• Current Research
  • Previous Research


Integrated Endurance and Resistance Exercise Countermeasures Using a Gravity-Independent Training Device

Principal Investigator:
Gregory R. Adams, Ph.D.

University of California, Irvine

Maintaining astronaut health and physical fitness is a major challenge of long-duration spaceflight. NASA has determined that current flight-rated exercise hardware is not appropriate for use on exploration vehicles. Dr. Gregory R. Adams will investigate the effectiveness of a new exercise device for use during long-duration spaceflights. The device is designed to maintain cardiovascular and musculoskeletal fitness of astronauts by providing high-resistance strength or low-resistance endurance exercises.

The project will have three phases. The first involves subjects using the device to perform strength and cardiovascular exercise during normal gravity conditions. The second and third phases call for subjects to exercise in conjunction with increased levels of inactivity, which simulates conditions of microgravity. Study participants do short-duration interval cardiovascular exercises designed to reduce the time needed for exercise. On alternate days, the device will be configured for strength training, which has been shown to result in increased muscle strength and size.

NASA Taskbook Entry

Technical Summary

Extended spaceflight, as well as existence on  Mars, will require exercise equipment and training protocols designed to maintain physical fitness and general health. NASA has determined that current flight-rated exercise hardware is not appropriate for use on future crew exploration vehicles. Studies will investigate protocols designed to maintain both cardiovascular and musculoskeletal fitness using a gravity-independent multi-mode exercise device (M-MED), which has been identified by NASA as potential flight hardware. M-MED can provide either high-resistance strength or low-resistance endurance-mode exercises.

Phase 1 is development of a ground-based, integrated strength and cardiovascular exercise training protocol under normal weight bearing conditions. Phases 2 and 3 are the application of this protocol with progressive levels of inactivity. Measurements will be obtained for total body physical work capacity, muscular mass, strength and sustained muscle endurance (i.e., extravehicular activity-related issues).

Cardiovascular-related exercise using M-MEDs "aerobic" mode configuration will be designed to minimize the time spent in exercise using high-power output and short-duration interval training. On alternate days, the M-MED will be configured for strength training which has been shown to result in increased muscle strength and size. These studies will validate the efficacy of concurrent endurance and strength training as a high-economy approach to flight crew physical fitness, using a scientifically proven exercise modality that has a high probability for use during prolonged spaceflight missions.


Earth Applications

To date, this project has demonstrated that a very modest amount of time invested in exercise using the M-MED can produce substantial increases in muscle function and cardiovascular fitness. In particular, the fact that M-MED based exercise induces performance gains at many movement speeds suggests that it may be superior to more traditional methods. In total, these findings show that this equipment and these protocols developed specifically for space flight related application may provide a basis for broader use in situations where space and time constraints may limit access to effective exercise.


This project's funding ended in 2012