Not too intense is doing goat standing on a Roman chair. You can do it with a barbell. If it's stronger, pull hard. Don't do straight legs, do bent legs. To do hard pulling, you must first make good moves to the coach. Never bend down and stick the barbell on your calf, otherwise the injury will not pay off.

Also, in order to improve the strength and waist strength, it is best to do a large number of groups of hard pull, each group is 3-5RM.