The present study concerns the effects of 21 days of sustained recumbence (bedrest) on skeletal muscle gene expression. 14 male subjects participated in normoxic bedrest (NBR) with muscle unloading for 21 days this is a substudy of tha PlanHab-study which apart from normoxic bedrest also involved hypoxic bedrest and hypoxic ambulation. Throughout both bedrest interventions each subject remained in a horizontal position at all times. He was allowed one pillow for the head and to occasionally lean on an elbow while eating or being transferred to a gurney. Muscular exercise was prohibited. During the HAMB confinement each subject was allowed to move freely within the hypoxic area. To mimic a normal level of physical activity subjects performed 30 minutes of low-to-moderate-intensity exercise twice daily. Muscle samples from Vastus lateralis.