"Your energy recovers over time at a rate of 1 energy point every 3 minutes. You can increase the rate your energy restores for a short period of time by using Talismans. The clock under your energy points (number 6) shows how much time is left before a new energy point is restored. Once you reach your maximum, the clock stops and your energy will not start restoring again until your energy points drop below the maximum level again. However, you can still gain energy points from awards or by using Food items in your inventory, and these will still be added to your current total energy points, even if the total is more than your maximum (see the example in the picture above, the player has 617 energy points, even though their clock has stopped restoring energy since they are above their maximum of 290 points)."   This is from the blue bar game help under guides.
Sometimes there are glitches... if it is not restorng you may need to contact G5,