Intragastric pressure at gastric empty state was measured by radio capsule method during various exercises in three human subjects. The E. I. L. Type. 70. pressure sensitive radio capsule of England make was used in this experiment.
1) The empty intragastric pressure at rest was 30.0-33.0 cmH₂O and the gastric peristalsis was 2-3 sec. in frequency and less than 3 cmH₂O in amplitude.
2) The resting gastric peristalsis was disappeared immediately after the onset of deep respiration or exercise. The pressure raised to maximum 76.0 cmH₂O at the end of deep abdominal inspiration.
3) The intragastric temperature raised during various exercises and increasing grade was showed in Table of the text.

It had been proposed by Kurata that relative threshold value F_th of single motor units depends on the gradient G (kg/sec) of the tension increase of muscle in such a manner as
F_th (≡T.G) =ρG^λ
Here T₁ is the time interval from the onset of EMG to the moment of recruitment of a motor unit and ρ is a proportional constant. The motor unit with a positive/negative value of λ is characterized to be static/phasic.
Morimoto and Hasegawa reported that the above relation also holds for the relaxation period, provided that Ftn and G are replaced by the tension at the moment of silence and the absolute value of G, respectively. In this case, the motor unit with a positive/ negative value of λ is characterized to be phasic/static.
In order to investigate the characteristics of motor units during relaxation period under the influence of pre-relaxation states, such as the increase of tension up to 4kg at the gradient of 0.5kg/sec and the state sustained at 4.0kg for 30sec. Single motor units of m, vastus medialis were studied by the same method as that of Morimoto and Hasegawa.
The following results were obtained;
1) Both at contraction and relaxation periods, the above relation was confirmed.
2) The motor unit with characteristics of recruitment modes was influenced by the pre-relaxation state, but its tendency was not definite. These results suggest that phasic/static characteristics of motor units are not stationary but fluctuate depending on the pre-relaxation states.

In this study, the relationships between the contractile properties of human motor units and their discharge patterns, characteristics of recruitment and others were examined. Action potentials of single human motor units in m, extensor digiterumwere detected by use of an inserted electrode. Tension curves of single motor units were recorded under the conditions that tension in finger extension was gradually increased, and that the subject relaxed his muscle as soon as he observed a sweep on a Braun tube triggered by the action potential of a single motor unit. About 100 twitch tension curves were summed up to obtain the average tension curve of a single motor unit. The τ-S diagrams were obtained from the mean discharge intervals (τ) of motor units at various sustained tensions and their standard deviations (S) . The λ values were also obtained from the relation F_th (-T₁G) =ρG^λ.
It was observed that the contraction time of the twitch tension curve of single human motor unit in a muscle was nearly proportional to τs (the τ values at a constant S value) . We presume that the regularity of discharging of motor unit affects the contraction speed in human muscle, because the motor unit with more regular discharging has longer contraction time of twitch.

Heart rate and R-R intervals of ECG during sleep were examined in healthy young men. Heart rate per minute were gradually decreased when the subject fell asleep. Whole through one night sleep data there were two typical heart rate variation patterns, namely stable stage and fluctuating stage. Sleep stages determined by EEG, EOG and EMG of chin corresponded with these two patterns; slow wave stage (Stage III/IV) showed the stable pattern, REM Stage and Stage I showed the fluctuating pattern, Stage II both patterns. The fluctuating pattern showed higher heart rate level.
Further studies computed R-R intervals and its variations of ECG revealed 4 typical patterns on the variations, and well corresponded with sleep patterns determined by the above methods. R-R interval varied from 1.39 to 0.67 sec during sleep. R-R interval variation befor onset of sleep showed lightly rythmical periodicity (20-40 sec) and small fluctuation (0.1 sec) (awaking pattern) . R-R intervals after onset of sleep extended gradually, fluctuating midly (0.1 sec) and did not show any periodicity (transient pattern) . R-R interval reached its maximum level then. At slow wave stage (S-III/IV) R-R interval showed mild fluctuation as the transient strage, and did not show any periodicity (stable pattern) . At REM stage and S-I it showed large fluctuation (more than 0.2 sec) and significant periodicity (10-30 sec) . At S-2 if the stage was in the course of deepening the sleep, it showed stable pattern and if it was in the course of lightening the sleep it showed fluctuating pattern.

A training experiment was carried out to investigate the difference in training effects between power-up type and bulk-up type strength training exercises from the aspects of muscle histochemical properties and capillary supply. The subjects were eleven healthy males. The power-up type group (five males) performed knee extension exercise for 5 sets at 90% of 1 RM (one repetition maximum) with a 3-min rest between sets (repetition method) . The bulk-up type group (six males) performed the same exercise for 9 sets at 80-40% of 1RM with a 30-s or 3-min rest between sets (interval method, multi-poundage system) . Both programs were carried out twice a week for 8 weeks.
The main results were as follows ;
1. Percentages of fiber types showed no recognizable changes in either group.
2. Fiber area was significantly increased for all fiber types (Type I, Type IIA, Type JIB) in both groups. However, the rate of increase was greatest for type IIA fiber, followed by type JIB fiber and then type I fiber. Moreover, the rate of increase for all fiber types in the bulk-up group was higher than that in the power-up group.
3. Percentage of fiber area showed no recognizable changes for any fiber types in the powerup group. However, the percentage area of type II fibers, especially type IIB fiber, was significantly decreased in the bulk-up group.
4. CC (Type I), CC (Type IIA) and CC (Type IIB) (number of capillaries in contact with each fiber type) were significantly increased in both groups. However, in comparison with CC (Type I), CC (Type IIA · Type IIB) showed a higher rate of increase in the power-up group. On the other hand, in comparison with CC (Type IIA · Type JIB), CC (Type I) showed a higher rate of increase in the bulk-up group. Also, compared with the power-up group, the bulk-up group showed a signifi-cantly higher rate of increase of CC (Type I) .
5. C/Fiber area (Type I), C/Fiber area (Type IIA) and C/Fiber area (Type IIB) (number of capillaries supplying each fiber area) were decreased in both groups.
The above results show that power-up type exercise leads mainly to hypertrophy of type I, type IIA and type IIB fibers without any change in percentage fiber type or percentage fiber area, whereas bulk-up type exercise leads mainly to hypertrophy of each fiber type with decreases in percentage area of type II fibers, especially type JIB fiber. Also, power-up type exercise leads mainly to an increase in the number of capillaries around type II fibers, whereas bulk-up type exercise leads mainly to an increase in the number of capillaries around type I fiber. However, capillary development around all fiber types did not necessary coincide with muscle hypertrophy in either exercise.
The authors reported previously that power-up type exercise is effective mainly for improving muscular strength and anaerobic power, whereas bulk-up type exercise is effective mainly for induc. ing hypertrophy and anaerobic endurance. The results of this study may help to clarify these effects from the viewpoint of the adaptations of muscle fibers and the capillary supply.

A study was conducted to assess gender differences of body fat distribution (i. e., total body fat mass, subcutaneous fat mass, and internal fat mass) in a homogeneous group of Japanese children. Body composition was estimated in 141 boys and 139 girls (aged 3-6 yr) using bioelectrical impedance analysis (BIA) . All subjects were apparently healthy. Determinations of impedance were made using a four-terminal impedance analyzer (TP-95 K, Toyo Physical, Inc., Fukuoka) . The lean body mass (LBM) was calculated using the equation of Kushuner et al. (1992) and Goran et al. (1993) . Total body fat mass (TFM) was calculated as the difference between body weight and LBM. The subcutaneous fat mass (SFM) was calculated using a modification of the equation derived by Skerjl et al. (1953) . The internal fat mass (IFM) was calculated as the difference between TFM and SFM. From ages 3 through 6 years, the mean LBM increased with age in boys and girls, but showed no significant gender differences. There were also no obvious gender differences in TFM and IFM within the same age range. Percentage body fat decreased in both sexes until the age of approximately 5-yr, and then increased again slightly at 6 yr, although it showed no significant differences between the sexes. The gender-specific pattern of fat accumulation during childhood was characterized by an almost steady increase of SFM in girls. These differences were independent of gender differences in physical characteristics.

To examine the personal space perception, measurements were conducted on both arms in 227 young men and women. Each subject, with his eyes closed, was instructed to stop the horizontal swing motion of his arm at the point he considered to be the middle of the range of possible motion on the horizontal plane, and this was repeated ten times.
Mean values of bisected angles were deviated from the middle points in the direction of the horizontal adduction, although there were large differences between the individuals. The deviation was larger in the right arms than that in the left, and it increased with the increasing range of motion of the horizontal abduction.
It was suggested that the gain of the personal space perception is higher in front of the body than in the side on the horizontal plane of the human shoulder.

The relations between the power output during exercise and its maximal duration have been investigated on three young male subjects throughout the performance of heavy constant loaded cycling exercises with different intensities, all of which lead to exhaustion during the period from about 20 seconds to about 100 minutes.
The Aerobic Power output (mean total oxygen intake during exercise) develops rapidly with the increase of the maximal duration of exercise amounting to a few minutes in every case, and then, levels off approximately in one case, but declines steadily in the other cases.
The Anaerobic Power output (oxygen debt per endurance time of exercise) decreases rapidly with the increase of the maximal duration of exercise amounting to about 5 minutes, and then decreases slowly.
The relation between the Total Power output (sum of the Aerobic Power output plus the Anaerobic Power output) and its maximal duration is summarized as the two equations : log P = a - b logt, in the case of the t shorter than about 5 minutes, and log P =a′ - b′log t, in the case of the t longer than about 5 minutes. Here, P is the Total Power, tis the maximal duration, and a, b, a′ and b′ are constants. In each subject, the values of the constants a and b respectively. are greater than the a′ and b′
The present investigation was supported by a Grant in Aid for the Miscellaneous Scientific Research from the Ministry of Education.

“Power-Duration Curves” had been measured on three middle aged subjects through-out the performance of heavy constant loaded cycling exercise with different intensities. And the results were compared with the results of previous investigation on young subjects for the purpose to know the properties of the physical work capacity of middle aged man.
The relations between the Total Power output (TP) and its maximal duration (t) is summarized as the following two equations: log TP=a-b·log t, in the case of the t shorter than about 5-6 minutes, and log TP=a′-b′·log t, in the case of the t longer than about 5-6 minutes. The relations between the Anaerobic Power output (AnP) and its maximal duration (t) is also summarized as the two equations: log AnP=c-d·log t, in the case of the t shorter than about 1-4 minutes, and log AnP=c′-d′·log t, in the case of the t longer than about 1-4 minutes. The above equations are applicable to the results of every subjects in each age group, then, the age difference in quality is hardly found. However, the values of the constants a, a′, c and c′ in the above regression equations are respectively lower in the middle aged subjects, the other hand, the age difference is scarcely found in the values of the constants b, b′, d and d. It is also said that the endurance time of the certain Aerobic Power output of the middle aged subjects are shorter than young ones within the experimental region.
It is considered that the one of the reasons, both of the endurance times of the certain Aerobic Power output and Anaerobic Power output are shorter in the middle aged subjects than young ones, is the maximal aerobic power and the maximal anaerobic capacity of the middle aged subjects are lower than young ones.
In this paper, the Aerobic Power is a mean total oxygen intake during exercise, the Anaerobic Power is a oxygen debt per endurance time of exercise. The term of the “Anaerobic” is not most suitable one, however it is used for convenience. The Total Power is defined as the sum of the Aerobic Power plus the Anaerobic Power.

To examine the variation in the knee extension force and the integrated electromyogram from rectus femoris, medial vastus and lateral vastus muscles with the knee joint angle in growing children, measurements were conducted in 61 school boys aged from 7 to 12 years old. Anthropometric measurements were also done on the body height, the lower limb length, and so on. Results obtained were as follows.
1) Ratio of the lower limb length comparing with the body height increased with the grade.
2) Maximal force at each joint angle in each grade was shifted peak from 70°to 90°with the grade.
3) The pattern of the integrated surface electromyogram from rectus femoris, medial vastus or lateral vastus muscle at each joint angle was the same in all of the grade. The integrated electromyogram at the maximal voluntary contraction was maximal at 45°of the knee joint angle in the rectus femoris muscle, at 110°in the medial vastus and at 90°in the lateral vastus muscle.