[External respiration and gas exchange in man exposed to simulated diving at 350 M].

Nine test subjects performed 4 dives in a He-O2 atmosphere at 3.5 MPa for 3-21 days. Their external respiration and gas exchange were measured at rest and maximum physical load.

[Functional state of various physiological systems of the human body during respiration of neon-oxygen mixture at depth up to 400 meters].

Hyperbaric neon-oxygen mixture has been studied for the effect of its high density under pressure of 41 ata on basic physiological functions of human organism. Typical changes of the cardiorespiratory system and tissue respiration parameters are revealed. Changes in physical working capacity are shown.

[Various aspects of determining physical work capacity of humans in hyperbaric environment].

Physical work capacity of man during real and stimulated dives is discussed in view of the reported data. The parameter is known to decrease as the breathing gas density and immersion depth increase. The factors limiting the work capacity growth are as follows: greater respiration resistance, higher energy cost of ventilation, CO2 retention, dyspnea, adverse circulation changes.