Half-distance (70.3®) triathlon training plan: 18 weeks

How many weeks do you need to train for a half-distance triathlon?

Plan for 16 to 20 weeks if you already swim, ride and run regularly. The race is a 1.9 km swim, a 90 km bike and a 21.1 km run. Research on first-timers used 20 to 24 weeks, so give yourself longer if you are new to one of the three sports.

In a 2020 study, 32 amateur athletes preparing for their first half-distance race trained for 24 weeks, and 31 of them finished. In a 2019 study, 14 amateur men did 7 weeks of general and 13 weeks of specific training. The race distances come from the organiser's FAQ (see Sources).

What are the phases of an 18-week half-distance plan?

The plan moves from general fitness to race-specific work and then to rest. Base builds an easy routine in all three sports, build adds long sessions and bricks, peak rehearses the race, and the taper cuts volume while you keep some race-effort work. Every fourth week is lighter.

Recovery weeks come in weeks 4, 8 and 12. Cut the hours by about 30 percent, keep the sessions easy and keep the routine. They let the training of the three weeks before them settle in.

How many hours a week does a half-distance triathlon need?

This plan builds from 6 hours to a peak of 11 hours. Many first-timers finish on less: in the 2020 study the group averaged 410 minutes (about 6.8 hours) a week over 24 weeks, and the mean finish time was 6 hours 28 minutes. More hours help only if you recover from them.

For hours by distance and by goal time, see how many hours a week each triathlon distance needs. To fit the plan into the time you have, change the volume and keep the structure.

• 6 to 8 hours at the peak: keep the long ride, the long run and one brick every week. Cut easy sessions first, then shorten the mid-week sessions.
• 9 to 11 hours at the peak: follow the table as written.
• 12 hours or more: add a second easy swim or an easy bike, not extra hard sessions.
• Whatever the total, keep about four in five sessions easy. Competitive endurance athletes were found to train this way in a 2010 review, and it fits the long, steady nature of a half-distance race. For easy running, see zone 2 running.

What does a training week look like in the peak phase?

A peak week has eight or nine sessions: two swims, three rides and three or four runs, one of which is the brick. Two sessions are hard, the long ride and the long run are steady, and the rest are easy. Put a rest day before the long ride.

One or two strength sessions of 30 minutes can replace an easy session in the base and build phases; see strength training for endurance athletes. Drop them in the last three weeks.

What are the long ride, long run and brick sessions?

These three sessions carry the plan. The long ride builds from 1 hour 30 minutes to 3 hours 30 minutes, the long run from 1 hour to 2 hours 5 minutes, and the brick, a ride followed straight by a run, starts in week 6. Add race effort in small blocks and not over the whole session.

• Long ride: ride easy to steady, and from week 10 add two blocks of 20 to 30 minutes at goal effort. Use the ride to practise the drinks and food you plan to take on race day; see fuelling a half-distance triathlon.
• Long run: run on the same day of the week, easy for most of it. In weeks 13 to 15 finish with 20 minutes at goal effort. Stay at or under about 2 hours 5 minutes, because the race run is 21.1 km and you do it after the bike.
• Brick: ride, change shoes quickly, and run 10 to 45 minutes at goal run effort. The first minutes feel awkward; that is the point of practising it. See brick workouts for more examples.

What does each week of the 18-week plan include?

The table lists the hours, the long sessions and the key set for each week. Everything else in the week is easy swimming, riding and running to fill the hours. Effort is by feel: easy means you could speak in full sentences; goal effort is the effort you can hold for the race leg.

How do you taper for a half-distance triathlon?

Taper over two to three weeks. Cut the volume by about 40 to 60 percent and keep the intensity and the number of sessions. A 2007 meta-analysis found that a 2-week taper with volume cut by 41 to 60 percent worked best, and a 2023 review supported tapers of up to 21 days.

1. Week 16: drop to about 8 hours. Keep the long sessions but make them shorter, and keep the brick short with a few minutes at goal effort.
2. Week 17: drop to about 6 hours. Keep every session, make each one shorter, and keep short blocks at race effort so your legs stay sharp.
3. Week 18: about 4 hours and 30 minutes before the race. Do short openers 2 days out, rest the day before, and lay out your kit and your plan for the swim, bike and run.
4. Check the cut-off times in your race's athlete guide; triathlon cut-off times explains how they work and how to compute the pace you need.

Some athletes feel flat in the first days of a taper. That is normal and not a sign that you lost fitness. Do not add sessions to feel better.

What if you have 16 or 20 weeks, or less time to train?

Keep the order of the phases and change their length. With 16 weeks, shorten the base. With 20 weeks, lengthen it. With less time, keep the long sessions and the bricks and cut everything else. Ask first whether the date is realistic, because a half-distance race is a long day.

• 16 weeks: start at week 3 of the table and keep weeks 4 to 18 unchanged.
• 20 weeks: add two weeks of easy base, then follow the 18 weeks. Use the extra time to swim more often if the swim is your weak sport.
• Under 12 weeks: choose a shorter race and follow the first triathlon plan, or move to a later date.