Triathlon guide: distances, transitions and your first race
A triathlon is a swim, a bike ride and a run, completed one after another against a single running clock. The shortest events take about an hour, and you do not need specialist equipment to finish your first one.
The standard distances
Race distances vary a little from event to event, particularly for pool-based races, but most fit one of five formats.
| Format | Swim | Bike | Run |
|---|---|---|---|
| Super sprint | 400 m | 10 km (6.2 miles) | 2.5 km (1.6 miles) |
| Sprint | 750 m | 20 km (12.4 miles) | 5 km (3.1 miles) |
| Olympic (standard) | 1,500 m | 40 km (24.8 miles) | 10 km (6.2 miles) |
| Middle distance (70.3) | 1.9 km (1.2 miles) | 90 km (56 miles) | 21.1 km (13.1 miles) |
| Full distance | 3.8 km (2.4 miles) | 180 km (112 miles) | 42.2 km (26.2 miles) |
The figure 70.3 is the total middle distance in miles. A full distance race is double that, at 140.6 miles, and finishes with a full marathon.
Which distance to start with
A super sprint or sprint is the right first race for almost everyone. Many are held at leisure centres, with the swim in a pool where swimmers set off at intervals, one lane at a time. This removes the two things newcomers worry about most: cold open water and a crowded mass start.
If you can swim 400 metres without stopping, ride a bike for 45 minutes and run a 5K, you can complete a sprint triathlon with eight to twelve weeks of training. You can browse events to see what is available near you.
What you need
- Swim: goggles and a swimsuit or tri suit. Open water races usually require a wetsuit when the water is cold, and many organisers hire them out. A swim cap is normally provided.
- Bike: any roadworthy bike, including a hybrid or mountain bike. A helmet is compulsory, and you will not be allowed to start without one.
- Run: your normal running shoes. Elastic laces save time and fumbling.
- Extras: a race number belt, so the number can sit on your back for the bike and be turned to the front for the run.
A tri suit, worn for all three stages, is convenient but not essential. In a pool race, pulling a T-shirt and shorts over your swimwear is fine.
How transitions work
The transition area is where your bike is racked and your kit is laid out. The change from swim to bike is called T1, and from bike to run T2. The clock keeps running, so transitions are sometimes called the fourth discipline.
- Rack your bike in an easy gear and lay your kit on a small towel beside it, in the order you will put it on.
- After the swim, put your helmet on and fasten it before you touch the bike. This is a rule at every race.
- Push the bike to the mount line and get on only once you have crossed it.
- At the end of the ride, get off before the dismount line, rack the bike, then take your helmet off.
- Change shoes if you need to and head for the run exit.
Walk through the swim exit, bike exit and run exit before the race so you know the route. Your timing chip, usually worn on the ankle, records each stage and each transition separately. Our guide to how chip timing works explains the technology.
Training for three sports
You do not need to train three times as much. For a sprint, two sessions a week of each discipline is plenty, and one of each will get you to the finish. Spend the most time on whichever is your weakest.
- Swim: technique matters more than fitness. A few coached sessions pay back quickly. If your race is in open water, practise in open water beforehand at a supervised venue.
- Bike: build up to riding a little further than race distance, and practise drinking while riding.
- Run: a standard training plan for your run distance works well.
- Brick sessions: a short run straight after a bike ride. Legs feel heavy and strange for the first few minutes off the bike, and practising this is the best preparation for it.
Rules worth knowing
- In most amateur races, riding close behind another cyclist to shelter from the wind, known as drafting, is not allowed. Leave a clear gap unless you are overtaking.
- Headphones are not permitted on any part of the course.
- Your number must be visible, on your back for the bike and on your front for the run.
- Normal road rules apply on open roads.
On the day
Arrive early. Registration, racking and the race briefing all take time, and transition often closes well before the first swimmer starts. Pace the swim gently, hold something back on the bike, and expect the first kilometre of the run to feel awkward before your legs settle. The race day checklist is a useful starting point for packing.