Walking - I have started regular walks to break up my day (I work at home). I bought a pedometer which really does motivate me, strange as I didn't think it would. I have a large park nearby and take a walk around there - I do 4 minutes normal pace and speed up for a minute or so.
I tried Davina McCalls excercises, a trial online, they are 1 minute short bursts of excercise. Things like punches and squats, I enjoyed it but.............didn't pay for ongoing access, so I stopped duh!!
Also looked online for some strength training routines using baked bean cans - for the arms and legs. Again they are short routines, maybe 5 minutes each time. I am definately finding a difference in relaxation and sleep when I keep these things up and the short sharp bursts seem to work for me.
I keep meaning to start a yoga class...............it keeps slipping down the to do list!