Fitness-related factors associated with survival in older women / 体力科学

This study evaluated the relation between physical fitness and survival. This prospective cohort study included 74–88-year-old women who were living at home and who reported no disability in activities of daily living. Subjects completed physical fitness tests assessing walking ability, muscular strength, flexibility, agility, and balance. They were administered a follow-up interview 14 years later. Of 63 older women, 58 died during that 14-year period. Among the 16 physical fitness measurements, significant association with survival time was found for 11 measurements using Cox proportional hazards model (Adjusted for age, BMI, and TMIG index of competence score). Among them, maximum walking time was an indicative main physical fitness factor for predicting the survival of elderly women. The hazard ratio per 1 s of 10m maximum walking time was 1.93 (95% Confidential Interval [CI], 1.54–2.41). Among muscular strength, flexibility, agility, and balance, the most influential physical fitness element to survival was agility (nerve reaction time). Therefore, the functional decline of the nervous system is expected to affect survival strongly. When 10 m maximal walking speed is 8.5 s or more, the median survival time of elderly women is 6.75 years (95%CI, 6.25–7.67), but if the time is less than 8.5 s it is 11.58 years (95%CI, 10.25–13.08, p<0.0001; log-rank test). The ability to move rapidly is identified as the main physical fitness factor associated with survival.

QUANTIFYING TIME SPENT IN MODERATE TO VIGOROUS INTENSITY PHYSICAL ACTIVITY VIA STEPPING RATE / 体力科学

The purpose of the present investigation was to examine the usefulness of the stepping rate for assessing the time spent in moderate to vigorous intensity physical activity (MVPA). In the present investigation, 11 young men wore two pedometers (LIFECORDER EX ; KZ, Walking Style ; WS) during controlled walking and jogging, as well as during free-living conditions for 3 days. In addition to the number of steps, the KZ determined the time spent in physical activity based on the intensity of the physical activity (light intensity physical activity (LPA); below 3 METs, and MVPA ; above 3 METs), and the stepping rate (≧60, ≧80, or ≧100 steps·min^-1). In contrast, the WS was defined as the physical activity for a stepping rate of 60 steps·min^-1 or more, continuously for longer than 10 min as the time spent in physical activity. Regarding the results, under continuous walking/jogging, the KZ-assessed LPA and MVPA well reflected the intensity of the physical activity. On the other hand, the WS accumulated the time spent in physical activity for longer than 90% of the actual exercise duration, regardless of the walking speed. Furthermore, the stepping rate corresponding to 3 METs was 102 steps·min^-1. Under free-living conditions, however, the KZ-detected MVPA differed significantly in comparison to the time of the physical activity as determined by the other algorithms, except for the time spent in a stepping rate of 80 or higher steps·min^-1. In conclusion, these results indicate that 100 steps·min^-1 is a useful stepping rate for the assessment of MVPA. However, under free living conditions, the stepping rate should be determined at a higher frequency than a one minute interval length in order to improve the accuracy of the MVPA assessment.

RELATIONSHIP BETWEEN OPEN-WATER SWIMMING PERFORMANCE AND AEROBIC CAPACITY / 体力科学

The purpose of the present investigation was to examine the relationship between the open water swimming (OW) performance and the swimming speed at 2, 3, and 4 mmol/l of blood lactate concentration (SSLA2, SSLA3, and SSLA4) or the critical swimming speed (CSS). Six male collegiate swimmers performed the 10 kilometers of OW, as well as the multi-stage graded swimming test, in order to determine the SSLA2, SSLA3, SSLA4. Furthermore, the CSS was calculated based on the personal best records for 50 to 1500 meters of free-style indoor swimming. As a result, the SSLA2, SSLA3, SSLA4, and CSS corresponded to 102±6%, 106±6%, 110±7%, and 106±5% of the average swimming speed of the OW, respectively. Thereafter, the SSLA2 did not differ significantly in comparison to the average swimming speed of the OW, whereas the SSLA3, SSLA4, and CSS differed significantly with the average swimming speed of the OW (p＜0.05). Furthermore, the average swimming speed during the OW significantly correlated with the SSLA2, SSLA3, SSLA4, and CSS, respectively (p＜0.05). These results suggest that the OW performance significantly correlated with the swimming speed at 2 to 3 mmol/l of the blood lactate concentrations and CSS. Furthermore, regarding these parameters, the SSLA2 may accurately reflect the average swimming speed of OW.

FITNESS-RELATED FACTORS ASSOCIATED WITH FALLING IN OLDER WOMEN / 体力科学

Purpose : The purpose of the present study was to conduct a 5-year follow-up on the effect of physical fitness on falling in older women. Methods : Thirty-nine older women (79.9±3.7 years old) living at home volunteered to participate as subjects. Walking speeds, muscular strength, flexibility, agility and balance were measured. For the following five years, we checked their record of falling accidents. The subjects were classified into two groups : the faller group (n=14) with at least one or more experiences of falling accidents in the past five years, and the non-faller (n=23). Results and Discussion : The physical fitness of the faller group was compared with that of the non-faller group five years ago. Normal and fast walking speeds in the faller group were significantly slower than those in the non-faller. In the faller group more members had reduced muscular strength and range of motion than in the non-faller. The reaction time in the faller group was significantly slower than in the non-faller. Falling accidents occurred easily because subjects' trunk and hip flexibility had become limited, and the delay in reaction time meant they couldn't recover as quickly from their loss of balance. Conclusions : From these results, it was suggested that functional decline in flexibility as well as agility and muscular strength would greatly affect falling in older women.

Fitness-Related Factors Associated with Changes in Walking Speed in Elderly Women / 体力科学

The purpose of the present study was to investigate the relation between the deterioration of walking speed and physical fitness. Sixty-two elderly women (80.4±4.0 years old) volunteered to participate as subjects. Walking speeds at normal and fast speeds on a 10 m straight course, as well as muscular strength, flexibility, agility and balance were measured.<BR>Normal and fast walking speeds decreased through aging, and mostly depended on the strength of lower extremity muscles (hip extensor, hip abductor, knee extensor and ankle plantar flexor ; normal walking : r=0.596-0.666, p<0.01, fast walking : r=0.623-0.727, p<0.01) . However, the distributions of walking speed to the strength of each measured muscle were divided into two phases. The weaker group of lower extremity muscle strength had much slower walking speed. The two groups, divided according to muscular strength (the sum of the T scores of the four muscular strengths of the lower extremity) showed the following differing results. In the “high” muscular strength group (n=31) the highest factor was lower extremity muscle strength, but it was the delay of nerve reaction time in the “low” muscular strength group (n=31) .<BR>From these results, it was clarified that the main factor in the deterioration of walking speed in elderly women was the decline of lower extremity muscle strength. However, it was suggested that the functional decline of the nervous system would greatly affect the decrease of walking speed in elderly with weaker muscular strength.

The effect of recovery mode on blood lactate removal during intervals in the water-polo games / 体力科学

The purpose of the present study was to elucidate the effective recovery mode during intervals in water-polo games from the viewpoint of blood lactate removal. Six male elite water-polo players (aged 20±2 years old) volunteered to participate as the subjects. Three different modes of recovery ; sitting (Rest), kicking of breast stroke on the spot (Kick), and backstroke swimming (Swim) were compared for breathing air or 60%O<SUB>2</SUB>. Blood lactate removal was expressed as the percentage decrease in blood lactate concentration from the end of preceding period to the end of the interval. The lactate removal in Swim was the highest (p<0.05) of the three kinds of recovery modes. Lactate removal indicated a higher value in order of Swim>Kick>Rest for breathing air. And it was facili tated in Swim (2.1%), Kick (5.4%) and Rest (8.1%) by 60%O<SUB>2</SUB> inhalation, although no significant differences were observed. From these results, it was suggested that the blood lactate removal during intervals in water-polo games would be facilitated by an active recovery mode like Swim, and that the inhalation of 60%O<SUB>2</SUB> would not bring any significant effects.

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.

EXERCISE CHANGE OF HEART RATE, BLOOD PRESSURE AND RESPIRATORY RATE IN RELATION TO SEX AND AGE / 体力科学

This report deals with the response of heart rate, blood pressure and respiratory rate when the subjects of different ages and sexes worked on a bicycle ergometer. The subjects were 126 healthy persons of both sexes. They consisted of 8 groups : prepuberty male (N=15) and female (N=16), puberty male (N=20) and female (N=18), young adult male (N=15) and female (N=16), middle aged male (N=17) and female (N=9) . All subjects tried pedalling exercise with 3 kinds of loads, i.e., 5kgm/kg/min, 10kgm/kg/min and 12.5 kgm/kg/min for 6 minutes.<BR>Heart rate was calculated from chest lead ECG and respiratory rate was measured by the thermistor method continuously recorded before, during and after exercise. Blood pressure was measured by Riva Rocci sphygmomanometer before exercise, at the early stage of recovery and in 10 minutes after exercise.<BR>The results of this study are summarized as follows<BR>1) In both sexes the heart rate decreased with age in resting status and exponentially increased during moderate and heavier exercise. A linear relationship was found between the work load and the exercise heart rate.<BR>In males the heart rate during light exercise was high in the prepuberty and the puberty, low in the young adult and the middle aged. But the heart rate during heavy exercise in the middle aged was extremely high. The heart rate in females was higher than that in males when the same work load was given in both sexes. The rising phase of heart rate in prepuberty was the earliest of 4 age groups.<BR>2) The systolic blood pressure and the pulse pressure in resting status increased with age. As for the blood pressure during exercise, it was low in the youth and high in the middle aged. The blood pressure after exercise in the middle aged males was the highest of 4 groups. Generally in all females the systolic blood pressure and the pulse pressure increased with work load, but the former levelled off during heavy exercise.<BR>3) The respiratory rate during exercise increased rapidly, but when the exercise was stopped, the increased respiratory rate returned rapidly to the resting level. As for the respiratory rate, in both sexes it decreased with age from the prepuberty to the middle aged in resting status and during exercise. The sex difference of the respiratory rate during heavy exercise was large.<BR>4) In the youth the correlation coefficient between the heart rate and the blood pressure was high. Therefore, it was suggested that the heart rate was important in adaptation to exercise.

EFFECT OF ANAEROBIC CAPACITY AND POWER ON THE PERFORMANCE OF LONG DISTANCE RUNNERS / 体力科学

(1) The purpose of the present study was to investigate the significance of anaero-bic energy release in two groups of distance runners whose maximal aerobic power was known to be comparable (Vo<SUB>2</SUB>max averaged 71.1±1.22 ml/kg· min) but differed each other significantly in their performance of 5, 000m run (group A ; n=6, timed in average 14'50″1±11″0 ; and group B ; n=6, timed in average 15'52″5±14″1) .<BR>(2) Twelve runners were subjected to 3 experimental series of treadmill running 1, exhaustive running, 2, two to four trials' of submaximal runnings for 15 min, and 3. running at the intensity corresponding to 90% of maximal oxygen uptake for 14 min, then the“last spurt”for 1 min at 120% of maximal oxygen uptake. In addition, they were asked to sprint up a staircase with their top speed.<BR>(3) Exhaustive running time on the treadmill and maximal oxygen debt in group A were 8'56″2±40″8 and 8454±923.7 ml, respectively. Both were significantly larger than 8'02″8±31″0 and 6787±1301.7 ml registered by group B (p<0.05) .<BR>(4) Differences between A and B groups in their cardio-respiratory responses during maximal treadmill running, threshold of anaerobic metabolism, anaerobic power, alactic and lactic oxygen debt, maximal lactate concentration, etc. were found to be not significant.<BR>(5) These results indicate that the variance in maximal oxygen debt may exert a modifying influence in either positive or negative directions which could be the reason why the same level of aerobic power does not guarantee a comparable performance level in actual running event.