| Correspondence |
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.