Humans have a high capacity to expend energy for many hours during sustained exertion. For example&colon; Cash over and beyond what competent people can intelligently expend is wasted. They expend their energy only when it's absolutely necessary. This is generally limited by a requirement to expend accumulated resources. Asexual organisms need not expend the energy necessary to find a mate. Hence, people with obesity need to expend more energy to breathe effectively. Hagfish therefore have to expend some energy for osmoregulation. We were compelled to expend some of our best divisions there. As they fight, units will expend their ammunition, forcing the player to pay attention. Our bodies expend energy through normal functioning as well as through exercise. Badgers are also thought to expend less energy while hunting in burrows. The production of siderophores also requires the bacterium to expend energy. Soldiers expend will points to take special actions. Sleep could be achieved by any number of complex activities that expend mental energy. Players expend fatigue points to cast spells, and must roll percentile dice to succeed.