Bears hardly lose any muscle when they hibernate, say zoologists at the University of Wyoming. Their finding could lead to new treatments for muscle wasting in humans, or ways to conserve muscle tissue during space flight. Henry Harlow and his colleagues made the discovery after analysing muscle biopsies from sedated bears at the start and end of hibernation. They believe the bears have evolved a way of conserving muscle so that if disturbed by predators, such as wolves or mountain lions, they could instantly fight or flee.