I find that the best way to start a homeschooling day is by making sure certain things are done BEFORE the kids are up; a load of wash thrown in, the bread in the bread machine, tidying up the playroom where we do lessons, and one more, the most important; some me, alone time. A cup of tea, a little breakfast and some exercise in whatever form it may take.
Yoga has always been my favorite; you move and stay sane and centered all at the same time. The past two months, I have been limited to seated yoga. I've tried a few videos and lots of youtube choices. Here is my current favorite:
Seated Yoga with David Procyshyn.
He is not as pretty as some of the women instructors, and his voice can put you to sleep, but the workout is very, very well done, with clear, move-by-move instructions, (very important, as my body does not always go in the direction the instructor thinks it should), and no background music, lights or distractions; a nice green field and silent birds. My the time I am through shavasana, I am relaxed to the point of a coma, yet energized to start my day with the munchkins.
Always remember to only go as far as is comfortable for you, right now, in yoga poses. It is a practice, and with time, you will grow more flexible and gain more stamina. It is not a contest. Use the extra time inbetween poses to shake out your knees or wiggle your hips.