Make sure you can walk comfortably in your backpacking shoes and break them in before the event.
Look into ultralight backpacking and thru-hiking methods of walking and packing. Bring only the indispensable items in your backpack and choose natural materials wherever possible.
Merino wool clothe is great (especially for underwear and base layers) for its quick-drying, anti-fungal, and anti-odour properties.
A fully packed backpack, including food and water, should not weigh over 15kg (for Lyra 8-10kg). The lighter, the better!
We recommend you backpack min 10km per week in the 2 months before the event and gradually increase the weight of your backpack until you feel comfortable hiking 15km with 15kg in one session by 2 weeks out.
During your physical preparation, don't forget to test the gear too!