I don't need to go to the gym - no special equipment needed.
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My routine; at least ten sit-ups before getting out of bed. Use a wall to stretch as high as possible, fingers spread, then stretch more! Stand on tip-toe stretch again! HIGHER!
Now do the plank and hold to count of thirty (or more)
After the plank, do the "dog" stretch, again for the count of thirty or more, same for the "cat" stretch.