I often tell my beginning piano students that they need to practice at least a few minutes at least 4-5 days a week. When the songs they're working on are only 9 notes long, they don't really need long practice sessions, and I sometimes get asked if all the practicing can just be done in one day (I can always tell who the logical thinkers are by this question!). However, by doing a little bit each day, it gets them into the habit of practicing, and helps them build good habits that will make progressing musically much easier.
I think that's kind of where I am right now. I'm not necessarily doing that much for exercise (an ever-varying mixture of a few free hand weights, some ab work, playing with a medicine ball, the elliptical machine, etc), but I feel good about developing exercising habits, and 9 out of 10 days, even if some of the days were a little wimpy, is a really good start for me!
In a side note, since I signed up for a Zumba class that starts in February (any Des Moines people want to join me?), I started looking at different beginner videos on YouTube. Today, I went through one a couple of times to see if I could get the hang of some of those steps. It was a total of (almost) 11 minutes, and it was tiring! My class is an hour long. So, for at least the first few weeks, I'm mostly hoping for a soft place to land when I pass out.
The good news is that doing the moves was really fun - so I should at least have a good time in class before I fall over!