ABSTRACT
<p>We developed a periodic hypobaric hypoxic environment (PHHE) system. Characteristics of this system varied between decreased pressure at an altitude of 1,500 m for 180 seconds and increased pressure at an altitude of 0 m for 180 seconds. The present study aimed to determine the effects of PHHE on physiological responses during endurance exercise and recovery after exercise. This study included 12 healthy men, and they provided written informed consent. All subjects performed a cycling exercise for 30 minutes and recovered after exercise for 10 minutes. The exercise protocol was performed with 20% maximum oxygen uptake for 6 minutes (warm-up), 40 % for 18 minutes (main exercise), and 20 % for 6 minutes (cool down). We established two experimental conditions: exercise with the PHHE and the control (C). The C condition involved exercise using the PHHE at an altitude of 0 m, and the atmospheric pressure was not changed. In the PHHE condition, the atmospheric pressure was changed periodically from 967 to 817 hPa (the external pressure was 1,008 hPa). Subjects’ heart rate (HR), blood pressure (BP), arterial oxygen saturation (SpO<sub>2</sub>), rating of perceived exertion, and respiratory responses were measured in both conditions. The SpO<sub>2</sub>, HR and systolic BP during exercise were significantly lower in the PHHE condition than in the C condition. The HR post-exercise was significantly lower. After exercise, the ln HF, an index of cardiac parasympathetic nervous system modulation, was significantly higher. In conclusion, during endurance exercise, cardiocirculatory responses in the PHHE condition were decreased.</p>
ABSTRACT
The purpose of the present study was to indicate the relationship between health-related quality of life (HRQOL) measures, the daily rhythm of oral temperature (OT), and lifestyle. Five-hundred young men volunteered to participate in this study. Their OT, measured using a digital thermometer, was recorded every 2h from the time they woke up to the time they went to sleep for 1 week. The daily rhythm of OT was calculated as a quadratic function using the 1-week data. The HRQOL was measured using the Short-Form 36-Item Health Survey version 2 (SF-36v2). The participants were divided into 3 groups: a high-value group (HG) with ≥ 55 points of each summary score and each subscale score, a middle-value group (MG) with score > 45 and < 55 points, and a low-value group (LG) with score ≤ 45 points. Lifestyle was assessed in terms of eating habits, sleeping and exercise, and the presence of unidentified complaints. At the mental component summary, the OT at the time of waking up and the peak OT in the HG were significantly higher than those in the LG. At the physical and mental component summary, lifestyle in the HG was more favorable. These data suggest that the daily rhythms of OT may reflect the mental health status of an individual. The entraining factors in circadian variation might play a role in improving mental health and reducing unidentified complaints. In conclusion, there appears to be an association between mental health status, lifestyle, and daily rhythms of OT.
ABSTRACT
Subjects evaluated by percentage body fat as obese, even though they are normal evaluated by BMI (calculated by height and weight), have recently come to be referred to as‘masked obesity’cases. The purpose of this study was to compare the characteristics of anthropometry and physical fitness between controls (20≤BMI<24, percent fat: men<20%, women<30%) and masked obesity (20≤BMI<24, percent fat: men≥20%, women≥30%) cases among young men and women. Subjects included 1985 unversity students among which 1278 were men (age 18.7 ± 0.9 yr) and 707 were women (age 18.6± 1.1 yr) . They performed anthropometry and physical fitness tests. Percentage body fat was calculated from the skinfold thickness of triceps and subscapula. Masked obesity showed up in 5.4% (69 persons) of men and 13.6% (96 persons) of women. The percentage of women with masked obesity was about 2.5 times higher than men. Furthermore, the percentage of masked obesity cases among obese subjects was 30.4% (69/227 persons) of men, and 66.2% (96/145 persons) of women. This value of women was about 2.2 times higher than men. Comparisons of values of control subjects and masked obese subjects were carried out in each BMI group (above 20, BMI 20-group ; above 21, BMI 21-group ; above 22, BMI 22-group; above 23, BMI 23-group) of men and women respectively. For anthropometry in women, the waist and waist-hip ratio of masked obesity cases of the BMI 21 and 22-groups were significantly higher than those of the controls. However the same trend was not found in men. For physical fitness in men, back strength of masked obesity cases in the BMI 20 and 23-groups, and 50 m dash in the BMI 20, 21, 23-groups were inferior to those of the controls. However the same trend was not found in women. These results suggest that masked obesity in women existed 2.5 times more often in men, and women have larger waists and men were inferior in muscle strength and power in comparison with non-obese subjects.