So, it seems Asda have ended their experiment with four day weeks.... as it has been rejected by staff.
But, given this move at the supermarket merely involved a reallocation of hours worked into 4 x 11hour shifts, its no wonder exhausted workers rejected the move.
The four day week was supposed to be (and is) about more efficient working in the four days, not merely longer shifts over the four days.
Asda's approach really was not what four day weeks are about at all!