People who need more energy and want to avoid stimulants that will make
them edgy should consider taking supplements of carnitine or
acetyl-l-carnitine, two forms of the same nutrient found naturally in
protein. Carnitine works by transporting fats in cells to where they are
burned for energy. By boosting the activity of the body's cellular
furnaces, carnitine can energize the heart, brain, and muscles to do
more. Doctors have also found carnitine and acetyl-l-carnitine helpful
in treating many conditions, including heart failure, muscle weakness
and failing memory. Carnitine can also enhance physical training.