MAXIMAL OXYGEN UPTAKE OF PERSONS WHO HAVE NO HABITUAL EXERCISE / 体力科学

Generally, a person who has higher cardiorespiratory fitness has lower lifestyle-related disease(LRD)morbidity rates and lower mortality rates. In Japan, Ministry of health, labor and welfare has defined the reference values of the maximal oxygen uptake(VO₂max)for health promotion by gender and age in 2006. The reference values were defined based on the systematic review of the japanese and foreign articles for the relationship between VO₂max and LRD. However, the articles based on japanese subjects were few. The purpose of this study is to examine the morbidity rates of LRD and VO₂max of japanese persons who have no habitual exercise. The subjects of this study comprise 141 males and 287 females aged from 20 to 69. The LRD morbidity rates of males and females suffered from dyslipidemia, hypertention, diabetes / impaired glucose tolerance were 78.7% and 58.5%, respectively. The mean VO₂max obtained by an incremental bicycle exercise at all group divided by gender and age did not achieve the reference values. The rate of the LRD subjects of males and females who achieved the reference values were 9.9%(n=11)and 4.8%(n=8), respectively. And the rate of the non-LRD subjects of males and females who achieved the reference values were 36.7%(n=11) and 14.3%(n=17), respectively. To obtain the habitual exercise and to keep higher physical activity is important to control a decline of VO₂max with aging and to prevent the LRD.

REFERENCE INTERVAL OF MAXIMAL OXYGEN UPTAKE (VO₂max) AS ONE OF THE DETERMINANTS OF HEALTH-RELATED PHYSICAL FITNESS IN JAPAN / 体力科学

Maximal oxygen uptake (VO₂max) is an important determinant of health-related physical fitness. In 2006, the Japan Ministry of Health, Labour and Welfare (JMHLW) officially declared a standard reference value and reference interval of VO₂max. However, these values were established on the basis of a systematic review of reports published in Western countries and were not based on actual VO₂max data of the Japanese population. Therefore, we conducted a study entitled “The study on a minimum zone of VO₂max as one of the determinants of health-related physical fitness in Japan” from 2004 to 2006 as a project of the Japanese Society of Physical Fitness and Sports Medicine (JSPFSM). In addition, we collected published VO₂max data of the Japanese population from the JSPEFM website. In the present study, we attempted to determine the reference interval of VO₂max with regard to age, gender, and different methods of exercise. Further, we established a cut-off value of VO₂max for determining metabolic syndrome (MS).1. Reference interval of VO₂maxFor both men and women, 325 and 364 values for the treadmill exercise, and 1175 and 2178 values for the cycle ergometer exercise, respectively, were collected. This data revealed a balanced distribution of VO₂max with regard to age. Data that satisfied the VO₂max criterion were used for the analysis. These data were regressed to age on gender and methods of exercise. The percentage of VO₂max was calculated using the following equation: %VO₂max = measured VO₂max × 100/age-estimated VO₂max. The iterative truncation method was used to calculate the reference interval of VO₂max (70%∼130% VO₂max) from the crude data of %VO₂max, and then converted to actual VO₂max. Thus, the reference interval of VO₂max for healthy Japanese was determined with regard to age, gender, and different methods of exercise.2. Cut-off value of VO₂max for determining MSUsing the VO₂max data of subjects with body mass index (BMI) of ≧25kg/m² and ≧2 MS risk factors, and the data of subjects with normal BMI without any risk factors, we calculated sensitivity and specificity. The cut-off value was determined using the receiver operating characteristic curve. This cut-off value was defined as the critical value of VO₂max that should be maintained to avoid MS and remain healthy.

INCLINATION OF EXPONENTIAL CURVE-FITTING MODEL FOR HEART RATE AND OXYGEN UPTAKE DURING INCREMENTAL EXERCISE AS INDEX OF CARDIO-PULMONARY FUNCTIONAL IN PATIENTS WITH ISCHEMIC HEART DISEASE / 体力科学

This study was conducted to clarify the validity and availability of inclination of exponential curve-fitting model for oxygen uptake (VO₂) and heart rate (HR) during incremental exercise (I-ECOH) as an index of cardio-pulmonary functional reserve in patients with ischemic heart disease (IHD). A treadmill exercise test was used to measure the VO₂(L/kg/min) and HR (beat/min) during incremental exercise of all subjects. I-ECOH was derived from the following equation : HR=A·exp^B·VO2. The constant "B" represents I-ECOH. The following two identifications were made : 1) the relation between peak oxygen uptake (VO₂peak) and I-ECOH in IHD patients with normal left ventricular function and with chronic heart failure (CHF); 2) the relation between I-ECOH and the New York Heart Association (NYHA) functional classification of IHD patients with CHF.There were significant differences among IHD patients with normal left ventricular function, CHF patients, normal controls and long distance runners in I-ECOH and VO2peak, respectively (p<0.001). There were inverse correlations between I-ECOH and VO2peak in IHD patients with normal left ventricular function (r=-0.64, p<0.001) and CHF (r=-0.63, p<0.001). I-ECOH could be used to discriminate effectively between NYHA functional classes (p<0.001).In conclusion, these results suggest that I-ECOH is adequate and useful as an index of cardio-pulmonary functional reserve in patients with ischemic heart disease.

EVALUATION OF SCUBA DIVING WORK LOAD / 体力科学

Divers' heart rates were measured under real ocean diving conditions with the purpose of evaluating the workload during SCUBA diving. For the subjects, all-out tests were conducted and evaluated in each of the following conditions: 1. ergometer cycling, 2. ergometer cycling using diving regulator, 3. fin-swimming in a swimming pool with diving equipment. No significant heart rate difference was found between the pre-dive and post dive of each subject; although, in novice divers, high heart rates such as 140/min or more were observed especially during the dive gear wearing phase on the topside and/or floating on the surface phase, suggesting there should be some high heart rate inducing factors, other than the exercise, like stress. Whereas, in the results of the all-out tests, the heart rate for fin-swimming was 16~18 beats/min lower, as well as 5.7~14.2 ml/kg/min lower for VO₂max, as compared to the ergometer cycling. This may suggest that fin-swimming like scuba diving could give a diver some degree of physical load without on increased heart rate.

EFFECT OF N-3 POLYUNSATURATED FATTY ACID SUPPLEMENTATION ON AEROBIC CAPACITY IN YOUNG WOMEN / 体力科学

N-3 polyunsaturated fatty acid supplementation has been recognized to affect the peripheral oxygen delivery system with increasing blood rheology. The purpose of the present study was to investigate whether n-3 polyunsaturated fatty acid supplementation, using purified perilla oil rich in α-linoleic acid, improves aerobic capacity in young women. Eighteen young, sedentary female college students were divided into an n-3 polyunsaturated fatty acid supplemented control group (PUFA-C, n=10) and an n-3 polyunsaturated fatty acid supplemented trained group (PUFA-T, n=8). All subjects took 20g of perilla oil (11g of n-3 polyunsaturated fatty acid) in addition to the usual diet throughout the experimental period of 4 weeks. PUFA-T subjects exercised for 30 min on a bicycle ergometer (intensity, 60% of VO₂max) 4 times a week for 4 weeks. Maximal oxygen uptake (VO₂max) and oxygen uptake at the ventilatory anaerobic threshold level (VT) significantly (p<0.05) increased after treatment in both groups. However, the endurance time in the exhaustive exercise test significantly (p<0.05) increased in the PUFA-T group only. Increasing rates of VO₂max and VT with treatment for the PUFA-C group were lower than those for the PUFA-T group (VO₂max, 12.6% vs 14.4%, VT, 9.7% vs 16.9%). After treatment, these values returned to baseline levels within 2 months of the recovery period without n-3 polyunsaturated fatty acid supplementation in both groups. Only for the PUFA-T group, VO₂max and VT at 2 months after the treatment period were significantly (p<0.05) higher compared with baseline levels. These results suggest that n-3 polyunsaturated fatty acid supplementation might have a beneficial effect on improving aerobic capacity with increasing peripheral oxygen delivery. However, n-3 polyunsaturated fatty acid supplementation was less effective than aerobic training.

EFFECTS OF DIET PLUS EXERCISE ON VISCERAL FAT IN OBESE WOMEN: WITH SPECIAL REFERENCE TO THE INCREASE IN VO2max / 体力科学

The purpose of this study was to determine the loss of visceral fat during weight loss program with diet only or diet plus exercise in premenopausal obese women (age 44±6 yr) . One hundred seventeen women (body mass index 29±3 kg /m<SUP>2</SUP>) were divided into diet only group (DO, n=40) and diet plus exercise group (DE, n=77) . DE was further divided into two groups: a group with a small change in VO<SUB>2</SUB>max (DE<SUB>1</SUB>, n=26) and a group with a large change in VO<SUB>2</SUB>max (DE<SUB>2</SUB>, n=51) . Height, weight, fat mass, %fat, fat-free mass (FFM), abdominal total fat area (TFA), visceral fat area (VFA), subcutaneous fat area (SFA) and VO<SUB>2</SUB>max (ml/kg FFM/min) were measured before and after weight loss. The changes of weight, fat mass, %fat were significantly larger in DE than in DO. No difference was found in the changes of weight, fat mass, %fat between the DE<SUB>1</SUB> and DE<SUB>2</SUB>. Percentage of change in VFA was significantly larger in DE<SUB>2</SUB> (41±15%) than in DE<SUB>1</SUB> (31±16%) . These data suggest that both weight-loss programs (DO and DE) contribute to a remarkable decrease in visceral fat. Addition of exercise training, which would induce an improvement in VO<SUB>2</SUB>max, to dietary restriction, may elicit a greater effect on visceral fat.

INCLINATION OF EXPONENTIAL CURVE-FITTING MODEL FOR OXYGEN UPTAKE AND HEART RATE DURING INCREMENTAL EXERCISE AS INDEX OF CARDIO-PULMONARY FUNCTIONAL RESERVE / 体力科学

A study was conducted to clarify the validity and availability of inclination of exponential curve-fitting model for oxygen uptake (VO<SUB>2</SUB>) and heart rate (HR) during incremental exercise (IECOH) as an index of cardio-pulmonary functional reserve in healthy subjects. A treadmill exercise test was used to measure the VO<SUB>2</SUB> (L/kg/min) and HR (beat /min) during incremental exercise of all subjects. The IECOH was derived from the following equation : HR=A⋅exp<SUP>B·VO<SUB>2</SUB></SUP>. The constant “B” represents the IECOH. The following three identifications were made : 1) the relationship between maximal oxygen uptake (VO<SUB>2</SUB>max) and IECOH in 82 healthy males ; 2) the relationship between IECOH and age in 428 healthy males and females ; 3) the effect of physical training in 8 healthy males.<BR>There was inverse correlation between IECOH and VO<SUB>2</SUB>max (r= -0.824) . And also, there were inverse correlations between IECOH detected from submaximal tests and VO<SUB>2</SUB>max (above r=-0.6) . There were no differences in the IECOH detected from maximal and submaximal tests. In Bland-Altman plot method, accuracy of measurment in the IECOH detected from submaximal exercise test was precise. There was a significant relationship between IECOH and age in male and female subjects (r=0.499 and r=0.310, respectively) . Physical training increased VO<SUB>2</SUB>max and decreased IECOH significantly. The VO<SUB>2</SUB>max before and after physical training correlated inversely with the IECOH before and after physical training (r=-0.514) .<BR>In conclusion, these results suggest that IECOH is adequate and useful as an index of cardio-pulmonary functional reserve which can be measured by the submaximal exercise test in healthy subjects.

REFERENCE RANGE AND ADOPTIVE CRITERION FOR MAXIMAL OXYGEN UPTAKE (VO2max) IN CONSIDERATION OF AGE AND GENDER-REFERENCE RANGE FOR VO2max ATTAINED BY MEANS OF THE ITERATIVE TRUNCATION METHOD / 体力科学

The existing adoptive criterion for VO<SUB>2</SUB>max was created for physically fit subjects who were soldiers and/or sportsmen. However, VO<SUB>2</SUB>max is widely used at present as one of the health-related physical fitness determinants from children to aged persons. It might be appropriate to determine the criterion and the critical values for VO<SUB>2</SUB>max in consideration of age and gender.<BR>The present study attempted to determine the reference range and critical values of the criterion for VO<SUB>2</SUB>max using the iterative truncation method. Voluntary VO<SUB>2</SUB>max was measured in 548 healthy volunteers, aged 8 to 82 years, using a treadmill. The % VO<SUB>2</SUB>max was calculated using the equation of %VO<SUB>2</SUB>max=measured VO<SUB>2</SUB>max × 100 gage-estimated VO<SUB>2</SUB>max. Crude data of %VO<SUB>2</SUB>max was applied to the iterative truncation method, and the reference range of %VO<SUB>2</SUB>max (70-130%VO<SUB>2</SUB>max) was determined. Physiological and biochemical parameters, within the values of 70-130%VO<SUB>2</SUB>max, were converted to a percentage using a similar equation of %VO<SUB>2</SUB>max. The value corresponding to 10% of the lower area of the distribution of each parameter was defined as the critical value, which was the minimum level to adopt as the VO<SUB>2</SUB>max. Taking a single or combined application of the critical value of each parameter, the adoptive ratio of VO<SUB>2</SUB>max was investigated.<BR>The present study indicated that there was no difference between VO<SUB>2</SUB>max selected by the iterative truncation method and that obtained by the existing criterion for VO<SUB>2</SUB>max. The combination of the critical value of HRmax and bLAmax was recommended as a criterion of VO<SUB>2</SUB>max. The reference value, critical value of VO<SUB>2</SUB>max and the critical real value of each parameter were shown as a mean of every 5-year interval with the distinction of gender.

ALTERED PRE-EXERCISE RESTING HEART RATE AFFECTS INDIVIDUAL HEART RATE-OXYGEN UPTAKE RELATION DURING EXERCISE / 体力科学

The circadian rhythm of heart rate is well known. The purpose of this study was to investigate the characteristics of the relation between heart rate and oxygen uptake during a graded exercise testing with and without previous exercise. Eight healthy male students, aged 18 to 21 years, performed the graded sub-maximal exercise two times using a treadmill, after walking on a treadmill at a speed of 60 m/min for a total of 4 hours (2 hours in the morning, 2 hours in the afternoon) and without previous prolonged walking. The apparent resting heart rate after one hour of walking in the afternoon (82.3±9.1 beats mm) was higher than in the morning (71.3±5.8 beats/min), and this phenomenon was observed continuously exercise heart rate at the end of 2 hours of walking (afternoon : 96.4±5.4, morning: 87.2±7.3 beats min) . On the other hand, the oxygen uptake during exercise did not alter at the end of walking (afternoon: 622±85, morning: 600±133 ml/min) . This walking intensity ranged from 17.1 to 26.6, with a mean of 20.5 percent of maximal oxygen uptake. The pre-exercise resting heart rate before the exercise testing altered from -4.8 to 13.1 beats/min with and without the presence of walking. The observed individual regression line between heart rate and oxygen uptake from the testing shifted along with the altered resting heart rate. Therefore, the calculated individual new regression lines with and without walking between net heart rate, excluding pre-exercise rest, and oxygen uptake were approximate to a constant line. It was concluded that the exercise energy expenditure could be calculated accurately (-2 to 7 % of errors) using net heart rate, as compared with overestimations of the actual energy cost using the higher resting heart rate.

Critical and desirable levels of health-related physical fitness (HRPF) in men-Established levels based on health examination and risk factors caused by lifestyle habits- / 体力科学

This study tried to establish both critical and desirable levels of health-related physical fitness (HRPF) including muscle strength (relative grip strength), flexibility and estimated VO<SUB>2</SUB>max. Subjects were 3102 males aged 20 to 59 years. Four batteries of health index score (HIS-A-D) were made based on health examinations and lifestyle habits. Subjects who had 0 to 1 points were defined as healthy individuals, and subjects who had more than 3 or 4 points were defined as unhealthy. Receiver-operating characteristic (ROC) curves were drawn by HRPF test in each battery of HIS. The HIS-B was selected as the most valid battery of HIS. Sensitivity, specificity and the Youden index were calculated using cut-off values which were mean values of each HRPF test measurement in each group who had 0, 1, 2, 3 and>4 points in HIS-B. The critical levels were defined the highest specificity and/or Youden index in each HRPF test. There were seen in groups having > 4 points. The desirable levels were defined as the HRPF test levels in healthy individuals who had 0 to 1 points in HIS-B. The critical and desirable levels of VO<SUB>2</SUB>max were 41.8 and 50.2 at 20y, 40.9 and 46.2 at 30y, 40.0 and 46.2 at 40y, and 37.8 and 45.5 ml/kg/min at 50y, respectively. The levels of other HRPF test were also calculated in the present study. Exercise guidance after health check-ups should be done to attain desirable levels rather than to just maintain critical levels of HRPF.

Difference in physiological responses to an incremental running test between middle- and long-distance runners / 体力科学

To obtain a viewpoint concerning evaluation of endurance type of athletes, we investigated the difference in physiological responses between middle- and long-distance runners in an incremental running test. Measurements were VO<SUB>2</SUB>max and time of its appearance, change of VO<SUB>2</SUB> from 1.5 min before exhaustion to exhaustion (ΔVO<SUB>2</SUB>), heart rate (HR), and blood lactate after exhaustion.<BR>Results were as follows.<BR>(1) The time of VO<SUB>2</SUB> max appearance in the middle distance runners was earlier than in the long distance runners.<BR>(2) VO<SUB>2</SUB>max was significantly higher in the long distance runners than in the middle distance runners.<BR>(3) Blood lactate after exhaustion and HRmax were significantly higher in the middle distance runners than in the long distance runners.<BR>(4) Blood lactate after exhaustion was significantly related to ΔVO<SUB>2</SUB> (r =-0.660, P<0.05) .<BR>These findings suggest that the endurance type of athletes could be evaluated from the time of VO<SUB>2</SUB>max appearance, blood lactate after exhaustion and HRmax in incremental running, and that VO<SUB>2</SUB>max appearance may be effected by high blood lactate accumulation.

The effect of maximal interval training for 10 weeks on arterial oxygen saturation during heavy exercise / 体力科学

The purpose of the present study was to investigate the effect of maximal interval training for 10 weeks on arterial oxygen saturation (SaO<SUB>2</SUB>) and ventilatory response during heavy exercise. Seven subjects volunteered for participation in the study. All subjects performed an interval training 4 days per week. Training protocol per day consisted of five periods of exercise of 3-min duration on a cycle ergometer at a power output on 100% maximal oxygen uptake (VO<SUB>2</SUB>max), interspersed with 2-min recovery cycle at 50%VO<SUB>2</SUB>max. VO<SUB>2</SUB>max and ventilatory data measured every week. SaO<SUB>2</SUB>, end-tidal oxygen partial pressure (PETO<SUB>2</SUB>), end-tidal carbon dioxide partial pressure (PETCO<SUB>2</SUB>) and the ventilatory equivalent for oxygen (VE/VO<SUB>2</SUB>) measured during 5-min heavy exercise at 90%VO<SUB>2</SUB>max every other week. VO<SUB>2</SUB>max significantly increased from 52.5±4.9 to 60.6±5.8 ml⋅ml<SUP>-1</SUP>⋅kg<SUP>-1</SUP> during the training. SaO<SUB>2</SUB> reduced significantly from 95.4±1.1 to 93.3±1.8%, similarly PETO<SUB>2</SUB> and VE/VO<SUB>2</SUB> reduced during the training. A significant positive correlation was found among SaO<SUB>2</SUB>, PETO<SUB>2</SUB> and VE/VO<SUB>2</SUB> during heavy exercise (SaO<SUB>2</SUB>-PETO<SUB>2</SUB>, r<SUP>2</SUP>=0.48, P<0.05 ; SaO<SUB>2</SUB>-VE/VO<SUB>2</SUB>, r<SUP>2</SUP>= 0.49, P<0.05; PETO<SUB>2</SUB> - VE/VO<SUB>2</SUB>, r<SUP>2</SUP>=0.81, P<0.05) . These results suggest that-50% of the arterial O<SUB>2</SUB> desaturation during heavy exercise can be accounted for by low ventilatory response. Therefore the maximal intervsal training induced arterial O<SUB>2</SUB> desaturation during heavy exercise, which can be half explained by low ventilatory response.

Effect of physical exercise in daily life on the aging process in healthy women in terms of aerobic capacity, serum lipid concentration, body composition and bone mineral density / 体力科学

A cross-sectional study was carried out to investigate the effect of physical exercise in daily lives of healthy women on the aging process in terms of maximal aerobic capacity (VO<SUB>2</SUB>max), body fat tissue mass (FTM), lean tissue mass (LTM), bone mineral density (BMD), serum triglyceride (TG), total cholesterol (TC), HDL-C and LDL-C concentrations, and systolic (SBP) and diastolic blood pressure (DBP) . These parameters are considered as risk factors of cerebrovascular disease and/or osteoporosis, which are the main causes of becoming bedridden and demented in middle-aged and older women. One hundred sixty-five healthy female volunteers aged 20 to 76 years participated in the study, 82 of whom were postmenopausal with a mean age at menopause of 49.7±3.1 years. Eighty-two of the subjects had been exercising regularly by jogging, swimming, aerobic dancing, or playing tennis more than twice a week for 2 years (Ex group), whereas 83 individuals had not been engaging in regular exercise (Cont group) . Serum lipid concentrations, SBP and DBP measurements at rest and treadmill VO<SUB>2</SUB>max and HRmax measurements were determined in the morning after an overnight fast. Whole-body BMD (TBMD), head, lumbar, arm and leg BMD, FTM and LTM were measured by dual-energy X-ray absorptiometry one to two hours after a light lunch. The mean and SD of each measurement were calculated for five-year age groups between 40 and 60 years and one group each under 40 and over 60 years.<BR>The results were as follows:<BR>1, VO<SUB>2</SUB>max (r=-0.590) and HRmax (r=-0.632) decreased significantly with age. The VO<SUB>2</SUB>max of the Ex group was significantly higher than that of the Cont group in all each age groups. However, no differences in the aging process in terms of HRmax were found between the two groups.<BR>2, Resting SBP (r=-0.391) and DBP (r=0.315) increased significantly with age. However, no hypertensive individuals (160/95 mmHg-) were found among the 165 subjects.<BR>3. Only serum TC (r=0.346) and LDL-C (r=0.339) among the blood constituents measured changed with age. No changes in serum HDL-C were detected with age. Lower TC (189.2±23.3 mg/dl) and higher HDL-C (72.2±10.9 mg/dl) were observed in eleven runners (49.7±7.7 years) among the subjects who participated frequently in official races than in subjects of the same ages in the Cont group. The highest serum HDL-C (75.8±15.8 mg/dl) and HDLC/TC ratios (0.362) were noticed among the subjects (n=26) who both regularly exercised and consumed alcoholic beverages.<BR>4. A tendency for FTM to increase and LTM to decrease with age were observed in both groups, and a lower %FTM (percentage of FTM to body weight) and higher %LTM were evident in the Ex group. Differences in %FTM and %LTM between the Ex and Cont groups at 40-45 years were significant.<BR>5. Partial and whole BMDs decreased significantly with age (TBMD-Age ; r=- 0.527) . Significantly higher leg BMDs in both the 20-39-year and 40-45-year groups, and spine and TBMD in the 20-39 years in the Ex group, who were premenopausal women, were shown. No significant differences in BMDs between the two groups were observed in postmenopausal women, but the Ex group tended to have higher partial and whole BMDs. The postmenopausal official race runners (n=5.52.6-1.5years) also had higher TBMD and leg BMD values than subjects of the same ages in the Cont group.<BR>6. Investigation of correlations between VO<SUB>2</SUB>max, LTM, FTM, BMDs and serum lipid concentrations, yielded a significantly higher correlation (r=0.669) between LTM (kg) and absolute VO<SUB>2</SUB>max (1/mm) . Although VO<SUB>2</SUB>max per LTM (VO<SUB>2</SUB>max/LTM) decreased with age (r=-0.595), VO<SUB>2</SUB>max/LTM in the Ex group was significantly higher than in the Cont group in each age group. The VO<SUB>2</SUB>max per body weight (ml/kg/min) was negatively correlated with %FTM (r=-0.442) and positively correlated with

Effect of high intensity intermittent training and resistance training on the maximal oxygen defieit and VO2max / 体力科学

This study examined the effects of (1) an intermittent training using a mechanically braked cycle ergometer and (2) resistance training using free weight on the maximal oxygen deficit and VO<SUB>2</SUB>max. For the first 6 weeks, six subjects trained using an intermittent training protocol five days per week. The exhaustive intermittent training consisted of seven to eight sets of 20 s exercise at anintensity of about 170% of VO<SUB>2</SUB>max with a 10 s rest between each bout. After the training, the maximal oxygen deficit increased significantly from 64.3±5.0 ml⋅kg<SUP>-1</SUP> to 75.1±5.7 ml⋅kg<SUP>-1</SUP> (p<0.01), while VO<SUB>2</SUB>max increased from 52.0±2.7 ml⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> to 57.6±2.9 ml⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> (p<0.05) . For the following 6 weeks, the subjects used the same intermittent training for 3 days per week and a resistance training for the other 3 days per week. The resistance training consisted of (1) 4 sets of 12 bouts of squat and leg curl exercise at 12 repetition maximum (RM) . (2) 2 sets of maximal bouts of the same exercise with a load of 90%, 80%, and 70% of 1 RM. After the training period, the maximal oxygen deficit increased further to the value of 86.8±5.9 ml⋅kg<SUP>-1</SUP>which was significantly higher than the value attained at the end of the intermittent training. On the other hand, VO<SUB>2</SUB>max did not increase significantly from the value observed at the end of the 6 weeks of intermittent training. Body weight was not significantly changed throughout the 12-week training period. Maximal circumference of the thigh did not changed during the first 6-week of the intermittent training period (pre-training: 57.1±1.2 cm, after 6-week training: 57.3±1.1 cm), while it increased significantly after the last 6-week combined training (59.0±0.8 cm, p<0.05) . In conclusion, this study showed that (1) high intensity intermittent training improves both the anaerobic and aerobic energy supplying systems, (2) additional resistance training with the intermittent training further increases the anaerobic energy supplying system, probably through increased muscle mass.

The amount of serum lipid peroxides and the activity of erythrocyte antioxidative enzymes in high-aerobic-capacity subjects before and after maximal exercise / 体力科学

We investigated the relationship between maximum oxygen uptake and the amount of lipid peroxide in serum before and after exhaustive exercise. The levels of serum lipid peroxides observed in a group of 6 males with high oxygen uptake were significantly lower than those of the low oxygen uptake control group (4 males) before and 0, 30 and 60 minutes after exercise. The amount of serum lipid peroxides increased slightly in each group after exercise. However, that amount decreased more quickly in the group with high oxygen uptake than the control group. Catalase and superoxide dismutase activities in erythrocytes showed no significant differences between both groups, nor between before and after exhaustive exercise.

Body composition, maximal oxygen uptake, and maximal oxygen debt on elite senior high school (Kyushu Bunka Gakuen) female volleyball players / 体力科学

A study was performed to evaluate the physical capacity of elite female volleyball players from Kyushu Bunka Gakuen Senior High School (Kyu. B. G.) . Twenty-four players were examined for body composition (underwater weighing), cardiorespiratory function (VO<SUB>2</SUB>max and O<SUB>2</SUB>debtmax by treadmill exercise test) and skinfold thickness, from 1988 to 1989.<BR>These measurements were compared with those of 16 second-class players from Nagasaki Prefecture, and also with the results of other investigations.<BR>The results were as follows :<BR>1. The mean parameters for the Kyu. B. G, players were : age, 17.5 yr ; height, 168.3 cm ; weight, 59.8 kg ; percentage body fat (%Fat ), 17.9% ; lean body mass ( LBM), 49.0 kg ; LBM/ Ht, 29.1 kg/m ; sum of eight skinfold thicknesses, 109.1 mm ; VO<SUB>2</SUB>max, 2.71 l/min, 45.7 ml/kg· min ; O<SUB>2</SUB>debtmax, 5.69l, 94.8 ml/kg.<BR>2. The average %Fat of the Kyu. B. G, players was significantly lower than that of the second-class players from Nagasaki Prefecture.<BR>3. The average VO<SUB>2</SUB>max (ml/kg·min) and O<SUB>2</SUB>debtmax (l, ml/kg) of the Kyu. B. G, players were significantly higher than those of the second-class players.<BR>4. The average %Fat and VO<SUB>2</SUB>max (ml/kg·min) of the Kyu. B. G, players were similar to those of Japan League and All Japan volleyball players.<BR>5. When the progress of physiological function due to training for 11 months was examined in five Kyu. B. G, players, the average VO<SUB>2</SUB>max (ml/kg·min) showed a significant increase of approximately 8%.<BR>These results indicated that the Kyu. B. G, players had a superior body composition, aerobic work capacity and anaerobic work capacity, equal to those of top volleyball players in Japan.

Effects of exercise intensity on renal clearance parameters / 体力科学

A study was designed to examine the effects of exercise intensity on renal clearance parameters. Five healthy male subjects underwent exercise tests on an bicycle ergometer at 4 different work loads for 15 min. The indicators of exercise intensity employed were the percentage of maximal oxygen uptake (%VO<SUB>2</SUB>max), heart rate (HR) and blood lactate level (La) . As parameters of renal clearance, para-aminohippurate clearance (CPAH), thiosulfate clearance (C<SUB>thio</SUB>) and creatinine clearance (C<SUB>cr</SUB>) were measured by the continuous infusion technique during the exercise.<BR>1) The renal clearance parameters during exercise decreased linearly as the exercise intensity increased. The percentage of maximal oxygen uptake at the onset of the decreases in %C<SUB>PAH</SUB>, %C<SUB>chiu</SUB> and %C<SUB>cr</SUB> were 36, 45 and 47%VO<SUB>2</SUB>max, respectively.<BR>2) Among the indicators of exercise intensity, the decrease in La showed the closest correlation with renal clearance during the exercise.<BR>3) The renal plasma flow, which was measured as C<SUB>PAH</SUB>, began to decrease linearly at a significantly lower exercise intensity than the glomerular filtration rate, which was measured as both C<SUB>thio</SUB> and C<SUB>cr</SUB>.<BR>The above results suggest that renal clearance parameters begin to decrease at the threshold as exercise intensity increases.

Validity of the maximal aerobic capacity estimated from submaximal cycling exercise and field performance tests in the elderly / 体力科学

Although maximal oxygen uptake (VO<SUB>2</SUB>max) or oxygen uptake corresponding to lactate threshold (VO<SUB>2</SUB>@LT) is considered the single best determinant of one's cardio-respiratory endurance or aerobic capacity, the direct measurement of these attributes requires elaborate equipment, trained personnel, special knowledge, and/or a maximal effort on the part of the subject who is tested. In addition, the measurement is time consuming. The current investigation was designed to examine the validity of aerobic capacity estimated from submaximal cycling exercise and field performance tests in the elderly. The subjects tested were 18 sedentary men and women aged 63 to 75 years (69.7±3.4) . Indirect VO<SUB>2</SUB>max tests were selected from those proposed by Astrand and Ryhming, Siconolfi et al., and Margaria et al. (step test), and YMCA. The VO<SUB>2</SUB>max values estimated by these methods, with the exception of the Siconolfi method, were found to have large errors when compared to the errors obtained in previous studies for younger subjects. There were no significant correlations between step test scores and VO<SUB>2</SUB>max and VO<SUB>2</SUB>@LT in the elderly. Correlations of 12-min distance walk with VO<SUB>2</SUB>max (r=.711) and VO<SUB>2</SUB>@LT (r=.714) were significant. Our findings suggest that 12min distance walk be a better aerobic capacity test than other indirect VO<SUB>2</SUB>max tests including Astrand and Ryhming test.

Effect of hyperoxic training on endurance capacity and perfomance at sea level / 体力科学

The purpose of the present study was to clarify if hyperoxic training would be more effective on endurance capacity and performance at sea level than normoxic training.<BR>Twelve healthy males who had not been performing any regular endurance training participated in this study as subjects. They were divided into the two groups on the basis of their Vo<SUB>2</SUB>max ; one was the hyperoxic training group (Hyperoxic G) and the other was the normoxic training group (Normoxic G) . Training intensity of Hyperoxic G was 85% of Vo<SUB>2</SUB>max obtained breathing hyperoxia (a gas mixture of 60% O<SUB>2</SUB> in N<SUB>2</SUB>) . That of the Normoxic G was 85% of Vo<SUB>2</SUB>max obtained breathing room air. Duration of the daily training was 10 min in the former, and 10 min 22 sec to 11 min 30 sec in the latter ; thus, the amount of work was equal for both groups. Training frequency and period was 3 days/week and 4 weeks, respectively.<BR>After training, all-out time and lactate threshold in the Normoxic G was significantly enhanced from 17 min 18 sec to 19 min 7 sec and 19.6 m<I>l</I>/kg⋅min to 23.0 m<I>l</I>/kg⋅min. But, Vo<SUB>2</SUB>max, maximal ventilation and heart rate during training were not significantly changed. On the other hand, in the Hyperoxic G, not only all-out time and lactate threshold were significantly enhanced from 17 min 56 sec to 19 min 33 sec and 19.7 m<I>l</I>/kg⋅min to 24.9 m<I>l</I>/kg⋅min, but Vo<SUB>2</SUB>max and maximal ventilation were significantly increased from 46.1 m<I>l</I>/kg⋅min to 51.0 m<I>l</I>/kg⋅min and 117.3<I>l</I>/min to 135.1 <I>l</I>/min. Furthermore, heart rate during training was significantly decreased.<BR>From these results, it was concluded that hyperoxic training would be more effective in improving endurance capacity than normoxic training.

Body composition, maximum oxygen uptake, and maximum oxygen debt in elite senior high school (Kunimi) soccer players / 体力科学

A study was performed to evaluate the physiological function of elite senior high school soccer players (Kunimi) . Forty-six players were evaluated for cardiorespiratory function (maximum oxygen uptake : Vo<SUB>2</SUB>max, maximum oxygen debt : Max O<SUB>2</SUB> debt), body composition (underwater weighing) and skinfold thickness, all parameters being measured four times over a two-year period.<BR>The following means were recorded : age, 17.8 yr ; height, 173.0 cm ; weight, 65.8 kg ; percentage body fat (%Fat), 10.0%; lean body mass (LBM kg), 59.2 kg ; LBM/Ht (kg/m), 34.2 ; sum of eight skinfold thicknesses, 63.5 mm ; Vo<SUB>2</SUB>max, 60.0 m<I>l</I>/kg⋅min ; maximum ventilation (V<SUB>E</SUB>max, BTPS), 136.8<I>l</I>/min ; maximum oxygen debt ; 8.2<I>l</I>, 124.8 m<I>l</I>/kg.<BR>Results for percentage body fat, Vo<SUB>2</SUB>max (m<I>l</I>/kg⋅min) and Max O<SUB>2</SUB> debt (m<I>l</I>/kg) were compared with values found in other soccer players at various levels.<BR>In summary, one of the most outstanding attributes of the Kunimi senior high school soccer players was a high level of both aerobic power and anaerobic power.