There are many types of cardio things you can try. The only limit is your creativity!
For example you could try:
Swimming
Walking (outdoors with sunshine helps the mood as well!)
Jumping rope
Biking (intensity kept moderate to low to ensure you do not create more stiffness and immobility with intense workouts)
Light jogging or running
Calisthenics
Light circuit training (being sure to pay CLOSE attention to form and function in every exercise!)
Elliptical (not our favorite because of how artificial the motion is but something may be better than nothing.)
Timing of Your Cardio
Some people feel their body is more "tuned up" after doing the TSR work, and therefore they do cardio after FAI Fix workouts. Other people like to feel warmed up before their FAI Fix workouts, so they do their cardio before. This is highly subjective.
The important thing is to find something that doesn't aggravate the hips or back and still gets the heart rate up.