Abstract
In order to realize a healthy and long-lived society, it is recommended to exercise for the purpose of health promotion and exercise therapy. Exercise rehabilitation, especially for patients with heart disease and respiratory disease, helps them avoid being bedridden and plays a major role in maintaining their QOL in daily life. On the other hand, excessive exercise load is contraindicated because it may exacerbate symptoms. Therefore, cardiopulmonary exercise training (CPX) is necessary to understand changes in gas exchange associated with breathing and circulation, and to determine the Anaerobic Threshold (AT), which is an indicator of optimal exercise load intensity. AT is the addition of an anaerobic energy production mechanism to an aerobic energy production mechanism. CPX is performed at the time of initial determination of AT and after implementation of rehabilitation to verify its effect and review AT. AT determination generally requires 10-15 minutes of gradual incremental workload. In this study, based on the AT intensity determined by gradual incremental workload, the subject performed his 3-5 min quantitative resistance exercise on a bicycle ergometer. During that time, the collected expired air was measured with a breath-by-breath type expired gas analyzer. Then, using physical work, we verified the change of V-slope due to the difference in load intensity. As a result, AT could be estimated from the slope from the inflection point of the V-slope of the constant load. This method makes it possible to shorten the CPX time when revising AT, leading to a reduction in the burden on the subject.
