To enjoy your Gillespie/Rabbit Pass trek you need have excellent fitness and some prior specific training may be required. This means being used to hiking for 6-8 hours a day on multiple consecutive days, ascending and descending up to 1000 vertical meters in a day whilst carrying an 6-9Kg pack. Hikers should be able to maintain a slow but steady pace for long periods of time. You will only be carrying your own gear but your pack will be considerably lighter without sleeping & camping equipment.
For the majority of the Rabbit Pass route, there is no formed track so the footing can be unstable and hikers need to be good on their feet and be comfortable on rough or slippery ground (you will not encounter deep mud). Recent experience on rough 'off-track' terrain including steep hills, scree and boulders is recommended.
During the crossing of Rabbit Pass there are sections with significant exposure to falling so you must have good balance and not be afraid of heights whilst using small footholds, handholds and ledges to ascend. On two sections of the crossing a rope and harnesses are used for safety. Experience scrambling, rock climbing or abseiling is not required but useful.
This is a remote backcountry trip so you need some experieince of multi-day trekking, camping and be comfortable in a range of weather conditions. Track times and distances in New Zealand can be deceiving and the nature of the terrain means that you seldom get long stretches of fast travel. There are unbridged rivers and streams to cross, steep ascents and descents, loose scree or exposed drops. Do not be deceived into thinking that days with short mileage will be easy, days that we travel less that 10km can be more tiring that days we travel considerably more distance.