Sos rehydrate the new sos rehydrate has landed same great formula new improved taste sos is designed for runners by runners and a doctor based on proven sports and medical science to replace all the electrolytes you loose when running sos is proud to sponsor team england the british milers club as well as the oregon track club sos is the only electrolyte drink that has 0 artificial sweeteners or preservatives and that provides the correct amount of electrolytes not a token gesture