Participants and War deck used meaning

In a war week, each one of the 50 clan members can use 4 war deck in each one of the 4 clan war days.
I see under /war/log as if the max deck used per member is 28 war deck used and not 16 (4 war days x 4 war decks), what is the meaning of the number 28? Does it count training day? If so, how can I filter out training days?