著者

Katsuyasu Kouda Masayuki Iki

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.29, no.4, pp.127-132, 2010-07-31 (Released:2010-08-01)

参考文献数

62

被引用文献数

34 49

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Hormesis is defined as a dose-response phenomenon characterized by low-dose stimulation and high-dose inhibition, and has been recognized as representing an overcompensation for mild environmental stress. The beneficial effects of mild stress on aging and longevity have been studied for many years. In experimental animals, mild dietary stress (dietary restriction, DR) without malnutrition delays most age-related physiological changes, and extends maximum and average lifespan. Animal studies have also demonstrated that DR can prevent or lessen the severity of cancer, stroke, coronary heart disease, autoimmune disease, allergy, Parkinson's disease and Alzheimer's disease. The effects of DR are considered to result from hormetic mechanisms. These effects were reported by means of various DR regimens, such as caloric restriction, total-nutrient restriction, alternate-day fasting, and short-term fasting. Mild dietary stress, including restriction of amount or frequency of intake, is the essence of DR. For more than 99% of their history, humans lived as hunter-gatherers and adapted to restrictions in their food supply. On the other hand, an oversufficiency of food for many today has resulted in the current global epidemic of obesity and obesity-related diseases. DR may be used, therefore, as a novel approach for therapeutic intervention in several diseases, when detailed information about effects of mild dietary stress on human health is obtained from clinical trials.

著者

Miyo Nakade Hitomi Takeuchi Nozomi Taniwaki Teruki Noji Tetsuo Harada

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.28, no.5, pp.239-245, 2009-09-30 (Released:2009-10-10)

参考文献数

32

被引用文献数

16 34

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Tryptophan (Trp) intake at breakfast promotes morning-typed circadian typology and higher sleep quality in Japanese children aged 0–6 yrs (Harada et al., 2007). This effect may be accelerated by morning exposure to sunlight, which has not yet been tested. This study aimed to investigate such an effect in Japanese children. In May, 2006, an integrated questionnaire was administered to 0–6-year-old children attending one of 12 kindergartens. 906 parents answered the questionnaire for their children and themselves (response rate: 67.4%). The integrated questionnaire included the revised version for children of the Morningness-Eveningness (M-E) Questionnaire and questions on sleep, nutritional balance, mental health, and sunlight exposure. Analysis was made on data from 744 children aged 2–6 (385 girls, 359 boys) whose average M-E score was 20.6±3.46. Children who had breakfast at regular times tended to be more morning-typed and were less frequently angry (p=0.001) and depressed (p=0.007). Children who had nutritionally well-balanced breakfasts tended to be more morning-typed (p<0.001), and woke up and fell asleep at earlier times (p<0.001). Children with higher protein intake tended to have higher M-E scores (p<0.001) and earlier bedtime and wake-up time (p=0.003). Children exposed to sunlight for 30–60 min on their way to kindergarten showed more distinctive shifting-effects to morning-type with protein intake than those exposed to sunlight for less than 20 min (p=0.006). A well-balanced breakfast might be a strong zeitgeber for circadian oscillators of children, and the morning-type driving effect of protein intake could be accelerated by morning exposure to sunlight.

著者

Ai Yoto Tetsuo Katsuura Koichi Iwanaga Yoshihiro Shimomura

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.3, pp.373-379, 2007 (Released:2007-07-20)

参考文献数

17

被引用文献数

51 83

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This study was designed to investigate the physiological effects of color in terms of blood pressure and the results of electroencephalogram (EEG) as subjects looked at the sheets of paper of various colors. A questionnaire was also used to assess psychological effects. Three colors (red, green, blue) were shown to each subject in randomized order. The various colors showed distinctly different effects on the mean power of the alpha band, theta band, and on the total power in the theta-beta EEG bandwidth and alpha attenuation coefficient (AAC). Scores of the subjective evaluations concerning heavy, excited, and warm feelings also indicated significant differences between red and blue conditions. Against to our prediction, blue elicited stronger arousal than did red as expressed by the results of AAC and the mean power of the alpha band, which conflicted with the results of the subjective evaluations scores. This phenomenon might be caused by bluish light's biological activating effect. The powers of the alpha band, and the theta band, and the total power of the theta-beta bandwidth as measured by EEG showed larger values while the subjects looked at red paper than while they looked at blue paper. This indicated that red possibly elicited an anxiety state and therefore caused a higher level of brain activity in the areas of perception and attention than did the color blue. Red paper's effect to activate the central cortical region with regard to perception and attention was considerably more distinguishable than was the biological activating effect of bluish light in our study.

著者

Jeong-Eun Song Yong-Shik Kim Jang-Yeul Sohn

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.6, pp.599-603, 2007-11-30 (Released:2007-12-30)

参考文献数

5

被引用文献数

5 8

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This study aims at examining the reduction of indoor air contaminants by plants placed in an indoor space. Field measurements were performed using Aglaonema brevispathum, Pachira aquatica, and Ficus benjamiana, which were verified as air-purifying plants by NASA. Three conditions for the amount of plants and positions were used in two separate rooms whose dimensions are identical. The concentration of Volatile Organic Compounds (VOCs) was monitored three hours after the plants were placed and three days after the plants were placed. The variations of concentration of Benzene, Toluene, Etylbenzene, and Xylene (BTEX), as well as Formaldehyde, which are all known as the major elements of Volatile Organic Compounds were monitored. The amount of reduction in concentration of Toluene and Formaldehyde was monitored 3 hours and 3 days after the plants were placed in the space. The reduction in the concentration of Benzene, Toluene, Etylbenzene, Xylene, and Formaldehyde was significantly greater when plants were present. When plants were placed near a window, the reduction of concentration was greater. The more plants were used, the more a reduction of indoor air contaminants occurred. The effect of reducing the concentration of air contaminants increased when the amount of plants increased, and when the plants were placed in sunny area. The concentration of Toluene was reduced by 45.6 μg/m3 when 10% of the model space was occupied by Aglaonema brevispathum.

著者

Bum-Jin Park Yuko Tsunetsugu Tamami Kasetani Hideki Hirano Takahide Kagawa Masahiko Sato Yoshifumi Miyazaki

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.2, pp.123-128, 2007 (Released:2007-04-15)

参考文献数

12

被引用文献数

79 287

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The purpose of this study is to examine the physiological effects of Shinrin-yoku (taking in the atmosphere of the forest). The subjects were 12 male students (22.8±1.4 yr). On the first day of the experiments, one group of 6 subjects was sent to a forest area, and the other group of 6 subjects was sent to a city area. On the second day, each group was sent to the opposite area for a cross check. In the forenoon, the subjects were asked to walk around their given area for 20 minutes. In the afternoon, they were asked to sit on chairs and watch the landscapes of their given area for 20 minutes. Cerebral activity in the prefrontal area and salivary cortisol were measured as physiological indices in the morning at the place of accommodation, before and after walking in the forest or city areas during the forenoon, and before and after watching the landscapes in the afternoon in the forest and city areas, and in the evening at the place of accommodation. The results indicated that cerebral activity in the prefrontal area of the forest area group was significantly lower than that of the group in the city area after walking; the concentration of salivary cortisol in the forest area group was significantly lower than that of the group in the city area before and after watching each landscape. The results of the physiological measurements show that Shinrin-yoku can effectively relax both people's body and spirit.

著者

Alicia Canda

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.28, no.2, pp.71-82, 2009-03-30 (Released:2009-04-04)

参考文献数

41

被引用文献数

6 15

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Knowledge of stature is necessary for evaluating nutritional status and for correcting certain functional parameters. Measuring stature is difficult or impossible in bedridden or wheelchair-bound persons and may also be diminished by disorders of the spinal column or extremities. The purpose of this work is to develop estimation equations for young adult athletes for their subsequent application to disabled persons. The main sample comprised 445 male and 401 female sportspersons. Cross validation was also performed on 100 males and 101 females. All were Caucasian, the males being over 21 and the females over 18, and all practiced some kind of sport. The following variables were included: stature, sitting height, arm span, and lengths of upper arm, forearm, hand, thigh, lower leg, and foot. Simple and multiple regression analyses were performed using stature as a dependent variable and the others as predictive variables. The best equation for males (R2=0.978; RMSE=1.41 cm; PE=1.54 cm) was stature: 1.346+1.023 * lower leg+0.957 * sitting height+0.530 * thigh+0.493 * upper arm+0.228 * forearm. For females (R2=0.959; RMSE=1.57 cm; PE=1.25 cm) it was stature: 1.772+0.159 * arm span+0.957 * sitting height+0.424 * thigh+0.966 * lower leg. Alternative equations were developed for when a particular variable cannot be included for reasons of mobility, technical difficulty, or segment loss.

著者

Zhaojia Ye Yasuyo Abe Yosuke Kusano Noboru Takamura Kazuyuki Eida Tai-ichiro Takemoto Kiyoshi Aoyagi

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.2, pp.69-73, 2007 (Released:2007-04-15)

参考文献数

24

被引用文献数

34 47

---

Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.

著者

C. G. Nicholas Mascie-Taylor Rie Goto

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.2, pp.109-112, 2007 (Released:2007-04-15)

参考文献数

7

被引用文献数

30 50

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Use of BMI as a surrogate for body fat percentage is debatable and universal BMI cut-off points do not seem appropriate; lower cut-off points than currently recommended by WHO should be used in some populations, especially in Asia. The adult WHO BMI database indicates that, on average, women are more obese than men, while men are more likely to be pre-obese than women. Urban rates of overweight and obesity are generally higher than rural rates in both sexes. The trend in pre-obesity and obesity over time is generally upward, with very marked increases in the USA and UK in both sexes over the last 10 years.

著者

Yuko Tsunetsugu Bum-Jin Park Hideki Ishii Hideki Hirano Takahide Kagawa Yoshifumi Miyazaki

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.2, pp.135-142, 2007 (Released:2007-04-15)

参考文献数

25

被引用文献数

100 202

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The physiological effects of “Shinrin-yoku” (taking in the atmosphere of the forest) were examined by investigating blood pressure, pulse rate, heart rate variability (HRV), salivary cortisol concentration, and immunoglobulin A concentration in saliva. Subjective feelings of being “comfortable”, “calm”, and “refreshed” were also assessed by questionnaire. The subjects were 12 male university students aged from 21 to 23 (mean±SD: 22.0±1.0). The physiological measurements were conducted six times, i.e., in the morning and evening before meals at the place of accommodation, before and after the subjects walked a predetermined course in the forest and city areas for 15 minutes, and before and after they sat still on a chair watching the scenery in the respective areas for 15 minutes. The findings were as follows. In the forest area compared to the city area, 1) blood pressure and pulse rate were significantly lower, and 2) the power of the HF component of the HRV tended to be higher and LF/(LF+HF) tended to be lower. Also, 3) salivary cortisol concentration was significantly lower in the forest area. These physiological responses suggest that sympathetic nervous activity was suppressed and parasympathetic nervous activity was enhanced in the forest area, and that “Shinrin-yoku” reduced stress levels. In the subjective evaluation, 4) “comfortable”, “calm”, and “refreshed” feelings were significantly higher in the forest area. The present study has, by conducting physiological investigations with subjective evaluations as supporting evidence, demonstrated the relaxing and stress-relieving effects of “Shinrin-yoku”.

著者

NAKADE Miyo TAKEUCHI Hitomi TANIWAKI Nozomi NOJI Teruki HARADA Tetsuo

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of physiological anthropology (ISSN:18806791)

巻号頁・発行日

vol.28, no.5, pp.239-245, 2009-09-01

参考文献数

32

被引用文献数

1 34

---

Tryptophan (Trp) intake at breakfast promotes morning-typed circadian typology and higher sleep quality in Japanese children aged 0–6 yrs (Harada et al., 2007). This effect may be accelerated by morning exposure to sunlight, which has not yet been tested. This study aimed to investigate such an effect in Japanese children. In May, 2006, an integrated questionnaire was administered to 0–6-year-old children attending one of 12 kindergartens. 906 parents answered the questionnaire for their children and themselves (response rate: 67.4%). The integrated questionnaire included the revised version for children of the Morningness-Eveningness (M-E) Questionnaire and questions on sleep, nutritional balance, mental health, and sunlight exposure. Analysis was made on data from 744 children aged 2–6 (385 girls, 359 boys) whose average M-E score was 20.6±3.46. Children who had breakfast at regular times tended to be more morning-typed and were less frequently angry (<i>p</i>=0.001) and depressed (<i>p</i>=0.007). Children who had nutritionally well-balanced breakfasts tended to be more morning-typed (<i>p</i><0.001), and woke up and fell asleep at earlier times (<i>p</i><0.001). Children with higher protein intake tended to have higher M-E scores (<i>p</i><0.001) and earlier bedtime and wake-up time (<i>p</i>=0.003). Children exposed to sunlight for 30–60 min on their way to kindergarten showed more distinctive shifting-effects to morning-type with protein intake than those exposed to sunlight for less than 20 min (<i>p</i>=0.006). A well-balanced breakfast might be a strong <i>zeitgeber</i> for circadian oscillators of children, and the morning-type driving effect of protein intake could be accelerated by morning exposure to sunlight.

著者

Flávio C. Magalhães Renata L. F. Passos Michele A. Fonseca Kenya P. M. Oliveira João B. Ferreira-Júnior Angelo R. P. Martini Milene R. M. Lima Juliana B. Guimarães Valério G. Baraúna Emerson Silami-Garcia Luiz O. C. Rodrigues

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.29, no.1, pp.1-12, 2010-01-31 (Released:2010-04-30)

参考文献数

49

被引用文献数

15 30

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To evaluate the effects of heat acclimation on sweat rate redistribution and thermodynamic parameters, 9 tropical native volunteers were submitted to 11 days of exercise-heat exposures (40±0°C and 45.1±0.2% relative humidity). Sudomotor function was evaluated by measuring total and local (forehead, chest, arm, forearm, and thigh) sweat rates, local sweat sodium concentration, and mean skin and rectal temperatures. We also calculated heat production (H), heat storage (S), heat exchange by radiation (R) and by convection (C), evaporated sweat (Esw), sweating efficiency (ηsw), skin wettedness (wsk), and the ratio between the heat storage and the sum of heat production and heat gains by radiation and convection (S/(H+R+C)). The heat acclimation increased the whole-body sweat rate and reduced the mean skin temperature. There were changes in the local sweat rate patterns: on the arm, forearm, and thigh it increased significantly from day 1 to day 11 (all p<0.05) and the sweat rates from the forehead and the chest showed a small nonsignificant increase (p=0.34 and 0.17, respectively). The relative increase of local sweat rates on day 11 was not different among the sites; however, when comparing the limbs (arm, forearm, and thigh) with the trunk (forehead and chest), there was a significant higher increase in the limbs (32±5%) in comparison to the trunk (11±2%, p=0.001). After the heat acclimation period we observed higher wsk and Esw and reduced S/(H+R+C), meaning greater thermoregulatory efficiency. The increase in the limb sweat rate, but not the increase in the trunk sweat rate, correlated with the increased wsk, Esw, and reduced S/(H+R+C) (p<0.05 to all). Altogether, it can be concluded that heat acclimation increased the limbs' sweat rates in tropical natives and that this increase led to increased loss of heat through evaporation of sweat and this higher sweat evaporation was related to higher thermoregulatory efficiency.

著者

Tomoko Ueno Tadakatsu Ohnaka

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.25, no.6, pp.357-362, 2006 (Released:2007-01-07)

参考文献数

30

被引用文献数

2

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In the present study, the influence of the long-term use of air-conditioning in summer on the cortisol rhythm was examined by measuring the rhythm in subjects who had been exposed to air-conditioning for a short [S] or long [L] time. Investigations were conducted twice in July and September. Atmospheric temperature and relative humidity near the subjects were measured for three days in each season. Saliva samples for cortisol analysis were collected every 2 hours during the daytime beginning at 8:00 h with subsequent sampling times at 10:00, 12:00, 14:00, 16:00, 18:00, 20:00 and 22:00 h. A questionnaire on sleep and duration of air-conditioning use was also undertaken. Ambient mean temperature was higher in the S group (mean±SD; 30.8±1.2°C in July, 28.0±0.8°C in September) than in the L group (28.0±1.2°C in July, 27.3±1.0°C in September) (p<0.01), while mean relative humidity did not differ. There were no differences in bedtime, waking time and sleeping hours either between groups or months. Diurnal patterns of salivary cortisol rhythm in July and September were similar in the S group, but the L group had a delayed rise of morning cortisol secretion in September compared with July. These results suggest that long-term exposure to an air-conditioned environment might adversely affect the human cortisol rhythm.

著者

Kakitsuba Naoshi Mekjavic Igor B. Katsuura Tetsuo

出版者

日本生理人類学会

雑誌

Journal of physiological anthropology (ISSN:18806791)

巻号頁・発行日

vol.28, no.6, pp.275-281, 2009-11

参考文献数

19

被引用文献数

1 4

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For evaluating the effect of body physique, somatotype, and physical constitution on individual variability in the core interthreshold zone (CIZ), data from 22 healthy young Japanese male subjects were examined. The experiment was carried out in a climatic chamber in which air temperature was maintained at 20-24℃. The subjects' body physique and the maximum work load were measured. Somatotype was predicted from the Heath-Carter Somatotype method. In addition, factors reflecting physical constitution, for example, susceptibility to heat and cold, and quality of sleep were obtained by questionnaire. The subjects wore a water-perfused suit which was perfused with water at a temperature of 25℃ and at a rate of 600cc/min, and exercised on an ergometer at 50% of their maximum work rate for 10-15min until their sweating rate increased. They then remained continuously seated without exercise until shivering increased. Rectal temperature (T_<re>) and skin temperatures at four sites were monitored by thermistors, and sweating rate was measured at the forehead with a sweat rate monitor. Oxygen uptake was monitored with a gas analyzer. The results showed individual variability in the CIZ. According to the reciprocal cross-inhibition (RCI) theory, thermoafferent information from peripheral and core sensors is activated by T_<re>, mean skin temperature (T^^-_<sk>), and their changes. Since T^^-_<sk> was relatively unchanged, the data were selected to eliminate the influence of the core cooling rate on the sensor-to-effector pathway before RCI, and the relationship between the CIZ and the various factors was then analyzed. The results revealed that susceptibility to heat showed a good correlation with the CIZ, indicating that individual awareness of heat may change the CIZ due to thermoregulatory behavior.

著者

Ryo Fujita Yoshinori Tanaka Yasuhiro Saihara Mitsuya Yamakita Daisuke Ando Katsuhiro Koyama

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.30, no.5, pp.195-201, 2011-09-30 (Released:2011-10-01)

参考文献数

29

被引用文献数

8 21

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The objectives of this paper were to determine the level of oxidative stress in atrophied gastrocnemius, and to verify the effect of molecular hydrogen (H2) saturated alkaline electrolyzed water (HSW) on gastrocnemius atrophy by modifying the redox status, indicated by 8-hydroxy-2′-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and superoxide dismutase (SOD)-like activity. Female Wistar rats were divided into four groups: (1) the control (CONT); (2) the Hindlimb unloading (HU, for 3 weeks) given purified normal water (HU-NW); (3) the HU given alkaline electrolyzed reduced water (HU-AEW); and (4) the HU given HSW (HU-HSW). We showed that 8-OHdG, but not MDA, significantly increased by 149% and 145% in HU-NW and HU-AEW, respectively, when compared with CONT. In contrast, there was a trend toward suppression in 8-OHdG levels (increased by 95% compared with CONT) by treatment of HSW, though this effect was not prominent. Additionally, SOD-like activity significantly increased in both HU-NW (184%) and HU-AEW (199%) when compared with CONT. This result suggests the elevation of O2−· in the atrophied gastrocnemius. However, upregulation of SOD-like activity in the HU-HSW was increased by only 169% compared with CONT, though this difference is too small to detect statistical significance. HU led to 13% and 15% reduction of gastrocnemius wet weights in HU-NW and HU-AEW, respectively, compared with CONT. And the reduction of gastrocnemius wet weights in HU-HSW was attenuated by 7% compared with CONT. The gastrocnemius wet weights in the HU-HSW group were significantly greater than those in the HU-AEW, but not statistically significant with HU-NW. These results indicate that HU causes an increase in oxidative stress, but, in this experimental protocol, continuous consumption of HSW during HU does not demonstrate successful attenuation of oxidative stress and HU-mediated gastrocnemius atrophy.

著者

Naoshi Kakitsuba Igor B. Mekjavic Tetsuo Katsuura

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.26, no.3, pp.403-408, 2007 (Released:2007-07-20)

参考文献数

12

被引用文献数

3 5

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The purpose of the study was to investigate the degree of subject variability in the peripheral and core temperature thresholds of the onset of shivering and sweating. Nine healthy young male subjects participated in three trials. In the first two trials, wearing only shorts, they were exposed to air temperatures of 5°C and 40°C until the onset of shivering and sweating, respectively. In the second experiment, subjects wore a water perfused suit that was perfused with 25°C water at a rate of 600 cc/min. They exercised on an ergometer at 50% of their maximum work rate for 10–15 min. At the onset of sweating, the exercise was terminated, and they remained seated until the onset of shivering, as reflected in oxygen uptake. In the first two trials, rectal temperature (Tre) was stable, despite displacements in skin temperature (Tsk), whereas in the third trial, Tsk (measured at four sites) was almost constant (30–32°C), and the thermoregulatory responses were initiated due to changes in Tre alone. The results of the first two trials established the peripheral interthreshold zone, whereas the results of the third trial established the core interthreshold zone. The results demonstrated individual variability in the peripheral and core interthreshold zones, a proportional correlation between both zones (r=0.87), and a relatively higher contribution of adiposity in both zones as compared with those of other non-thermal factors such as height, weight, body surface area, surface area-to mass ratio, and the maximum work load.

著者

Paulo Gentil Elke Oliveira Martim Bottaro

出版者

Japan Society of Physiological Anthropology

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.25, no.5, pp.339-344, 2006 (Released:2006-10-01)

参考文献数

38

被引用文献数

27 47

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Mechanical stimuli have often been suggested to be the major determinant of resistance training adaptations; however, some studies suggested that metabolic changes also play an important role in the gains of muscle size and strength. Several resistance training methods (RTM) have been employed with the purpose of manipulating mechanical and metabolic stimuli; however, information about their physiological effects are scarce. The objective of this study was to compare the time under tension (TUT) and blood lactate responses among four different RTM reported in the literature. The four RTM were performed in a knee extension machine at 10 repetition maximum (RM) load by 12 recreationally trained young men. The RTM tested were: 10RM, super-slow (SL—subjects performed one 60-second repetition with 30 seconds for eccentric and 30 seconds for concentric phase), functional isometrics (FI—in each repetition, a five-second maximal isometric contraction was executed with the knees fully extended) and adapted vascular occlusion (VO—subjects performed a 20-second maximal isometric contraction with the knees fully extended and immediately proceeded to normal isoinertial lifts). According to the results, all RTM produced significant increases in blood lactate levels. However, blood lactate responses during FI (4.48±1.57 mM) and VO (4.23±1.66 mM) methods were higher than the SL method (3.41±1.14 mM). The TUT for SL (60 s), FI (56.33±6.46 s), and VO (53.08±4.76 s) methods were higher than TUT for 10RM (42.08±3.18 s). Additionally, TUT for the SL method was higher than TUT during the VO method. Therefore, the SL method may not be recommended if one wants to provide a high metabolic stimulus. The FI method appeared to be especially effective in promoting both type of stimuli.

著者

Hiromitsu Kobayashi

出版者

日本生理人類学会

雑誌

Journal of PHYSIOLOGICAL ANTHROPOLOGY (ISSN:18806791)

巻号頁・発行日

vol.28, no.5, pp.225-230, 2009-09-30 (Released:2009-10-10)

参考文献数

29

被引用文献数

13 35 29

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The effects of paced breathing (PB) on the reproducibility of heart rate variability (HRV) measurements were examined in 55 male subjects (age range: 20–54 years). Spectral components of HRV were measured under a combination of two respiratory conditions (spontaneous and 4s PB) and two postures (standing and supine). The procedures were repeated 3 weeks after the first measurement. Log-transformed low-frequency (lnLF) and high-frequency (lnHF) components of HRV were calculated from a 205s electrocardiography (ECG) recording. The coefficients of interindividual variations of lnHF and lnLF (ca. 13–16%) and the intraindividual variations of the frequency components (5–6%) were not significantly affected by PB. The coefficients of intraindividual variation of heart rate, ln HF and ln LF did not correlate with age in either posture. Effect sizes of PB on the intraindividual variation ranged from −0.04 to 0.13. Although intraclass correlation coefficients (ICCs) were slightly improved by PB in some cases, the differences were negligible. The above results suggest that PB provides a limited improvement in the reproducibility of HRV measurements, and metronome-guided respiration is not necessarily required for HRV measurement if subjects are reminded to avoid irregular respiration.