My take on it is that this type of training takes you through the immediate and non-oxydative energy systems. The incomplete rest periods never really allows you to get out of the non-oxidative energy system and brings into the early stages of the oxidative energy system.
This can potentially, completely, deplete muscle glycogen stores bringing about the EPOC effect so your body is burning fat stores for energy while trying to replenish glycogen stores.
Just my
