Riding a bicycle in the sky?
If you are looking for an exercise combined with thrill and adventure, you could go visit Davao City to try sky cycling. Sky cycling is basically about pedalling your way to the end of the 200 meters fine cable. To finally finish the course, you have to pedal back to where you started, giving you a 400 meters to pedal in total.
This may look tiring and scary, but if you have a brave heart, this is definitely a must try.