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1.
The resting energy expenditure (REE) of 43 men and 41 nonpregnant women aged 18–42, of the Iban tribe in rural Sarawak, was measured using the Oxylog and analyzed in relation to fat mass (FM) and fat-free mass (FFM) derived from measurements of skinfold thickness, to estimates of the specific energy expenditure of the FFM, and to microclimatic variables. Measured REEs exceeded values predicted from FFM by 9–22%, but were consistent with the metabolic rates expected of Western adolescents of comparable body size and composition. In both sexes, body fat content significantly influenced REE after accounting for nonlinear effects of variation in FFM. This is consistent with reported high adipocyte metabolic rates in obese Westerners, and with the hypothesis that Iban may possess a relatively large capacity for fat mobilization and storage. Therefore, in some populations, terms representing both FM and FFM should be included in equations describing REE. These findings are consistent with postulated evolutionary advantages of efficiency in regulation of energy turnover. © 1993 Wiley-Liss, Inc.  相似文献   

2.
The aim of this study was to examine the changes and relationships of immune and stress parameters of basketball players during a basketball season. Eight members of National Taichung University basketball team volunteered to participate. Saliva samples were collected at rest and before the start of practice or competition at seven time points during the intense training, competition and recovery period. Salivary immunoglobulin A (sIgA), cortisol, and lactoferrin were measured during training and competition period and compared with those measured at the fourth recovery week. Relationships among immune and stress parameters were evaluated. Compared with those detected at the fourth recovery week, significant decreases in secretion rates and absolute concentrations of sIgA and lactoferrin were observed at times of intense training and competition. In addition, significant increases in secretion rates and absolute concentrations of salivary cortisol were observed during intense training and competition period and the first week of recovery. Moreover, a significant inverse correlation (r = −0.28; P < 0.05) that existed between secretion rates of sIgA and cortisol as well as a positive correlation (r = 0.32; P < 0.05) that existed between secretion rates of sIgA and lactoferrin was measured. Our results demonstrated that the secreted cortisol was induced and the mucosal immunity of the participants was suppressed during the basketball season. The inverse correlation existed between secretion rates of sIgA and cortisol may indicate a possible role of cortisol in the strenuous exercise-induced immunosuppression. Our results also suggest that a delicate balance may exist between mucosal innate and adaptive immune responses.  相似文献   

3.
Immune changes and increased susceptibility to infection are often reported in elite athletes. Infectious episodes can often impair training and performance with consequences for health and sporting success. This study monitored the occurrence of episodes of upper respiratory symptoms (URS) and the variation in circulating NK cells, CD56bright and CD56dim NK cells subpopulations, over a winter swimming season. Nineteen national elite swimmers and 11 non-athlete controls participated in this study. URS episodes were monitored using daily log books. Blood samples were taken at rest at four time points during the season: before the start of the season (t1—middle September), after 7 weeks of an initial period of gradually increasing training load (t2—early November), after 6 weeks of an intense training cycle (t3—late February) and 48 h after the main competition (t4—early April) and from the controls at three similar time points (t1—early November; t2—late February; t3—early April). In the swimmers, the occurrence of URS clustered around the periods of elevated training load (67 %). No URS were reported at equivalent time points in the non-athletes. Athletes showed a decrease in the percentage (t2 = 21 %; t3 = 27 %; t4 = 17 %) and absolute counts of circulating NK cells (t2 = 35 %; t3 = 22 %; t4 = 22 %), coinciding with the periods of increased training load, never recovering to the initial values observed at the start of the season. The reduction in the CD56dim and an increase in the CD56bright NK cell subpopulations were significant at t2 and t3 (p < 0.05). Concomitant with the fall in values of NK cells, in athletes that shown more than three URS episodes, a moderate correlation (r = 0.493; p = 0.036) was found between CD56bright/CD56dim ratio and the number of URS episodes after the more demanding training phase (t3). At t3, a lower value of CD56 cell counts was found in the group who reported three or more URS episodes (t = 2.239; p = 0.032). A progressive significant decrease in the expression of CD119, the receptor for IFN-γ, on the CD56dim cells was found over the season and an elevation in Granzyme B expression was coincident with the more demanding training phases. Periods of highly demanding training seem to have a negative impact on innate immunity mediated by NK cell subsets, which could partially explain the higher frequency of URS observed during these training phases.  相似文献   

4.
OBJECTIVE: The menopause transition is characterized by luteal phase defect anovulatory cycles, and changes in body weight and body composition. Resting metabolic rate (RMR) is increased in the luteal phase of the menstrual cycle. We evaluated whether progestin administration increases RMR and influences body composition of perimenopausal women. DESIGN: Thirty-six perimenopausal women were randomly allocated to receive either calcium (1 g/day) continuously plus the progestin nomegestrol acetate (NOMAc; 5 mg/day for 10 days x month for 12 months) or calcium alone. Body composition, RMR, energy intake, and climacteric and psychological symptoms were evaluated at baseline and after 12 months. In the NOMAc group, body composition and RMR analyses were performed twice during the first month of treatment. One evaluation was performed after almost 8 days of NOMAc adjunct, and an another before or almost 15 days after NOMAc administration. RESULTS: Resting metabolic rate was increased by NOMAc administration of 54.5 +/- 73.8 kcal/24 h (P < 0.01). In women treated with NOMAc, fat mass decreased by 1.2 +/- 0.6 kg (P < 0.001). In comparison with controls, body weight (P < 0.05) and body mass index (P < 0.05) were also reduced after 12 months of therapy with NOMAc. CONCLUSIONS: In perimenopausal women the use of NOMAc increases RMR. During the menopause transition, cyclic NOMAc administration may contribute to reduce negative modification of body composition.  相似文献   

5.
Magnesium plays significant roles in promoting strength. Surveys of athletes reveal that intake of magnesium is often below recommended levels. We aimed to understand the impact of magnesium intake on strength in elite male basketball, handball, and volleyball players. Energy and nutrient intake were assessed from seven-day diet record. Strength tests included maximal isometric trunk flexion, extension, and rotation, handgrip, squat and countermovement Abalakov jump, and maximal isokinetic knee extension and flexion peak torques. Linear regression models were performed with significance at p<0.1. Mean magnesium intake was significantly lower than the recommended daily allowance. Regression analysis indicated that magnesium was directly associated with maximal isometric trunk flexion, rotation, and handgrip, with jumping performance tests, and with all isokinetic strength variables, independent of total energy intake. The observed associations between magnesium intake and muscle strength performance may result from the important role of magnesium in energetic metabolism, transmembrane transport and muscle contraction and relaxation.  相似文献   

6.
Lactation is the most energetically demanding part of human reproduction; yet, compared with pregnancy, we know little about the strategies women in different settings employ to cope with these increased energy demands. This paper takes a biocultural approach and reports longitudinal data on the anthropometry, dietary intakes and energy expenditure of a sample of 23 rural, lactating Ribeirinha women living in subsistence-based communities in the eastern Amazon. The dietary intakes of these lactating women were insufficient to meet their lactating energy needs and were least sufficient during resguardo, a 40-day period in the immediate postpartum when the women observed a series of food taboos and work restrictions. Instead, the women in this study met the increased energy demands of lactation by drawing on their energy reserves and reducing their energy expenditure in physical activity. The women showed a significant reduction in weight (P<0.001), BMI (P<0.001) and in circumferences (hip, P=0.01; waist, P=0.03) and skinfolds (thigh, P=0.03) in the gluteal femoral region. Total daily energy expenditure (TDEE) was lowest during resguardo and increased as lactation progressed (P=0.01). While the practice of resguardo reduced maternal energy expenditure and allowed women more time to spend with their newborn infants, it came at a cost (low dietary intake), which appears to be related to the loss of the adult woman from subsistence activities. By taking a biocultural approach this study illustrates the role the social environment plays in shaping the experience of lactating women.  相似文献   

7.
背景:女性绝经后雌激素水平下降、年龄增长、活动水平下降都可能引起静息能量消耗的降低,进而引起绝经后女性体成分变化,导致疾病,如肥胖、骨折。 目的:观察绝经前、围绝经期、绝经后妇女体成分及静息代谢率的变化。 方法:收集门诊就诊的2 312例妇女,其中绝经前1 310例、围绝经期790例、绝经后212例,测定体成分和静息能量消耗。 结果与结论:①围绝经期和绝经后女性的全身脂肪百分比显著高于绝经前女性。②3组间的静息代谢率无显著差异,经体质量校正后围绝经期女性的每千克体质量静息代谢率显著低于绝经前女性。③绝经后女性的骨密度、股骨颈抗骨折能力、下肢最大肌力、下肢肌肉分布系数显著低于围绝经期女性和绝经前女性(P < 0.05)。④体质量、下肢肌肉分布系数与每千克体质量静息代谢率呈正相关,身高、体质量指数、全身脂肪含量与每千克体质量静息代谢率呈负相关。以上结果表明,绝经后女性体成分发生变化,身体脂肪含量增加,肌肉含量减少,骨量减少;骨骼、肌肉、关节功能处于退行性变;体成分改变与静息能量消耗之间存在一定的相互关系。 中国组织工程研究杂志出版内容重点:组织构建;骨细胞;软骨细胞;细胞培养;成纤维细胞;血管内皮细胞;骨质疏松;组织工程  相似文献   

8.
The relationships between knee joint isokinetic strength, biological maturity status and body size were examined in 14-16-year-old basketball players, considering proportional allometric modeling. Biological maturity status was assessed with maturity offset protocol. Stature, body mass, sitting height, and estimated thigh volume were measured by anthropometry. Maximal moments of force of concentric and eccentric muscular actions for the knee extensors and flexors were assessed by isokinetic dynamometry at 60°?s(-1). Regression analysis revealed a linear relation between maximal moments of force of the knee extensors in both muscular actions and knee flexors in concentric actions were moderately high (0.55?≤?r?≤?0.64). As for knee flexors in eccentric actions, a squared term of maturity indicator was significant indicating that the relationship with maturity offset tended to plateau approximately 2?years after PHV. Incorporating maturity indicator term with body size term (body mass or thigh volume) in the allometric models revealed that the size exponents for both body mass and thigh volume were reduced compared with simple allometric modeling. The results indicate a significant inter-individual variation in lower-limb isokinetic strength performance at 60°?s(-1) in concentric and eccentric muscular actions in late adolescent basketball players. The variability in performance is related to inter-individual variation in estimated time before or after peak height velocity, as well as differences in body size. Proportional allometric models indicate that the influence of estimated time from age at peak height velocity on isokinetic strength performance is mostly mediated by corresponding changes in overall body mass.  相似文献   

9.
10.
To determine the daily energy requirement of elite synchronized swimmers during moderate-intensity training, the average daily energy expenditure measured by the doubly labeled water method, was calculated for nine female Japanese national team synchronized swimmers [four senior; mean (SD) 22.5 (1.0) years old, 52.2 (3.6) kg, and five junior; 17.6 (1.1) years old, 52.8 (2.3) kg]. Their total energy expenditure (TEE) was 11.5 (2.8) MJ · day−1 [2738 (672) kcal · day−1]. When compared with estimated energy requirements derived from “Recommended Dietary Allowances for the Japanese”, 12.1 (0.6) MJ · day−1 [2897 (139) kcal · day−1], there was no difference between mean actual and estimated energy requirements. However, there were considerable differences observed on an individual basis. Their energy intake, estimated from 7- day self-reported dietary records, was 8.9 (1.7) MJ · day−1 [2128 (395) kcal · day−1], which was significantly lower than their TEE (P < 0.05). Resting energy expenditure (REE), as determined by indirect calorimetry, was 5.2 (0.3) MJ · day−1 [1247 (75) kcal · day−1]. Their physical activity level (TEE/REE) was 2.18 (0.43). These results demonstrate that the TEE values of elite female synchronized swimmers are not dissimilar to those reported for athletes participating in other sports, especially competitive swimmers during moderate-intensity training. Accepted: 26 May 2000  相似文献   

11.
Being able to compare the energy cost of physical activity across and between populations is important. However, energy expenditure is related to body size, so it is necessary to appropriately adjust for differences in body size when comparisons are made. This study examined the relationship between the daily energy cost of activity and body weight in 47 children aged 6-10 years. Log-log regression showed weight1.0 to be an inappropriate adjustment for activity energy expenditure in children, with a more valid adjustment being weight0.3. Clearly, both weight dependent and non-weight dependent activities are part of everyday living in children. This balance influences how energy expenditure is correctly adjusted for body size. Investigators interpreting data of energy expenditure in children from children of different body sizes need to take this into consideration.  相似文献   

12.
Being able to compare the energy cost of physical activity across and between populations is important. However, energy expenditure is related to body size, so it is necessary to appropriately adjust for differences in body size when comparisons are made. This study examined the relationship between the daily energy cost of activity and body weight in 47 children aged 6–10 years. Log–log regression showed weight1.0 to be an inappropriate adjustment for activity energy expenditure in children, with a more valid adjustment being weight0.3. Clearly, both weight dependent and non-weight dependent activities are part of everyday living in children. This balance influences how energy expenditure is correctly adjusted for body size. Investigators interpreting data of energy expenditure in children from children of different body sizes need to take this into consideration.  相似文献   

13.

Objectives

The general perception is that menstrual cycle is a factor related to body weight and body composition fluctuations in women. The lack of a standardized methodology of the so far conducted studies has led to controversial results. The aim of the current study is to identify if there are any changes in body weight and body composition during the menstrual cycle.

Methods

In the current study measurements of body weight, circumferences, skinfolds and body composition with bioelectrical impedance analysis were conducted twice per week in 42 women during their menstrual cycle.

Results

Body weight was found to be statistically significantly higher during menstruation compared to the first week of the menstrual cycle by 0.450 kg, which could be attributed to a statistically significant increase of 0.474 kg observed in extracellular water. No other statistically significant changes were observed regarding body composition.

Conclusions

An increase of approximately 0.5 kg was observed during women's menstrual cycle, mostly due to extracellular fluid retention at menstruation days. These findings could be taken into account to interpret body weight and composition periodic fluctuations in women of reproductive age.  相似文献   

14.
15.
Changes in body composition attendant on force feeding   总被引:2,自引:0,他引:2  
  相似文献   

16.
目的研究解偶联蛋白3基因(UCP3)启动子区-55(C>T)多态与中国人静息能量消耗、体脂参数的关系。方法在300名中国人(正常体重91人,超重/肥胖209人)中,用聚合酶链反应-限制性片段长度多态性(polymerase chain reaction-restrictionfragment length polymorphisms ,PCR-RFLP)检测UCP3基因启动子区-55(C>T)变异,并测定其静息能量消耗、体脂含量及分布。结果UCP3基因启动子区-55(C>T)多态基因型频率与肥胖及肥胖类型均无相关。正常体重组TT基因型者静息能量消耗水平显著高于CT及CC基因型者(P<0·05) ;超重/肥胖组各基因型者间比较亦有同样趋势。在超重/肥胖组,TT基因型者FM/FFM值与CT及CC基因型者差异有显著意义(P<0·01)。结论UCP3基因启动子区-55(C>T)多态与中国人静息能量消耗相关,该变异可能通过对静息能量消耗的影响调节机体的能量代谢。  相似文献   

17.
Cerebellum is a key structure involved in motor learning and coordination. In animal models, motor skill learning increased the volume of molecular layer and the number of synapses on Purkinje cells in the cerebellar cortex. The aim of this study is to investigate whether the analogous change of cerebellar volume occurs in human population who learn specialized motor skills and practice them intensively for a long time. Magnetic resonance image (MRI)-based cerebellar volumetry was performed in basketball players and matched controls with V-works image software. Total brain volume, absolute and relative cerebellar volumes were compared between two groups. There was no significant group difference in the total brain volume, the absolute and the relative cerebellar volume. Thus we could not detect structural change in the cerebellum of this athlete group in the macroscopic level.  相似文献   

18.
目的 研究解偶联蛋白3基因(UCP3)启动子区-55(C〉T)多态与中国人静息能量消耗、体脂参数的关系。方法 在300名中国人(正常体重91人,超重/月巴胖209人)中,用聚合酶链反应一限制性片段长度多态性(polymemse chain reaction-restriction fragment length polymorphisms,PCR—RFLP)检测伙巧基因启动子区-55(C〉T)变异,并测定其静息能量消耗、体脂含量及分布。结果 UCP3基因启动子区-55(C〉T)多态基因型频率与肥胖及肥胖类型均无相关。正常体重组1T基因型者静息能量消耗水平显著高于CT及CC基因型者(P〈0.05);超重/肥胖组各基因型者间比较亦有同样趋势。在超重/肥胖组,TT基因型者FM/FFM值与CT及CC基因型者差异有显著意义(P〈0.01)。结论 UCP3基因启动子区-55(C〉T)多态与中国人静息能量消耗相关,该变异可能通过对静息能量消耗的影响调节机体的能量代谢。  相似文献   

19.

Purpose

Triathletes lose body mass during an Ironman triathlon. However, the associated body composition changes remain enigmatic. Thus, the purpose of this study was to investigate Ironman-induced changes in segmental body composition, using for the first time dual-energy X-ray absorptiometry (DXA) and peripheral quantitative computed tomography (pQCT).

Methods

Before and after an Ironman triathlon, segmental body composition and lower leg tissue mass, areas and densities were assessed using DXA and pQCT, respectively, in eight non-professional male triathletes. In addition, blood and urine samples were collected for the determination of hydration status.

Results

Body mass decreased by 1.9 ± 0.8 kg. This loss was due to 0.4 ± 0.3 and 1.4 ± 0.8 kg decrease in fat and lean mass, respectively (P < 0.01). Calf muscle density was reduced by 1.93 ± 1.04 % (P < 0.01). Hemoglobin, hematocrit, and plasma [K+] remained unchanged, while plasma [Na+] (P < 0.05), urine specific gravity and plasma and urine osmolality increased (P < 0.01).

Conclusions

The loss in lean mass was explained by a decrease in muscle density, as an indicator of glycogen loss, and increases in several indicators for dehydration. The measurement of body composition with DXA and pQCT before and after an Ironman triathlon provided exact values for the loss in fat and lean mass. Consequently, these results yielded more detailed insights into tissue catabolism during ultra-endurance exercise.  相似文献   

20.
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