The aim of this study was to estimate changes in hemodynamic (systolic blood pressure and heart rate) and respiratory (oxygen uptake, carbon dioxide elimination, minute ventilation, tidal volume, and respiratory rate) responses of 26 healthy men while performing interval training with three different pause time distributions (60, 120, and 180 s) under an anaerobic threshold as a load of the exercise phase of 60 s by cycle ergometry with 10 bouts. The hemodynamic and respiratory responses in the tenth exercise phase tended to increase, compared with those in the first bout, but did not change significantly over the three sessions, with the exception of minute ventilation and tidal volume. Responses were not influenced by the length of the pause phases. However, we recommend setting the pause phase at more than 120 s because biogenic stress is still high at 60 s, and may lead to the appearance of breathlessness owing to minute ventilation at 60 s, which was significantly increased, compared with the others.
