Correspondence                                                                                                          | Spaceflight Vol 45:480, 2003

A better way to exercise in space


Astronaut Ed Lu, now reaching the end of his six
month stint on the Space Station, exercises on the
Treadmill Vibration Isolation System in the Zvezda
module.
                                                                    NASA

Sir, The present exercise regimes on space flights of usually up to an hour twice a day, have been shown to be ineffective in counteracting a significant loss of skeletal muscle and bone even on space missions of just a few weeks [1,2].

This is conducive not only to complications of osteoporosis for example, but to partial loss of the reservoirs for magnesium and water, with in turn potential serious insults to the entire cardiovascular system.

An alternative exercise program, perhaps less monotonous, was suggested to me about 10 years ago, when I visited in Oslo, Norway, Kaare Rodahl, MD, an expert in exercise physiology [3], requesting his advice about alternative exercise programs for space missions.

Although he emphasized that he had not studied specifically space-related exercise countermeasures, he pointed out to me that an exercise program of 15 minutes out of every waking hour might prove to be more beneficial with less monotony.

Assuming that eight hours is allotted for sleep, such a program would provide as much as four hours of exercise per day, thereby doubling the duration existing at this time. Although this schedule would reduce cardiovascular endurance capacity [3], I believe this program would be more tolerable; it would still however, require a special breed of astronauts - those who find exercise pleasurable.

William J. Rowe, MD  Virginia, USA

References

1. W.J. Rowe, Interplanetary Travel and Permanent Injury to Normal Heart, Acta Astronautica, 40, pp.719-722,1997.
2. W.J. Rowe, Potential Myocardial Injuries to Normal Heart With Prolonged Space missions: The Hypothetical Key Role of Magnesium, Mag Bull 22, pp.15-19, 2000.
3. P.O. Astrand, K. Rodahl, Textbook of Work Physiology Physiological Bases of Exercise, third edition, McGraw-Hill, New York, 1986.