男子青少年公路自行车运动员的蛋白质摄入和体内氮平衡关系研究

PROTEIN INTAKE AND NITROGEN BALANCE IN JUNIOR ROAD CYCLIST

蛋白质摄取在青少年发育过程中起着非常重要的作用,作为青少年公路自行车运动员,蛋白质的补充不仅要满足其自身发育的需要,还要满足运动训练对蛋白质的额外需求.本研究通过对11名15岁青少年男子公路自行车运动员和10名普通同年龄段的青少年日常生活的膳食调查并测定氮平衡,一方面初步分析青少年公路自行车运动员日常营养情况,另一方面通过对尿氮的分析,确定青少年公路自行车运动员日常蛋白质摄取量.研究中发现,运动员组和对照组均存在日常能量摄入不足的情况.脂类物质摄取比例正常,但是饱和脂肪酸和不饱和脂肪酸摄取比例失调,不饱和脂肪酸摄取比例偏低.两组均存在钙、镁、铁、锌、铜、维生素D、维生素C、维生素E和总纤维素摄入不足的情况.通过对尿氮的分析,我们发现当运动员组每日蛋白质摄取量在1.6 g以上时可以保持正氮平衡.但是由于总能量摄取不足,因此一方面要提高运动员组糖原物质的补充,另一方面要增加蛋白质的摄取量,每日摄取的蛋白质量应该高于1.6 g/kg体重.

It plays very important roles of protein intake during adolescents' growth and development.As junior road cyclist,the requirement of protein intake daily is not only for growth and development,but also for extra need during exercises.The present investigation intended to determine the nitrogen balance and protein intake in10 healthy male non-active adolescents and 11 junior road cyclist,both groups aged about 15 years old.As well as assessment of nutrient intake,Nitrogen excretion rate was determined and nitrogen balance was calculated from the mean daily protein intake and the urinary excretion.We found that their diets were quite inappropriate in terms of the intakes of carbohydrate,unsaturated FFA,some minerals(calcium,magnesium,zinc,copper),vitamins(D,C,E) and fibre.A positive nitrogen balance was observed from a mean protein intake of more than 1.6 g·kg^(-1) body mass day^(-1) in these cyclist.As the shortness of total energy intake,thus,the present investig ation indicated that as to give rise of carbohydrate,also give rise of a higher protein intake that is usually recommended.The daily intake of protein should more than 1.6 g·kg^(-1) body mass.