All Senku had to do was motion to the rocks and Thor understood. It wasn't exactly backbreaking work, even if he was starting to feel a bit of the strain by the time they were done. He'd not done this type of labour in a long time and it was starting to show, but he wasn't exactly exhausted like he would be after a fight, either. The rocks got moved to where Senku wanted them and Thor stepped back with the work complete.