This is a great thread from Quora with more than a hundred different suggestions to get ourselves up and running on a daily basis
Just review it every other day, get some new ideas to ponder upon and implement on your own
I really liked Nelson Wang’s comment which gives a great list of possibilities that at least one should be achievable:
If you can’t run, do 100 pushups.
If you can’t do 100 pushups, do 100 sit-ups.
If you can’t do 100 sit-ups, do 100 squats.
If you can’t do 100 squats, do 100 lunges.
If you can’t do 100 lunges, do 100 bicep curls.
If you can’t do 100 bicep curls…
Write 100 words.