Figure 1. Study design. The subjects, randomly divided into 2 groups, were assigned to supplementation either 400mg of GE or 400mg of placebo (maltodextrin) under capsule forms (2 capsules) with their breakfast during one month. After one month of supplementation and two weeks of wash out period, the treatments were reversed. Effort test, blood and urine samples were done at day 0 (D0) and day 30 (D30) of each period.