Central Otago horsewoman Susie Latta will ride, ride and ride some more this weekend.
Latta (44), a farmer from Macraes Flat, is one of the leading contenders at the national endurance championships in Mayfield, Mid Canterbury.
She and her mare, Tkiwa, won the South Island title and are firmly in contention for the World Equestrian Games, in France in August.
About 100 horses, with riders aged from 8 to 70-plus, are entered for competition over three days.
Endurance riding is split into three classes (160km, 120km and 102.5km) and takes place on a track split into four loops.
After completing each loop, the horses have a short break while they are checked by a veterinarian to ensure they are fit to continue.
The start times of 1am and 3am mean that the first two loops will be completed in the dark.
The combination with the fastest time is the winner, providing the horse meets the ''fit to continue'' criteria as determined by veterinary staff.
The horses are monitored throughout the ride and will be withdrawn if they are judged to be unsound or metabolically unfit.
Latta said Tkiwa had proven a very ''tough and determined'' horse. The mare was ''very smart, yet honest and can be prone to moody moments''.
''In short, she has plenty of attitude. She is the most giving horse I have ever had and I believe that we have forged an amazing bond of determination, strength and courage both with, and from, each other.''
Tkiwa, a bay part-bred Arabian mare born in 2003 and bred by the Latta family, is by Euralea Light My Fire out of the standardbred mare Truly Scrumptious (by Admiral Halsey).
Tkiwa has clocked up 2700km in endurance events, including four three-star 160km events, and four two-star 120km events.
The youngest rider at the national championships is 8-year-old Kate James, from Oamaru, who will compete in the 100km junior ride.
On the entry list is reigning 160km champion Andrea Smith and Glenmore Tariq, and her daughter, young rider 160km champion Georgia Smith, with Glenmore Vixen.
Among the entries are all of New Zealand's combinations aiming for World Equestrian Games selection.
Three combinations - Andrea Smith, Georgia Smith and Mark Tylee - have already met selection criteria.
The team of five to go to France will be chosen in late May.