I totally agree with the poster who said "there's nothing wrong with just planning to alternate cardio/weights on successive days and grab whichever DVD fits the bill on any given day."
This is what works for me. I have never followed a rotation in my life and it has been years since I managed 6 days a week workouts. If I manage 3 or 4 during my daughter's busiest times of the year (hello soccer season!), then I consider myself to be doing very well.
I suffer from depression most of the time and have bouts of it at different times each year that either derail me in part or totally. So mine is more of a stop-start-pause-start again fitness regime! I also have what must be the lowest boredom threshold of anyone I know and so rotations and 6 days a week exercising is never going to work for me.
I say, "so what?" I have to do what works for me and if that involves a large dose of acceptance and forgiveness for my own shortcomings, well then, I think those are pretty essential.
In the fall I had 3 crappy things happen that dumped me into very bad depression. I tried to come out of it with exercise only to find that every time I worked out, it triggered a migraine. Then the medication the doctors prescribed for the migraines started giving me fainting spells, the inability to concentrate and a whole slew of other symtoms that mirror panic attacks. Quite delightful! So I didn't work out for 6 months throughout the winter. As a result, my body composition has changed: I have not gained any weight, but I have less muscle tissue and more fat tissue. Nice!
So, I am in the same boat as you. I don't much like this place or the skin I am in right now. I am trying to work out whenever I can and I am not setting up any expectations for myself that might become terribly unrealistic. When I get like this, the first thing I always do, and this always works for me, is I set out through town to just walk. Not powerwalk, not walk with sprinting intervals, just walking. I listen to great music or a great book on CD and just let myself move and enjoy the physicality of it all.
Lack of motivation happens to absolutely everybody at different times. Others find they have entered moments in their life when exercising is really a chore or the last thing they want to or can think about. It's life, it happens. You will come out of this too. For now, think about just moving because you know that you will feel 100% better while doing it and afterwards, better than before. Don't set up any goals that you might not reach. Instead pick a DVD for FUN and because the music is great. Do a workout for the physical and emotional release it gives you, not for better biceps. Right now it is your brain that needs the change. We can take care of the biceps later! Cardio only for 2 weeks? Sure. Just circuits for 3? If it works for you. Nothing but yoga for the next month? Go ahead.
Do it only because you want to and because you feel you could sing or jump for joy while you are doing it.
Clare