skinfold thicknesses were thicker in controls. In girths, lengths and widths there were only few significant differences between the groups. Stepwise multiple regression analysis indicated that skinfold thicknesses (supraspinale and medial calf) influenced L2-L4 BMD only in controls 38.2% (R2x100). Supraspinale and iliac crest skinfold thicknesses characterised L2-L4 BMC 43.9% (R2x100). Calf girths influenced BMD in L2-L4 52.3% (R2x100) in controls. BMC in L2-L4 was dependent only on mid-thigh girths 35.9% (R2x100). BMD in L2-L4 was dependent on tibiale-laterale height 30.0% (R2x100). Biiliocristal breadths together with sitting height characterised BMC in L2-L4 BMD 62.3% (R2x100). In conclusion, we found that the relationships between anthropometry, body composition and bone parameters in young rhythmic gymnasts are weak. In control group first of all lower body anthropometric parameters significantly correlated with BMD and BMC in spine.  相似文献   

8.
Prior to hibernation, mammals accumulate large amounts of fat in their bodies. In temperate mammalian species, hibernation is improved by increasing the levels of poly-unsaturated fatty acids (PUFA) in the body. The saturation of fatty acids (FA) in both white adipose tissue (WAT) and membrane phospholipids of mammals often reflects their diet composition. We found that the greater mouse-tailed bat (Rhinopoma microphyllum) accumulates large amounts of fat at the end of summer by gradually shifting to a fat-rich diet (queen carpenter ants, Camponotus felah). PUFA are almost absent in this diet (<1 % of total FA), which contains a high fraction of saturated (SFA) and mono-unsaturated (MUFA) fatty acids. We found similar low levels of PUFA in mouse-tailed bat WAT, but not in their heart total lipids. The expression of two appetite-stimulating (orexigenic) hypothalamic neuropeptides, AgRP and NPY, increased in parallel to the shift in diet and with fat gain in these bats. To the best of our knowledge, this is the only documented example of specific pre-hibernation diet in bats, and one which reveals the most saturated FA composition ever documented in a mammal. We suggest that the increase in expression levels of NPY and AgRP may contribute to the observed diet shift and mass gain, and that the FA composition of the bat’s specialized diet is adaptive in the relatively high temperatures we recorded in both their winter and summer roosts.  相似文献   

9.
Considering membranes and membrane components as possible pacemakers of the main processes taking place inside mitochondria, changes in phospholipids or fatty acids could play a central role linking different mechanisms involved in cumulative damage to cell molecules and dysfunction during periods of high stress, such as rapid growth and aging. Changes affecting either lipid class or fatty acid compositions could affect phospholipid and membrane properties and alter mitochondrial function and cell viability. In the present study, mitochondrial oxidative status and mitochondrial membrane phospholipid compositions were analyzed throughout the life-cycle of zebrafish. TBARS content significantly increased in 18-month-old fish while aconitase activity decreased in 24-month-old fish, which have been related with oxidative damage to molecules. Mitochondria-specific superoxide dismutase decreased in 24-month-old animals although this change was not statistically significant. Age affected both mitochondrial phospholipid content and the peroxidation index of most phospholipid classes suggesting that oxidative damage to mitochondrial lipids was occurring.  相似文献   

10.
11.
In this 12-month RCT, we examined whether aerobic impact exercise training (3x/week) could facilitate breast cancer survivors' recovery by enhancing their bone structural strength, physical performance and body composition. After the adjuvant chemo- and/ or radiotherapy, 86 patients were randomly assigned into the training or control group. Structural bone traits were assessed with pQCT at the tibia and with DXA at the femoral neck. Agility (figure-8 running), jump force and power (force platform), grip strength and cardiovascular fitness (2-km walk test) were also assessed. Training effects on outcome variables were estimated by two-way factorial ANCOVA using the study group and menopausal status as fixed factors. Bone structural strength was better maintained among the trainees. At the femoral neck, there was a small but significant 2% training effect in the bone mass distribution (p=0.05). At the tibial diaphysis, slight 1% to 2% training effects (p=0.03) in total cross-sectional area and bone structural strength were observed (p=0.03) among the postmenopausal trainees. Also, 3% to 4% training effects were observed in the figure-8 running time (p=0.03) and grip strength (p=0.01). In conclusion, vigorous aerobic impact exercise training has potential to maintain bone structural strength and improve physical performance among breast cancer survivors.  相似文献   

12.
13.
Changes in body composition were studied in three groups of young adult female rats; the treatments were (1) ad libitum food intake to obtain normal growth, (2) restricted food intake to cause body weight loss, and (3) restricted followed by ad libitum food intake to obtain recovery of lost body weight. In each of the three groups of rats the percentage body water was linearly and negatively correlated with the percentage body fat, the weight of body water was linearly and positively correlated with the weight of body protein, and the ratio of the weight of body protein to water was relatively constant at 1:3.20 +/- 0.02 (mean +/- standard error). The percentage body water in the fat-free body was linearly and negatively correlated with fat-free body weight during normal growth between 109 and 334 g body weight but positively correlated during body weight loss and recovery. During recovery of body weight rats laid down more fat and less protein than during normal growth through the same body weight range and the percentage of digestible energy retained as body tissue was increased.  相似文献   

14.
15.
During lactation, female small mammals frequently reduce their fat reserves to very low levels. The function of this reduction is unclear, as calculations suggest that the contribution of the withdrawn energy from fat to the total energy balance of lactation is trivial. An alternative hypothesis is that reducing fat leads to a reduction in circulating adipokines, such as leptin, that play a role in stimulating the hyperphagia of lactation. We investigated the role of circulating leptin in lactation by repleting leptin levels using miniosmotic pumps during the last 7 days of lactation in Brandt's voles (Lasiopodomys brandtii), a model small wild mammal we have extensively studied in the context of lactation energy demands. Repletion of leptin resulted in a dose-dependent reduction of body mass and food intake in lactating voles. Comparisons to nonreproducing individuals suggests that the reduced leptin in lactation, due to reduced fat stores, may account for ~16% of the lactational hyperphagia. Reduced leptin in lactation may, in part, cause lactational hyperphagia via stimulatory effects on hypothalamic orexigenic neuropeptides (neuropeptide Y and agouti-related peptide) and inhibition of the anorexigenic neuropeptide (proopiomelanocortin). These effects were reversed by the experimental repletion of leptin. There was no significant effect of leptin treatment on daily energy expenditure, milk production or pup growth, but leptin repletion did result in a reversal of the suppression of uncoupling protein-1 levels in brown adipose tissue, indicating an additional role for reducing body fat and leptin during peak lacation.  相似文献   

16.
(1)Protein synthesis and content have been studied in skeletal muscle, liver, foetuses and placentas of pregnant rats given a protein-deficient diet. Changes which occurred during the anabolic and subsequent catabolic phases of pregnancy are compared with those in well-fed pregnant and in protein-deficient non-pregnant rats. (2) The normal increase in liver protein did not occur during pregnancy in the protein-deficient group. (3) Protein deficiency affected protein content of the placenta earlier and more severely than that of the foetus. (4) Rates of protein synthesis in liver, placentas and foetuses were enhanced above control values by protein deficiency. (5)_Muscle protein increased normally during the anabolic phase of pregnancy but fell during the catabolic phase, unlike values for weel-fed animals. (6) Muscle protein synthesis rates rose by similar amounts in well-fed and protein-deficient animals during the anabolic phase of pregnancy. The fall to starting values during the catabolic phase was sharper and earlier in protein-deficient animals, which could reduce demands on the body amino acid pool by an amount equivalent to over 50% of the needs for protein deposition in foetuses and placentas. Thus, changes in muscle protein synthesis in both anabolic and catabolic phases of pregnancy may afford some protection to foetal protein synthesis.  相似文献   

17.
Insulin-like growth factor (IGF)-I is a biomarker that may have greater utility than other conventional nutritional biomarkers in assessing nutritional, health, and fitness status. We hypothesized that the IGF-I system would directionally track a short-term energy deficit and would be more related to changes in body composition than other nutritional biomarkers. Thirty-five healthy men (24 +/- 0.3 yr) underwent 8 days of exercise and energy imbalance. Total and free IGF-I, IGF binding proteins-1, -2, and -3, the acid labile subunit, transferrin, ferritin, retinol binding protein, prealbumin, testosterone, triiodothyronine, thyroxine, and leptin responses were measured. Dual-energy X-ray absorptiometry assessed changes in body mass and composition. Repeated-measures ANOVA, correlation analysis, and receiver operator characteristic curves were used for statistical analyses (P < or = 0.05). Body mass (-3.8%), fat-free mass (-2.2%), and fat mass (-12.9%) all decreased. Total and free IGF-I, IGF binding protein-3, and the acid labile subunit and prealbumin, but not transferrin, retinol-binding protein, and ferritin, directionally tracked the energy deficit and losses in body composition. The correlation (r = 0.43) between changes in free IGF-I and body and fat-free mass was the only significant association observed. Receiver operator characteristic curve analysis revealed that a baseline value < 1.67 for the molar volume ratio of IGF-I to acid labile subunit had an area under the curve of 0.745 and was a significant discriminator for those subjects losing >5% body mass. The IGF-I system is an important adjunct in the overall assessment of adaptation to stress imposed by high levels of physical activity superimposed on energy and sleep restriction and is more closely associated with losses in body mass and fat-free mass than other conventional nutritional biomarkers.  相似文献   

18.
On the basis of the known amino acid sequence of statherin, a human salivary protein, mixed synthetic oligonucleotides were synthesized and used to screen a cDNA library constructed from human parotid-gland mRNA. A cDNA clone coding for statherin was isolated from this library and has been completely sequenced. The cDNA represents a full-length (or nearly full-length) copy of an approximately 640-bp statherin mRNA. Statherin appears to be coded by a single-copy gene that maps to chromosome 4q11-4q13 when somatic-cell hybrids are used.  相似文献   

19.
The objective of this study was to examine the effects of the antioxidant alpha-lipoic acid (ALP) versus a medium chain triglyceride oil mixture (MCTo), which was designed to increase energy expenditure and to improve lipid profiles containing medium chain triglycerides, phytosterols, and omega-3 fatty acids in the form of flaxseed oil. A total of 48 hamsters were fed a) hypercholesterolemic (HC) control, b) HC MCTo, c) HC ALP, or d) HC MCTo/ALP diet for 4 weeks. No differences were observed on food intake, body weight, total body water, lean and fat mass, and tissue thiobarbituric acid reactive substances (TBARS). ALP alone had no effect on total cholesterol (TC); however, MCTo feeding increased TC with (P < 0.03) and without (P < 0.003) ALP when compared with control. ALP increased HDL levels compared with control (P < 0.04) and MCTo/ALP (P < 0.007) groups. MCTo, with (P < 0.0001) or without (P < 0.006) ALP, increased non-HDL cholesterol levels versus control. The non-HDL:HDL cholesterol ratio was decreased by ALP compared with MCTo (45%) and MCTo/ALP (68%) (P < 0.0001), a similar trend was seen when compared with the HC control (22%) group (P < 0.14). Triglyceride levels were not altered by any dietary treatment. Liver and heart tissue reduced glutathione (GSH) was increased (P < 0.05) by all three treatments when compared with control. Both tissues showed an increase (P < 0.05) in oxidized glutathione (GSSG) when fed ALP as compared with other treatments. Hamsters fed ALP had a lower (P < 0.05) GSH/GSSG ratio compared with other treatment groups. In conclusion, MCTo feeding does not elicit beneficial effects on circulating plasma lipids and measures of body composition. In addition, our results do not clearly support an improvement in oxidative status through supplementation of ALP. However, our results do support the existence of beneficial effects of ALP on circulating lipoprotein content in the hamster.  相似文献   

20.
AIM: To study the effects of growth hormone (GH) deficiency (GHD) and GH replacement therapy (GHRx) on bone mineral density (BMD) and body composition. METHODS: 59 GHD children participated (age range 0.4-16.9 years); the follow-up period was 6 years. Lumbar spine BMD (BMD(LS)), total-body BMD (BMD(TB)), and body composition were measured prospectively using dual-energy X-ray absorptiometry. RESULTS: Mean BMD(LS )and BMD(TB) were significantly reduced at the time of the diagnosis. The bone mineral apparent density of the lumbar spine (BMAD(LS)) was reduced to a lesser degree. The BMAD(LS) increased to normal values after 1 year; BMD(LS) and BMD(TB) normalized 1 year later. At the time of the diagnosis, the lean body mass was reduced and steadily increased during GHRx. Percentage of body fat was increased at baseline and normalized within 6 months. The severity of GHD was not associated with the BMD at diagnosis or the response to GHRx. CONCLUSION: Areal BMD(LS) and BMD(TB) and, to a lesser extent, BMAD(LS) are decreased in GHD children, but normalize within 1-2 years.  相似文献   

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