Charles, look into a TRX system. Can make a person regret owning it in short order for the amount of workout options it provides and ensuing pain one willingly inflicts upon his or herself. Her last position gave her one so it’s one thing we use. It has ten minute workout plans that can be utilized as well.
Also, sprints.... empty, dragging something heavy, carrying five gallon water jugs, and more regular sprints.
Burpees..... something like 5, sprint 50-100yds five more, rinse and repeat until unable. Or 45 minutes has passed.
We are primarily cardio people, so we tend to just run, or ride, or paddle.