ABSTRACT
We investigated both the acute effects of maximal exercise and the chronic effects of training on nonspecific immunity in 15 winter-sports athletes during different periods of training : (a) before the athletic season, in summer, when the athletes were undertaking extensive endurance training to enhance aerobic capacity, (b) during the winter sports season, in early winter, when endurance and athletic training were being undertaken, and (c) after the winter sports season, in spring, when the athletes were resting (detraining for a month) . The mean value of the maximal oxygen uptake in each training period was (a) 65.4 (SD 4.6) mL·kg<SUP>-1</SUP>·min<SUP>-1</SUP>, (b) 63.1 (SD 5.5) mL· kg<SUP>-1</SUP>·min<SUP>-1</SUP>, and (c) 58.3 (SD 5.8) mL·kg<SUP>-1</SUP>·min<SUP>-1</SUP>, respectively. Following maximal exercise, acute peripheral leukocytosis due to lymphocytosis and neutrophila was observed in every period. The capacity of isolated neutrophils to produce reactive oxygen species upon stimulation with opsonized zymosan measure by luminol-dependent chemiluminescence (LDCL) was significantly enhanced after maximal exercise before and during the athletic season. However, the degree of enhancement was smaller during after-season detraining, suggesting that the conditioning state affected the exercise-induced changes in neutophil functional status. Serum opsonic activity also showed a similar pattern. As for the chronic effects of training, the resting values of the neutrophil count, especially the segmented neutrophil count, the neutrophil LDCL response and the serum IgG level, declined significantly in the pre-season training period. Since the subjects were engaged in exhaustive endurance training under heat exposure at that time, the nonspecific immune status might have been partially compromised due to chronic overload.
ABSTRACT
Twenty endurance-trained athletes (five male speed-skaters, eleven male and four female cross-country skiers, 16-18 years) ran on a treadmill by a protocol of incremental graded increase in workload until exhaustion during an endurance training period in off-season summer. Immediately after exercise, all developed peripheral leukocytosis (1.9 times; p<0.01) due mainly to lymphocytosis (2.6 times; p<0.01) with a predominant effect on large granular lymphocyte (natural killer cell) count (5.9 times ; p<0.01) . Monocyte count was also enhanced 2.3 times (p<0.01) . These increases were transitory and returned to the pre-exercise levels 1 h later. Peripheral neutrophilia was also observed by 43% (p<0.01) immediately after exercise and remained elevated by 25% (p<0.01) 1 h after exercise, but a shift to the left did not take place. The capacity of isolated neutrophils to produce reactive oxygen species was assessed by luminol-dependent chemiluminescence which detects mainly myeloperoxidase (MPO) -mediated formation of such hyperreactive oxidants as HOCl. The maximum intensity of chemiluminescence (peak height) upon stimulation with opsonized zymosan was significantly enhanced following exercise (p<0.05) . Similar results were obtained when phorbol myristate acetate was employed as nonphagocytic soluble stimulus (p<0.01), suggesting that the capacity of neutrophils to degranulate MPO rather than phagocytosis was enhanced following exercise. In addition, the enhancements of chemiluminescence were positively correlated with the increase in segmented neutrophil count. These data indicate that maximal exercise not only mobilized mature neutrophils from the marginated pool into the circulation, but also augmented their capacity to generate reactive oxygen species of higher reactivity.
ABSTRACT
This study was designed to find out about the body composition of ordinary Japanese adults, and to clarify how gender and age have effects on it. The subjects were volunteers living in the northern, central and western parts of Japan. They consisted of 154 males and 142 females aged 20 to 59 years. Their body height and weight did not differ by more than 1 S. D. from the mean of the given age category cited in the Japanese Ministry of Education Annual Report. Body composition was estimated from densitometry using an underwater weighing method and pulmonary residual volume measurement. Within each age group, there were significant differences in body height, weight, body density, percentage body fat, lean body weight, fat per 1 m of body height and lean body weight per 1 m of body height, but there was no significant difference in fat between males and females. Percentage body fat and fat increased significantly with age in both genders. The rate of increases of fat were calculated to be 14.2% for males and 10.7% for females per decade. Lean body weight decreased significantly with age in males, decreasing at a rate of 3.3%. However, the lean body weight of females stayed constant over the given ages of this study. These results show that the difference in body weight between males and females is caused by lean body mass, not by fat.
ABSTRACT
A somatometric study attempting to investigate the standard values for body density at adolescence was performed by densitometry in a series of seventy-four subjects, 47 males with a median age of 21.5±1.7 years and 27 females averaging in age at 20.1±1.1 years. And also a simple equation for the estimation of body density from measured skinfold thickness was investigated.<BR>Results obtained were as follows:<BR>1. The body density was determined to be 1.0750±0.0118 (mean±standard deviation) for men and 1.0428±0.0090 for women, respectively. The corresponding body fat contents (fat%) were 11.0±4.7% and 24.1±3.8%.<BR>2. Various indices of physical construction, viz., relative body weight, Rohrer's index, Vervaeck index, Ponderal index and Hirata's index, were noted to show a generally close correlation with the body fat content determined by the densitometry, the correlation with Rohrer's index being most prominent.<BR>3. Of the skinfold thickness in seven different regions of body surface (chest, abdomen, crista iliaca, upperarm, subscapular, thigh and buttock), that of the abdomen displayed the closest correlationship with the estimated body density in both men and women.<BR>4. The circumference of various parts of the trunk and extremities such as the shoulders, chest, abdomen, hips, thight, brachial biceps, forearm, wrist, knee, gastrocnemius muscles or ankle was found notably less closely correlated with the body density in both sexes than the skinfold thickness was, thus indicating poor usefulness of these parameters.<BR>5. Assessments were made as to goodness of fit between the body density estimated by the previously proposed equations and the measured values. The equation of Wilmore (r=0.825) showed the highest goodness of fit in men and that of Sloan (r=0.768) in females, respectively, indicating their reliably high accuracy.<BR>6. Twenty-one different combinations of two each out of the seven regions of skinfold thickness measurement were analyzed for coefficients of their multiple correlation with the measured body density. In both males and females, the abdomen-thigh combination was noted to show the highest correlation coefficients.<BR>The multiple regression equations for this pair of regions were formulated to be: Y=1.09482-0.00119 abdomen S, mm-0.00085 thigh S, mm for men, and Y=1.07028-0.00082 abdomen S, mm-0.00035 thigh S, mm for women.<BR>Only four males (8.50) and a female (4%) exhibited differences over than 0.01 between the body density estimated be these equations and the measured value.<BR>The results indicate noticeable accuracy of the estimation of body density by these equations which we believe are commendable.