It weird how going through that pain can give so much pleasure. I guess it's like the "runner's high" that they talk about. Not particularly great as you are going through it, but fantastic afterwards and as such kind of addictive. And very motivating.
My other source of motivation is using one of these latest gadget watches while I exercise – it not only ensures I can start each set at the right time, but gives instant feedback on total exercise minutes, heart rate and calories burnt. And it keeps a permanent record of each workout. Again, very motivating.
The point of sharing this is to suggest that anyone can find a type of exercise that motivates them do it daily. By doing this, you too can experience the benefits of being fit, healthy and feeling great.
The pain bit, of course, is the personal bit. Some people like pushing themselves through lots of pain, and some just like to cruise through their exercise. The point is, even if it's cruisey, any exercise is better than doing nothing at all.
For me it's about living one of my personal values – that you need a little bit of pain, or "suffering", in your life to be able to have the good bits. Constantly living the good life just cannot be good for you in the end. It may be for a while, but I believe it must come home to roost at some point.
So why not experience some "suffering" daily – as I mentioned, it will not only be good for your health, it will be great for your mind, and specifically your discipline, which will likely help you in other parts of your life. And its only for such a short time each day.
Experiment with your exercise options until you find the stuff that works for you – then do it regularly, vary it slightly each time and I'm sure you will reap the benefits.
Then, you too, can experience some long-term gain from some short-term pain.