You have to enjoy the training: practice only sports that you like. Most of the things that you do not like are not good for your health.

If you are short of ideas as to which sport you would really enjoy, try Wikipedia's list of sports.

We are convinced that you will find a sport that you will enjoy on that list. If not, work on your creativitiy and invent your own sport or physical exercise.

And if that still does not work, you might need to read this.