Stamina, simply put, is a measure of a soldier's physical endurance. It is consumed by various actions such as jumping and the use of most Implants. It can also be lost by taking damage; however, Stamina will slowly regenerate over time. This process is accelerated while crouched and still, and halts when moving.
If a soldier's Stamina falls to zero, he or she will become 'fatigued' and unable to run or use any implants. This state will persist until at least 20 stamina points are recovered by resting.
Jumping costs 10 stamina points.
Stamina is shown as a teal bar in the Bio pane.