The Recovery Phase 12 seconds slow

We follow the intense 8 seconds fast with 12 seconds slow.by way of recovery

During the recovery period of high intensity interval training HIIT, an amazing thing happens the  lactic acid, the burning unpleasant feeling in tired muscles, is allowed back into the system.  It can then be available for energy. So during the rest rest periods – the 12 seconds slow -  lactic acid gets mopped up. Everyone has felt this.  Your muscles start burn, so you slow down for a while, then you are able go again as the burn eases. Now we know why.