Mens sana in corpore sano. First, allow me to clarify that I'm not trying to sell you anything, except maybe an idea - and that one I'll give you for free. It's nothing new, but it's possible that you just haven't thought of it before.
If you're reading this, you probably want to get in shape, which means that you haven't been working out much recently, right? I've been studying for years and I didn't take care of my physical condition during that time, until I graduated with my first M.A. At about that time I realized two things: I was in a really bad shape, and stress can (at least to some extent) be controlled by physical exercise. And stress is a bitch - I've been trying my best to avoid it ever since.
Anyway, I was spending most of my time at home, reading and sometimes writing. So I came up with a method of exercising that suited me very well: I could do it at home, without buying any new equipment, and I could do it with very little need to sweat. And it turned out to be a surprisingly powerful method!
The first thing to do is to think of a motivator. Anything that can drive you to do the exercise should work. Eventually this can be replaced by just the desire to follow the method, or it can be changed to something else. I chose to use alcohol as my motivator.
The idea is then to draw a table with columns for date, daily total, and between them columns for all the exercises you're going to be doing. They can include just the basic pushups and stomach crunches, but the more variety, the better. They should include walking, and carrying, because these you will probably do daily anyway.
For each exercise you figure out what amount of effort will reward one point, and then you'll just mark the points in the table as you get them done. For example, walking to work could be one point, carrying a bag of groceries another, and doing 25 pushups a third. Then you need to have a goal for the amount of daily exercise. It can take a while to find a suitable amount, but for me it eventually turned out to be 15 points. It doesn't matter that much, if some days you can't get all the points done, you don't have to start from scracth the next day. Instead, you continue from the previous day and try to get the average effort per day to the same level.
When you have attained your daily goal, you can use that to reward yourself with your chosen kind of reward - for me it was a dose of alcohol (a shot of whiskey or a bottle of beer). When you take your reward, just mark one of the daily totals as used.
It also helps to have a routine for doing the exercises. I used to do them every hour, on the hour, usually in sets of two exercises, such as stomach crunches followed by dumbell curls.
You probably noticed that I'm talking about my method in the past tense. That's not because I had stopped using it (completely), but because I recently bought a barbell (cf. the picture) and new dumbells, and I've been using the work out courses in the booklet that came with them. I still use my own method, but the now most of the exercises I do are in the weight lifting courses, and I don't mark them in their separate columns. Instead, I added a column for the courses and another for chores I have to do, which includes cleaning the appartment and washing dishes, as well as studying.
I am already in better shape than I've ever been, and although I now sweat when doing the work out with the weights, I didn't have to, when I was doing the old method. Having some basic equipment, such as dumbells and some kind of bar for chinups helps, but they aren't necessary for that method to get you in shape. Just remember to do different kinds of exercises, for the stomach and the back especially, if you're normally doing some kind of sitting work (as opposed to manual labour). But I have to say, the barbell is a very good tool for excerices, probably the best along with the chin up bar (the name of which I actually don't know).
I'd like to hear if this method actually helps you!