The purpose of this report is to investigate the changes in pulmonary functions in Japanese divers during a simulated heliox dive to successive depths of 250 and 300m (26 and 31 ATA). Pulmonary measurements of vital capacity (VC) and its components, forced expiratory volume in I sec (FEV 1.0), and maximal voluntary volume (MVV) were made during the dive. Compared to pre-dive, there were significant increases in tidal volume and expiratory reserve volume at depths, and VC at 31 ATA and post-dive; inspiratory reserve volume decreased significantly at depths in contrast to increased expiratory reserve volume. These results mean an alteration in the pattern of breathing during the dive. The striking effects were found on FEV 1.0 and MVV which decreased linearly with increasing inspired gas density.

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Six divers conducted identical incremental exercise on an underwater ergometer in a dive tank at a depth of ten feet. Each subject participated in six trials, using a different fin type during each trial (A : Brevets, B : Dacor, C i Aqua Lung, D : Power Plana, E : Sherwood, and F : graphite Power Plana). Oxygen consumption, heart rate, ventilation, breathing frequency and kick rate were monitored continuously throughout the 16 minute incremental exercise, to assess the effect of each fin on physiological responses. Results suggest that incorporating vents and stabilizers in fin design did not enhance performance. However, subjects reported a Iower rating of exertion, when the angle of the vents was such that the upstroke was emphasized.

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The relationship among 1) Iactate threshold (the point at which blood lactate concentration begins to increase above a resting value during an incremental exemcise), 2) onset of blood lactate accumulation (OBLA ; the point at which blood lactate reaches a concentration of 4 mM), 3) VO_2max, 4) 12-min running performance, 5) PWC₁₇₀, and 6) step test score was assessed using nineteen female students who volunteered to be subjects. The lactate threshold, OBLA and VO₂_a_x for these females averaged 0.85±0.30 1·min^-1 in VO₂ (±SD), 1.80±0.35 1·min^-1 and 2.121±0.30 1·min^-1, respectively, and corresponded to approximately 85%, 86%, and 80% of the values obtained for males. The lactate threshold was significanty related with V0_2max (r= 0.78 ; P<0.01), 12-min running performance (r=0.69 ; P<0.01), PWC₁₇₀ (r=0.79 ; P<0.01), the step test score (r=0.47 ; P<0.05) and OBLA (r=0.87 ; P<0.01). The OBLA was also significantly related with V0_2max (r=0.68 ; P<0.01), 12-min running performance (r=0.51 ; P<0.05 and, PWC₁₇₀ (r=0.80 ; P<0.01). With the exception of PWC₁₇₀ the magnitude of the correlation of the lactate threshold with other endurance indices was greater than that of OBLA. It is concluded that the lactate threshold is a useful index for endurance ability in females and that, although OBLA was also related to endurance ability, there were lower correlations than observed for the lactate threshold.

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To determine the effect of the duration of incremental exercise on the point at which arterial blood lactate concentration (HLa) increases above the resting value (Iactate threshold : LT) and on the point at which HLa reaches a constant value of 4 mM (onset of blood lactate accumulation : OBLA), eight male students performed two different kinds of incremental exercise. In addition, the workloads corresponding to OBLA, which were obtained during both incremental exercises, were investigated for the validity of endurance training intensity. Incremental exercise bicycle tests consisted of 25 watts increase every minute (the 1-min test) and every 4 minutes (the 4-min test), respectively. VO₂ VCO₂, and V_Ewere measured by the Douglas bag method. Arterial blood samples were obtained from a catheter inserted into the radial artery. Blood HLa was analyzed by the enzymatic method. LT and OBLA were determined from the relationships between the HLa and VO₂ during the two kinds of incremental exercise tests. At the level of LT, OBLA, and maximal exercise, there was no significant difference in ventilatory and gas exchange parameters except for the workloads. Each subjects also performed two submaximal bicycle exercises for 15 minutes which intensities were corresponded to OBLA. During the submaximal exercise performed with the workload that had been determined with the 1-min test, HLa Increased gradually with duration and attained 8.8±1.2 mM after the end of exercise. On the other hand, when the submaximal exercise was performed with the workload which had been determined with the 4-min test, HLa remained at the predetermined value (4.0±0.4 mM). It was concluded that the lactate steady state condition was necessary to determine the endurance training intensity.

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There are large differences of physique and physical fitness of the schoolchildren among geographical areas in Japan. The measurements of physique and physical fitness of children were undertaken in an elementary school of central area of Tokyo in this study. Subjects were 327 children aged from 9 to 12 years. The height, weight, chest gjrth, abdominal girth, sitting height and skinfold thickness were measured. The physical fitness measurements were made on muscular strength (grip and back strengths), flexibility (trunk extension and standing trunk flexion), agjlity (side step test) muscular power (vertical jump) and endurance activity (step test). The results were compared with standards regarding age and sex differences. The mean values of height, weight, chest girth and sitting height were almost equal in the standard value of comparable age and sex. The values of grip and back strengths were inferior by the standard values in each group; especially back strength showed a remarkable low value. On the other hand, it has been shown that their vertical jump scores were excellent than the standard values. There were the groups that maesured values of side step and standing trunk flexion showed rather excellent values compared to the standards. The score of step test was very inferior than the standards. It has been shown that the schoolchildren in this study had generally average values in physique and inferipr in physical fitness. The trends that were especially inferior to muscular strength and endurance activity were observed. These results is partly due to the influences from the present social state of the living environment condition such as motorization, Iaborsaving, etc.

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