Stress, workload and physiology demand during extravehicular activity: a pilot study

N Am J Med Sci. 2012 Jun;4(6):266-9. doi: 10.4103/1947-2714.97205.


Background: Extravehicular activity (EVA), such as exercise performed under unique environmental conditions, is essential for supporting daily living in weightlessness and for further space exploration like long Mars mission.

Aim: The study was planned stress, workload, and physiological demands of simulated Mars exploration.

Materials and methods: In this study, the six-person crew lived (24 hours) for 14 days during a short-term stay at the Mars Desert Research Station. The heart rates, salivary cortisol, workload, peak oxygen uptake or maximal aerobic capacity of the crew are measured before, during and after an EVA.

Results: Data for heart rate showed the same trend as peak oxygen uptake or maximal aerobic capacity, with a maximal increase to 85% of peak. The rating of subscale showed a significant increase in EVA as compared to run. Salivary cortisol levels and heart rates were increased in both groups, although significant increased of cortisol levels and heart rates more in EVA as compared to hill running crew members.

Conclusion: Further study is required on large scale taken into account of limitations of this study and including other physiological and psychological parameters in Mars analog environment.

Keywords: Cortisol; Extravehicular activity; Heart rate; Peak oxygen uptake; Saliva; Stress.