For starters, creatine increases the phosphocreatine (PC) stores in skeletal muscles. Greater PC stores help muscles produce ATP more rapidly allowing for longer durations of high intensity effort, which ultimately increases total work output producing more gains!
Creatine also acts as an osmolyte, which means it draws water into muscle cells, causing a cell volumization effect. Researchers believe this volumizing effect may play a role in muscle growth.
Additionally, creatine is also noted to increase satellite cell signaling, which supports muscle repair and new muscle growth.
Supplementing with creatine may even help reduce levels of myostatin — a protein that can slow or inhibit new muscle growth. Limiting myostatin activity, therefore, increases growth potential.