RESULTS
The results of the Profilaktika experiment indicated that the crew member’s state of physical
conditioning has clearly marked phases. During the first phase, their performance declined
significantly, with subsequent restoration of the preflight (or near-preflight) level. This pattern
was clearly reflected in the results of all tests. It must also be noted that the cost of the
locomotion load was significantly higher than that of the cycle ergometer. This may be related
to the fact that during performance of a running test with a load equivalent to 70% of one's
body weight—a load that is absent during the cycle ergometer test—the physiological cost was
determined through activity, not just dynamically, but through the tonic muscle system, which
required greater expenditures to support its functionality.
Comparative analysis of the various modes of physical training used aboard the International
Space Station demonstrated the high effectiveness of intense exercise characterized by
sequencing intensive walking and quick running (so-called interval training) and the significantly
lower effectiveness of training in the moderate capacity zone with an aerobic energy supply.
Interval training provides a high level of physical performance and levels out the negative
changes in the oxygen transport system caused by microgravity. The mechanisms of energy
supply for muscle activity remained at the preflight level in a group of crew members who
performed interval training in the course of one flight, while another group who trained at
lower intensity exhibited a significantly higher physiological and energy costs (less efficient).
Analysis of physical performance showed a significantly higher level in the locomotion test,
which makes it possible to assess not only the level of physical conditioning. It was also possible
to asses the physiological load caused by the need to maintain posture, which is reflected in the
magnitude of shifts in autonomous functions and in energy supply mechanisms.
PUBLICATION(S)
Popov DV, Khusnutdinova DR, Shenkman BS, Vinogradova OL, Kozlovskaya IB. Dynamics of
physical performance during long-duration spaceflight (First Results of “Countermeasure”
Experiment). Journal of Gravitational Physiology. July 2004;11(2):231-232.
This investigation is complete and all results are published.