Cardiorespiratory Reactions During Submaximal Exercise in Humans after 14-Day Simulated Lunar Gravity

• Published in: Human physiology Vol. 49; no. 6; pp. 609 - 616
• Main Authors: Puchkova, A. A., Shpakov, A. V., Katuntsev, V. P., Stavrovskaya, D. M., Primachenko, G. K.
• Format: Journal Article
• Language: English
• Published: Moscow Pleiades Publishing 01-12-2023; Springer Nature B.V
• Subjects: Biomedical and Life Sciences; Biomedicine; Carbon dioxide; Gravity; Heart rate; Human Physiology; Immobilization; Life Sciences; Oxygen consumption; Physical training; Physiology; physical performance; cardiorespiratory system; lunar gravity; head-up bed rest; cardiopulmonary exercise testing
• ISSN: 0362-1197; 1608-3164
• DOI: 10.1134/S0362119723700500

The paper presents the main results of our study on the influence of the physiological effects of simulated lunar gravity on cardiorespiratory responses to exercise in humans. Twelve healthy male volunteers aged 19–31 years (
M
±
SD
: 22.5 ± 4.0 years) took part in the study. They were under 14-day head-up bed rest (HUBR) at +9.6° angle relative to the horizon as a model of the physiological effects of lunar gravity. Cardiopulmonary exercise testing (CPET) was performed 7 days before the onset of HUBR and on the next day after the end of the experimental exposure. A three-stage cycle ergometer test with 5-min steps at 125, 150, and 175 W was used as a CPET protocol. Exposure of the subjects to simulated lunar gravity reduced their tolerance to physical load. This was indicated by more pronounced changes for such parameters of the cardiorespiratory system as heart rate, minute ventilation of the lungs, ventilatory equivalents for oxygen and carbon dioxide, as well as a less pronounced increase in oxygen consumption and oxygen pulse during CPET after 14 days of exposure to HUBR.