沙棘与运动能力

沙棘含有胡罗卜素、黄酮类、挥发油、氨基酸、维生素及微量元素等多种活性化学成分，具有降血糖、降血脂、降血压、抗菌和抗病毒多种药理活性。国内外大量的研究均提示：使用沙棘在增加肌肉耐力和运动能力、抑制自由基生成和促进自由基清除、抗疲劳和增强免疫能力等方面有明显的效果。毒性实验表明该药物安全无毒。     

The Governor has a sweet tooth – Mouth sensing of nutrients to enhance sports performance

Abstract

The oral–pharyngeal cavity and the gastrointestinal tract are richly endowed with receptors that respond to taste, temperature and to a wide range of specific nutrient and non-nutritive food components. Ingestion of carbohydrate-containing drinks has been shown to enhance endurance exercise performance, and these responses have been attributed to post-absorptive effects. It is increasingly recognised, though, that the response to ingested carbohydrate begins in the mouth via specific carbohydrate receptors and continues in the gut via the release of a range of hormones that influence substrate metabolism. Cold drinks can also enhance performance, especially in conditions of thermal stress, and part of the mechanism underlying this effect may be the response to cold fluids in the mouth. There is also some, albeit not entirely consistent, evidence for effects of caffeine, quinine, menthol and acetic acid on performance or other relevant effects. This review summarises current knowledge of responses to mouth sensing of temperature, carbohydrate and other food components, with the goal of assisting athletes to implement practical strategies that make best use of its effects. It also examines the evidence that oral intake of other nutrients or characteristics associated with food/fluid intake during exercise can enhance performance via communication between the mouth/gut and the brain.     

Probiotics supplementation for athletes – Clinical and physiological effects

Abstract

Probiotic supplementation has traditionally focused on gut health. However, in recent years, the clinical applications of probiotics have broadened to allergic, metabolic, inflammatory, gastrointestinal and respiratory conditions. Gastrointestinal health is important for regulating adaptation to exercise and physical activity. Symptoms such as nausea, bloating, cramping, pain, diarrhoea and bleeding occur in some athletes, particularly during prolonged exhaustive events. Several studies conducted since 2006 examining probiotic supplementation in athletes or highly active individuals indicate modest clinical benefits in terms of reduced frequency, severity and/or duration of respiratory and gastrointestinal illness. The likely mechanisms of action for probiotics include direct interaction with the gut microbiota, interaction with the mucosal immune system and immune signalling to a variety of organs and systems. Practical issues to consider include medical and dietary screening of athletes, sourcing of recommended probiotics and formulations, dose–response requirements for different probiotic strains, storage, handling and transport of supplements and timing of supplementation in relation to travel and competition.     

烹饪工艺和营养专业人才培养方案的探索

随着社会所需人才的不断变化,高职教育为了培养更适合社会需求的人才,培养方案也在不断更新之中.在高职"工学结合"模式下就烹饪工艺和营养专业人才培养方案的调整进行了探讨.     

野生蔬菜野茼蒿营养成分分析及重金属元素风险评估

测定了浙江金华北山地区野生蔬菜野茼蒿(Crassocephalum crepidioides)食用部分的营养成分及不同器官、不同生境中Ca、Mg、Fe、Zn、Cu、Cd、Cr、Pb这8种金属元素含量,计算其地上、地下器官对这些元素的富集系数,并将野茼蒿与该地区其他23种野生蔬菜进行了营养成分含量的对比,对野茼蒿的营养价值和重金属风险进行了综合评估。研究结果表明:(1)野茼蒿食用部分的含水量、粗蛋白、粗脂肪、可溶性糖和灰分的鲜重含量分别为91.96%、1.95%、0.57%、2.20%和1.27%,其中粗蛋白含量比白菜、萝卜、黄瓜等经常食用蔬菜要高;(2)基于营养指标,应用PAST软件对43种蔬菜进行系统聚类表明,43种蔬菜大体上分成两类,野茼蒿营养价值与番茄、绿豆芽相近;(3)野茼蒿食用部分Cr、Cd、Pb三种有毒重金属元素含量分别是1.43、0.33、0.39 mg/kg,均已超标,其地上、地下部分Cd的富集系数分别为2.99和1.99;(4)与其他23种野生蔬菜相比,其重金属元素的综合风险指标排列第16位。作为一种有风味和特色的野生蔬菜,从蛋白质、可溶性糖、粗脂肪等指标看,野茼蒿的营养价值并不太高;由于野茼蒿对某些重金属具有一定的富集效应,食用时应注意其可能的风险。     

中华绒螯蟹的营养需求与性早熟研究进展

饵料是中华绒螯解生存的物质基础，性早熟为近年来中华绒螯蟹养殖过程中遇到的一个突出问题，如何配制营养更为丰富的饲料？如何避免性早熟问题的发生？本文对近年来国内外关于这些问题的研究进展做了总结。     

温度对杨梅果实采后营养物质变化和腐烂的影响

杨梅果实在采后贮藏过程中,糖、酸、维生素C等营养成分都是逐渐下降的,其下降速度和程度与温度成正比,低温能较好地保持果实的营养成分和品质.以食用品质尚好为标准,在0～2℃,10～12℃,20～22℃下的贮藏期约分别为9～12d,5～7d和3d.     

运动训练中补充抗氧化剂：有益还是有害？

运动过程中骨骼肌产生的高水平反应物会导致肌肉损伤和肌肉功能受损,一般认为补充抗氧化剂可以保护肌肉不受损伤。无论对于运动爱好者还是专业运动员,抗氧化剂都是最常用的运动补剂之一。目前备受关注的是用额外口服抗氧化剂的方法来支持内源性防御系统,从而实现预防或减轻氧化应激、减少肌肉损伤并改善运动表现。目前有大量已发表的研究对该主题进行了讨论,大多数研究表明,抗氧化剂可以减轻运动引起的氧化应激,但大多数研究都未发现其对肌肉损伤和肌肉功能有任何影响。此外,越来越多的证据表明,抗氧化剂对健康和训练适应有消极作用。本文深入分析总结了关于活性物质（Reactive Species）在体内的作用以及服用抗氧化剂对维持健康和提高身体性能的功效的文献。     

Chronic ingestion of a low dose of caffeine induces tolerance to the performance benefits of caffeine

This study examined effects of 4 weeks of caffeine supplementation on endurance performance. Eighteen low-habitual caffeine consumers (<75 mg · day^?1) were randomly assigned to ingest caffeine (1.5–3.0 mg · kg^?1day^?1; titrated) or placebo for 28 days. Groups were matched for age, body mass, V?O_2peak and W_max (P > 0.05). Before supplementation, all participants completed one V?O_2peak test, one practice trial and 2 experimental trials (acute 3 mg · kg^?1 caffeine [precaf] and placebo [testpla]). During the supplementation period a second V?O_2peak test was completed on day 21 before a final, acute 3 mg · kg^?1 caffeine trial (postcaf) on day 29. Trials consisted of 60 min cycle exercise at 60% V?O_2peak followed by a 30 min performance task. All participants produced more external work during the precaf trial than testpla, with increases in the caffeine (383.3 ± 75 kJ vs. 344.9 ± 80.3 kJ; Cohen’s d effect size [ES] = 0.49; P = 0.001) and placebo (354.5 ± 55.2 kJ vs. 333.1 ± 56.4 kJ; ES = 0.38; P = 0.004) supplementation group, respectively. This performance benefit was no longer apparent after 4 weeks of caffeine supplementation (precaf: 383.3 ± 75.0 kJ vs. postcaf: 358.0 ± 89.8 kJ; ES = 0.31; P = 0.025), but was retained in the placebo group (precaf: 354.5 ± 55.2 kJ vs. postcaf: 351.8 ± 49.4 kJ; ES = 0.05; P > 0.05). Circulating caffeine, hormonal concentrations and substrate oxidation did not differ between groups (all P > 0.05). Chronic ingestion of a low dose of caffeine develops tolerance in low-caffeine consumers. Therefore, individuals with low-habitual intakes should refrain from chronic caffeine supplementation to maximise performance benefits from acute caffeine ingestion.