The general body temperature is evidence that demonstrates to the average person that the body's muscles, organs, and brain produce heat in various ways. This idea is further supported by a recent study that claims our muscles have developed a sophisticated strategy to keep us warm even when they aren't working.
According to University of Queensland researchers, mammals' resting muscles produce more heat, which can then be circulated to other body areas.
"Cold-blooded animals, like frogs and toads, and warm-blooded mammals, such as humans, use the same basic muscle structures to generate force for posture and movement," UQ School of Biomedical Science Associate Professor Bradley Launikonis said.
"The muscles in both groups continue to work when resting, similar to a car engine idling, to maintain readiness for contraction at any given moment, which uses energy and generates a small amount of heat."
"However, mammals have evolved their muscles to become heat generators while their muscles are resting, giving them with a major advantage in regulating their body temperature when outside temperatures drop," Dr Launikonis said.
The modification enables the muscle of the mammal to withstand increases in the concentration of dissolved calcium in the muscle fluid, which pushes the muscle to expend energy to eliminate the dissolved calcium.
According to Dr. Launikonis, the mammalian body uses the heat produced as a byproduct of this process to keep itself warm.
"This has been developed, in part, by evolutionary isolation of one calcium channel in the muscle of mammals, compared to the two that still exist in cold-blooded animals.
"This study advances the knowledge of our evolution as mammals and provides a foundation for further harnessing our resting muscle to consume energy while resting.
"This could, for example, assist with weight loss in people with obesity."
