Supplemental D-ribose absorbs easily and quickly through the gut and into the bloodstream. About 97% gets through. Studies have shown that any amount of D-ribose you give to energy-starved cells gives them an energy boost. At the University of Missouri, researcher Ronald Terjung has shown that even very small doses (the equivalent of about 500 mg) of D-ribose increase energy salvage in muscles by more than 100%. Larger doses increase the production of energy compounds by 340-430%, depending on the type of muscle tested, and improve the salvage of energy compounds by up to 650%. Most amazing is that when muscles are supplemented with D-ribose, they continue to add to their energy stores even while they actively work! Until this study was reported, it was thought that muscle energy stores were only refilled in muscles at rest.