What should you wear to race a duathlon?

Runners and cyclists taking part in the London Duathlon — Credit: London Duathlon

Duathlon is the off-season sport of choice for triathletes. With water temperatures too cold the swim is dropped so you will usually complete a run, followed by a cycle and then another run. But what should you wear?

You can read more about what a duathlon is here, if this is the first time you’ve come across them!

Well, the good news is you need less kit. Losing the swim means no wetsuit, cap or goggles. There’s no need to leave flip-flops somewhere for collection later and you don’t need to plan for being wet and having soggy kit to stash.

On the flipside though, the weather and air temperatures are obviously lower which can mean you need to plan more for being chilly, or too hot if you run warm when you run. So what to wear?

First of all you need to take into account the weather conditions and aerodynamics. After all, you still want to be competitive and that means thinking about being as streamlined as possible.

Athelte cycling in London Duathlon wearing a tri-suit and aero helmet — Wearing an aero tri-suit will give you extra speed on race day. Credit: London Duathlon

Start with a tri-suit

The body is 80% of your drag, so wearing a tri-suit is always going to be the best option. By combining good position and clothing you could save up to 30-40 watts, which could equate to 90 secs-2 mins over a 40km course.

When it comes to suits it’s a good shout to opt for a sleeved version. The shoulders are a very sensitive area so by wearing an aero suit you’ll cut drag. A sleeved suit arguably looks better and gives a little more warmth too – add arm warmers and calf sleeves designed for racing if you want to cover more skin yet still keep aero.

You’re going to save around 15-20 watts with an aero suit compared to shorts and a jersey. Some of the more top-end brands have a tri-suit with different panels that are designed to reduce drag but also allow you to move more freely.

Find our tri-suit buying guide and group test here.

Wearing a tri-suit will also mean you are wearing shorts with a chammy suitable for running – whereas if you opt for cycling shorts you’ll feel like you’re running with a nappy on and in normal running shorts or tights, you can imagine how painful the bike might be!

Of course there is an element of distance coming into play as well. If the race has a shorter bike, then you’ll get away with a tri-suit with a smaller chammy. Or if new to duathlon and racing a shorter distance there’s no reason you can’t just wear shorts and a t-shirt. Save the upgrades for once you’ve got a feel for racing and know exactly what you want.

Man racing London Duathlon wearing shorts and a tee — There’s no reason you can’t race a duathlon in shorts and tee. Credit: London Duathlon

Consider the weather conditions

When it comes to the weather, always make sure you layer up well – and think about how you’ll feel once you get into the race. Will you be hot running, but then cooler on the bike once wind chill affects you?

There is an element of speed versus practicality here. Keeping your base layers under your suit rather than over them will make sure you keep the aerodynamics of the tri-suit, but it’s worth investing in a good once which will wick sweat and also respond to changes in body temperature.

Come the really harsh race day weather though and you may want to think more practically, unless you’re really looking for a winning time.

Come strong winds or heavy rain and you may want a bit more ‘armour’. Opting for a lightweight waterproof jacket which can be added at any point in the race you need it would be a good idea. Just remember to have your race number on a number belt so you can still wear it on top.

Female runner crossing the line of London duathlon — Consider the weather when choosing your race day kit. Credit: London Duathlon

Other accessories that may be useful would be similar to a triathlon. Elastic laces will help quickly remove and put on your run shoes. For the run, maybe add a cap or visor and sunglasses if you’ll face strong light – or choose a light tint if it won’t be sunny but you prefer to cycle with eyewear on for protection.

Finally, know your own body. If you know your hands get cold, then investigate lightweight gloves suitable for wearing throughout the race. Likewise if you struggle with cold feet, choose a good pair of socks that are comfortable for running but which don’t hold water if it rains.

Conclusion

Like any race kit choices, what you go for is very personal. Basing it around a good tri-suit will pay dividends though and from there, think about adding light layers suitable for the distance of race and weather conditions you’ll experience on the day.

Balancing speed with comfort is always worth thinking about. It’s no good getting a PB if you’re cold and wet and miserable, but equally you don’t want to be hot and bothered and weighed down by apparel that isn’t suited to race day!

About

Helen has been 220's Editor since July 2013, when she made the switch from marathons to multisport. She's usually found open-water swimming and has competed in several swimruns as well as the ÖtillÖ World Series. Helen is a qualified Level 2 Open-Water Swim Coach focusing on open-water confidence and runs regular workshops at the South West Maritime Academy near Bristol. She is also an RLSS UK Open Water Lifeguard trainer/assessor.