My husband and I, who are in our 60s and reasonably fit, took 2 hours to do the full loop. This was because we wanted to take in the full beauty and diversity of the rainforest and wait patiently in case there were lizards and other wildlife to spot. The track itself can be steep and rugged at times, but not too difficult if you are careful and, in my case, have a walking pole. If you want to cover the distance without too much delay, then I'd say you can do it in a hour - but if you can, take the opportunity to slow down and enjoy the experience.