Corvalen Ribose contains pure D-ribose, a safe and clinically researched ingredient that supports the natural way our bodies produce adenosine triphosphate (ATP), the energy currency of the cell. Unless our hearts have an adequate supply of ribose, they simply cannot satisfy their astonishing energy demand. Our bodies make ribose naturally, but in times of stress the need is greater than our supply to satisfy the loss of energy from our cells. That is why supplementing with D-ribose can support proper heart function and helps maintain healthy stroke volume during and after high intensity exercise. One of the original studies performed by Schneider et al in 1985 found that supplementation with D-ribose after cardiac ischemia resulted in a significant shorter duration of diastolic recovery time vs. the control group (2.8 days vs. 9.4 days). Another study by Olman et al in 2003 showed beneficial effects on diastolic function and quality of life in compromised patients after only 3 weeks of supplemental D-ribose. Although D-ribose is a five-carbon monosaccharide, it does not raise blood sugar. 56 servings.