The 20 Week Half Ironman Training Plan To Complete Your First Race

Training for a Half Ironman triathlon is undoubtedly tough, especially for beginners.

This multi-sport event is truly a test of physical and mental endurance and requires impressive aerobic fitness to complete. 

Although most people who venture into the world of triathlons begin with a sprint triathlon, if you have your sights set on a 70.3 triathlon, we have created a 20-week beginner Half Ironman training plan to help novice triathletes progress over the course of 20 weeks to complete their first 70.3 triathlon. 

Ready to get training? Keep reading for our 20-week beginner Half Ironman training plan.

We will cover: 

  • What Is a Half Ironman Triathlon?
  • 20 Week Half Ironman Training Plan for Beginners

Let’s get started!

Cyclists in a Half Ironman.

What Is a Half Ironman Triathlon?

Usually called an Ironman 70.3 due to the total distance of the race in mileage, a Half Ironman involves 70.3 miles of self-propelled travel, broken down into a 1.2-mile swim, 56-mile bike, and 13.1-mile run, sequenced back to back.

Owing to the name, a Half Ironman triathlon is exactly half as long as a full Ironman triathlon, which is 140.6 miles (a 2.4-mile swim, 112-mile bike, and a 26.2-mile run, which is a full marathon).

When called an Ironman 70.3, the Half Ironman event refers to a specific branded triathlon event, so a Half Ironman triathlon is not only a specific distance triathlon but also a triathlon put on by a specific company called Ironman.

There are about 133 official Ironman 70.3 triathlons per year held worldwide, but in addition to these official Ironman 70.3 races, there are other triathlons that cover the same distances for each leg as a Half Ironman (1.2-mile swim, 56-mile bike, and 13.1-mile run).

However, when those events are put on by organizations other than Ironman, they are just called “70.3 triathlons.”

According to a RunTri analysis of more than 67,000 finishers in 40 Half Ironman triathlons, the average Half Ironman finish time is about 6 hours, with the 1.2-mile swim segment time being approximately 45 minutes, the 56-mile bike segment in 3 hours, and the 13.1-mile run portion in 2:15.

Swimmers in a triathlon.

20 Week Half Ironman Training Plan for Beginners

Although this beginner Ironman 70.3 training plan starts fairly gently and with minimal time commitment, you will be doing some long workouts and aggressive progressions as the training plan unfolds to help prepare you for your Half Ironman triathlon

If you have a longer time to train, you can add a week of recovery every so often into the plan or build up more gradually if one of the disciplines has a workout jump that is too challenging for you. 

Most of all, it’s very important to listen to your body rather than the Ironman 70.3 training plan. If you feel overly fatigued or experience excessive soreness or signs of an injury, make sure to rest or modify your workouts accordingly. 

We advise wearing a heart rate monitor, as some of the workouts will have specific heart rate zone-based efforts.

Make sure that you are also working on your nutrition, fueling appropriately before and after your workouts, and consuming enough calories, protein, carbohydrates, and fluids to support your training.

20 Week Half Ironman Training Plan

Download The Training Plan Here

Enter your email, and I’ll send you this free training plan now, in PDF and Google Sheets formats (completely customizable), in both miles and kilometers.  

Previous visitor or not seeing where to sign up?

Head over to our triathlon training plan database for full access to all plans.

download this free training plan in pdf or google sheet
Week 1 Focus: Establishing a triathlon workout routine
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
Warm-up: Brisk walk for 5 min; Workout: 8 x 2 minute run/1 min walk;
Cool-down: 5 min walk; (34 min total)
Bike:
20 minutes at an easy effort
Swim:
10 x 25m taking 30 seconds of rest after each length
RestRun:
Warm-up: Brisk walk for 5 min; Workout: 4 x 5 minute run/2 min walk;
Cool-down: 5 min walk
Swim:
10 x 50m (1 full lap) with 45 seconds of rest
Rest
Week 2 Focus: Building your base
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
Warm up: Brisk walk for 5 min; Workout: 1 x 8 minute run/2 min walk; 5 minute run; Cool-down: 5 min walk
Bike:
30 minutes at an easy effort
Swim:
5 x 100m (2 full laps), taking 60 seconds of rest after each 
RestRun:
2 miles (3 km), taking walking breaks as needed
Swim:
Easy distance:
10 minutes without stopping
Rest
Week 3 Focus: Starting to add some speed
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
3 miles (5 km) easy (zone 2-3)
Bike:
45 minutes at an easy effort
Swim:
10 x 50m in zone 4, with 60 seconds of rest
RestRun:
3.5 miles (6 km) without stopping
Bike:
40 minutes total:
5-minute warm-up, then 10 x 2-minute intervals in zone 4 or about 85% of max heart rate, 1 minute of recovery, 5-minute cool-down
Rest
Week 4 Focus: Recovering from the work you’ve been doing
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
4 miles (6 km); 4 x 75m strides
Bike:
50 minutes at an easy effort
Swim:
Easy distance:
20 minutes without stopping
RestRun:
Warm-up: Jog for 5 min; Run 3 miles (5 km) with 10 x 1 minute hard (zone 4) with 1-minute easy jog (zone 1); Cool-down: 5 min walk
Swim/Bike Brick Workout: Swim:
15 minutes without stopping and then immediately bike for 45 minutes (zone 3)
Rest
Week 5 Focus: Ramping up your training now that you’re getting fit
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
4.5 miles (7 km); 4 x 75m strides
Bike:
60 minutes at an easy effort
Swim:
3 x 300m in zone 3, with 90 seconds of rest
RestSwim:
Easy distance:
20 minutes without stopping
Brick workout:
Bike:
30 minutes and then immediately run 15 minutes 
Rest
Week 6 Focus: Preparing for the race experience with a race simulation
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
5 miles (8 km); 4 x 75m strides
Bike:
70 minutes at an easy effort
Swim:
3 x 400m in zone 3, with 90 seconds of rest
RestSwim: 1000m easy effort (zone 2)Race simulation: Swim 500m, Bike 10 miles, Run 2 milesRest
Week 7 Focus: Building endurance
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
5.5 miles (9 km); 4 x 75m strides
Bike:
75 minutes at an easy effort
Swim:
4 x 400m in zone 3, with 90 seconds of rest
RestBrick workout: Bike:
45 minutes (zone 2) and then immediately run 15 minutes (zone 3)
Bike:
40 minutes total:
5-minute warm-up, then 5 x 3-minute intervals in zone 4 or about 85% of max heart rate, 1 minute of recovery, 5-minute cool-down
Rest
Week 8 Focus: Sprint triathlon simulation or trial
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
6 miles (10 km); 4 x 75m strides
Bike:
40 minutes at an easy effort (zone 2)
Swim:
20 minutes easy (zone 2 effort)
RestBike or run easy for 15-20 minutes Sprint Triathlon Simulation or Official EventRest
Week 9 Focus: Recovery before the next build phase
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
5 miles (8 km); 4 x 75m strides
Bike:
15 miles (24 km) at an easy effort (zone 2-3)
Swim:
6 x 200m in zone 3, with 90 seconds of rest
RestBike:
18 miles (29 km) easy effort
Swim:
800m easy effort; 4 x 25m sprints
Rest
Week 10 Focus: Adding volume
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
7 miles (11 km); 4 x 75m strides
Bike:
20 miles (32 km) at an easy effort
Swim:
3 x 500m in zone 3, with 90 seconds rest; 4 x 25m sprint
RestBrick workout: Bike:
60 minutes (zone 2) and then immediately run 30 minutes (zone 3)
Bike:
45 minutes total:
10-minute warm-up, then 25 minutes at tempo pace, 10-minute cool-down
Rest
Week 11 Focus: Building endurance and strength
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
8 miles (13 km); 4 x 75m strides
Bike:
25 miles (40 km) in zone 2 with 2 x 20 minutes in upper zone 3
Swim: 1000m easy effort; 4 x 25m sprintsRestRun:
6 miles (10 km) with 2 x 10 minutes at tempo pace with 90 sec recovery
Swim:
8 x 200m (zone 3-4) with 60 seconds rest 
Rest
Week 12 Focus: Race simulation
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
8 miles (13 km); 4 x 75m strides
Bike:
30 miles (50 km) with 10 x 3 minutes (zone 4) with 1 minute of recovery
Swim: 1,200m easy effort; 4 x 25m sprintsRestBike:
20 minutes easy
Mini Race Simulation: Swim 1,200m,
Bike:
25 miles (40 km),
Run:
5 miles (8k)
Rest
Week 13 Focus: Building endurance
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
5 miles (6-7 km) with 10 x 90 seconds in zone 4, with 60 seconds of recovery
Bike:
75 minutes In zone 2 with 2 x 20 minutes in upper zone 3
Swim: 1500m easy effort (zone 2)RestRun:
10 miles (16 km); 4 x 75m strides
Swim:
5 x 300m zone 4, 4 x 25m sprints
Rest
Week 14 Focus: Building strength in all disciplines
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
10 miles (16 km); 4 x 75m strides
Bike:
35 miles (56 km) with 10 x 3 minutes (zone 4) with 1 minute of recovery
Swim:
5 x 400m in zone 3, with 90 seconds of rest
RestSwim: 1500m easy effort (zone 2)Bike:
25 miles (40 km) at an easy pace 
Rest
Week 15 Focus: Building endurance and strength
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
12 miles (20 km); 4 x 75m strides
Bike:
40 miles (64 km) with 10 x 3 minutes (zone 4) with 1 minute of recovery
Swim:
4 x 500m with 90 seconds rest (zone 3)
RestRun:
5 miles (6-7 km) with 10 x 90 seconds in zone 4, with 60 seconds of recovery
Swim/Bike: Swim: 1,200m/Bike 20 miles (32 km)Rest
Week 16 Focus: Getting ready to race a half marathon
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
8 miles (13 km); 4 x 75m strides
Bike:
60 minutes with 10 x 3 minutes (zone 4) with 1 minute of recovery
Swim:
30 minutes easy (zone 2 effort)
RestBike or run easy for 15-20 minutes Half Marathon Race or 13.1-mile runRest
Week 17 Focus: Heavy bike week
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
5.5 miles (9 km); 4 x 75m strides
Bike:
45 miles (72 km) with 10 x 3 minutes (zone 3) with 1 minute of recovery
Swim: 1800m easy effort (zone 2)RestBike:
60 minutes with 3 x 10 minutes at tempo pace (upper zone 3) with 2 minutes of recovery
Swim:
6 x 300m zone 3, 4 x 25m sprints
Rest
Week 18 Focus: Building strength for your longest bike ride
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
12 miles (20 km); 4 x 75m strides
Bike:
75 minutes in zone 2 with 2 x 20 minutes in upper zone 3
Swim:
4 x 500m with 90 seconds rest (zone 3)
RestSwim: 2000m easy effort (zone 2)Bike:
60 miles (100 km) at an easy pace 
Rest
Week 19 Focus: Building confidence before the race experience
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
10 miles (16 km); 4 x 75m strides
Bike:
60 minutes with 10 x 3 minutes (zone 4) with 1 minute of recovery
Swim:
2 x 1000m in zone 3, with 90 seconds of rest
RestRun:
6 miles (10 km) with 12 x 45 seconds in zone 4, with 60 seconds of recovery
Swim/Bike: Swim: 1,500m/Bike 30 miles (50 km)Rest
Week 20 Focus: Getting ready to race your first Half Ironman triathlon!
MondayTuesdayWednesdayThursdayFridaySaturdaySunday
Run:
6 miles (10 km); 4 x 75m strides
Bike:
50 minutes at an easy effort (zone 2)
Swim:
30 minutes easy (zone 2 effort)
RestBike or run easy for 20 minutes RACE!Rest
A person running.

We can’t say that it will be easy, but if you have the time, dedication, and motivation to train, who is to say you can’t make your dream a reality with our Half Ironman training plan?

If you would are perhaps interested in starting with something a bit shorter, you can check out our guide to triathlon distances to explore all triathlon options.

Download The Training Plan Here

Enter your email, and I’ll send you this free training plan now, in PDF and Google Sheets formats (completely customizable), in both miles and kilometers.  

Previous visitor or not seeing where to sign up?

Head over to our triathlon training plan database for full access to all plans.

download this free training plan in pdf or google sheet
A person swimming in open water.
Photo of author
Amber Sayer is a Fitness, Nutrition, and Wellness Writer and Editor, and contributes to several fitness, health, and running websites and publications. She holds two Masters Degrees—one in Exercise Science and one in Prosthetics and Orthotics. As a Certified Personal Trainer and running coach for 12 years, Amber enjoys staying active and helping others do so as well. In her free time, she likes running, cycling, cooking, and tackling any type of puzzle.

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