Challenge London - formerly London Triathlon - is the world’s largest city centre triathlon, and welcomes people of all abilities – from elite international triathletes to people taking part to raise money for charity.

Here's a guide to this year's event.

When and where is it?

Challenge London takes place this coming Sunday (August 6). Each wave starts at The ExCel in East London, on the northern quay of the Royal Victoria Dock – between Canary Wharf and London City Airport.

Participants have been able to choose from several distances, including Challenge Middle Distance (1.9km swim, 80km cycle, 21.1km run), Olympic Distance (1.5km swim, 40km cycle, 10km run), Sprint (750m swim, 20km cycle, 5km run) and Super Sprint (400m swim, 19k cycle, 2.5k run). There is also a team relay option meaning people can team up with friends and family and complete a section each.

Each distance begins with a Docklands swim, followed by a cycle to Westminster, before heading back to The ExCel to begin their run.

Is it too late to enter?

Unfortunately, it is. If you don’t have a place, fear not though; there is still plenty of fun to be had cheering on the people taking part and marvelling at the speed of the elite athletes at the front.

What time does the race start?

It’s an early one. The professional athletes get underway at 6.30am (men) and 6.35am (women). From then there are regular starts throughout the morning, with the final wave setting off at midday.

How do I get to the start line if I’m taking part?

Everyone taking part will have already received their start time and organisers recommend people arrive at The ExCel (E16 1XL) one-and-a-half hours beforehand to leave enough time to collect their race pack, timing chip, and swim cap, walk to the transition area, rack their bike, and familiarise themselves with the course. They should aim to arrive at the start 20 minutes before their scheduled time so they are there for their wave’s race briefing.

Participants travelling by car should use the car park at the eastern end of The ExCel, which can be accessed via Royal Albert Way from Gallions Reach roundabout, via Royal Docks Road (A1020) from Newham Way and The North Circular (A406). These roads will likely be busy though – with road closures in place – so leave plenty of time and have the QR code you have been sent for race pack collection ready to show you’re taking part.

Are there road closures?

Yes, there will be a number of road closures in place locally from 4.30am on the day of the race, including:

  • Victoria Embankment / Westminster Bridge to The Highway / Butcher Row / Limehouse Link Tunnel will remain closed until 12.30pm.
  • Limehouse Link Tunnel / Aspen Way / East India Tunnel WB will be closed until 2pm.
  • Lower Lea Crossing / Tidal Basin Roundabout / Western Gateway / Seagull Lane / Royal Albert Way will close until 4pm.

The closures will mean some local bus services will be diverted or terminate earlier than usual. Taking everything into account, your best bet would be to drive or cycle.

What about rail services?

Given the early start it is always best to check timetables the day before, but the following stations are the nearest to The ExCel, listed here with approximate distances from station to venue.

  • Custom House. Half a mile from The ExCel.
  • Prince Regent. 0.1 miles from The ExCeL.
  • Canning Town. 1.6 miles from The ExCeL.
  • West Ham. 1.8 miles from The ExCeL.
  • Stratford. 3.5 miles from The ExCeL.

    Bikes are allowed on the Elizabeth Line and DLR off-peak and at weekends but are limited to a maximum of two bikes per set of doors. The good news is the Elizabeth Line is now running on Sundays, but participants are warned there may be a limited number of early morning services.

Will there be a bag drop?

No. But people taking part are allowed to place a small, soft-sided bag such as a rucksack in the transition area – with a maximum size of 50cm x 40cm x 25cm allowed. Larger bags will be subject to searches upon arrival. All property is left at the owner’s risk.

How do I get my race pack?

Participants can collect their race pack the day before or on the day of the race itself. On Saturday people can collect their pack from the South Halls at The ExCel between 4.30pm and 6.30pm. Pre-event bike racking will also be available at the same time.

Anyone planning to collect their race pack on Sunday should aim to arrive at the race pack collection point 90 minutes before their scheduled start time.

What is in the race pack?

There are lots of important bits in the race pack. Participants will receive:

  • Security wristband. This must be attached to their wrist and not taken off until they have retrieved their bike from the transition area after the race.
  • Two bike numbers. Before the race, participants need to stick one on their helmet, and the other on the handlebars of their bike, with the number facing forward. Again, these shouldn’t be removed until after the race.
  • Race number. Participants must display their race number on their back during the bike phase and their front during the run phase.
  • Timing chip. Everyone taking part will be given a reusable timing chip, which they’ll need to return after the race – with a £25 charge for anyone who doesn’t. The chip should then be fitted round the left ankle and not removed until after the race. Organisers suggest participants put their wetsuit over the timing chip strap to keep it secure during the swim and avoid the need to take it off and put it back on again during transition.
  • Swim cap. Everyone will also be given a swim cap which must be worn during the swim stage.

What if I’m taking part in the relay?

If you are competing in the team relay the team captain will need to pick up your race pack on the day of your event. Your team will have one timing chip that will act as a baton between team members and must be passed over to the next team member in transition.

How do I store my bike?

Once participants have received their race pack – either the day before, or on race day – they will be directed into the transition area to rack their bike.

Racks are divided into waves and each person taking part will have received a wave number via email. Racks will have corresponding wave numbers and be marked with stickers on the horizontal bars. These sticks each identify a race number. Simply rack your bike at the position which matches your number.

Participants should take care to rack their bike in the opposite direction to the bike either side, so your back tire should be next to the front tire of the bikes immediately to the left and right.

The swim is first up, right?

That’s right. Participants should arrive at the swim start queuing area 20 minutes before their wave is scheduled to get underway. The queuing system will take you down to the dockside where you will walk into the water one at a time.

From there participants will set off in either mass starts, or pulse starts, depending on which wave they are in. If you’re in a pulse start that means people setting off every two-and-a-half seconds until the wave is fully away.

It is important to get to the queuing area in time to receive your wave’s pre-race briefing, which will explain which buoys relate to your wave.

During the swim stage most people use front crawl or breaststroke. Backstroke is not allowed because it can be confused with someone indicating they are in difficulty.

The water is tested against EU bathing standards; however, organisers would still advise participants to try to avoid swallowing the docks water.

The swim exit pontoon dips into the water so you can swim onto it before standing up. Lifeguards will be on hand to help you out if required. Once you have exited the water, you must remove your wetsuit before you re-enter the ExCeL and climb the stairs back to transition.

What safety measures are in place for the swim?

For a lot of people – particularly first-timers – the swim can be the most daunting part of the race.

If this is your first triathlon, or swimming is not your strongest discipline, organisers recommend you position yourself towards the back of the wave. It may add a few seconds to your time, but it will enable you to get into your rhythm and enjoy the swim more.

Safety support is provided by Swim Safety Ltd and consists of fully qualified lifeguards in kayaks and rescue boats as well as bank-based lifeguards on the pontoons. All lifeguards are members of either the BCU Lifeguards or Surf Lifesaving GB.

If you do get into difficulty, lie on your back and raise your arm in the air; a kayak will come to you and if necessary, arrange a safety boat to take you to the water’s edge.

So, what is the rest of the course like?

The cycle stage begins outside The ExCel and heads into central London, following The Thames down to the turning point in Westminster (the split for the shorter distances is at Billingsgate). The distance option you’ve selected will dictate how many laps you do but there are plenty of sights to look out for, including Canary Wharf, the London Eye, and the Houses of Parliament.

The run starts back at The ExCel and follows a loop up to Royal Albert Dock and back to the finish at Royal Victoria Dock. Again, the number of laps will depend on the distance entered.

Are there toilets?

There are toilets in transition, on the run route, and within the main boulevard in The ExCeL.

Will there be aid stations on the course?

There will be automatic re-fill stations along the boulevard as you arrive to the event where participants can refill their own water bottles as well as a refill station in the event village.

There will also be an aid station on the bike route for Middle Distance participants only.

Water will not be available on the bike route for the Olympic, Sprint or Super Sprint participants, who will need to carry their water with them.

On the run route all participants will have access to water at two aid stations as well as water at the finish. On the run there will be additional nutrition made available to Middle Distance participants only.

Will there be a changing area or showers?

For Middle Distance athletes only there will be both male and female changing facilities available in the transition area. For all other participants there are no changing facilities or showers on site.

If you are not taking part in the Middle Distance event, organisers recommend arriving ready to race and bringing some warm clothes for afterwards.

Is there a cut-off time?

There are. Cyclists must be clear of Westminster by 11.30am, and the course between Stansfield and Billingsgate by 1pm.

The run must be finished before 2.30pm.

Where are the best places for spectators?

The event village is hard to beat if you’re cheering on a friend or loved one. You’ll get a great view of them running through the event village during their running laps and be able to see the finish line in the hall, which also has food and drink outlets, seating, and toilets.

You can also access the dockside from here to see the swim.

In terms of spots out on the actual course, access is limited, but there are several places you can go nearby to get a great view:

  • Access to the dockside for the swim. This is via the event village in the ExCeL South Halls. Follow the stairs down to the dock edge. For those with accessibility needs there are also lifts at this location. Due to building works at the venue, there is no access/exit from the east end of the dockside. To exit this area, you will have to re-enter The ExCeL and head to the east exit via the central boulevard.   
  • Access to the bike route. Exit The ExCeL via the western entrance, make your way down the steps or ramp to the taxi rank, and immediately turn right passing across Western Gateway, following the road under the upper walkway to Seagull Lane.  
  • Access to the run route. Head to the east exit of The ExCel, turning immediately right before the DLR walkway bridge leading to Price Regent Station. Proceed along the upper deck alongside the Aloft hotel and use the temporary staircase to access the lower level. Please note access via the staircase to the entrance of Aloft hotel on the lower level will not be permitted. Those requiring step free access for wheelchairs and push chairs (not including bikes) can use the lift located in the Aloft hotel. Once on the lower level follow the path that will take you towards the roundabout at Festoon Way. Continue to follow the path until you have gone past the DoubleTree Hotel. Turn right and use the hotel car park towards the dock edge. Pass underneath Connaught Bridge to access the area outside the Boat Club from where you’ll be able to see the run route.

Presumably the elite athletes will be worth watching as well?

Definitely. There is a fantastic elite field taking part this year and well worth the early start for spectators.

Sam Laidlow (FRA), ranked fourth in the PTO rankings, will compete against the likes of James Teagle (GBR), Matt Trautmann (RSA), and Caleb Noble (AUS) in the 20-strong male pro field, while Els Visser (NED) will be one to watch out for in the women’s field. She already claimed victory at Ironman New Zealand and second place at Challenge Wanaka this season. She will be up against the likes of Renée Kiley (AUS), who is coming off a third-place finish at Challenge Wales, and top seeds Fenella Langridge (GBR) and Magda Nieuwoudt (RSA).

Inspired to give triathlon a go or missed out on this year’s event?

Don’t worry. Places for the 2024 race will go on sale soon, so keep an eye on the organiser’s website at: https://challenge-london.com.   

If you can’t wait for 2024, there is always the London Duathlon – a run, bike, run challenge in Richmond Park on September 2. It is a great first step on your way to a triathlon.  

Places are still available via the LimeLight Sports Club website at: https://limelightsports.club/event/london-duathlon-2023.