Differing effects of aquatic movement in either deep or shallow water on the physiological responses among middle-aged, female and recreational synchronized swimmers / 体力科学

This study examined the physiological response to different water depths in recreational synchronized swimming. Nine middle-aged, female, recreational swimmers carried out the same team free routines in deep water (deep-water synchronized swimming: DWS) and shallow water (shallow-water synchronized swimming: SWS). Heart rate (HR) was measured continuously during each performance, combined with estimation of metabolic equivalent (MET) values using individual linear regression equations of HR-oxygen uptake. These equations were created using the results of 12 water activities. Blood lactate concentration and systolic blood pressure were measured at the 1/3 and 2/3 stages and immediately after each performance period. HR and estimated METs during DWS (mean±SD, 152.9±7.5 beats·min^-1 and 7.3±1.2) were significantly higher than those measured during SWS (131.8±11.3 beats·min^-1 and 5.7±0.8). Blood lactate concentration and systolic blood pressure measured immediately after DWS were significantly higher than those measured after SWS. With DWS, blood lactate concentration at the 2/3 stage and immediately after the performance were significantly higher than those measured at the 1/3 stage, whereas in SWS no significant difference was found in these values at any time period. In conclusion, the exercise intensity of DWS was high and SWS moderate. The predominant sources of energy may be phosphocreatine stores and aerobic metabolism during these performances. It is possible that glycolysis may also play an important role in energy requirements during the 2/3 stage and immediately after a DWS performance.

EFFECTS OF WIND AND RAIN ON THERMOREGULATORY AND CARDIOVASCULAR-RESPIRATORY RESPONSES DURING RUNNING IN HUMANS / 体力科学

The effects of wind and rain on exercising humans have not been fully investigated in the field of sports science. The purpose of this study was to investigate the characteristics of thermoregulation and cardiovascular-respiratory responses during exercise in a climate chamber that allowed control of wind and rain. Seven healthy males performed treadmill running at 70%VO_2max for 30 min under three conditions (CON, control ; WIND, wind only; WIND&RAIN, both wind and rain). The temperature was 27.0℃ under the three conditions. Relative humidity was 60%RH except under the WIND&RAIN condition (100%RH under WIND&RAIN condition). The wind velocity corresponded to running velocity in the open air and the precipitation was 90 L/h. Under the WIND&RAIN condition, both body trunk and extremities skin temperature (T_sk) showed a clear decrease for the first 5 minutes after the start of running, and was significantly lower during the running period than under the other two conditions (p<0.05). Rectal temperature (T_re) did not differ significantly among the three conditions. An interaction was observed between conditions and time in terms of minute ventilation (VE) (p<0.05). Under WIND and WIND&RAIN conditions, VE was higher than under CON condition while running. Oxygen consumption, heart rate and respiratory exchange ratio did not differ significantly among the three conditions. These results indicate that wind and rain in a natural environmental condition with neutral temperature (27.0℃), cause a decline in T_sk, and may become factors that influence performance, similarly to temperature and humidity.

Characteristics of underwater walking using water flow machine / 体力科学

Six young males walked in a swimming pool, swimming flume and land treadmill at 0.4, 0.6 and 0.8 m·⋅<SUP>-1</SUP>. At 0.6 and 0.8 m⋅s<SUP>-1</SUP>, VO<SUB>2</SUB>and HR values were significantly lower for the swimming flume walking than for the swimming pool waking. At rest and 0.4 m⋅s<SUP>-1</SUP>, there were no significant VO<SUB>2</SUB>differences between swimming flume walking and land treadmill walking ; while significantly lower HR values were found for swimming flume walking. There was no significant difference in the VO<SUB>2</SUB>-HR relationship between land treadmill waking and swimming pool waking. On the other hand, a significant downward sift in the regression line was observed in swimming flume waking compared to land treadmill walking. The differences between the two types of underwater walking exercise may produce a different effect concerning the muscle pump on leg muscles. Soleus, and especially lateral gastrocnemius muscles, showed lower electromyogram activity at push-off phase during swimming flume walking compard with swimming pool walking. This activity may contribute to the lower VO<SUB>2</SUB>and HR values during swimming flume walking. It is apparent that the swimming flume walking has different physiological and kinematic characteristics such leg muscles EMG activity walking or swimming pool walking.

Physiological analysis of synchronized swimming in recreational female middle-aged swimmers / 体力科学

This study was designed to analyze physiologically recreational synchronized swimming and speed swimming. Two types of recreational synchronized swimming (Long face-in time performance : LFIP and Short face-in time performance : SFIP) and maximum exertion in the 200-m free style swimming (200 mFR) were measured in six recreational middle-aged female swimmers. LFIP and SFIP were conducted in shallow water. The percentage of face-in time for LFIP was about 10% longer than that of SFIP. Heart rate (HR) during each exercise was measured continuously. Blood lactate concentration (La), the rate of perceived exertion (RPE) and systolic and diastolic blood pressure (SBP, DBP) were measured after each exercise. Average HR during the LFIP, SFIP and 200 mFR were 133±12, 132±13 and 153±12 beats·min<SUP>-1</SUP> (mean ± SD), respectively. La was 2.4±0.7 mmol·1<SUP>-1</SUP>for LFIP, 2.2±0.6 mmol·1<SUP>-1</SUP>for SFIP and 5.7 ± 2.4 mmol·1<SUP>-1</SUP>for 200 mFR, respectively. SBP was 181±32 mmHg for LFIP, 166±22 mmHg for SFIP and 185±30 mmHg for 200 mFR, respectively. No significant differences were observed in blood pressure among the three exercises. SBP of 200 mmHg or higher after LFIP and 200 mFR was observed in some subjects. HR, La and RPE for LFIP and SFIP showed no significant differences, but were significantly lower than those of 200 mFR. These results show that the exercise intensity of LFIP was moderate and was similar to that of SFIP. LFIP, however, caused a marked rise in SBP. Thus, SFIP may be more recommended for health promotion to recreational middle-aged swimmers than LFIP.

A Demonstrative Study on Physiological Properties Observed in Walking along Various Routes in Forests on the Basis of Chronological Changes in the Energy Consumption. Conditions for establishing promenades in forests / 日本温泉気候物理医学会雑誌

Walking exercise in forests, referred to as “shinrin-yoku, forest-air bathing and walking, ” has been attracting attention as a method for promoting mental and physical health utilizing the environment and topography of forests in the recent time. Walking exercise in forests has characteristics arising from the natural environment and topography of forests with beautiful trees, twittering of birds, and favorable fragrances of woods, etc. However, scientific verification of such specific effects is necessary in order to make walking an authentic method to health promotion. This study intended to physiologically investigate it from physical and scientific point of view. For this purpose, we determined chronological changes in energy consumed in walking exercise in forests with a portable oxygen intake measuring device, on the basis of data on the respiratory and circulatory systems such as heart rate and the amounts of ventilation and oxygen intake. The results suggested that the changes in these parameters showed the movement correlated with the changes in topography of forests, including the inclination and demonstrated that selection on the resting locations was related to the comfortable rhythm of walking. Furthermore, it was indicated that exercise loading to living body tended to increase in association with increases in the upward inclination, resulting that the energy consumed in walking was less though the amounts of exercise loading to lower limbs tended to be very large at a download inclination of 36.0 degrees or larger. This demonstrative study suggested that to determine chronological changes in physiological loading conditions related to the walking route was effective to establish promenades in order to perform comfortable and effective forest bath.

Exercise intensity during a free routeine in well trained synchronized swimmers / 体力科学

A study was conducted to clarify the exercise intensity and metabolic condition during a free routine of synchronized swimming with respect to heart rate (HR), blood lactate concentration (La) and the rate of perceived exertion (RPE) . Six well trained female synchronized swimmers participated as subjects. HR during the free routine was measured continuously. La and RPE during the free routine were measured intermittently from the start to end of each stage. Maximum heart rate (swimmingHRmax : S-HRmax) was determined by measurement of maximum oxygen uptake using a swimming flume. Peak blood lactate concentration (Peak La) was measured after the maximum front crawl stroke of 100 m. The average values and S. D. of S-HRmax and Peak La were 180.0±3.8 beats · min<SUP>-1</SUP> and 9.6 ± 1.0 mmol · 1<SUP>-1</SUP>, respectively. Average values, S. D. and ranges of HR and %S-HRmax during the free routine were 137.6±25.5 (60-180) beats · min<SUP>-1</SUP> and 76.5± 14.3 (34.5-96.8) %, respectively. HR during the free routine showed a decrease in the breath-holding phase. Average values and S. D. of La, %Peak La and RPE at the fourth stage were 5.4±1.2mmol·1<SUP>-1</SUP>, 57.0±17.2% and 17.7±0.8, respectively. La, %Peak La and RPE at the fourth stage were significantly higher than those at the other stages, and La, %Peak La and RPE at the third stage were significantly higher than those at the second stage. These results suggested that the overall intensity of the free routine was moderate, but that part of the free routine included high-intensity activity and the percentage of anaerobic metabolism during the free routine increased in the final stages

Comparison of the front crawl leg kick and arm stroke characteristics of male age-group and college swimmers / 体力科学

The purpose of this study was to determine the physiological responses, stroke rate and stroke length of front crawl leg kick and arm stroke of age-group and college swimmers and to elucidate the characteristics of male age-group swimmers, which have not been highlighted adequately. The subjects were ten 11.8-to 12.4-year-old well-trained male elementary school swimmers (group E) and nine 20.1-to 21.1-year-old well-trained male college swimmers (group C) . All the subjects were categorized into similar swimming levels for their ages. All the experiments were performed in a swimming flume (AQUAGYM made by IHI) . The water velocities during leg kicking and arm stroking were 60 and 70%, respectively, of the maximal velocity at maximal oxygen uptake (Vmax) . The oxygen uptake (VO<SUB>2</SUB>), heart rate (HR), pulmonary ventilation (V<SUB>E</SUB>), tidal volume (TV), respiratory rate (RR) and blood lactate (BL) level of each group were significantly higher during leg kicking than arm stroking at both velocities. VO2, V<SUB>E</SUB>; and TV were significantly higher in group C than group E during leg kicking and arm stroking at both velocities, but HR, RR and BL did not differ significantly. The leg kick to arm stroke VO<SUB>2</SUB> ratio at 70% Vmax was significantly higher in group E than group C. The stroke rate at the same velocity was significantly lower and the stroke length was significantly higher in group C than group E, but the kick rate and length did not differ significantly. VO<SUB>2</SUB>·SR<SUP>-1</SUP> and VO<SUB>2</SUB> KR<SUP>-1</SUP> at both velocities were significantly higher in group C than group E. VO<SUB>2</SUB> Wt<SUP>-1</SUP> SR<SUP>-1</SUP> at 70% Vmax was significantly higher in group C than group E, but VO<SUB>2</SUB> Wt<SUP>-1</SUP> KR<SUP>-1</SUP> at both velocities was significantly lower in group C than group E. These results clarified the differences between group E and group C, which must be considered carefully when designing a training program for age-group swimmers.

Equations for predicting body density in male and female athletes / 体力科学

This study was designed to determine prediction equations of body density (BD) for athletes using anthropometric variables and to examine validity of the prediction equations. The subjects were 211 male and 198 female athletes aged 18 to 22 years. The subjects were measured for standing height, body weight, skinfold thickness, girth as well as body composition. Body composition was estimated from densitometry using underwater weighing method and pulmonary residual volume measurement. Skinfold thickness was measured at 9 sites on the right side of the body with an Eiken-type ski nfold caliper and 7 measures of girth were taken using a cloth tape. All measurements were done three times from April to October : pre-, mid- and post-competitive season, in order to find out a suitable site reflecting body composition change. Using multiple regression analysis, equations to estimate BD were obtained from standing height, body weight, skinfold thicknesses and girths. The effective prediction equations for BD were as follows : For Males<BR>ED=1.11104-0.00053 (sum of chest, abdomen and quadriceps skinfold thicknesses in mm) -0.00027 (waist girth in cm) .<BR>R=0.851, SEE=0.0051.<BR>For Females<BR>BD=1.11861-0.00054 (sum of abdomen, triceps and subscapula skinfold thicknesses in mm) -0.00054 (waist girth in cm) .<BR>R=0.826, SEE=0.0062.<BR>A cross-validation analysis of these prediction equations for BD correlated highly with hydrodensitometrically determined BD (r=0.832, SEE=0.0053 for males and r=0.812, SEE= 0.0062 for females) . Thus the prediction equations developed in the present study will be applicable to athletes.

Characteristics of cardiorespiratory responses to the latter stage of a simulated triathlon / 体力科学

The most characteristic feature of the triathlon is integration of the three endurance activities including of swimming, cycling and running, into a continuous task. So, it is necessary to identify the cardiorespiratory responses during the triathlon to develop a beneficial training program. Twelve male triathletes conducted a simulated triathlon test in a laboratory. This test consisted of continuous swimming, cycling and running using a flumepool, a bicycle ergometer and a treadmill, respectively. The exercise intensity and duration were 60% of maximal oxygen uptake during swimming, cycling and running for 30, 75 and 45 min, respectively. The results demonstrated that the residual effects of the prior exercise stage were observed during the latter exercise stage : The prior swimming stage produced an increment of oxygen uptake and heart rate during the cycling stage ; Prior swimming and cycling stages increased oxygen uptake, minute ventilation, heart rate and ventilatory equivalent to those during the running stage. These results suggest that the residual effects of the preceding exercise decreased the mechanical and respiratory efficiency by increasing the physiological demands of conducting the subsequent exercise. Therefore, triathletes are recommended to train themselves in a continuous task rather than separately.

Energy expenditure during sport activities by means of a portable device for the measurement of oxygen / 体力科学

Energy expenditure during sport activities has been determined traditionally by the Douglas Bag Method and the Motion Time Study. However, those two methods do not yield accurate values when used in long continuous and/or vigorous physical activities. This study, therefore, measured oxygen uptake by means of a portable device “Oxylog”, and determined the energy expenditure of many sport activities. The experiments were carried out with 13 untrained male subjects (UTS), and 30 trained male subjects (TS) . The 30 trained men consited of ten tennis players, ten badminton players and ten basketball players. UTS played one set of doubles (tennis), one set of singles (badminton), two sets of singles (table tennis), two games (bowling) and jogged 10 minutes, But TS played only their major sports : one set of doubles (tennis), one set of singles (badminton) and two 20-minute halves (basketball) . The results were 0.172±0.017kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for jogging (UTS), 0.146±0.028kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for badminton (TS), 0.133±0.021kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for basketball (TS), 0.130±0.018kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for badminton (UTS), 0.102±0.016kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for tennis (TS), 0.096±0.014kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for tennis (UTS), 0.089±0.019kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for table tennis (UTS), and 0.055±0.009kcal⋅kg<SUP>-1</SUP>⋅min<SUP>-1</SUP> for bowling (UTS) . In comparison with UTS, TS exhibited higher values in tennis and badminton. This is considered to result from TS's better training. This result indicates that energy expenditure in playing sports activities depends on the level of player's ability. The method employed in of this study is believed to be the best choice at present. Many other sport activities must be reexamined in detail using this method.

Body composition of young and middle-aged japanese / 体力科学

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.

Effect of more amount intake of protein in competitive season on body composition and various body functions. In case of varsity throwers / 体力科学

The present study examined the effects of having bigger amount of protein than usual in competitive season on lean body weight (LBW), cross-sectional area of thigh and abdomen, muscle strengths, blood constituents and urinary urea nitrogen. Seventeen male varsity throwers (javelin, discus, hammer and shot put) ranging from 19 to 22 years of age, were divided into two groups ; Group A (N=9) with a more protein diet (2.1 g·kg<SUP>-1</SUP>·d<SUP>-1</SUP>), and Group B (N=8) with a usual amount diet (1.5 g·kg<SUP>-1</SUP>·d<SUP>-1</SUP>) . The experimental period was 62 days. During this period, they practiced six days a week. Three days were for throwing practice. Other three days were for weight training. All subjects lived in the same dormitory, and their life styles were similar to each other. The averaged daily diet of Group A evaluated by means of a weighing method had 3824 kcal with 175 g of protein (2.0 g·kg<SUP>-1</SUP>·d<SUP>-1</SUP>), 115 g of fat and 552 g of carbohydrate. The averaged daily diet of Group B had 3441 kcal with 130 g of protein (1.5 g·kg<SUP>-1</SUP>·d<SUP>-1</SUP>), 76 g of fat and 559 g of carbohydrate. All the intakes of vitamins (A, B<SUB>1</SUB>, B<SUB>2</SUB>, C) and minerals (calcium and iron) of the diet of each group were higher than the Japanese recommended dietary allowance. After the period, body weight, %fat, fat and LBW of both groups did not change significantly. Muscle strengths and cross-sectional areas in abdomen and thigh of both groups did not change significantly. Urinary urea nitrogen of both groups did not change significantly. Blood constituents (RBC, Hb, Ht, TP, Alb, BUN) of each group were still in normal ranges in spite of significant changes. No significant changes in body composition and muscle strengths were found in each group. These results, therefore, indicated that the more protein diet (2.0 g·kg<SUP>-1</SUP>·d<SUP>-1</SUP>) was not effective for increasing LBW and muscle strength of varsity throwers in competitive season.

EFFECT OF THE WELL-REGULATED DIET ON BODY COMPOSITION AND PHYSICAL WORKING CAPACITY OF FEMALE COLLEGE GYMNASTS / 体力科学

Competitive gymnasts are confronted with the problem of weight loss before a competition. They intend to decrease body fat, but not muscle. One of the most reasonable method for the purpose is a dieting. Neverthless, a dieting often leads to decrease not only body fat but also lean body weight (LBW) of which 47% is composed of muscle. That is, a dieting has the possibility of decreasing the competitive performance. The well-regulated diet is, therefore, required very much for weight loss of the gymnasts. The body composition (under-water weighing), physical working capacity (submaximal endurance capacity, muscle strength and vertical jump) and blood constituents of seven female gymnasts were measured before and after the 33 day-diet. They, ranging from 18 to 22 years of age, were high ranked athletes in Japan. The diet program was arranged by the dietitian taking gymnasts' favours into consideration. The averaged daily diet evaluated by means of a dietary recall had 1194 kcal with 54.7g of protein, 28.5g of fat and 179.9g of carbohydrate. On the other hand, the usual intakes just before the dieting were 1722 kcal in energy, 43.0g in protein, 57.1g in fat and 269.2g in carbohydrate. All the intakes of vitamins and minerals of the diet were higher than the Japanese recommended dietary allowance (RDA) . They practiced about four hours a day, six days a week, during the diet period. The daily energy expenditures before and at the last stage of the dieting were 2332 kcal and 2551 kcal on the average respectively, which were estimated through motion and time study. After the dieting body weight decreased significantly from 52.11kg to 48.35kg, of which difference was composed of 2.99kg of body fat and 0.77kg of LBW. The decrease of body fat was statistically significant, but LBW was not so. Concerning all the physical working capacities in oxygen uptake and heart rate, muscle strength except trunk extension strength, and vertical jump, there were no significant changes after the dieting. But respiratory exchange ratio (R) decreased significantly at the same work loads. This decrease suggested increased usage of stored body fat as energy during daily practice, and might support the significant decrease of body fat. Most of blood constituents were still in normal ranges in spite of significant changes. Marked change was found in serum FFA which increased three times after the dieting. This change also meant the increased usage of body fat after the dieting. These data indicated that the diet program arranged in this study proved successful and the wellregulated diet was very effective in conditioning the body composition and the physical working capacity of female gymnasts.

RESPIRATORY-CARDIOVASCULAR SYSTEM OF OBESE MEN RELATED TO VO<SUB>2max</SUB> AND BODY COMPOSITION / 体力科学

In order to investigate an effect of the excess fat of obese men on the respiratory-cardiovascular system, VO<SUB>2</SUB>max was measured for seven obese, 16 ordinary and seven lean men. All subjects were university students, ages 18 to 25 years. Body composition was determined by densitometry. Furthermore, six non-obese young men participated in an added-weight experiment so as to estimate an effect of the excess fat of obesity. Results showed that there were no statistically significant differences in the absolute values of VO<SUB>2</SUB>max, VEmax, and HRmax among the groups. Concerning the relative value of VO<SUB>2</SUB>max to body weight, the obese group showed a significantly lower value of 40.4 ml/kg-min than the lean and ordinary group values of 51.5 and 48.8 ml/kg-min, respectively. However, no significant difference was found between the relative values of VO<SUB>2</SUB>max per lean body mass of any of the groups. VO<SUB>2</SUB>max for the obese group was 54.0 ml/kg-min, 56.0 for the lean group and 57.7 for the ordinary group. Such trends were very similar to the results of the added-weight experiment. Based on the values for the subjects in this study, this leads to the conclusion that the excess fat of obese men might act only as an inactive load and might not affect the ability of the respiratory-cardiovascular system. Besides, the threshold of obesity for men proposed by Behnke and Wilmore might be reasonable from the viewpoint of the absolute and the relative values of VO<SUB>2</SUB>max.

INVESTIGATION OF LEAN BODY MASS AS A LIMITING FACTOR OF MAXIMUM OXYGEN UPTAKE / 体力科学

Total muscle mass is thought of as one of the intrinsic limiting factors of aerobic power. But it is not yet clarified how the total muscle mass limits the magnitude of aerobic power. The purpose of this study was to clarify the relationship between total muscle mass and aerobic power and to make a further discussion conscerning its limiting factors. 17 sedentary students with a mean age of 19.3 (18-23) years, and 17 varsity footballers 19.9 (19-21) years old, were measured for lean body mass, which was an approximate indicator of the total muscle mass, by underwater-weighing method and VO<SUB>2</SUB> max by bicycle ergometer. The correlationship between lean body mass and VO<SUB>2</SUB>max for sedentary students was found to be higher (r=0.821) than for footballers (r=0.595) . It was also shown that footballers had a significantly larger VO<SUB>2</SUB>max per 1kg of lean body mass than sedentary students. Previous studies showed that the increment of VO<SUB>2</SUB>max through endurance training was caused by the increment of such factors as mitochondria, maximum cardiac output and maximum stroke volume, and was not by lean body mass. So, it was concluded that lean body mass was a reasonable limiting factor for sedentary students, but was not a stable factor of VO<SUB>2</SUB>max because of lower linearlity for footballers and the significant difference on VO<SUB>2</SUB>max per 1kg of lean body mass between two groups.