ABSTRACT
Changes in the amount of urinary protein and β<SUB>2</SUB>-microglobulin (β<SUB>2</SUB>-MG) were observed after middle-distance running in 46 primary school boys, 46 junior high school boys, 74 high school boys and 51 male college students, aged between 6 and 21 years.<BR>The running distance was varied according to age : 800 m for 6- to 7-year-olds, 1, 200 m for 8- to 9-year-olds, 1, 700 m for 10- to 11-year-olds and 1, 500 m for 12- to 21-year-olds.<BR>Urine was collected from each subject before and 30 min after running, and total urinary protein was analyzed by the Lowry method and β<SUB>2</SUB>-MG by the reverse passive hemagglutination method.<BR>For all subjects at rest, total urinary protein was 14.2-19.1 mg/d<I>l</I> on average and increased to 24.6-96.2 mg/d<I>l</I> at 30 min after running, while β<SUB>2</SUB>-MG at rest was 3.10-7.12 μg/d<I>l</I> and increased to 30.53-1202.87 μg/d<I>l</I> at 30 min after running.<BR>Urinary protein originating in blood plasma and that in non-blood plasma was calculated on the basis of the study of Poortmans (1968) . Urinary protein originating in blood plasma after running was 2.54-6.58 times higher than that before running, whereas non-blood plasma after running was 1.04-1.92 times higher than that before running. This suggests that the increased urinary protein after running mainly originates from blood plasma. In terms of age, urinary protein from non-blood plasma in boys aged 6 to 11 years showed a greater increase than that in boys over 12 years old.<BR>The ratio of β<SUB>2</SUB>-MG to urinary protein after running was 7.0-80.6 times higher than that before running. The correlation coefficient between urinary protein and β<SUB>2</SUB>-MG became higher after running than that before running. These findings indicate that low-molecular-weight urinary protein is predominantly reabsorbed in the proximal renal tubule. In terms of age, the increase in the above ratio in 12-14-year-olds was lower than that in 1521-year-olds, suggesting that the reabsorption ability of the proximal renal tubule matures with age.
ABSTRACT
Body condition and nutritional intake of female competitive gymnasts (four athletes who participated in Universiade championships and seven athletes who passed preliminary trials for World championships) were investigated during intensive training camp, where they improved their technical skill of gymnastics and regulated their body weight through body training and dietary intake.<BR>The results are summarized as follows;<BR>1) Daily energy intake, protein intake (per 1 kg of body weight) and iron intake during training camp of Universiade and World athletes were 1, 566±292 kcal (mean±standard deviation), 1.29±0.08 g/kg, 6.6±1.6 mg, 1, 367±267 kcal, 1.24±0.19 g/kg, 6.6±1.4 mg respectively on the average. Each intake of them was low during training camp.<BR>2) The lower their daily energy intake, the more their body weight decreased. High correlation between energy insufficient (needed energy minus intaked energy) per 1 kg of body weight and body weight losses was observed. And also, high correlation between decrease of body weight and proportion of energy intake per basal metabolism was observed.<BR>3) Changes in body composition during the first training camp were detected; decrease of their body weight, body fats and lean body masses. Compared with the second training camp, the amount of body fats decreased, while the amount of lean body masses increased.