Over the years, I’ve grown to appreciate circuit training and I especially like the flexibility of modifying the exercises. When I’m short on time, I’ve found that circuits are a good way to get that bare minimum training in.
Some I do include:
Punching bags, bars/rope, core, kicking bags
Core (8-10 minutes of various exercises)
Over winter break, I discovered a format which I’ve modified to incorporate martial arts related conditioning.

One of the keys to both progressing and enjoying exercise is variety.
With circuits, you have the flexibility to change:
Intensity
Duration
Time-based or rep-based
Target areas
Types of exercises (adjust for tight space or lack of facilities/equipment)
If you train circuits, what are some of your favorites?