2002 Fiscal Year Final Research Report Summary
The Effect of Normobaric Hypoxia on Endurance Capacity
| Project/Area Number |
12480013
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
体育学
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| Research Institution | Nippon Sport Science University |
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Principal Investigator |
ITO Masamitsu Nippon Sport Science University, Department of Physical Education, Lecturer, 体育学部, 講師 (20307995)
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| Co-Investigator(Kenkyū-buntansha) |
IGAWA Shoji Nippon Sport Science University, Department of Physical Education, Professor, 体育学部, 教授 (60112976)
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| Project Period (FY) |
2000 – 2002
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| Keywords | NORMOBARIC HYPOXIA / ENDURANCE / LIVING / ENDURANCE TRAINING / INTERVAL TRAINING / MAXIMUM OXYGEN UPTAKE / BLOOD PROFILES |
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| Research Abstract |
In the present study, the effects of living or training in normobaric hypoxic conditions on endurance capacities were examined. Subjects stayed and slept in a nomobaric hypoxia room (16.4%, 15.6% or 14.9%) 10 hours per day for 7 days. The 14.9% group exhibited the lowest SpO_2 on the first day, though the values were recovered to approximately 95% in the all groups on the last day. EPO values increased significantly in the 15.6% and 14.9% groups in the early phase of the experiment. The blood profiles did not change except for reticulocyte which increased significantly. Significant increases in VE and VO_2 max were found only in 14.9% group, indicating that 14.9% or below were necessary to increase VO_2max. In the experiment in which subjects were stayed and slept in the room (14.9%O_2) 10 hours per day for 6 days, diastolic blood pressure was elevated, suggesting arteriolar vasoconstriction and increased arterial blood flow. In addition, NK cell activities were higher compared to the pre values.
VO_2max and oxygen supplying capacity of the vastus lateralis muscle tended to increase following four weeks of endurance training under the normobaric hypoxic condition (15.6%O_2). These results indicated that the endurance training under normobaric hypoxia was effective for improving respiration and circulation functions. The four weeks of interval training with cycle ergometers under the same condition did not lead to significant changes in blood profiles and VO_2max. On the other hand, the lactate threshold and mean mechanical power of cycle ergometry were significantly improved. Interval training could be used to improve lactate buffering capacity.
To be concluded, the normobaric hypoxic condition was proved to be valid to improve endurance capacities.
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