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BACKGROUND:Cardiopulmonary exercise test plays a significant role in the evaluation of cardiopulmonary function, but it is limited by expensive equipments and professional personnel, and moreover, the subjects need to bear the maximal exercise intensity. As a result, it is extremely urgent to find a submaximal exercise test characterized by simple operation, low cost and easy to be popularized and used. OBJECTIVE:To compare the maximal oxygen uptake in cardiopulmonary exercise test and 6-minute stair climbing and descending test. METHODS:Sixty-seven volunteers were recruited to undergo the cardiopulmonary exercise test using the Bruce protocol, and then, the maximal oxygen uptake was detected. After that, al the participants were subjected to 6-minute stair climbing and descending test, folowed by determination of the maximal oxygen uptake. RESULTS AND CONCLUSION:The maximal oxygen uptake in the cardiopulmonary exercise test was significantly higher than that in the 6-minute stair climbing and descending test (P < 0.01), and there was a highly positive correlation and consistency between the maximal oxygen uptakes in the two tests (r=0.911,P < 0.01). Therefore, 6-minute stair climbing and descending test can be used to detect the maximal oxygen uptake, which may become an effective method for evaluating cardiopulmonary function.
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Objective To observe the effects of high fat diet and 6?week voluntary wheel running on the structure of hypothalamus, pituitary and testis and sex hormone levels in pubertal male rats. Methods Forty 3?week?old male Spra?gue?Dawley rats were randomly divided into following groups: the control group fed with normal diet (C), training group fed with normal diet ( CE) , control group fed with high fat diet ( D) , and training group fed with high fat diet ( DE) , 10 rats in each group. The groups C and D were bred for 8 weeks freely, and the groups CE and DE were assigned to have vol?untary wheel running twice/d, 1 h/time, 5 d/w, for 6 weeks after a 2?week adaptive feeding. Eight weeks later, blood sample was collected to detect the serum T, E2 , FSH and LH, and the E2 and T of testis were also detected. The histology of hypothalamic, pituitary, and testis tissues was observed by light microscopy. Results ( l) Compared with the group C, the group D had significantly decreased levels of serum T and E2 and testicular T (P<0?05), and significantly increased serum E2, FSH and LH levels (P<0?05). In the group D, vacuolar lipid droplets were increased in the hypothalamus, e?osinophils and basophils were reduced in the pituitary, and the area of seminiferous tubules, percentage of sperm cells, and quantity of Leygid cells were significantly decreased in the testis. (2) Compared with the group D, the serum T and testic?ular T concentrations were increased, but the serum E2, FSH and LH were decreased significantly (P<0?05) in the group DE, and vacuolar lipid drops were increased in the hypothalamus, eosinophil cells were increased in the pituitary gland, and the area of seminiferous tubules was increased but not significantly in the testis. Conclusions 6?week voluntary wheel exercise can improve the high fat diet?induced abnormal secretion of sex hormones, but not effectively improve the histologi?cal changes in hypothalamus, pituitary gland and testis.