This study was carried out to compare the nutrient intake, urinary excretion of mineral (Na, K, Ca, Mg, Zn, Fe, Cu ), and the ratios of creatinine (Cr), body mass index (BMI) and basal metabolic rate (BMR) to the amount of mineral in 24-hour urine between both the male university students with few exercise (non-exercisers) and male university distance runners. The propriety of ratios of Cr, BMI and BMR was also examined in order to estimate intake of mineral for the male university distance runners. There were no significant differences in the intakes of energy, protein and carbohydrate between the both groups of subjects, and those major nutrients were at reasonable levels for the both groups of subjects. On the other hand, neither the intake levels of VB6, Ca, Mg, and Cu in the non-exercisers, nor niacin, Mg and Cu in the male university distance runners reached the level of Recommended Dietary Allowance for the Japanese. The intakes of retinol, VB1, VB6 and Ca were higher in the male university distance runners than in the non-exercisers. The urinary excretion and excretion ratio to intake of Zn, excretion ratio of Na, ratios of Cr, BMI and BMR of Zn, and Cr ratio of Na were higher in the non-exercisers than those in the male university distance runners. So as to achieve the same levels of Cr ratios of Ca and Zn as the non-exercisers, the male university long distance runners should take larger amounts of those minerals than the non-exercisers. It was suggested that the ratio of BMR rather than that of Cr ratio to urinary excretion of mineral would be suitable for the estimation of a desirable intake level of mineral for the male university distance runners.
The purpose of this study is to investigate the degenerative change of the cervical spine in American football (AF) players. The subjects were 27 collegiate AF players who had an annual radiological examination of the cervical spine. X-ray films of the lateral view were read by digital scanner and the anterior and posterior height of each spine (C 3-C 6) was measured. The subjects were divided into two groups based on experience of AF in high school (inexperienced and experienced) or the position played (lines and backs) . Although the anterior height did not change from the first grade to fourth grade, the posterior height of C 4, C 5 and C6 significantly increased (P <0.05) . The experienced group showed a faster increase in the rate of posterior height than the inexperienced group. Also, the backs group showed a faster increase in the rate of posterior height than the lines group. The increased posterior height, which sometimes includes bony spur, results in kyphotic change of cervical alignment and impingement of the cervical nerve root. The faster growth rate in experienced or backs groups suggests that higher mechanical stress to the cervical spine and younger start of AF caused degeneration.
The effects of electrical acupuncture at the patellar tendon and electrical stimulation of the femoral nerve on patellar tendon blood flow were evaluated using laser Doppler flowmetry in anesthetized rats. In most subjects the blood flow in the patellar tendon rapidly decreased for 30 seconds after the start of local electrical acupuncture and then increased above baseline. Changes in blood flow did not necessarily follow changes in arterial blood pressure. Changes in tendon blood flow induced by electrical stimulation of the femoral nerve were similar to those induced by electrical acupuncture at the patellar tendon. Arterial blood pressure and heart rate were not affected by electrical stimulation of the femoral nerve. Phentolamine administration abolished the decreased patellar tendon blood flow seen after initiating electrical acupuncture at the patellar tendon, whereas atropine abolished the increased patellar tendon blood flow seen after terminating electrical acupuncture at the patellar tendon. Furthermore, atropine did not evoke increased blood flow following electrical stimulation of the femoral nerve. These results suggest that the decrease of blood flow seen after initiating electrical acupuncture may be controlled by sympathetic vasoconstrictor nerves and the increase of blood flow following electrical acupuncture may be controlled by cholinergic vasodilator nerves.
It is known that lactic anions and hydrogen ions (H+) produced during intense exercise are partly transported or diffused from muscle to blood resulting in the production of non-metabolic CO2 through the bicarbonate buffering system. The purpose of the present study was to examine the reliability of the estimation of non-metabolic CO2 output using respiratory gas analysis during incremental exercise. Six healthy subjects underwent an incremental pedaling exercise test accompanied by respiratory gas and arterial blood sampling. The rate of non-metabolic CO2 output (VCO2-NM) was calculated by subtracting projected metabolic VCO2 from actual VCO2 after CO2 threshold (CT) . CT was determined using a modified V-Slope method. Bicarbonate (HCO3-), pH, CO2 partial pressure and lactate concentration were measured from arterial blood samples using automatic analyzers. The kinetics of VCO2-NM and HCO2- were compared throughout the exercise test. VCO2-NM was significantly correlated with HCO3-decrease after CT (r=0.976, p<0.001) and the kinetics of VCO2-NM and HCO3- decrease were similar during exercise. Furthermore, the amount of non-metabolic CO2 output (NM-CO2) calculated integrating VCO2-NM above CT was significantly correlated with the difference in HCO3-between CT and exhaustion (r=0.929, p<0.01) and with the difference in arterial blood pH between rest and exhaustion (r=0.863, p<0.05) . However, NM-CO2 was not significantly related to maximum ventilation (r=0.111, ns) . These results suggest that the estimation of non-metabolic CO2 output during incremental exercise proposed in the present study is reliable. It was also suggested that the primary factor which influenced nonmetabolic CO2 output during incremental exercise was the addition of H+ into blood and not hyperventilation.
The purpose of this study was to examine the effect of hopping tempo on the stretch reflex of the soleus muscle at the landing phase during continuous hopping. The M 1 and M 2 components of stretch reflex of the soleus muscle and angular velocity of the ankle joint were recorded at the landing phase during hopping under four hopping tempos with frequencies of 1.0, 1.5, 2.0, and 2.5 Hz. The electromyogram (EMG) activities in the soleus muscle during the landing and the jumping phases were separated under 1.0, 1.5 and 2.0 Hz conditions, but EMG's for both phases were overlapped under 2.5 Hz condition. Furthermore, at 1.0 and 1.5 Hz, a non-active EMG phase was observed between the landing and the jumping phases ; but this non-active phase disappeared at 2.0 Hz. The M 1 and M 2 components at 2.0 Hz showed significantly (p<0.01) larger values than those at 1.0 and 1.5 Hz. However, there was no significant difference observed between the components at 1.0 and 1.5 Hz. The M 2 component showed a significantly (p <0.01) smaller value than the M 1 component at 1.0 and 1.5 Hz ; but there was no significant difference at 2.0 Hz. The angular velocity of the ankle joint showed no significant difference under any of the conditions. These findings suggest that stretch reflex at landing during hopping may be inhibited at the motion pattern of the inactive phase between the landing and the jumping phases in EMG's. In addition, the stretch reflex is not only related to mechanical muscle stretching, but is also under the influence of the superior nerve center.
In order to clarify the effect of exercise on the walking performance and the muscle volume in lower limbs, elderly athletes long continuing to be trained and untrained elderly were compared with regard to their muscle cross-sectional area (CSA) of m. psoas major, thigh muscle and crus muscle and their walking ability. The subjects used consisted of thirty-six 80's-aged male and 70's-aged female elderly athletes and twenty-four elders having no regular exercise (control male group : CM, control female group : CF) . The elderly athletes were further divided into two groups in accordance with their results of Japan Fitness Test (high performance male group : HPM, low performance male group : LPM, high performance female group : HPF, low performance female group : LPF) . The walking performance was evaluated by analyzing their walking speed, stride-length and step rate during walking along a 15 m-strip of passage at normal and fast paces using videotaping. The muscle CSA was determined at m. psoas major, thigh muscle (extensors and flexors) and crus muscle (m. tibialis anterior and m. triceps surae) using MRI. As for the walking speed and stride-length at the normal pace, only HPM and HPF showed significantly higher values than CM and CF (male : p<0.05, female : p<0.01) . Meanwhile at the faster pace, HPF and LPF showed significantly higher values than CF in female (HPF : p<0.01, LPF : p<0.05) and in the case of males, only HPM have a higher value only of the walking speed than CM (p<0.05) . The CSA of m. psoas major in HPM and HPF significantly higher than that in CM and CF (all p<0.05), while in CSAs of knee extensor muscles and m. triceps surae, the statistical differences were not consistent among male and female groups. The results suggested that greater muscle mass of m. psoas major could influence higher walking speed in elderly people, and might be affected by regular exercise training.