The Journal of Physical Fitness and Sports Medicine
Online ISSN : 2186-8123
Print ISSN : 2186-8131
ISSN-L : 2186-8131
Volume 7 , Issue 1
Showing 1-13 articles out of 13 articles from the selected issue
Review Article
  • Ayako Satonaka, Nobuharu Suzuki
    2018 Volume 7 Issue 1 Pages 1-7
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    This review article explores how to keep individuals with cerebral palsy healthy all their life. Many of these individuals live very sedentary lives, remaining at home after leaving school or completing childhood rehabilitation programs. Aerobic fitness in such individuals is known to decline rapidly in adulthood. Therefore, in order to keep aerobic fitness from falling into decline, the physical activities and aerobic fitness of these individuals must be appropriately and rigorously managed. The authors recently showed the validity of submaximal exercise testing and provided some findings that would contribute to improving aerobic fitness in these individuals. These studies indicate that even NEAT (Non-Exercise Activity Thermogenesis) or brief and frequent daily physical activity, rather than just conventional exercises or sports, could improve aerobic fitness. However, other studies recommend that these individuals engage in exercises or sports that they may not be interested in or that require facilities or occasions that are inaccessible. In conclusion, in addition to a standard exercise regimen, realistic and tangible interventions for daily physical activities need to be made available to individuals with cerebral palsy.

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Short Review Article
  • Yuka Kurosaka, Hideki Yamauchi, Shigeru Takemori, Kumiko Minato
    2018 Volume 7 Issue 1 Pages 9-14
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    This paper discusses the effects of dietary restriction and physical exercise on the maintenance of good health, focusing on intrahepatic fat accumulation, a type of ectopic fat accumulation. Excessive intrahepatic fat accumulation eventually progresses to fatty liver, which may evolve into liver cirrhosis and liver cancer. Physical exercise and dietary restriction are generally accepted as the major non-pharmacological remedies against intrahepatic fat accumulation. However, a combination of diet and physical activity has not necessarily shown expected synergistic or additive effects. In fact, dietary conditions antagonistically blocked the effect of physical activity on fatty liver, and physical inactivity adversely exacerbated the effect of dietary restriction on intrahepatic fat accumulation. These diverse combination effects, as well as etiology-dependent diversity in the activation of cellular signaling pathways leading to fatty liver, suggest the need to optimize remedies for the efficient amelioration and prevention of intrahepatic fat accumulation in a case-dependent manner. As a tentative step to constructing a prescription formula for optimal remedies, the probable advantage of physical exercise over dietary restriction at preventing fat spillover from adipose tissue to liver is noted.

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  • Naoyuki Kurokawa
    2018 Volume 7 Issue 1 Pages 15-18
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    Natural disasters have the potential to disrupt human life and society in a variety of ways. This is true of typhoons, floods, earthquakes, tsunamis, and a host of other events. On March 11, 2011, a large earthquake occurred off the Pacific coast of Tohoku, Japan. Called the 2011 Tohoku Earthquake, it was the most powerful earthquake recorded in Japanese history, and triggered powerful tsunami waves and an unprecedented nuclear accident. The tsunami caused serious damage to coastal areas in the Tohoku district. Since then, the area’s environment has undergone a huge change. Such environmental change may affect the growth and development of children living in and around damaged areas. Recently, data from investigation results have been revealed showing the relationship between the 2011 Tohoku Earthquake and child growth in Japan. These results are most likely related to changes in both the environment and the socioeconomic status of individuals living in the affected areas. Since the environment and areas in which children still live are in a transitional period from reconstruction efforts, the level of child growth and development will also have changed. Accordingly, future studies and investigations aim to determine if these secular trends are continuing, and intend to examine possible explanations and consequences.

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Regular Article
  • Koichiro Tanahashi, Jun Sugawara, Yuriko Sawano, Seiji Maeda
    2018 Volume 7 Issue 1 Pages 19-24
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    Retrograde and oscillatory shear can induce profound pro-atherogenic effects on endothelial cells, and increase with advancing age in peripheral conduit arteries. Habitual aerobic exercise ameliorates conduit artery retrograde and oscillatory shear in middle-aged and older adults; however, the mechanisms underlying the change in conduit artery shear rate patterns caused by habitual aerobic exercise remains unclear. This study investigated the role of sympathetic vasoconstrictor tone in the habitual aerobic exercise-induced change in conduit artery shear in middle-aged and older adults. Fifteen healthy middle-aged and older adults (aged 52-67 years; 4 men, 11 women) were divided into physically-active and sedentary control groups, based on reported exercise history. We measured brachial artery shear rate patterns at rest and during sympathetic nerve activity stimulation (via lower body negative pressure [LBNP] at -20 mmHg). At rest, the physically-active group showed smaller brachial artery retrograde and oscillatory shear compared to a sedentary control group (p < 0.05). The levels of brachial retrograde and oscillatory shear were elevated by the LBNP stimulation in the physically active group (p < 0.05), but not in the sedentary control group. Our results suggest that the attenuated basal sympathetic vasoconstrictor tone may contribute to the habitual aerobic exercise-induced decreases in conduit artery retrograde and oscillatory shear at rest in middle-aged and older adults.

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  • Naofumi Yamamoto, Susumu S. Sawada, I-Min Lee, Yuko Gando, Ryoko ...
    2018 Volume 7 Issue 1 Pages 25-33
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    The stability of the relative order of cardiorespiratory fitness (CRF) during adulthood has not been sufficiently investigated. This study investigated the tracking of CRF over a 7-year follow-up period in Japanese male adults aged 18-53 years. A total of 3,718 male workers who underwent three submaximal exercise tests (a first test and again 3 and 7 years later for a second and third test) were included. CRF was defined as the maximal oxygen uptake estimated from a submaximal exercise test using a cycle ergometer. Spearman correlation coefficients for CRF in the first and second tests, the second and third tests and the first and third tests were 0.61, 0.62 and 0.54, respectively. A moderate kappa coefficient, indicating the degree of agreement for quartiles, was obtained for all follow-up periods (kappa coefficient = 0.43-0.53). The changes in quartiles for all three time measurements indicated that approximately 70% of participants had stable (participants in the same quartile for all three measurements) or moderately stable (participants who exhibited changes varying by one quartile from the initial quartile) CRF levels. These findings showed moderate CRF tracking during adulthood over a period of up to 7 years.

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  • Kosuke Hirata, Eri Miyamoto-Mikami, Noriko Kimura, Naokazu Miyamoto
    2017 Volume 7 Issue 1 Pages 35-40
    Published: January 25, 2017
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    The passive material properties of a muscle, as evaluated by shear or Young’s modulus, can vary depending on the muscle cross-sectional area (CSA), since intramuscular compositions such as adipose tissue and connective tissue change with muscle hypertrophy and atrophy. However, the relationship remains unclear between the passive material properties and CSA of a muscle. Therefore, we examined whether passive muscle shear modulus is related to muscle CSA in the human hamstring. The shear modulus and anatomical CSA of the biceps femoris, semitendinosus, and semimembranosus were measured in 71 healthy young males with the hip flexed at 70° and knee fully extended. The shear modulus of each muscle was measured using ultrasound shear wave elastography. Muscle CSA was assessed using panoramic ultrasound imaging. There were individual differences in muscle shear modulus as well as muscle CSA. The coefficients of variation (CVs) of muscle shear modulus were 41.4% (range: 8.8 - 54.3 kPa), 33.0% (range: 8.4 - 57.3 kPa), and 41.1% (range: 18.2 - 107.1 kPa) for the biceps femoris, semitendinosus, and semimembranosus, respectively. There were no significant correlations between shear modulus and CSA in each or overall hamstring muscle (absolute r < 0.113). The present findings indicate that, although the passive material property of muscle is not the same among individuals, it is substantially independent of the muscle CSA, at least in the hamstring.

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  • Satoshi Oikawa, Seiji Maeda, Takayuki Akimoto
    2018 Volume 7 Issue 1 Pages 41-45
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    Endothelial function is an important factor for maintenance of blood pressure (BP) homeostasis. Recently, microRNA (miRNA) has emerged as a potential regulator of endothelial function. However, the role of miRNAs in maintenance of BP homeostasis is unknown. In the present study, we investigated the potential role of endothelial miRNAs in BP regulation in vivo by using endothelial cell (EC)-specific Dicer knockout (KO) mice and measured BP before and after 8 weeks of high salt loading intervention. The EC-specific Dicer homozygous KO mice showed embryonic lethality. The EC-specific Dicer heterozygous KO mice (Het) showed a significant decrease in expression of Dicer mRNA in lung compared to wild-type (WT) mice. However, there were no differences between WT and Het mice in heart rates, systolic and diastolic blood pressures before and after 8 weeks of high salt loading. In this study, we demonstrated that the endothelial Dicer is essential for embryonic development. Additionally, we could not observe any phenotype in the hemodynamic parameters of EC-specific heterozygous Dicer KO mice.

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  • Kazufumi Terada, Toshiaki Nakatani
    2018 Volume 7 Issue 1 Pages 47-55
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    A randomized controlled trial was conducted to investigate the interactive influence of massage and exercise on health-related physical fitness in middle-aged and older adults. Thirty-eight healthy males aged 40 to 69 years were randomly assigned to one of three groups: an exercise and self-massage intervention group (S group, n = 13), exercise training only intervention group (T group, n = 13), or control group (C group, n = 12). Subjects in S group underwent structured manual self-massage comprising static stretching of the entire body and Oriental Medicine techniques such as manual massage and stimulation of acupuncture points (physical care). An exercise regimen for both S group and T group was comprised of group-based and home-based training, including resistance training of upper and lower limbs and abdominal muscles, endurance training, and plyometric training for 12 weeks. The major outcome measures were the 30-second chair-stand test (CS-30), vertical jump (VJ), shoulder horizontal adduction (SHA, muscle–strength test), 30-second sit-up test (SU-30), center of foot pressure (CoP), and the chair sit-and-reach test (CSR). The S group showed significantly greater post-intervention improvements (p < 0.05) in measures of CS-30 (+22%), VJ (+23%), SU-30 (+14%), locus length per unit area in CoP, with eyes closed (L/A) (-18%), and CSR (+44%). Whereas, the T group showed improvements in CS-30 (+11%), VJ (+20%), SHA (+15%), and L/A (-24%). The C group experienced no significant changes. There were no significant differences between the T and C groups. The S-group’s post-intervention CS-30 and VJ values were significantly higher than those of the C group (p < 0.05). A concurrent massage intervention (physical care) was shown to enhance exercise effects.

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  • Tomonobu Ishigaki, Toshihiro Ikebukuro, Keitaro Kubo
    2018 Volume 7 Issue 1 Pages 57-64
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    The purpose of this study was to compare changes in blood circulation and collagen fiber orientation in the Achilles tendons after repeated eccentric contractions (ECC) with different loads. Thirteen healthy male subjects performed two ECC protocols with different loads and then remained relaxed for 40 min after ECC. Each leg was randomly allocated to low-load protocol (180 repetitions at 50% of one repetition maximum [1RM]) and high-load protocol (75 repetitions at 120% of 1RM). Before and after ECC, blood volume and oxygen saturation in the Achilles tendons were measured using a laser oxygenation monitor. Tendon collagen fiber orientation was also estimated from the coefficient of variation (CV) of echogenicity on transverse ultrasonic images of the Achilles tendon. In the low- and high-load protocols, blood volume in the tendon was significantly higher than the resting level until the end of the recovery period, although oxygen saturation returned to the resting level at the 20-min point of recovery. The CV of echogenicity was significantly lower than the resting level until the end of the recovery period. No differences in the changes in these variables were observed between the two protocols. These results suggest that blood volume and collagen fiber orientation in tendons are changed to the same degree by repeated eccentric contractions with the same amount of work regardless of the magnitude of the load.

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  • Hiroko Nakayama, Hideaki Onishi, Motoko Nojima, Katsuhito Ishizu, ...
    2018 Volume 7 Issue 1 Pages 65-74
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    The aim of this study was to compare scapular kinematics between men and women during shoulder flexion, scapular plane elevation, and shoulder abduction. Eleven healthy men and 11 healthy women participated in this study. As participants performed shoulder flexion, scapular plane elevation, and abduction at a consistent speed, an electromagnetic motion capture system was used to analyze scapular motion. The change in scapular orientation from its resting position was calculated at 30°, 60°, 90° and 120° of humeral elevation. The study found that scapular upward rotation and posterior tilt angles increased significantly with each successive humeral elevation angle, but less so in women than in men. Scapular internal or external rotation differed significantly according to the plane of elevation, that is the scapula was internally rotated during flexion, with no change during scapular plane elevation, and it was externally rotated during abduction. This variation was more marked in women. This study revealed gender differences in scapular kinematics during shoulder motion. During shoulder elevation, the scapulothoracic joint played a greater role in men than in women, whereas the glenohumeral joint played a greater role in women.

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Short Communication
  • Munehiro Matsushita, Kazuhiro Harada, Takashi Arao
    2018 Volume 7 Issue 1 Pages 75-80
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    Communicative and critical health literacy (HL) are thought to play an important role in improving healthy behaviours. However, no study has examined the relation between these types of HL and physical activity. The purpose of this study was to examine the relation of these types of HL to overall (“total”) physical activity and the different domains (work-related “work”, travel-related “travel”, and recreational “recreation”) of physical activity in Japanese adults. This study was an internet-based cross-sectional survey. The analysis included 3,132 participants. The survey included the following variables: 1) communicative and critical HL, 2) physical activity measured by the Global Physical Activity Questionnaire (GPAQ), and 3) confounders (gender, age, marital status, living with family, household motor vehicles, body mass index, household income, educational status, and employment status). To examine the relation of communicative and critical HL to physical activity, logistic regression analysis was performed to calculate the odds ratio (OR) and 95% confidence interval (95% CI) for “active” physical activity in total and each domain (“work”, “travel”, and “recreation”) of physical activity stratified by gender. In men, high HL was significantly related to total (OR: 1.81, 95% CI: 1.47-2.22), travel (1.76, 1.42-2.18), and recreation physical activity (1.75, 1.39-2.21); but not significantly related to work physical activity (1.22, 0.94-1.58). In women, high HL was significantly related to total (1.43, 1.15-1.77), travel (1.38, 1.11-1.71), and recreation physical activity (2.12, 1.63-2.76); but not significantly related to work physical activity (1.31, 0.97-1.78). This study suggests that a high level of communicative and critical HL was significantly related to high level of total, travel-related, and recreational physical activity in Japanese adults.

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  • Eri Oyanagi, Masataka Uchida, Michael J. Kremenik, Hiromi Yano
    2018 Volume 7 Issue 1 Pages 81-85
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    In the present study, we determined whether or not exercise-induced high physical activity could be transmitted via altered gut microbiota. We collected cecal material from male C57BL/6N mice for 12 weeks under two conditions: voluntary wheel running (EX) and sedentary condition (SED). After depleting endogenous gut microbiota, cecal microbiota transplantation (CMT) was initiated in the recipient mice by placing cecal contents of either EX or SED mice into the oral cavity directly with the feeding of a high-fat diet (HFD). After a breeding period of 8 weeks, the physical activity test of the HFD (EX-CMT and SED-CMT) mice was examined. Although EX donor mice were attenuated with increasing body mass and body fat, and induced hypertrophy of the heart was compared with SED donor mice, those parameters did not show any difference between EX-CMT and SED-CMT mice. Nevertheless, high physical activity was observed in EX-CMT mice compared to SED-CMT mice (p < 0.01). These results suggest that exercise-induced high physical activity might be transmitted to un-exercised HFD mice via its altered gut microbiota.

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  • Ayumi Goto, Keiichi Sekine, Rieko Oshima, Ichika Sakon, Mayu Iwam ...
    2018 Volume 7 Issue 1 Pages 87-93
    Published: January 25, 2018
    Released: January 19, 2018
    JOURNALS FREE ACCESS

    Heat stress (HS) is a potent stimulus for activating glucose metabolism in skeletal muscles. However, the effect of short-term HS on protein turnover in skeletal muscles is unclear. This study aimed to investigate the effect of short-term HS on protein synthesis and protein degradation in skeletal muscles. The epitrochlearis muscle was isolated from male Sprague–Dawley rats weighing 150-160 grams (g) and incubated with or without HS at 42°C for 10 or 30 min in alpha minimum essential medium. HS for 30 min significantly decreased phosphorylation of 70-kDa ribosomal protein S6 kinase at Thr389 and 4E-binding protein 1 at Thr37/46. Correspondingly, HS for 30 min decreased the rate of protein synthesis. In contrast, HS had no effect on the expression of autophagy-related proteins, including microtubule-associated protein light chain 3 and p62, or on the mRNA expression of muscle-specific ubiquitin ligases, including muscle RING-finger 1 (MuRF1) and atrogin-1/MAFbx. These findings suggested that short-term HS for approximately 30 min is a physiologically relevant stimulus that suppresses protein synthesis signaling in skeletal muscles.

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