The distances tell only part of the story in Kona.

A 3.8km ocean swim, 180km bike ride and 42.2km marathon stand between athletes and the famous finish on Ali‘i Drive. But the heat, humidity and exposed roads of Hawaii’s Big Island make this a challenge which goes well beyond covering 226km.

On Saturday 10 October, professional men and women will race on the same day in Kona for the first time since 2019, alongside age-group athletes chasing their own world championship ambitions.

The route takes them through some of triathlon’s most recognisable landmarks: Kailua Bay, the Queen Ka‘ahumanu Highway, the turnaround at Hawi and the Energy Lab.

Each presents a different challenge — and getting through one discipline quickly means little if the effort leaves an athlete unable to cope with the next.

Swim: 3.8km in Kailua Bay

The day begins at Dig Me Beach, beside Kailua Pier, with a single-loop ocean swim in Kailua Bay.

Athletes start in the water and follow an out-and-back route in a clockwise direction before returning to the pier for the first transition.

It is straightforward to describe, but racing it is another matter. Swells, navigation and the battle to find clear water or a useful set of feet can all influence how much energy an athlete spends before reaching their bike.

But the water is extremely buoyant which adds a plus point for what is an incredibly condition-dependent leg of the race.

For the professionals, this is also where the first important groups form. A few seconds at the swim exit can determine whether an athlete starts the ride among their rivals or faces an immediate chase.

And that’s the point – it’s as much about the gaps behind as the athlete(s) at the front.

Laura Siddall, a former Kona top-10 finisher, and helping again with our coverage this year, says: “It’s a simple one lap, straight out from the beach, around the Body Glove boat and back to the Pier.”

Once back on land, the race changes quickly. Athletes collect their bikes and prepare for the longest section of the day.

Bike: 180km through the lava fields to Hawi

The bike begins with a busy opening section around Kailua-Kona before heading onto the Queen Ka‘ahumanu Highway — better known throughout triathlon as the Queen K.

Early on, athletes are establishing their positions and working out who has emerged from the swim ahead of or behind them.

Then the course opens up, taking riders through the exposed volcanic landscape towards the climb to Hawi and its turnaround.

The lava fields provide Kona’s unmistakable backdrop, but there is little shelter from the conditions. Riders must deal with the heat and be ready for strong crosswinds, particularly when maintaining control of the bike becomes as important as maintaining speed.

Nor is this a flat ride. The highway rolls, the approach to Hawi climbs, and turning for home does not mean the hard work is over.

As Siddall explains: “Once at the turnaround, the descent down from Hawi still amazingly has a significant amount of climbing as you head back to the Queen K.”

That return journey can expose an overly ambitious first half. Riders still have a marathon ahead of them, making pacing, fuelling and hydration central to their chances of reaching Ali‘i Drive strongly.

Siddall offered a useful checkpoint: “If you are still riding strong by the Airport (about 10km from T2) you are probably doing well.”

The final kilometres bring athletes back towards town and the second transition, where the full cost of the bike effort is about to become clear.

The last time the men raced here in 2024, Patrick Lange took full advantage of those who overcooked the bike as he swept through the field on the marathon for a third Kona crown.

And for the women last year neither Taylor Knibb nor Lucy Charles-Barclay, who were first and second off the bike with more than five minutes back to the rest, made it to the finish.

Remember too that we now have the 20-metre drafting rule which adds another dynamic.

Run: 42.2km via Ali‘i Drive and the Energy Lab

The marathon begins with an out-and-back along Ali‘i Drive, where the crowds provide an energetic welcome to athletes starting the final discipline.

But that atmosphere is only one part of the Kona run experience.

The route then climbs Palani Road and heads onto the Queen K, taking athletes away from the bustle of town and onto exposed, rolling highway.

This is where the marathon can become a more solitary contest with the conditions, fatigue and the consequences of everything that has come before.

The course leads to HOST Park at the Natural Energy Laboratory of Hawaii Authority, universally known in triathlon as the Energy Lab.

Its reputation owes much to its place deep into the race, when athletes are already carrying hours of exertion. Staying fuelled, managing the heat and maintaining forward momentum can matter more than any ambitious pace planned before the start.

Siddall summed up its notoriety last year: “The infamous Energy Lab, where what goes in doesn’t necessarily come out.”

Those who emerge still have the return along the highway to negotiate before the descent down Palani Road and the closing section through town.

Finally comes Ali‘i Drive and one of endurance sport’s most celebrated finish lines.

For some, it will mark a world title. For others, simply getting there will be the achievement they have spent years pursuing.

Why Kona is about more than the route

An ocean swim, a rolling bike course and a marathon with exposed stretches would be demanding anywhere. In Kona, the conditions connect all three.

An athlete who uses too much energy chasing a swim group may pay for it on the bike. A rider who pushes too hard towards Hawi may discover the consequences on the Queen K during the marathon.

The course rewards speed, but also judgement: how hard to push, when to be patient and how to keep taking on fuel and fluids as the day unfolds.

That balance is what makes Kona so compelling. The strongest athlete early in the race is not always the one who reaches Ali‘i Drive first.