How to Prepare for a Half Ironman (70.3) Properly

Get Fast Podcast, Ep 161, with Gerard and Jordan Donnelly

How long you need to prepare for a half Ironman depends on your experience and your current fitness. Once you have a base of endurance and strength, the key is race-specific sessions at the power and pace you plan to race, with your nutrition practised at that same intensity. Gerard Donnelly's main point is that your run will only go to plan if your swim, bike and nutrition do.

How much time do you need to prepare for a 70.3?

Gerard's answer is "it depends", and he says that's a reality answer. Two things decide it: your experience in the sport, and your fitness right now. The less of each you have, the more time you need.

• New to triathlon and not very fit: at least six months, and some people need 12 months, especially if they've never ridden a bike or done a triathlon.
• Intermediate to experienced: four to six months is generally a good time frame.
• Experienced and already training well: you can get race ready for a new event in eight to ten weeks.

You can get through a 70.3 on less preparation. Gerard says a beginner with 12 weeks can finish, but it will be a horrible experience. The longer you give yourself, the better you'll perform, so decide early whether your goal is to finish, finish comfortably or chase a best time.

How should you prepare for the swim?

The 1.9 km swim could be in a lake, a river or the ocean, and each feels different. Technique matters more in swimming than on the bike or run, so get your stroke critiqued and practise the advice you're given. Alongside that, build your aerobic fitness in the water.

When you can, swim outdoors in conditions similar to race day. Build your distance slowly from wherever you start, even if that's 500 metres. Gerard says swimming past the race distance in training does a lot for your confidence on the day.

How should you prepare for the 90 km ride?

Start with endurance and strength. Build your rides up gradually and include plenty of hills. Once your body is coping, without you spending the rest of the weekend flat on the couch, move into the race-ready phase. That can start anywhere from 10 weeks to four weeks out, depending on your fitness and experience.

Race-ready sessions mean riding at exactly the power and speed you expect on race day, in your time trial position. Examples Gerard gives:

• One solid effort of 60, 75 or 90 km at race power
• A long ride broken into intervals such as 4 x 30 minutes, 3 x 40 or 2 x 60 at race power

These sessions teach you what speed your power gives you on an out-and-back course, so on race day you can focus on your numbers and ignore everyone else. They're easier than people expect, because a 70.3 is ridden well below threshold. Jordan puts it at 75 to 90% of FTP. Midweek, the work stays the same: VO2 and threshold sessions to lift your FTP, so you can ride faster next race.

Practise your nutrition in these sessions. Fuelling while riding at 50 or 60% of FTP tells you little about race day.

How should you prepare for the run?

The run is dictated by how you swim and ride. Gerard sees it at most 70.3 races: athletes start the run looking like one runner and finish looking like another. If you overcook the swim and bike, no amount of run training will save you. Gerard calls nutrition the fourth leg, because getting it wrong has the same effect.

The number one thing for running well, he says, is endurance strength and conditioning:

• Endurance runs: at talking pace, with elevation built up gradually over months. Runners who only train on flat ground tend to fall apart in the second half.
• Race-pace runs off the bike: after some big race-specific rides, start with a 5 km run at race pace and build toward 7, 10 or 13 km. These are only for athletes with several races behind them, because the load is high.

The goal is to run the same pace from start to finish. Gerard says the run is usually where TriVelo athletes find the biggest part of a personal best.

What else should you get right?

• Lead-up races: B and C races let you practise the night before, the morning and the warm-up, and they show you your mistakes before your A race. You can also simulate one, such as a 1 km swim, 60 km ride and 12 km run.
• Taper: there's no single right taper. Most TriVelo athletes taper for seven to ten days or more, still doing some intensity but in shorter sessions, with volume cut back. Lead-up races help you find what suits you.
• Race plan: use numbers you've actually done in your last month of training, such as a swim pace per 100 m, a riding speed from your power and a run pace.
• Nutrition: never try something new on race day. Keep notes after each session, and aim to be slightly under-fuelled rather than over, since you can always top up.
• Recovery: allow one to two weeks depending on your level and the race. Don't do nothing. Keep moving with easy zone one or two work, coffee rides or walks around the office.

Related

• How we coach triathletes
• Ironman and 70.3 coaching
• Real athlete results
• Coaching questions, answered
• Apply for coaching