When would we be required to carry our backpacks?


Hi my name is Adele from Australia. I am doing the euro adventure trip and I read that for this tour we are only able to bring [^] backpacks.
I was wondering how often and when we would be required to carry our backpack?
If it’s not too often, I would be more Likely to bring the advised size and weight, rather then going under of fear that I would have to carry it around with me a hell of a lot.
Is admin able to answer this question?