Effect of hypoxia on aerobic capacity in athletes with low blood hemoglobin level
3
Issued Date
2024
Copyright Date
1993
Resource Type
Language
eng
File Type
application/pdf
No. of Pages/File Size
x, 128 leaves : ill. (some col.)
Access Rights
open access
Rights
ผลงานนี้เป็นลิขสิทธิ์ของมหาวิทยาลัยมหิดล ขอสงวนไว้สำหรับเพื่อการศึกษาเท่านั้น ต้องอ้างอิงแหล่งที่มา ห้ามดัดแปลงเนื้อหา และห้ามนำไปใช้เพื่อการค้า
Rights Holder(s)
Mahidol University
Bibliographic Citation
Thesis (M.Sc. (Physiology))--Mahidol University, 1993
Suggested Citation
Chantana Akaratham Effect of hypoxia on aerobic capacity in athletes with low blood hemoglobin level. Thesis (M.Sc. (Physiology))--Mahidol University, 1993. Retrieved from: https://repository.li.mahidol.ac.th/handle/123456789/99350
Title
Effect of hypoxia on aerobic capacity in athletes with low blood hemoglobin level
Alternative Title(s)
ผลของสภาวะขาดออกซิเจนต่อความสามารถทางแอร์โรบิคในนักกีฬาที่มีระ ดับฮีโมโกลบินในเลือดต่ำ
Author(s)
Abstract
The influence of blood hemoglobin concentration (Hb) on the reduction in aerobic capacity during acute exposure to hypoxia was investigated in eleven healthy male athletes of the Royal Thai Air Force (R.T.A.F.). Their ages and Hb ranged from 20-29 years and 12.1-14.9 g/dl,respectively. According to their Hb, the subjects were divided into two groups: control and anemia. For the subjects whose Hb equal or more than 14 g/dl were defined as the control and those who had Hb level less than 14 g/dl we or the anemia. Each subject performed an incremental exercise test until exhaustion on a bicycle ergometer at both normoxia and hypoxia. Hypoxia was induced by inspiration of 14.5 %O2 with N2 balance (equivalent to an altitude of approximately 10,000 feet).The maximum rate of 02 consumption (VO2max) and anaerobic threshold (AT) of each subject were determined. The results showed that despite the difference in Hb , the normoxic VO2max and the VO2 at AT of the two groups of subjects were similar. It was found that for all subjects at normoxia the VO2max was independent on Hb and was significantly decreased at hypoxia. The reduction in V02max at hypoxia from that at normoxia (VO2max) was directly correlated with the normoxic V02max but was inversely correlated with [Hb]. That is,at any Hb , the higher in normoxic VO2max the greater V02max occurred, and at any normoxic VO2max , the lower in Hb the greater AVO2max was observed. Hence, the athletes with high normoxic V02max and low Hb exhibited considerably high VO2max. Percent arterial oxygen saturation(SaO2),heart rate (HR) and minute ventilation V(,E) at rest and during exercise were also determined Blood lactate was measured before and immediately after the exercise test. SaO2 was found to be decreased from normoxic values both at rest and during maximal exercise at hypoxia. The effect of hypoxia on the exercise -induced decrease in SaO2 was more pronouced in athletes who exhibited high V02max compared to those with low V02max and also in the high VO2max athletes with low Hb than those with. normal Hb. Only in the anemic athletes, maximal exercise heart rate (HRmax) at hypoxia was lower than the normoxic value. It was also found that subject who exhibited great reduction HR(,max) at hypoxia showed high VO2max while such the relationship was not appeared in the non-anemic athletes. Under hypoxic condition, the decline in postexercise blood lactate was correspoded to the reduction in maximal work load; however, the former values in the anemia was higher than the control even though the hypoxic maximal work load was similar between the two subject groups. During incremental exercise, VE at the point where VO2max was achieved in both subject groups under normoxia were not changed by hypoxia exposure. Similar to V02max change, the level of VO2 at AT expressed in term of ml/kg/min was markedly decreased by hypoxia in athletes who possessed high VO2 at AT. The decrease was correlated with the lowering in SaO2. Under both environmental conditions, comparison between the anemic and the control athletes showed no effect of Hb on the AT and its related parameters such as SaO2, 02pulse, VE ,and work load. Only HR at the AT showed lower in the anemia than the control under hypoxia. The results of this study indicated that:1) aerobic capacity determined by V02max and VO2 at AT,was decreased at hypoxia in proportion to its normoxic level; 2) the reduction in the aerobic capacity was attributed to the decreased SaO2; 3) low Hb in the anemic athletes could magnify [delta]Vo2max but not [delta]Vo2 at AT during acute hypoxic exposure indicated that,under hypoxic condition, the anemia exerted deterioration on VO2 during maximal exercise but not submaximal exercise at the level of AT; 4) no effect of anemiaon VO2 at any level of exercise intensity could be found under normoxic condition; 5) the exact mechanisms responsible for the more marked reduction in VO2max at hypoxia in the anemia than the control were unknown. However, possible contributing factors for this might be those which caused lowering in ill arterial O2 transport. These might include the low [Hb], the reduction in CaO2 and HR(,max).
Description
Physiology (Mahidol University 1993)
Degree Name
Master of Science
Degree Level
Master's degree
Degree Department
Faculty of Science
Degree Discipline
Physiology
Degree Grantor(s)
Mahidol University