70.3 Middle Distance Triathlons 2026 - 2027

A standard middle-distance triathlon covers 70.3 miles in total: a 1.2-mile swim, 56-mile bike ride and 13.1-mile run. In kilometres, that’s roughly 1.9km, 90km and 21.1km. You’ll sometimes hear the format called a half-distance triathlon as well. IRONMAN 70.3 refers to branded races over the same distance, but IRONMAN doesn’t own the format; independent organisers hold middle-distance events too. It sits between an Olympic triathlon and a full iron-distance race.

The UK middle-distance season generally runs from late spring until early autumn, with most races falling between June and September. Open-water temperatures and the long time competitors spend outside make winter racing impractical, so there isn’t much of a year-round calendar at this distance. The choice can also be quite small compared with sprint racing. If you’re arriving late in the season without enough time to prepare, it’s usually better to choose a shorter event and plan your middle-distance race for the following year.

Entry to a UK middle-distance triathlon will often cost somewhere between £70 and £200, although premium events can exceed £300. Be careful with unusually cheap figures on multi-distance booking pages, as the lowest price may belong to a sprint wave rather than the middle-distance race. Travel, accommodation and equipment aren’t included either, and those costs can easily pile up to be more costly than the entry fee.

Most athletes will aim for around 16 to 24 weeks of focused training for a middle-distance triathlon, assuming they already swim, cycle and run regularly. If you’re new to one or more disciplines, it’s fair to say that you’ll need longer. Completing a sprint triathlon or Olympic-distance event first isn’t compulsory, but it gives you a useful chance to practise open-water swimming, transitions, pacing and fuelling - all of these are key for a successful and enjoyable middle distance event.

UK middle-distance bike courses vary from fast road circuits to demanding rural routes, so you shouldn’t assume that the 90km will be flat. Superfeet Sandman has described a relatively flat course, while races around Wimbleball Lake and Bala bring a very different landscape. A route that’s merely described as “road” may still include substantial climbing, and silence about elevation doesn’t mean there aren’t any hills. Check the organiser’s route map, total ascent and gradient profile before entering, especially if most of your cycling has been on flat ground during your training.

Many middle-distance triathlons begin between 6am and 8am, but that isn’t a fixed rule. Your wave may be later than the headline time, and transition normally closes before the first swimmer enters the water. Final race instructions should tell you when to register, rack your bike, attend the briefing and join your wave.