My daughter's school has PE in one two hour block so that the teachers can have their non contact time in a two hour block. There is an arguement that the children spend more of their time running about and less of their time changing. However I feel that one two hour PE session a week is not enough for fitness.
Its interesting to see the chinese teachers making the children start the day with exercises. I would not want children to have chinese style PE lessons, but there is a lot to be said for regular PE. I feel that children who are struggling with PE should have a complusory after school PE lessons.