Tackling Your First Duathlon

So you’ve decided to take on the challenge of a duathlon - great move!

With lots of running and relatively short cycling elements, duathlon is a great introduction to the world of multi-sport racing.

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What is Duathlon?

Duathlon is the winter time cousin of triathlon, but with no swimming and with a little extra running. That makes makes it a great sport if you’re thinking about trying a triathlon in the future or if you’re just looking for something to progress your overall fitness during the winter and spring.

Mixing up the type of racing you do is a great way to increase motivation and spending time on the bike has great crossover benefits for your overall fitness too.

While many triathletes turn to duathlon at the start of each year, there are lots of people who concentrate solely on duathlon. Racing duathlons in the the winter and spring is the perfect way to get fit for your first triathlon, or for other summer challenges like adventure racing, cycling sportives and running events.

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The Basics

In its simplest form, a duathlon is any run-bike-run event. The vast majority of duathlons that are staged in Ireland are ‘sprint distance’. This begins with a mass-start 5km run followed by a 20km cycle and finally a 2.5km run to the finish line - all without any break. These distances do vary however and sometimes the run legs are a little longer - it all depends on the physical attributes of the race course.

Bikes are picked up and dropped off in a ‘transition area’ beside the finish line, which is also where the duathlete is allowed leave any additional clothing or gels required for the race.


Your regular running kit will serve you perfectly well in a duathlon but do bring gloves and a jacket as the wind chill while cycling can get pretty cold. 

In terms of bike equipment, any functioning bike will do - some duathletes will invest in skin suits, teardrop helmets and bikes that cost as much as a family car but don’t let that put you off - most people race on standard bikes and there are even a few bikes with baskets and bells on. Remember it’s not the bike but the rider that determines how fast you can travel.  

A helmet is compulsory in all events, as is a Race Licence of One Day Licence which insures you and others should an accident happen.

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How to Get Started

Once you have pulled your bike out of the shed and got your running kit organised the best approach is to just enter a race and find out of you like it. Every duathlon has lots of first timers and the sport is very welcoming to newcomers.

There are dozens of races available for entry on the Race Calendar page of our website.

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Racing Tips 

The first thing to remember when tackling a duathlon is that the first run leg is only the start of the race! There’s a lot of racing left so if you are matching your personal best time you might be going a little too hard.

The biggest challenge a runner faces when tackling a duathlon however is the infamous jelly-leg phenomenon. This is deadened, heavy feeling most people get in their legs on the second run after spending time pedalling the bike.

While it can be hard to avoid, there are a few strategies to deal with it according to former Irish Marathon National Champion turned duathlete Gary Crossan.

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“It really helps if you have practiced some brick sessions (biking and running on the same day). The legs can feel like jelly, and you’ll hear a lot of duathletes talk about jelly legs - having jelly legs when you get off the bike and having to run another two or three kilometres is always a tricky one. You should also practise dismounting the bike and running with the bike so you don’t make a mistake heading in to transition.”

Because most runners are already quite fit, adapting to the bike is reasonably straight forward but Gary advises that mixing some biking in to your training is a good idea: “You need to forget about running five or six days a week and switch it up by adding in some days on the bike. This can just be commuting in to work, you just need to get used to turning the legs over.”

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Taking the Next Steps

If you enjoy your first duathlon, or if you’ve already got a few under your belt, completing the BMW Duathlon National Series is a great way to take things to the next level. This year’s series is made up of seven races over a three month period including the Duathlon National Championships in Dublin’s Phoenix Park.

Athletes compete for the overall champion title but also within age groups, which means you are never too far away from a podium position. Athletes are scored off their best three races which must include the National Championships.