Hi Leah,
I am your age. I find too that I need at times to take
exercise some days in smaller increments. I'll defer on the
jogging question.
What has helped me is Gilads and his sister Ada's dvds.
I do a half hour of one of their dvds. I have recently added
a Pilates stick workout as well.
My focus now is to start a barre rotation/Bar Method Fluidity
with a Gilad/Ada dvd and Pilates stick workout. On alternate
weeks instead of Gilads series I am doing the Nia workouts.
Nia is a dance approach that you can do at different levels
even in the same workout. I am able to adjust it according to how
I feel that day.
Good luck with your rotation plan, thought I would share what is
currently working for me.