A faster running speed is associated with a greater body weight loss in 100-km ultra-marathoners

In 219 recreational male runners, we investigated changes in body mass, total body water, haematocrit, plasma sodium concentration ([Na(+)]), and urine specific gravity as well as fluid intake during a 100-km ultra-marathon. The athletes lost 1.9 kg (s = 1.4) of body mass, equal to 2.5% (s = 1.8) of body mass (P < 0.001), 0.7 kg (s = 1.0) of predicted skeletal muscle mass (P < 0.001), 0.2 kg (s = 1.3) of predicted fat mass (P < 0.05), and 0.9 L (s = 1.6) of predicted total body water (P < 0.001). Haematocrit decreased (P < 0.001), urine specific gravity (P < 0.001), plasma volume (P < 0.05), and plasma [Na(+)] (P < 0.05) all increased. Change in body mass was related to running speed (r = -0.16, P < 0.05), change in plasma volume was associated with change in plasma [Na(+)] (r = -0.28, P < 0.0001), and change in body mass was related to both change in plasma [Na(+)] (r = -0.36) and change in plasma volume (r = 0.31) (P < 0.0001). The athletes consumed 0.65 L (s = 0.27) fluid per hour. Fluid intake was related to both running speed (r = 0.42, P < 0.0001) and change in body mass (r = 0.23, P = 0.0006), but not post-race plasma [Na(+)] or change in plasma [Na(+)] (P > 0.05). In conclusion, faster runners lost more body mass, runners lost more body mass when they drank less fluid, and faster runners drank more fluid than slower runners.     

Relationship between peak oxygen uptake and regional body composition in Japanese subjects

PurposeTo investigate the link between peak oxygen uptake and regional body composition by dual energy X-ray absorptiometry (DEXA) in Japanese subjects.MethodsA total of 93 men (42.2 ± 12.3 years old) and 106 women (43.5 ± 12.3 years old) were enrolled in this cross-sectional investigation study. Peak oxygen uptake was measured by the breath-by-breath method. Regional body composition i.e., body fat mass, lean body mass, and body fat percentage was evaluated using DEXA. In addition, metabolic risk parameters were also evaluated.ResultsPeak oxygen uptake was 37.6 ± 8.7 mL/kg/min in men and 31.1 ± 6.4 mL/kg/min in women, and decreased with age in both genders. Peak oxygen uptake was significantly correlated with total body fat percentage (men: r = −0.684, p < 0.0001; women: r = −0.681, p < 0.0001). These associations remained even after adjusting for age and total lean body mass. However, peak work rate was positively and significantly correlated with leg lean body mass.ConclusionPeak oxygen uptake was closely correlated with total body fat percentage in both genders. Aerobic exercise as well as leg resistance training might be useful for improving peak oxygen uptake in Japanese subjects.     

长期运动训练对速滑运动员体成分的影响

为探讨长期运动训练对速滑运动员身体成分的影响,采用美国产身体成分分析仪310e对吉林省8名男子速滑运动员的瘦体重、体重指数(BMI)、体脂百分率、身体水分、身体水分占瘦体重的百分比等几项生理指标进行测试。结果表明,长期速滑训练能有效减少体脂,瘦体重相对增大;BMI指数接近于正常人的标准;身体水分占瘦体重的百分比偏低,有轻微的脱水现象。     

青年男子柔道运动员身体骨密度调查研究

采用双能X线骨密度仪(DXA)全身扫描测试的方法,对长期柔道专项训练的青年男子运动员19名(柔道组)和21名无正规的运动训练史的同龄男大学生(对照组)的骨密度(BMD)及某些身体指标进行对比分析,结果显示,柔道组和对照组骨密度、瘦体重和体脂百分率存在着显著性的差异(P<0.01);同时,柔道组BMD与身高、体重、瘦体重及体脂百分率具有较高的相关性。结果提示,身高、体重、瘦体重及体脂百分率等可影响骨密度值的大小,运动能提高全身骨密度。     

Isokinetic Leg Flexion and Extension Strength of Elite Adolescent Female Track and Field Athletes

Abstract

Sixty-two elite adolescent (age: 16.39 ± 1.62 yrs) female track and field athletes volunteered to be measured isokinetically for peak torque of the leg flexors and extensors. The sample included 16 throwers, 11 jumpers, 12 middle-distance runners (> 400 m), and 23 sprinters. A Cybex II isokinetic dynamometer was used to measure dominant leg strength at 180°/sec. One-way ANOVA revealed significant between group differences for absolute flexion and extension (Nm), extension/body weight (Nm/Kg), and extension/lean body weight (Nm/Kg). Scheffe post-hoc comparisons showed that, for absolute leg extension strength, throwers were stronger than middle-distance runners (by 54.4%), sprinters (35.6%), and jumpers (23.6%). For absolute leg flexion movements, throwers were stronger than middle distance runners (37.4%) and sprinters (32.1%). Jumpers had greater extension peak torque values than middle-distance runners relative to body weight (14.0%), and throwers were stronger than middle-distance runners for extension/lean body weight (14.9%)). No other comparisons were significant. However, when strength was expressed relative to body weight or lean body weight, there were few differences between events for flexion or extension. Given that absolute strength scores were correlated with body weight and lean body weight, peak torque/body weight or peak torque/lean body weight may be more sensitive than absolute values as indicators of underlying factors (such as training status or fiber type composition) responsible for the differences in muscular strength between groups.     

Predictor variables of performance in recreational male long-distance inline skaters

We investigated the associations between selected anthropometric and training characteristics with race time in 84 recreational male long-distance inline skaters at the longest inline marathon in Europe, the 'Inline One-eleven' over 111 km in Switzerland, using bi- and multivariate analysis. The mean (s) race time was 264 (41) min. The bivariate analysis showed that age (r = 0.30), body mass (r = 0.42), body mass index (r = 0.35), circumference of upper arm (r = 0.32), circumference of thigh (r = 0.29), circumference of calf (r = 0.38), skin-fold of thigh (r = 0.22), skin-fold of calf (r = 0.27), the sum of skin-folds (r = 0.43), percent body fat (r = 0.45), duration per training unit in inline skating (r = 0.33), and speed during training (r = -0.46) were significantly and positively correlated to race time. Stepwise multiple regression showed that duration per training unit (P = 0.003), age (P = 0.029) and percent body fat (P = 0.016) were the best correlated with race time. Race time in a long-distance inline race such as the 'Inline One-eleven' over 111 km with a mean race time of ～260 min might be predicted by the following equation (r(2) = 0.41): Race time (min) = 114.91 + 0:51* (duration per training unit, min) + 0:85* (age, years) +3:78* (body fat, %) for recreational long-distance inline skaters.     

Body Mass and Circumference of Upper Arm Are Associated With Race Performance in Ultraendurance Runners in a Multistage Race—The Isarrun 2006

In the present study, we investigated the association of anthropometric parameters with race performance in ultraendurance runners in a multistage ultraendurance run, in which athletes had to run 338 km within 5 consecutive days. In 17 male successful finishers, calculations of body mass, body height, skinfold thicknesses, extremity circumference, skeletal muscle mass (SM), and percentage body fat (%BF) were performed before the race to correlate anthropometric parameters with race performance. A positive association was shown between total running time and both body mass (r² = .29, p < .05) and upper arm circumference (r² = .23, p < .05). In contrast, body height, skinfold thicknesses, extremity circumference, SM, and %BF showed no association with race performance (p > .05). We concluded that in a multistage ultraendurance run, body mass and upper arm circumference were negatively associated with race performance in well experienced ultraendurance runners. In contrast, body height, skinfold thicknesses, circumferences of the other extremities, SM, and %BF showed no association with race performance.     

Body composition characteristics of elite Australian rugby union athletes according to playing position and ethnicity

This study describes the body composition traits of modern-day elite rugby union athletes according to playing position and ethnicity. Thirty-seven international Australian rugby athletes of Caucasian and Polynesian descent undertook body composition assessment using dual-energy X-ray absorptiometry and surface anthropometry. Forwards were significantly taller, heavier and had a greater total fat mass and lean mass than backs. Backs displayed a higher percentage lean mass and lower sum of seven skinfolds and percentage fat mass. While no whole body composition differences were seen between ethnicities, significant regional differences were observed. In the periphery (arm and leg) regions, Polynesians had a greater proportion of fat mass (53.1% vs. 51.3%, P = 0.052, d = 0.5) and lean mass (49.7% vs. 48.6%, P = 0.040, d = 0.9), while in the trunk region a lower proportion of fat mass (37.2% vs. 39.5%, P = 0.019, d = 0.7) and lean mass (45.6% vs. 46.8%, P = 0.020, d = 1.1). Significant differences were also seen between Caucasian and Polynesian forwards in leg lean mass (31.4 kg vs. 35.9 kg, P = 0.014, d = 2.4) and periphery lean mass (43.8 kg vs. 49.6 kg, P = 0.022, d = 2.4). Elite Polynesian rugby athletes have different distribution patterns of fat mass and lean mass compared to Caucasians, which may influence their suitability for particular positions.     

Overweight and obesity in young adults with patellofemoral pain: Impact on functional capacity and strength

PurposeThis study aimed to (a) investigate the proportion of overweight/obesity in a cohort of young adults with patellofemoral pain (PFP) and (b) explore the association of body mass index (BMI), body fat, and lean mass with functional capacity and hip and knee strength in people with PFP.MethodsWe included a mixed-sex sample of young adults (18−35 years old) with PFP (n = 100). Measurements for BMI, percentage of body fat, and lean mass (assessed by bioelectrical impedance) were obtained. Functional capacity was assessed by the Anterior Knee Pain Scale, plank test, and single-leg hop test. Strength of the knee extensors, knee flexors, and hip abductors was evaluated isometrically using an isokinetic dynamometer. The proportion of overweight/obesity was calculated based on BMI. The association between BMI, body fat, and lean mass and functional capacity and strength was investigated using partial correlations, followed by hierarchical regression analysis, adjusted for covariates (sex, bilateral pain, and current pain level).ResultsA total of 38% of our cohort had their BMI categorized as overweight/obese. Higher BMI was associated with poor functional capacity (ΔR² = 0.06−0.12, p ≤ 0.001) and with knee flexion strength only (ΔR² = 0.04, p = 0.030). Higher body fat was associated with poor functional capacity (ΔR² = 0.05−0.15, p ≤ 0.015) and reduced strength (ΔR² = 0.15−0.23, p < 0.001). Lower lean mass was associated with poor functional capacity (ΔR² = 0.04−0.13, p ≤ 0.032) and reduced strength (ΔR² = 0.29− 0.31, p < 0.001).ConclusionBMI, body fat, and lean mass should be considered in the assessment and management of young people with PFP because it may be detrimental to function and strength.     

短期封闭式综合干预对肥胖男少年体成分、瘦素及睾酮的影响

目的:探寻短期(15天)封闭综合干预对肥胖男少年体成分、瘦素及性激素的影响,为防治少年肥胖,改善性发育不良提供科学的实验依据.方法:10名体脂含量正常男少年为对照组,10名肥胖男少年为实验组(给予短期综合干预),干预前测定对照组与实验组相关指标进行组间比较,干预后测定实验组相关指标进行组内比较.结果:干预前实验组体成分、血糖、胰岛素、瘦素均显著高于对照组(P＜0.01;P＜0.01;P＜0.01;P＜0.05),睾酮显著低于对照组(P＜0.05);干预后实验组体重、体脂含量、体脂率、瘦体重、血糖、胰岛素、瘦素、睾酮均显著下降(P＜0.01;P＜0.01;P＜0.01;P＜0.01;P＜0.01、P＜0.01、P＜0.01、P＜0.05);胰岛素与体重、体脂含量、体脂率、瘦体重呈正相关(P＜0.05;P ＜0.01;P＜0.01;P＜0.05),瘦素与体脂含量、体脂率、胰岛素呈正相关(P＜0.05;P＜0.01;P＜0.05).结论:短期(15天)的综合干预能有效地减少肥胖男少年的体脂含量,改善胰岛素抵抗和瘦素抵抗,但对改善肥胖男少年性发育不良暂时无明显影响,长期的影响还有待进一步的研究.     

Esports players,got muscle? Competitive video game players’ physical activity,body fat,bone mineral content,and muscle mass in comparison to matched controls

BackgroundEsports players, like traditional athletes, practice for long hours and, thus, are vulnerable to the negative health effects of prolonged sitting. There is a lack of research on the physical activity and the health ramifications of prolonged sitting by competitive players. The purpose of this study was to investigate activity levels, body mass index (BMI), and body composition in collegiate esports players as compared to age-matched controls.MethodsTwenty-four male collegiate esports players and non-esports players between 18 and 25 years of age signed a written consent to participate. Physical activity was examined using daily activity (step count) with a wrist-worn activity tracker. A questionnaire assessing physical activity was also administered. Secondary outcomes included body-fat percentage, lean-body mass, BMI, and bone mineral content measured using dual X-ray absorptiometry.ResultsThe step count in the esports players was significantly lower than the age-matched controls (6040.2 ± 3028.6 vs. 12843.8 ± 5661.1; p = 0.004). Esports players exhibited greater body-fat percentage (p = 0.05), less lean body mass (p = 0.003), and less bone mineral content (p = 0.03), despite no difference in BMI between the esports and non-esports players.ConclusionAs compared to non-esports players, collegiate esports players were significantly less active and had a higher body-fat percentage, with lower lean body mass and bone mineral content. The BMIs showed no difference between the 2 groups. Esports athletes displayed significantly less activity and poor body composition, which are all correlated with potential health issues and risk of injury. BMI did not capture this difference and should not be considered as an accurate measure of health in competitive esports players.     

The improvement in walking speed induced by resistance training is associated with increased muscular strength but not skeletal muscle mass in older women

Objective: The purpose of the present study was to analyze whether improvements in fast walking speed induced by resistance training (RT) are associated with changes in body composition, muscle quality, and muscular strength in older women. Methods: Twenty-three healthy older women (69.6?±?6.4 years, 64.95?±?12.9?kg, 1.55?±?0.07?m, 27.06?±?4.6?kg/m²) performed a RT program for 8 weeks consisting of 8 exercises for the whole body, 3 sets of 10–15 repetitions maximum, 3 times a week. Anthropometric, body composition (fat-free mass [FFM], skeletal muscle mass [SMM], legs lean soft tissue [LLST], fat mass), knee extension muscular strength (KE1RM), muscle quality index (MQI [KE1RM/LLST]), and 10-meter walking test (10-MWT) were performed before and after the intervention. Results: Significant (P?<?.05) changes were observed from pre- to post-training for FFM (+1.6%), MQI (+7.2%), SMM (+2.4%), LLST (+1.8%), KE1RM (+8.6%), fat mass (?1.4%), and time to perform 10-MWT (?3.7%). The percentage change in 10-MWT was significantly associated with percentage change in MQI (r?=??0.46, P?=?.04) and KE1RM (r?=??0.45, P?=?.04), however not associated percentage of changes in SMM (r?=?0.01, P?=?.97), LLST (r?=??0.22, P?=?.33), and body fat (r?=?0.10, P?=?.66). Conclusion: We conclude that the improvement in the 10-MWT after an 8-week RT program is associated with increases in lower limb muscular strength and muscle quality, but not with muscle mass or body fat changes in older women.     

运动处方锻炼减脂及心脏功能的效果观察

观察不同运动处方锻炼对单纯性肥胖女大学生减脂及心脏功能的效果。将30名受试者随机分为对照组、综合锻炼组和简易锻炼组,分别于实验前后测体重、体脂百分比(PBF)、躯干脂肪质量(TFM)评价减脂效果;测心率(HR)、每搏量(SV)和左心室有效泵力绝对值(VPE)评价心脏功能。结果表明:实验后,综合组与简易组的体重、PBF、TFM、HR均明显低于实验前和对照组(P<0.01);简易组的SV明显高于实验前和对照组(P<0.01);综合组的SV与实验前和对照组相比也明显升高(P<0.05);简易组的VPE明显大于实验前和对照组(P<0.01);综合组的VPE与对照组的各项指标均未见显著性改变。     

The role of anthropometric characteristics in modern pentathlon performance in female athletes

In order to determine the role of body build characteristics in modern pentathletes, 65 female participants at the IXth World Modern Pentathlon Championships, 1989 (Wiener Neustadt, Austria) were investigated. Of these, 54 participated in the competition; the other 11 were reserves. Their mean ( + S.D.) age was 22.34 ± 3.97 years (range 16.08–32.58 years). Anthropometric characteristics (body mass, lengths, breadths, girths and skinfolds), somatotype and body composition estimates were determined. Compared with other female athletes (e.g. swimmers, runners, fencers), the elite modern pentathletes were rather tall (x = 168.1 cm) and, as indicated by the body mass index (x = 21.6), they had a high mass relative to their stature. Based on skinfolds, body fat was estimated as 16%, and anthropometrically determined somatotype was on average 2.5–3.9–2.8. The relationship between the athletes’ anthropometric characteristics and modern pentathlon performance was investigated by means of Pearson zero‐order correlations between the physical traits and the competitive performance scores. Significant correlations were found mainly for the ‘fat’ variables, such as skinfolds, percent fat and the endomorphy component, r varying from –0.34 to –0.58, which indicated an inverse relationship between the amount of fatness and modern pentathlon performance. To investigate this relationship further, Pearson zero‐order correlations were calculated between the respective factor scores, derived from a rotated factor pattern (Varimax) carried out on selected somatic variables, and the performance scores. The results demonstrated that, in relation to anthropometric characteristics, modern pentathlon performance in females is mainly associated with the ‘fat development’ factor, and to a lesser degree with the ‘bone‐muscle development’ factor. Variables representing linearity of physique seem to be unrelated to modern pentathlon performance. Stepwise regression analysis revealed that 42.4% of the variance in modern pentathlon performance can be explained by the following anthropometric variables: sum of 10 skinfolds, biacromial breadth and humerus diameter. To obtain a high level of modern pentathlon performance, it would seem that a female athlete must above all have a low level of body fatness and, to a lesser degree, a relatively high level of lean body mass.     

广西重竞技小级别优秀运动员体成份调查分析

对广西重竞技小级别5个项目48名运动员进行体成份分析,结果发现:男子项目中,举重运动员的BMI、体脂百分比及腰臀比均明显高于古典跤、自由跤和拳击,差异有显著性(P<0.05);女子项目中,BMI和腰臀比存在明显差异(P<0.05);提示举重运动员应加强体成份控制,同时,有必要建立不同运动项目体成份的参照标准。     

ATriple Iron triathlon leads to a decrease in total body mass but not to dehydration

A loss in total body mass during an ultraendurance performance is usually attributed to dehydration. We identified the changes in total body mass, fat mass, skeletal muscle mass, and selected markers of hydration status in 31 male nonprofessional ultratriathletes participating in a Triple Iron triathlon involving 11.4 km swimming, 540 km cycling and 126.6 km running. Measurements were taken prior to starting the race and after arrival at the finish line. Total body mass decreased by 1.66 kg (SD = 1.92; -5.3 kg to +1.2 kg; p < .001), skeletal muscle mass by 1.00 kg (SD = 0.90; -2.54 kg to +2.07 kg; p < .001), and fat mass by 0.58 kg (SD = 0.78; -1.74 kg to +0.87 kg; p < .001). The decrease in total body mass was associated with the decrease in skeletal muscle mass (r = .44; p < .05) and fat mass (r = .51; p < .05). Total body water and urinary specific gravity did not significantly change. Plasma urea increased significantly (p < .001); the decrease in skeletal muscle mass and the increase in plasma urea were associated (r = .39; p < .05). We conclude that completing a Triple Iron triathlon leads to decreased total body mass due to reduced fat mass and skeletal muscle mass but not to dehydration. The association of decrease in skeletal muscle mass and increased plasma urea suggests a loss in skeletal muscle mass.     

用DEXA 技术测量体成分及可行性研究

采用DEXA技术测量人体成分，并对测量的瘦体重，脂肪含量与骨矿物质含量进行了相关分析，结果显示，受试者全身骨矿物质含量与全身瘦体重，脂肪含量，体重均呈中度正相关关系，双臂骨矿物质含量与双臂瘦体重，脂肪含量呈高度正相关关系，双腿骨矿物质含量与双腿瘦体重呈高度正相关关系，与双腿脂肪含量呈中度相关关系，躯干骨矿物质含量与躯干瘦体重呈中度正相关关系，与躯干脂肪含量呈低度正相关关系，全身及各个部位的骨矿物质含量与相应部位的体成分的相关分析表明，用DEXA技术进行身体成分的研究是有可行的。     

Relationship of running economy, ventilatory threshold, and maximal oxygen consumption to running performance in high school females

The purpose of the study was to relate three determinants of distance running success, (a) maximal oxygen consumption (VO2max), (b) ventilatory threshold (VT), and (c) running economy (RE), to actual running time in a 5-km race (ART). Twenty-four female runners (M age = 15.9 years) from four high school teams that competed at the Massachusetts All-State 5-km Cross Country Championship Meet and placed 1st, 7th, 19th, and 20th were tested in the laboratory. The mean VO2max of these runners was 61.7 ml.kg-1.min-1, HRmax 201 b.min-1, VEmax 100 L.min-1, and RER 1.10. The VT occurred at 79% of the VO2max, and HR of 184 b.min-1 (92% of HRmax). The velocity at VT (vVT) and velocity at VO2max (vVO2max) was correlated with ART, r(22) = .78 and .77 (p less than .001), respectively. The VO2 at VT and at maximal exercise was correlated with ART by r(22) = -.66 and -.69 (p less than .001), respectively. The VO2 at 215 m.min-1 (8 mph) was poorly related to ART, r(22) = -.05, p greater than .05. It was concluded that either of the derived variables vVT and vVO2max appear to explain significant variation in distance running performance among adolescent female cross country runners.     

Bone mass in girls according to their BMI,VO2 max,hours and years of practice

The accumulation of bone mass during puberty is related with bone health in adulthood. This accumulation is influenced by diverse factors such as body mass index (BMI), maximal oxygen uptake (VO₂ max), hours of training and years of sport practice. For this reason, the objective of this study is to analyse the influence of these variables on bone mass in young female athletes. The sample is formed of 120 healthy girls with ages between 9 and 13 (11.32?±?1.6?years old), divided into two groups depending on their BMI, VO₂ max, hours of training and years of sport practice. The participants completed a series of tests to evaluate level of sexual development, body composition (fat mass, lean mass and bone mass) and physical condition. The results show higher values of total lean mass, total fat mass and percentage of body fat in the groups with higher BMI in prepubertal girls and pubertal girls (p?2 max, in the prepubertal group, girls with lower VO₂ max had higher values of total fat mass (p?p?2 max also showed a higher total fat mass (p?相似文献   

对我省重竞技运动员体脂的调查

对我省部分重竞技项目运动员体脂的调查,结果发现,我省重竞技项目运动员的去脂体重明显低于我国同项目优秀运动员,体脂百分比明显高于我国同项目优秀运动员。