Hi Jessica,
Depending on what you are doing in the class you can offer breaks along the way. I like to give longer breaks 15-20 minutes so they can get up move around, grab a snack or soda, go to the restroom. It is almost impossible to give a 5 minute break. No matter how you try the students just can't get back to the class within 5 minutes. This is why I give them longer breaks where they can refocus their minds.
I offer mini-breaks within the class. The students don't know they are breaks but they are. For example, I will lecture for 15-20 minutes, then I will put them into work groups. They have to get up move their chairs into their groups. This takes a couple of minutes and they have let their minds go from lecture to the new assignment that they are going to work on in the group.
Also, I use silence to give them mini-breaks. I will share a concept with them, then pause for 5 seconds before going on. When they move their heads, and look at me they have made a mental shift. This is refreshing for them.
Hope these suggestions are helpful to you. If you have any other questions please let me know.
Gary