Triathlon is a multi-discipline sport consisting of a swim, followed by bike course and ending with a run. Triathlons are raced by men and women of all ages, children, juniors and athletes with disabilities. Elite triathletes race under slightly different rules, which allow drafting on the bike, and so it is rare that amateur, or age group, triathletes find themselves up against the professionals. Instead, we have the age group system in which athletes compete against others of the same sex and in 5-year age bands.

To race in the vast majority of races in the UK membership of the British Triathlon Association is required for insurance purposes. You can buy a day membership for each race, but if you intend to do more than 6 races it’s more economical to become a full member of BTA.


To accommodate all different skill levels, there are several different distances for triathlon races. Super Sprint and Sprint distances vary from race to race, but the other distances are consistent with the lengths shown in the table below. The Half and Full distances are commonly referred to as Half Ironman and Ironman distances respectively. Half Ironman races can also be referred to as Ironman 70.3’s, with the number 70.3 representing the total mileage of the race.

Distance Swim Bike Run
Super Sprint 200m – 400m 10km 2.5km
Sprint 400m – 750m 20km 5km
Olympic/Standard 1500m 40km 10km
Half/70.3 Ironman 1900km 90km 21km (half marathon)
Full Ironman 3800m 180km 42km (full marathon)