If you’re at a school that does “warmups” as part of class, then think carefully about why they’re included.

If it’s a hobbyist school and they have warmups, remember that you’re paying for instruction and mat time. I’ve never heard of anyone that enjoys the warmups, and I’m certain that everyone would prefer to cut it out and either pay less in tuition or simply have more time for instruction, drilling, or sparring.

It doesn’t make a lot of sense to me unless it’s a competition school, and even then, it’s questionable. It can be useful for burning calories, but when you consider the time and effort, it’s not as helpful for your jiu-jitsu as it should be.

Strength and conditioning shouldn’t be part of a jiu-jitsu class, because that kind of training requires a different process. Class should be for learning and practice, and then strength and conditioning takes place elsewhere. Strength is improved in the weight room, and conditioning is improved with sparring.