Specialized physiological studies in support of manned space flight

The areas of physiological research reported include: (1) evaluation of the single-breath method for determining cardiac output, (2) optimum protocol for the assessment of cardio-pulmonary competence, (3) body fluids and electrolytes under conditions of single and combined stress, (4) re-evaluation of the open-circuit method for measuring metabolic rate with regard to the alleged metabolic production of gaseous nitrogen, and (5) the use of the forced-oscillation method to determine total respiratory conductance in healthy subjects and pulmonary patients.