Both Natalya Coyle and Arthur Lanigan-O'Keeffe are competing for Ireland
Natalya Coyle and Arthur Lanigan-O'Keeffe both begin their Modern Pentathlon campaigns on Thursday afternoon in Brazil.
Rio 2016 will be the second Olympic Games for the duo, with Coyle earning a top-ten finish in London four years ago Lanigan-O'Keeffe going into the event as the reigning European Champion.
Despite its title as a Modern Pentathlon, the event has been in the Olympic Games for over 100 years. The "Modern" in the title was used to differ the event from the Pentathlon from the ancient Olympic Games.
The competition takes place over two days, with the fencing section being held on Thursday in the men's and women's competitions. The women's competition will be completed on Friday, with the final four events of the men's event taking place on Sunday.
In a system that is similar to the decathlon or heptathlon in athletics, a points system is used. The 32 competitors face each other in a round-robin fencing competition. Each match lasts 60 seconds and the winner is decided by who scores the first hit.
The second competition is a 200 metres freestyle race in the swimming pool. The competitors are split into six separate heats, but it's a race against the clock. There are no rankings given on placings. It's all down to time.
A bonus fencing round has also been introduced for Rio 2016, that sees all athletes guaranteed at least one more match, starting with the two-lowest ranked fencers. They compete in a winner-stays-on event where all the athletes will compete with the chance of earning bonus points.
The third event is a showjumping competition. Each competitor is randomly paired with a horse for the competition less than half an hour before the event. Each athlete will be expected to jump 12 fences, and control the horse around the course.
The winner is decided in the final event which involves laser shooting and 3.2km cross-country run. The leader of the competition after the first three events starts first, with the remaining 31 following at random intervals depending on the points gained. The first athlete to cross the line becomes the Olympic Champion.
Both Coyle and Lanigan-O'Keeffe go into the event hopeful of top-ten finishes and could even compete to medal. The sport is not widely known in Ireland, but that could easily change come the end of the Olympic Games.