Green rooibos made from unfermented rooibos leaves contains high amounts of aspalathin. Dietary green rooibos is expected to increase physical endurance and decrease physical fatigue, because aspalathin has antioxidant activity and stimulates glucose uptake in muscle tissue. The aim of this study was to validate the effects of green rooibos and aspalathin by using a swimming mouse model. Dietary green rooibos and aspalathin tended to increase swimming time in mice. This beneficial effect might be induced by increased glycogen accumulation in the liver and skeletal muscles.