Designing methods for musculoskeletal conditioning in weightlessness.

There is an immediate need to find methods to combat the skeletal muscle deconditioning that occurs in microgravity. Important features to be considered for any ergometer or exercise method to be used as a countermeasure against musculoskeletal deconditioning in space include heavy muscular loading of the postural muscles of the lower limbs and that eccentric and concentric muscle activations can be performed. Those are major requirements to produce optimal gains in strength and muscle mass at 1-g and probably to counteract muscle atrophy and strength loss in microgravity. Resistance exercise with a strength-ergometer, using the fly-wheel principle was carried out at a low oxygen cost and required no external power supply. We have developed a resistance training system employing this ergometer so that force and power production easily can be monitored and calibrated. It is suggested that the features of this ergometer meet the presented requirements for use during long-term space missions.