The effects of speech production on physiologic responses during submaximal exercise.

PURPOSE To investigate the effects of speech production on physiological responses during sub maximal exercise of various intensities. METHODS Three constant levels running at work intensities corresponding to 65%, 75%, and 85% of the subjects' (N = 14) VO(2) max were performed with and without talking. These loads were chosen to represent the range of training intensities, which are most often used by the general population for improving cardiovascular fitness. During both sessions, various cardiopulmonary variables were measured breath-by-breath. RESULTS Oxygen uptake, ventilation, breathing frequency, CO(2) production, total respiration cycle time, and expiration time decreased significantly while blood lactate, blood pressure, and end tidal CO(2) increased. There were no significant differences between talking and being silent in heart rate, inspiration time, and in tidal volume. CONCLUSIONS Speech production during sub maximal exercise results in a significant reduction in minute ventilation and oxygen uptake with an accompanying elevation of lactic acid and blood pressure. These findings are of particular relevance for planning rehabilitation or training programs for ill as well as for healthy populations.