T25 and Insanity were made by a coach. The latter is very strong and not suitable for people who have no sports foundation. Both belong to HIIT. If it's just shaping and reducing fat, I suggest you do these two aerobics at home. Just choose one according to your own situation. Pay attention to the standard movements when jumping. That's all that matters. You can go to the post bar and have a look. There are many experiences shared by the Great God, so I won't elaborate here.