The Zona Plus is a small handheld isometric therapy device that has been scientifically proven in the overall management of cardiovascular fitness. Unlike many other natural therapies, the Zona Plus has substantial scientific support and has received favorable reviews by many prominent doctors and physicians. More than ten published studies have demonstrated that isometric therapy, including that provided by Zona Plus (and its predecessor the CardioGrip) are effective in improving cardiovascular health/fitness. Articles about the Zona Plus method can be found in distinguished peer-reviewed medical journals such as The International Journal of Cardiology, The American Journal of Physiology-Heart and Circulatory Physiology and The European Journal of Applied Physiology.