Considerations for protein intake in managing weight loss in athletes

Abstract

A large body of evidence now shows that higher protein intakes (2–3 times the protein Recommended Dietary Allowance (RDA) of 0.8 g/kg/d) during periods of energy restriction can enhance fat-free mass (FFM) preservation, particularly when combined with exercise. The mechanisms underpinning the FFM-sparing effect of higher protein diets remain to be fully elucidated but may relate to the maintenance of the anabolic sensitivity of skeletal muscle to protein ingestion. From a practical point of view, athletes aiming to reduce fat mass and preserve FFM should be advised to consume protein intakes in the range of ～1.8–2.7 g kg^?1 d^?1 (or ～2.3–3.1 g kg^?1 FFM) in combination with a moderate energy deficit (?500 kcal) and the performance of some form of resistance exercise. The target level of protein intake within this recommended range requires consideration of a number of case-specific factors including the athlete's body composition, habitual protein intake and broader nutrition goals. Athletes should focus on consuming high-quality protein sources, aiming to consume protein feedings evenly spaced throughout the day. Post-exercise consumption of 0.25–0.3 g protein meal^?1 from protein sources with high leucine content and rapid digestion kinetics (i.e. whey protein) is recommended to optimise exercise-induced muscle protein synthesis. When protein is consumed as part of a mixed macronutrient meal and/or before bed slightly higher protein doses may be optimal.     

浅谈利用Google Earth辅助矿产资源管理

Google Earth作为免费软件,三维模型上能十分的丰富和强大,但坐标转换导入功能薄弱,ArcGIS 9.2以上版本支持Google Earth数据(KML/KMZ格式)的矢量数据式转换。文章介绍了一种借助ArcGIS软件实现坐标拐点快速转换并投放到Google Earth地图中的方法和途径,同时介绍了利用Google Earth辅助矿产资源管理的方法。     

植物提取物补充对延迟性肌肉酸痛干预效果

通过查阅相关文献,以“延迟性肌肉酸痛”“植物提取物”“DOMS”和“plant extracts”等中英文检索词,分别在中国知网、万方数据库、Webofscience数据库、PubMed数据库和EBSCO系列数据库中,对自1983年6月至2020年5月的相关文献进行检索,最终选取81篇文献进行综述,以探讨植物提取物补充对延迟性肌肉酸痛干预效果,并阐述相关研究进展。结果表明:植物提取物干预与物理、药物和单一营养素干预相比,能从DOMS的炎症反应和氧化应激过程入手来预防延迟性肌肉酸痛的相关症状。但在当前研究中,有关植物提取物的补充效果仍缺乏一些大样本和大规模的实验证明,未来人们的研究方向应着眼于探究更多种类的植物提取物对延迟性肌肉酸痛的干预效果,以及确定在实际应用中具体的最优补剂方案。     

青少年短道速滑运动员的营养补充

科学的营养补充对青少年短道速滑运动员的体力和运动能力的发挥以及运动后的恢复起着至关重要的作用。针对短道速滑项群特点、青少年发育特征和训练环境特点等项目特点,总结出青少年短道速滑运动员在训练中所需能量为热量、碳水化合物、蛋白质、脂肪、水和无机盐和维生素;并分别提出各种所需能量营养补充的方法和手段,为青少年短道速滑运动员的训练和比赛提供理论参考。     

对女子举重运动员血清生长激素、胰岛素样生长因子和骨密度值的研究

为了了解生长激素和胰岛素样生长因子-1等对骨密度值的影响，采用放免法、定量超生法，对高水平女子举重运动员跟骨骨密度值、血清生长激素、胰岛素样生长因子-1、睾酮、雌二醇等进行了研究。结论：运动组跟骨骨密度值与运动员机能状况有关，跟骨骨密度值受血清生长激素的影响可能更为显著。提示，血清生长激素和跟骨骨密度值一定程度上可能反映运动员机能状况。     

女大学生骨质状况调查与相关影响因素分析

为了解女性大学生的骨质状况,探索影响骨峰值的相关因素,对苏州地区199名女性大学生的前臂和跟骨骨密度、形态学指标、身体机能指标进行了测试,并对月经状况和体育锻炼情况进行了调查。研究结果表明,女性大学生的骨健康状况不容乐观,苏州地区女性大学生的骨密度均值低于全国同龄女性;体脂肪量、上臂皮褶厚度、克托莱指数与骨密度呈显著正相关;握力、平衡能力、月经状况和体育锻炼,是骨量生长期女性骨密度的有效影响因子。     

松针与运动性疲劳

对松针在国内外的已知种类、营养价值、保健效能、药理研究进行了综述，提出了松针在运动性疲劳方面的优势。     

矿产资源型县域经济的内涵、特征与发展趋势——以河北省为例

矿产资源型县域经济是我国县域经济的重要类型,具有鲜明的内部特征和外部特征,其以当地自然矿产资源的采选和加工业为主导产业,占县域工业经济总量的30%以上,在县域经济发展中发挥着支撑作用,近几年遇到巨大的困难和挑战,急需改变传统的发展路径,实施发展方式的转型。     

营养状况差异对中学生身体素质的影响——以辽宁省中学生为例

以2009年辽宁省初中在校学生为调查对象,采用文献资料法、测量法及数理统计法进行调查与分析,特别探讨了中学生不同营养状况与身体素质的关系。结果显示,营养状况良好的初中男生,其上肢力量、下肢爆发力及肌耐力三项素质总体好于其他组;而营养状况良好的初中女生与偏瘦组比较,除腰腹力量有显著性差异外,下肢爆发力和肌耐力均无显著差异（P〉0.05）,但总体好于其他组。研究结论：良好的营养状况是提高身体素质的有力保障。     

BMD and Serum Intact Osteocalcin in Postmenopausal Osteoporosis Women

India seems to have the highest prevalence of osteoporosis. With growing awareness of osteoporosis and its impact on life span especially in India, special attention is being paid to early detection, management and treatment of postmenopausal osteoporosis in women. Measurement of BMD and osteocalcin are of value in estimating bone turnover rates. The aim of this study is (1) to measure the specific, sensitive bone formation marker such as osteocalcin and BMD in postmenopausal osteoporosis women and postmenopausal non-osteoporosis women; (2) the follow up study to evaluate the impact of specific antiresorptive therapy (alendronate + calcium + vitamin D) regimen in postmenopausal osteoporosis by assaying osteocalcin and BMD. Sixty clinically diagnosed postmenopausal osteoporosis patients and 60 normal subjects (postmenopausal non-osteoporosis women) were recruited as control. Mean bone mineral density T score and Z score was significantly decreased (P < 0.001) in postmenopausal osteoporosis patients as compared to controls. Highly significant increase in the mean score of BMD—T score and Z score from baseline to post therapy of 3 months was observed in postmenopausal osteoporosis women. Serum osteocalcin levels were significantly increased (P < 0.001) as compared to control group. Serum osteocalcin levels were decreased significantly (P < 0.001) from baseline to post therapy of 3 months in postmenopausal osteoporosis women. BMD is the best quantifiable predictor of osteoporotic fracture and osteocalcin is specific, sensitive, promising, currently used marker for better prognosis of osteoporosis and for monitoring responses to antiresorptive therapy.