Glycogen is not only a source of energy that fuels your body during exercise, but it's also one of the main factors for your muscles to look big and full. (fitnessandpower.com)
That's the difference between regular hybrids and plug - in hybrids, one has a hybrid drivetrain while the other has an all - electric drivetrain and only the source of energy alternates between fully electric, using energy that has been taken from the grid, and hybrid, after this stored electricity has been exhausted. (myelectriccarforums.com)
They are considered an engineering tour de force because their only source of energy is natural gas — conveyed by a single steel umbilical cord — which is then generated into heat and power. (religion-online.org)