Your body has a pretty good way of adapting to your training style. Whether it be running, weight lifting or a sport you regularly train, sure enough you can have a hard enough training session to have your heart pumping and sweat dripping.
There is something extra challenging about taking it the next step and getting involved in a whole new arena. Test yourself and your fitness with something completely new. Be a beginner, learn a new skill and watch your fitness skyrocket. Boxing, Tennis, Swimming only to name a few are our current favourites, and goodness has it been addictive!