ABSTRACT
Generally, a person who has higher cardiorespiratory fitness has lower lifestyle-related disease(LRD)morbidity rates and lower mortality rates. In Japan, Ministry of health, labor and welfare has defined the reference values of the maximal oxygen uptake(VO<sub>2</sub>max)for health promotion by gender and age in 2006. The reference values were defined based on the systematic review of the japanese and foreign articles for the relationship between VO<sub>2</sub>max and LRD. However, the articles based on japanese subjects were few. The purpose of this study is to examine the morbidity rates of LRD and VO<sub>2</sub>max of japanese persons who have no habitual exercise. The subjects of this study comprise 141 males and 287 females aged from 20 to 69. The LRD morbidity rates of males and females suffered from dyslipidemia, hypertention, diabetes / impaired glucose tolerance were 78.7% and 58.5%, respectively. The mean VO<sub>2</sub>max obtained by an incremental bicycle exercise at all group divided by gender and age did not achieve the reference values. The rate of the LRD subjects of males and females who achieved the reference values were 9.9%(n=11)and 4.8%(n=8), respectively. And the rate of the non-LRD subjects of males and females who achieved the reference values were 36.7%(n=11) and 14.3%(n=17), respectively. To obtain the habitual exercise and to keep higher physical activity is important to control a decline of VO<sub>2</sub>max with aging and to prevent the LRD.
ABSTRACT
The purpose of this study was to compare changes in oxygenation in the Vastus Lateralis (VL) and Rectus Femoris (RF) muscles during a ramp-loaded bicycle exercise. Twelve healthy males participated in the experiment. The test consisted of a leg arterial occlusion at rest and a ramp-loaded exercise (20 watts/min) using a bicycle ergometer until exhaustion. The changes in deoxygenation in each muscle was measured by near infrared spectrometer (NIRS) . The probes of NIRS were placed on VL and RF approximately 12 cm above the right knee. Oxy-Hb/Mb signals from NIRS were calculated as 100% at rest, with 0 % being the lowest value during the leg arterial occlusion. Pulmonary gas exchanges (VE, VO<SUB>2</SUB>, VCO<SUB>2</SUB>) were measured with an expiratory gas analyzer. In 10 subjects, muscle oxygenation level in VL decreased linearly until the deoxygenation limiting point (DOLP) -the point in exercise at which the deoxygenation rate decreases noticeably. However, in 2 subjects, the DOLP was not detected, and the muscle oxygenation level decreased linearly until exhaustion. The muscle oxygenation level in RF also decreased linearly until 70%VO<SUB>2</SUB>max, although the deoxygenation rate was smaller than that in VL. Thereafter, the muscle oxygenation level in RF continued to decrease until exhaustion. No DOLP was found in any subjects in RF. Compared with the muscle oxygenation level in RF at any points during the exercise, those in VL were lower until 90%VO<SUB>2</SUB>max (P<0.001) . However, the difference in muscle oxygenation levels between VL and RF at exhaustion was not noted. This study indicated that the patterns of deoxygenation in VL and RF during a ramploaded bicycle exercise were different.