Japanese Journal of Physical Fitness and Sports Medicine
Online ISSN : 1881-4751
Print ISSN : 0039-906X
ISSN-L : 0039-906X
Volume 52, Issue 3
Displaying 1-14 of 14 articles from this issue
  • NA DU, KAZUO OGURI, LIPING ZHAO, JUNICHI KUROKAWA, YOSHIHIRO KATO, SAC ...
    2003 Volume 52 Issue 3 Pages 231-239
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of this study was to investigate the effects of short-term living and training at an altitude of 1, 300 to 1, 800 m on physiological responses of high school elite endurance athletes. Fifteen male and seven female senior high school elite athletes, aged from 15 to 18, from three different sports (cross-country skiing, long-distance running and endurance cycling), participated in our study. The short-term (6 days) altitude exposure did not elicit abnormal responses of body tempera-ture, body weight, blood pressure or urine samples. There were also no significant changes in blood parameters examined before and after altitude exposure. Resting heart rate (HR) increased at altitude and presented an initial peak value followed by a steady decline on the following days of altitude exposure. Blood lactate concentration and exercise peak llR examined by submaximal 20-m shuttle run test decreased after the ascent to altitude and still showed lower values at postaltitude than at prealtitude. We conclude that 6-day living and training at an altitude of 1, 300 to 1, 800 m elicits positive decrements of exercise blood lactate and exercise peak HR as well as adaptive changes of resting IlR for these high school elite endurance athletes, which are probably related to an attenuation of muscle glycogen utilization and alterations in the autonomic neural system taken at altitude.
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  • MINENORI ISHIDO, TOMOE HIRANO, TOMIE NISHIZAWA, NORIKATSU KASUGA
    2003 Volume 52 Issue 3 Pages 241-247
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The contractile and morphological effects of chronic overload induced by synergist gastrocne mius and soleus ablation were studied in regenerating plantaris muscle of rats after injuries produced by eccentric exercise. Rats were randomly divided into control (C), eccentric exercise (E) synergistic ablation (S) and eccentric exercise+synergistic ablation (ES) groups. At 6 weeks after the experimental treatment, contractile or morphological muscle properties were measured. The maximum tetanic tension of ES group was significantly larger than that of S group (p<0.05), although there was not significant difference between C and E groups. There was not significant difference in contraction time between S group and ES group. While there was not significant difference in mean cross-sectional area of any fiber types between C group and E group, all fiber types of ES group were significantly smaller than that of S group (p<0.05) . It is concluded that the overload on injured muscle by eccentric exercise may restrain muscle hypertrophy.
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  • HIDEYUKI TOBE
    2003 Volume 52 Issue 3 Pages 249-254
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    This study investigated the effect of habitual snacking on the diet-induced thermogenesis (DIT) in non-obese young women. Thirteen women aged 1823 yrs old were divided into two groups group one was of six women who consumed snacks; candy, cookies, chocolate, etc., “very frequently” between meals almost everyday, group two was of seven women who seldom consumed snacks. The BMI of both groups were matched (19.7±1.0kg/m2) . The DIT was measured 5 h after ingestion of a meal (2220 kJ=531 kcal) using the Douglas bag technique. Each subject had their DIT measured on eight occasions to obtain average DIT values because DIT had large intra-individual variability. Indeed, each subject's DIT values were markedly different (the mean intra-individual CV=39.6%) . There was no significant difference between the two groups in percentage of body fat, resting metabolic rate (RMR), or RMR/body weight. The mean value of DIT (± SD) of group one (6.4±1.2%) was lower than that of group two (7.8±0.9%) (p<0.05) . Also, the main effects of the groups and the time after ingesting the test meal on postprandial energy expenditure were significant (two-way ANOVA; p<0.001), but the interaction between the group and the time after ingesting the test meal was not significant. In conclusion, eating habits with habitual snacking blunt DIT in young women.
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  • MIKAKO SATO, YASUHIRO SUZUKI, FUMIKI MORIMATSU, KAORU TAKAMATSU
    2003 Volume 52 Issue 3 Pages 255-263
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The present study examined the effect of the long-term intake of chicken breast extract (CBEX), which contains carnosine and anserine, on carnosine content in skeletal muscles of humans and on short-period exercise performance with high intensity.
    Before and after CBEX was orally given to 13 healthy male subjects for 30 days, pieces of their muscle (M. vastus lateralis) were excised and carnosine concentration in the muscle was measured. Before and after the test period, the subjects exercise performance (mean and peak power body weight) was determined by pedaling for 30 sec. On the basis of baseline concentrations of carnosine, the subjects were classified into two groups: low (n=8) and high (n=5) carnosine-baseline groups. In the former group, intake of CBEX increased carnosine concentration in the muscle (p<0.05), resulting in significant correlation between increased rate of carnosine concentration and mean power. These results suggest that exercise performance depends on carnosine concentration in the muscle, and that taking carnosine-containing foods may improve exercise performance.
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  • MASATAKA TOUNO, RAFAMANTANANTSOA HOBY HASINA, NAOYUKI EBINE, HSUEN-YIN ...
    2003 Volume 52 Issue 3 Pages 265-274
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    This study examined total energy expenditure (TEE) of Japanese firefighters under normal working conditions, and also evaluated several field methods for measuring TEE in comparison with the doubly labeled water (DLW) method. Ten male subjects belonging to Tokyo metropolitan firefighters departments, aged 30.0±2.8 yrs (mean±SD), were monitored for five consecutive days. While TEE was assessed by an accelerometer (AC) and activity records (AR) in additoin to DLW, energy intake (El) was evaluated by dietary record. There were three emergency calls over the assessment period, but no real operation of fire suppression. TEE obtained by the DLW method (4009±611 kcal/d) was significantly higher than that estimated by AC (2531±186 kcal/d) or AR (3704±476kcal/d) ; but significantly correlated with AR (r=0.876, p<0.01) . El (3539±286 kcal/d) showed no significant relationship with DLW. These results suggest that compared with AC, AR would be more feasible for estimating TEE of firefighters, who perform special activities carrying heavy equipment. The mean value of physical activity level (PAL) (2.2±0.3) indicates that firefighters can be categorized as heavy workers like soldiers or policemen.
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  • AKITOSHI SOGABE, NAOKI MUKAI, HITOSHI SHIMOJO, HITOSHI SHIRAKI, SYUNPE ...
    2003 Volume 52 Issue 3 Pages 275-284
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    [Purpose] A leg press generally included in a weight training program to develop the quadriceps. However little is known about the mechanism of the load in lower extremity by the different knee alignment. The purpose of this study is to compare the muscle activity in the different knee align ment during leg press exercise. [Methods] Four normal knee and Five gene varum performed the leg press using three stance of narrow, medium and wide stance with the load of 75%/1 RM. Surface EMG date were collected (1000Hz) from vastus medialis (VM), vastus lateralis (VL), rectus femoris (RF), adductor longus (AL), biceps lemons (HF), tibialis anterior (TA), gastrocnemius (GAS), soleus (SQL) . Integrated EMG (iEMG) values were calculated for each muscle during each rep. A video camera recorded the performing form during leg press from the frontal plane. [Results and Discussion] As the leg press was to strengthen of the thigh muscle, VM, VL and RF of both groups worked strongly. However SQL of genu varum worked as strong as the level of activity of the thigh, iEMG of the SQL showed low value significantly by using wide stance. When the genu varum group performed maximal knee flexion using the narrow, their ankle was valuus on the video screen. This result may become cause of SQL higher activity during leg press. From this we can derive the argument that it will be necessary to take that stance into consideration when athletes who are genu varum performs leg press.
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  • YASUNORI MORIOKA, SHIZUO ITO, KEIICHI OHBA, TAKAKO HARA, JIN UCHIMARU, ...
    2003 Volume 52 Issue 3 Pages 285-294
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    This study was conducted to clarify the relationship between power estimated by blood lactate movement during intermittent running test (Maximal Anaerobic Running Test : MART), and velocity of middle distance running (V 800 m, V 1500 m) . The subjects were well-trained male middledistance runners (n=8) .
    MART consisted of a variable number of 20 seconds runs on a treadmill with a 100 seconds recovery period between runs. The runs were performed ona a 4° incline. After 40 second recovery, earlobe blood samples were taken and blood lactate concentrations were analyzed. The first run was performed at 250 m/min. Velocity of the treadmill was increased by 25 m/min for each consecutive run until volitional exhaustion.
    The power requirement associated with the absolute value of blood lactate (La) and relative value of peak blood lactate (PBLa) was determined from the La or %PBLa vs power curve by linear interpolation from the two consecutive La values which were above and below the desired value.
    Results were summarized as follows:
    (1) Maximal power (Pmax) for MART was correlated positively with V800m (r=0.880, P<0.01) and V1500m (r=0.948, p<0.001) .
    (2) Power estimated at 40% value of PBLa (P40%La) correlated positively with V 1500 m (r=0.903, P<0.01), and at 60% value of PBLa (P60%La) was correlated positively with V800m (r=0.835, P<0.01) and 1500m (r=0.936, p<0.001) .
    These results indicate that MART is a valid test for estimating middle distance running performance and P40%La, and P60%La are important indexes with 800-m and 1500-m running.
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  • YOSHITAKE OSHIMA, TOSHIKAZU SHIGA, TOSHIO MORITANI, IZURU MASUDA, TATS ...
    2003 Volume 52 Issue 3 Pages 295-303
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    The purpose of the present study was to develop a new method that enables individualized determination of the optimal exercise intensity for health promotion. Our study was based on the following observations : (1) physical activity at ventilatory threshold (VT) has been useful for enhancing physical fitness and even improving medical conditions such as heart failure, hypertension and diabetes, (2) exercise intensity at VT is characterized by suppressed vagal activity, and (3) vagal activity can be evaluated by analyzing heart rate variability (HRV) . In the first study we defined a criteria for determining the exercise intensity corresponding to VT using HRV analysis (heart rate variability threshold, THRV) . In 16 normal subjects, a time series of ECG RR interval were recorded and the means of the sum of the squared differences in successive RR intervals (MSSDs) were calcu-lated during a ramp exercise test with a cycle ergometer. Based on the values of MSSD and the dif-ferences in successive MSSDs (ΔMSSD) at the intensity of VT, we defined the criteria of THRV as follows : MSSD<25 msec2and ΔMSSD<6 msec2. Another exercise test with a cycle ergo-meter was performed to evaluate the relationship between THRV and VT in 63 normal subjects. Heart rate (HR) and oxygen uptake (VO2/wt) at THRV were 111.8±13.2 beats/min and 15.2±4.4 ml/kg/min, and HR and VO2/wt at VT were 116.2±11.6beats/min and 16.5±3.7ml/kg/min, respectively. There was a significant correlation between THRV and VT (HR : r=0.82, p<0.001, VO2/wt : r=0.88, p< 0.001) . Thus, THRV and VT provided almost identical exercise intensities. As a result, we propose that, similar to VT, THRV can be used as an indicator of the optimal exercise intensity suitable for health promotion in normal subjects.
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  • -EFFECTS OF SIMULTANEOUS EXERCISE OF KNEE EXTENSORS AND FLEXORS-
    TORU TAKEKAWA, EUN SANG SOO, MASAHIRO ABO, HIROSHI FUJITA, SATOSHI MIY ...
    2003 Volume 52 Issue 3 Pages 305-311
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
    Purpose : We examined the effect of therapeutic exercise on osteoarthritis (OA) of the knee. Objects and Method : We evaluated seven women with bilateral OA of the knees of over Grade I on the Kellgren and Lawrence scale. The patients were instructed in therapeutic exercise for both knees. The exercise was to tie a Thera-Band ® around the leg just above both ankles in the 8 figure, and then, in a sitting position, extend one leg while simultaneously retracting the other, repeating alternatively every 5 seconds. One set consisted of repeating this motion 10 times, and 2 sets were performed per day. Before exercise, 1 month, and 3 months after exercise, we evaluated the effect of this therapy by the JOA score, isokinetic muscle strength of knee extensors and flexors, and surface EMG signals recorded from rectos femoris (RF), vastus medialis (VM), vastus lateralis (VL), and biceps lemons (BF) . The integrated signal, the root mean square (RMS), and the mean power frequency (MPF) parameters were extracted.
    Result : The parameters of the JOA score, muscle strength of knee flexors, integrated EMG from RF, VM, VL, and RMS from VM, VL were significantly increased at 3 months after exercise. MPF from VM at 3 months after exercise decreased significantly.
    Conclusion : We thought a proper balance of knee extensors and flexors are related to the improvement of symptoms of OA of the knee. The decrease of MPF might suggest the possibility of muscle fiber type change. It is also possible that pain reduction results from the improvement of balance between knee extensors and flexors as well as from the increase of knee joint stability. Therapeutic exercise with the Thera-Band R is extremely easy and is effective in promoting con-tinuous exercise.
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  • [in Japanese]
    2003 Volume 52 Issue 3 Pages 313-317
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 2003 Volume 52 Issue 3 Pages 319-328
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 2003 Volume 52 Issue 3 Pages 329-334
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 2003 Volume 52 Issue 3 Pages 335-347
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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  • 2003 Volume 52 Issue 3 Pages 348-356
    Published: June 01, 2003
    Released on J-STAGE: September 30, 2010
    JOURNAL FREE ACCESS
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