5. Isokinetic Testing
   This testing provides an objective measure of pre- and post-bed rest isokinetic muscle strength and endurance in select muscle groups for the evaluation of proposed countermeasures. Decreased muscle function is a consistent finding following both bed rest and spaceflight. In addition to maintenance of crew health, muscle function may be a significant determinant of emergency egress success and ability to work in altered gravity environments. Muscle strength and endurance may be an important factor in exiting the vehicle and moving toward a safe distance from the Space Shuttle. In addition, muscle strength and endurance may play an important factor in performing various tasks in an extravehicular mobility unit in altered gravity environments such as Mars and the Moon.

   Using the same testing protocols that are used for long-duration spaceflight crew members allows more direct comparison of these results from bed rest than has been previously possible. These results allow NASA to identify and refine potential exercise countermeasures during these ground-based simulations to more efficiently implement exercise prescriptions for spaceflight. Also, by using the same testing protocols as used for participants in long-duration spaceflight, NASA is able to more accurately predict crew members' responses to testing after their mission.

6. Cycle Ergometry
   This research test is used to monitor aerobic exercise capacity before, during, and after bed rest to assess the effectiveness of proposed countermeasures. Aerobic capacity is measured using a graded exercise test to assess the functional capacity of the cardiovascular system.

   Image right: Cycle used by subjects for Cycle Ergometry testing.

   NASA uses the results from these tests to develop prescriptions for exercise countermeasures to be used during spaceflight. Decreased aerobic capacity is a consistent finding following both bed rest and spaceflight. Reduced exercise capacity has been noted in subjects performing no countermeasures during bed rest as short as 7 days and may be related to duration of exposure. Following both short (Space Shuttle) and long-duration spaceflight (Mir and ISS missions), loss of aerobic capacity also has been observed in crew members despite the performance of inflight aerobic and resistive exercise countermeasures. These data suggest that there is a rapid decrease in aerobic capacity in the first months of spaceflight, but crew members return toward baseline as the mission progresses. However, aerobic capacity again is reduced during testing 5 to 7 days after landing.

   Exercise tests are conducted before and following bed rest. These tests are performed on a cycle ergometer with the subject in the upright (seated) position following the same protocol as NASA astronauts.

7. Functional Fitness
   The Functional Fitness Test is a medical requirement in which all astronauts who undergo long-duration spaceflight participate. It is used by NASA to establish baseline muscle strength, endurance, and flexibility of astronauts before spaceflight and to monitor their rehabilitation after long-duration missions.

   Testing in the bed rest campaigns includes the bench press, leg press, push-up, pull-up, a sit and reach test and a modified sit-up. These tests are an accurate assessment of whole-body muscle strength and endurance.

   These data provide a valuable comparison on the loss of total body muscle strength, endurance, and flexibility in spaceflight and bed rest. These data are used to determine the usefulness of future countermeasures designed to combat muscle deconditioning experienced by long-duration crew members. These data are also used to monitor subject rehabilitation.
   
   

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