Fig. 2: Changes contributing to reduced muscle strength in 1 G (left) and µG (right).

Changes at a cellular level in response to muscle unloading in experienced in microgravity resulting in muscle atrophy in humans. IGF-1 insulin-like growth factor-1, PI3K phosphatidylinositol 3 kinase, Akt/PKB protein kinase B, regulated in DNA damage and development, ROS reactive oxygen species. The arrows and inhibition symbol show the association of molecules under loading condition, ↑ shows upregulation and ↓ downregulation of molecules under reduced gravity condition. Created with BioRender.com.