Intense Exercise during Long Space Flights Can Help Astronauts Protect Aerobic Capacity
Bethesda, Md. (August 29, 2014) — Most people don’t think much about their aerobic capacity while at work. But for astronauts carrying out missions on the International Space Station (ISS), maintaining their cardiovascular stamina during long space flights is part of the job. They must be prepared to perform physically demanding tasks or emergency maneuvers at any time during flights that can last between three and six months in a weightless environment.
In an effort to protect their aerobic capacity and prepare their bodies, astronauts routinely perform in-flight cardiovascular and strength exercises. But the effect of exercise on astronauts traveling to the ISS was not known because aerobic capacity (V̇O2peak) had only been studied in shorter trips, not during and after longer space flights.
To understand whether the routinely prescribed exercise was effectively maintaining V̇O2peak, researchers Alan D. Moore Jr., et al., with the National Aeronautics and Space Administration (NASA) Human Research Program followed 14 astronauts (nine men and five women) who traveled on space flights between 91 and 192 days. On average, the subjects exercised 30 minutes a day on five to six days each week at an average intensity of 73% of peak heart rate. The research team measured V̇O2peak at approximately nine months and three months before launch; on day 15 of the flight; every subsequent 30 flight days; and day one, 10 and 30 following re-entry to Earth.
The research team observed a ~17% overall reduction in V̇O2peak by flight day 15 across the study sample. While some astronauts experienced a significant decline in V̇O2peak (a dip that rebounded later in the space flight), other astronauts did not experience any substantial change in V̇O2peak. Interestingly, the astronauts with the highest V̇O2peak experienced the greatest reduction in capacity, but according to the authors, “this finding should not be interpreted that a high preflight aerobic capacity is undesirable. Although the astronauts with high capacities tended to lose more, they typically remained at higher levels than crew who started at lower levels.
“These results provide evidence that, although many astronauts experience a decline in V̇O2peak during ISS missions, use of the aerobic exercise hardware aboard the ISS combined with exercise prescriptions of sufficient exercise intensity can be used to effectively prevent decline in aerobic capacity,” the researchers wrote.
The article “Peak exercise oxygen uptake during and following long-duration spaceflight” is published in the Journal of Applied Physiology. It is highlighted as one of this month’s “best of the best” as part of the American Physiological Society’s APSselect program. View the full study here: http://ow.ly/AP7t7. Read all of this month’s selected research articles at http://apsselect.physiology.org/.
NOTE TO JOURNALISTS: To schedule an interview with a member of the research team, please contact Stacy Brooks at firstname.lastname@example.org or 301-634-7209.
Physiology is the study of how molecules, cells, tissues and organs function in health and disease. Established in 1887, the American Physiological Society (APS) was the first U.S. society in the biomedical sciences field. The Society represents more than 11,000 members and publishes 14 peer-reviewed journals with a worldwide readership.
Astronauts May Need More Intense Workouts To Maintain Muscle Fitness In Space
Released April 2, 2009 - A new study suggests that astronauts need to modify their workouts to avoid extensive muscle loss during missions onboard the International Space Station.
Physiology Researcher Using Batman to put POW! into Physiology
Released March 4, 2011 - Physiologist E. Paul Zehr writes about how he uses the Batman character to discuss the various components of exercise and physical training and illustrate how the body’s physiological systems respond.
Exercise Has Benefits, Even When It’s Done in Space
Released March 22, 2012 - Astronauts living on the International Space Station show small effect on cardiovascular health when accompanied by an exercise regimen.
Conference Sponsored by the APS Focuses on the Integrative Biology of Exercise
Released September 20, 2012 - Latest conference to be sponsored by the American Physiological Society focuses on the molecular mechanisms involved in exercise-mediated physiological changes in the body, including metabolic, cardiovascular, neurological, and dynamic molecular and cellular pathways. Entitled Integrative Biology of Exercise VI, the meeting will be held October 10-13, 2012 in Westminster, Colorado.
APS' October Conference Examines Integrative Biology of Exercise
Released September 10, 2012 - The effects of physical inactivity are, literally, hazardous to your health. The conference, Integrative Biology of Exercise VI, co-sponsored by The American Physiological Society, brings together national and international scientists for presentations and discussions aimed at better understanding the mechanisms and consequences of inactivity on the human body.