Abstract
[Purpose] This study was conducted to determine the relationship between the exercise tolerance and
trunk posture. [Subjects and Methods] Twelve healthy males participated in the study. Exercise tolerance
was measured using a cycle ergometer cardiopulmonary exercise tests in two postures, upright and slumped.
Respiratory function tests and maximum inspiratory and expiratory pressure (MIP and MEP) were
measured in each posture. [Results] The forced vital capacity and forced expiratory volume in one second
decreased significantly in the slumped posture. The MIP and MEP did not vary significantly. The V・O2 max
and anaerobic threshold (AT) point were not different significantly, but the duration of exercise was shorter
in the slumped posture. The Borg scale (used to quantify the perception of dyspnea and lower limbs muscle
fatigue, at rest and during exercise) and respiratory rate were increased significantly with the slumped
posture. [Conclusion] Postural changes were noted to affect the duration of exercise, but the V・O2 max and
AT point remained unaffected in healthy people. Modification of posture might help prolong the duration of
exercise, by improving respiratory function and by reducing the unnecessary muscle activity.
