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12-Week Half-Ironman Training Plan

12-week half-Ironman training plan race ready

This 12-week Half-Ironman training plan is for athletes comfortable racing at the Sprint or Olympic triathlon distance, looking to complete their first Half-Ironman (70.3). 

It is also tailored to the busy triathlete, primarily built around one longer training session per day, instead of two shorter sessions to save time transitioning between workouts. 

This plan is only 12 weeks long, which is generally accelerated for Half-Ironman training. It would be best if you were working out regularly (3-4x per week) before starting this plan. 

How to Approach this 70.3 Training Plan

12-week 70.3 training plan approach

If you have not completed a triathlon before and are looking to jump in head first with a Half-Ironman, you can utilize this plan, but author Ryan Grange from Z2 Endurance Coaching recommends that you should be able to swim, bike, and run for at least 60 min nonstop before attempting this plan.

Weekly workouts should be completed at a tempo pace to work on building your threshold/speed in each sport. It should be difficult for you to hold a conversation while training, but you should not be so out of breath that you have to stop before the end of the session. 

Weekend workouts should be completed at an easier pace (3-4 out of 10 effort) to help you develop endurance. Ryan’s 12-week Half-Ironman training plan is broken down into four phases, as prescribed below.  

Phase 1 – General Triathlon Prep

12-week half-ironman 70.3 training plan run

The first phase of this plan is designed to get you into a routine of swim/bike/run training and build fitness and endurance in each discipline. This will be the least volume-heavy phase of training, however, time and volume build week over week so you continue to improve and gain fitness in each sport.

Week 1
Monday Swim 45 Min/~1700 Yds + 40 Min Strength
Tuesday Bike 45 Min
Wednesday Run 45 Min
Thursday Swim 50 min/~2000 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Bike 120 Min
Sunday Run 60 Min
Week 2
Monday Swim 50 min/~1900 Yds + 40 Min Strength
Tuesday Bike 50 Min
Wednesday Run 45 Min
Thursday Swim 55 Min/~2200 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Bike 135 Min
Sunday Run 90 Min
Week 3
Monday Swim 50 min/~2000 Yds + 40 Min Strength
Tuesday Bike 50 Min
Wednesday Run 45 Min
Thursday Swim 60 Min/~2400 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Bike 150 Min
Sunday Run 100 Min
Week 4 – Recovery Week
Monday Swim 30 Min (Easy)
Tuesday 40 Min Strength
Wednesday Bike 40 Min Easy
Thursday Run 40 Min Easy
Friday Rest & Recovery
Saturday Bike 60 Min
Sunday Run 40 Min

Phase 2 – Race Prep

Half-Ironman Triathlon Bike Training

The Race Prep phase of this 70.3 training plan begins incorporating brick workouts (bike into run) to get you accustomed to the bike-to-run transition during a race. These are key workouts each week, and the run portion should be completed as quickly after the bike as possible (<5 minutes) to simulate a race. 

Pro tip – set up your run gear prior to your bike workouts to simulate race transitions as much as possible. This phase also incorporates a race practice session, which will be your longest workout in this plan. 

Make sure to take this practice seriously, and use it as an opportunity to test out your race day gear setup (kit, wetsuit, etc.).

Week 5
Monday Swim 55 Min/~2200 Yds + 40 Min Strength
Tuesday Bike 60 Min
Wednesday Run 50 Min
Thursday Swim 65 Min/~2600 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Brick Workout: Bike 165 Min + Run 20 Min
Sunday Run 110 Min
Week 6
Monday Swim 60 Min/~2400 Yds + 40 Min Strength
Tuesday Bike 60 Min
Wednesday Run 50 Min
Thursday Swim 70 Min/~2800 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Brick Workout: Bike 180 Min + Run 20 Min
Sunday Run 120 Min
Week 7
Monday Swim 65 Min/~2600 Yds + 40 Min Strength
Tuesday Bike 75 Min
Wednesday Run 50 Min
Thursday Swim 75 Min/~3000 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Race Practice: Swim 40 Min, Bike 210 Min, Run 60 Min
Sunday Rest & Recovery
Week 8 – Recovery Week
Monday Swim 30 Min (Easy)
Tuesday 40 Min Strength
Wednesday Bike 40 Min (Easy)
Thursday Run 40 Min (Easy)
Friday Rest & Recovery
Saturday Bike 60 Min
Sunday Run 40 Min

Phase 3 – Race Peak

Half-Ironman 70.3 Swim Training Plan

The short race peak phase is when you will be in peak shape to complete the Half-Ironman race. Don’t be fooled though; this is also when you will be the most exhausted from the training load, and workouts will feel the toughest to complete in proper form, as would the race at this point. 

These two weeks are designed to maximize fitness gains without putting too much stress on the body and minimize the risk of injury right before race day. Make sure to keep your mind focused on your ultimate goal for these two weeks of robust training.

Week 9
Monday Swim 55 Min/~2200 Yds + 40 Min Strength
Tuesday Bike 75 Min
Wednesday Run 60 Min
Thursday Swim 75 Min/~3000 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Brick Workout: Bike 210 Min + Run 30 Min
Sunday Run 90 Min
Week 10
Monday Swim 50 min/~1900 Yds + 40 Min Strength
Tuesday Bike 75 Min
Wednesday Run 60 Min
Thursday Swim 70 Min/~2800 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Brick Workout: Bike 180 Min + Run 30 Min
Sunday Run 100 Min

Phase 4 – Taper

12-week half-ironman training plan for bike

The taper phase of any triathlon training plan is arguably the most important. This is when we pull back on the training load, to allow your body to rest and realize the full benefit of all of the hard work you put in. 

This final phase of the Half-Ironman training plan is a slow decrease over two weeks, and you should not be fully resting for this entire time. Although it is okay to take workouts a little easier as you wrap up training, it is important to stick to the plan and keep your body moving so you are ready to go on race day!

Week 11
Monday Swim 45 Min/~1700 Yds + 40 Min Strength
Tuesday Bike 75 Min
Wednesday Run 60 Min
Thursday Swim 65 Min/~2600 Yds + 40 Min Strength
Friday Rest & Recovery
Saturday Bike 90 Min
Sunday Run 60 Min
Week 12
Monday Rest & Recovery
Tuesday Bike 60 Min
Wednesday Run 30 Min
Thursday Swim 20 Min, Bike 30 Min
Friday Rest & Recovery
Saturday Run 20 Min
Sunday Race Day!
*If your race is on Saturday, instead of resting on Friday, complete the 20-minute run scheduled for Saturday the day before the race.

Additional Input for Half-Ironman Training

12-week Half-Ironman Training Plan swimming

In addition to following this 12-week Half-Ironman training plan, Coach Ryan offers additional tips and resources to support your journey and race day success.

Open Water Swimming

Before any triathlon, make sure you are practicing safe open-water swimming. You should have logged multiple open water swim sessions in an environment similar to your race venue before race day. 

When swimming in open water, make sure you only swim in designated areas during the daytime, with a training buddy, and wear a bright swim cap or pull buoy. It is recommended that at least one of the swims in this plan per week takes place outdoors, as well as the race practice session. 

For more swim-specific guidance, see related posts on:

Training Gear

This beginner training gear guide from Coach Ryan is full of recommendations for both beginner and experienced triathletes. You don’t need every piece of triathlon gear to begin training; many athletes start with what they have at home, however, this article has a number of links for you to explore and add to your gear closet. 

Training Outdoors

Although many of the workouts in this plan can be done indoors, it is recommended that you do as much training outdoors in an environment similar to your race as possible. 

Things like weather, elevation, and heat can’t always be simulated indoors, so training outdoors will only enhance your training. Make sure when training outdoors that you are following all traffic and other laws and are wearing safe clothing and equipment for doing so. 

Active Recovery Weeks

This Half-Ironman training plan has two active recovery weeks – weeks 4 and 8. Although this plan is only 12 weeks long so is somewhat limited in terms of general preparation, it is important to give your body a rest on occasion. 

The workouts during these recovery weeks should still be completed at a tempo pace but will be shorter and less frequent than a typical week. This will allow your body to recover actively, preventing burnout and injury.

Strength Training

Check out this free strength guide for running and triathlon by Coach Ryan. There are a number of exercises with descriptions and videos you can try out with little to no equipment. 

Try choosing 6-8 exercises from this list across the full body to combine for a 40-minute workout, as noted throughout the training plan. If you are short on time for training, feel free to skip one of the strength sessions each week as needed. 

Get Coached

Coach Ryan, who created this 12-week 70.3 training plan, is a seasoned triathlon coach with Z2 Endurance Coaching. He specializes in coaching beginner and intermediate athletes, from providing custom triathlon training plans to 1:1 coaching services.

Ryan is an experienced endurance athlete who’s completed multiple Ironman and half-Ironman distance races, including several marathons. Learn about Coach Ryan or explore more into Better Triathlete’s coach match program.

Ryan Grange Triathlon Endurance Coach
Ryan Grange
Triathlon Coach at Z2 Endurance Coaching | Website

Ryan Grange is a USAT-certified triathlon coach and the owner of Z2 Endurance Coaching. He has been racing for over 10 years and coaching beginner triathletes for 2 years. He is passionate about training and getting new people into the sport of triathlon, and even more passionate about making his run shoes match his outfits.