70.3 Half Ironman Training Overview

The 70.3 distance—1.9km swim, 90km bike, 21.1km run—represents the sweet spot of triathlon racing. It's long enough to test your endurance but short enough that you can recover and race multiple times per year. Here's everything you need to know about training for this challenging distance.

Understanding the 70.3 Distance

Discipline	Distance	Typical Time
Swim	1.9km (1.2 mi)	30-60 min
T1	-	3-8 min
Bike	90km (56 mi)	2:20-3:30
T2	-	2-5 min
Run	21.1km (13.1 mi)	1:30-2:30
Total	113km	4:30-7:00

Use our 70.3 Calculator to estimate your finish time based on your current abilities.

Training Timeline

Minimum Preparation Time

Background	Recommended Prep
Complete beginner	6-9 months
Completed sprint/Olympic	16-20 weeks
Experienced triathlete	12-16 weeks

Ideal Training Phases

Base Phase (8-12 weeks): Build aerobic endurance
Build Phase (6-8 weeks): Add race-specific intensity
Peak Phase (3-4 weeks): Sharpen with reduced volume
Taper (1-2 weeks): Rest and prepare

Weekly Training Volume

By Experience Level

Level	Swim	Bike	Run	Total Hours
Beginner	3-4km	120-180km	25-35km	8-12
Intermediate	5-7km	180-250km	35-50km	12-16
Advanced	7-10km	250-350km	50-70km	16-20+

Sample Week: Intermediate Athlete

Day	Morning	Afternoon/Evening
Monday	Rest or yoga	Swim 2,500m easy
Tuesday	Run intervals 50 min	-
Wednesday	Bike intervals 90 min	Swim technique 1,500m
Thursday	Easy run 40 min	-
Friday	Swim main set 3,000m	-
Saturday	Long ride 3-4 hours	-
Sunday	Brick: 90 min bike + 45 min run	-

Weekly Total: ~7,000m swim, 5-6 hours bike, 3+ hours run

Key Workouts for 70.3

Swimming

Threshold Set:

Warm-up: 400m easy
Main: 5 x 400m at CSS pace, 30 sec rest
Cool-down: 200m easy
Total: 2,600m

Open Water Simulation:

3 x 600m continuous
Practice sighting, drafting, turns

Use our CSS Calculator to establish your swim training zones.

Cycling

Sweet Spot Workout:

15 min warm-up
2 x 20 min at 88-92% FTP
10 min recovery between
15 min cool-down

Long Ride with Race Simulation:

3-4 hour ride
Middle 90 min at target race intensity (72-78% FTP)
Practice race nutrition throughout

Know your FTP before planning bike workouts.

Running

Tempo Run:

15 min warm-up
30-40 min at half marathon race pace
10 min cool-down

Long Run:

90-100 min at easy pace
Include 20-30 min at goal race pace in middle

Brick Workouts

Race Simulation Brick:

90 min bike at race intensity
Immediate transition
45 min run, first 20 min at goal pace

Learn more about brick workouts for triathlon.

Pacing Strategy

The Golden Rule

Never race the bike at standalone bike race intensity. Save energy for the half marathon.

Target Intensity by Discipline

Discipline	Target Intensity	Feel
Swim	Controlled, steady	Could go faster but choosing not to
Bike	72-78% FTP	Comfortably hard, sustainable
Run	Even or negative split	Start conservative, build

Bike Pacing Guidelines

Level	Target IF	250W FTP Example
Beginner	0.72-0.75	180-188W avg
Intermediate	0.75-0.78	188-195W avg
Advanced	0.78-0.82	195-205W avg

Read our triathlon bike pacing guide for detailed bike leg strategies.

Nutrition Strategy

Pre-Race (24-48 hours)

Increase carbohydrate intake
Stay well hydrated
Avoid new foods
Light, easily digestible meals

Race Morning

Breakfast 3-4 hours before start: 400-600 calories
Small snack 1 hour before: 100-200 calories
Sip water/electrolytes leading up to start

During the Race

Discipline	Target Intake
Swim	Nothing
Bike	60-90g carbs/hour, 500-750ml fluid/hour
Run	30-60g carbs/hour, fluid at aid stations

Total race calories: ~1,500-2,500 depending on size and pace

See our complete triathlon nutrition guide for detailed fueling strategies.

Race Week Schedule

Monday (6 days out)

Easy swim 1,500m
Light strength/mobility

Tuesday (5 days out)

Short run with strides: 30 min + 4 x 100m
Easy spin 30 min

Wednesday (4 days out)

Swim openers: 1,500m with some pace work
Rest

Thursday (3 days out)

Bike openers: 45 min with 3 x 5 min at race intensity
Short jog 15 min

Friday (2 days out)

Travel day if needed
Very light activity only
Course preview if possible

Saturday (1 day out)

15 min easy swim
20 min easy bike
10 min easy jog
Check in, rack bike, prep transition

Sunday (Race Day)

Execute your plan
Trust your training

Common Mistakes to Avoid

1. Insufficient Long Rides

Your long ride should reach 4-5 hours at least twice before race day. The 90km bike leg requires endurance you can't fake.

2. Not Practicing Nutrition

Test your race nutrition in training. GI issues are the #1 reason for DNFs at 70.3 distance.

3. Running Too Much

Many athletes over-emphasize running because it's their weakest discipline. This leads to injury. Build run volume gradually.

4. Bike Too Hard

The most common race day mistake. If your bike split looks great but your run falls apart, you went too hard on the bike.

5. Ignoring Open Water

Pool swimming doesn't prepare you for race conditions. Practice open water swimming at least 5-6 times before racing.

Typical 70.3 Finish Times

See our triathlon pace chart for detailed time breakdowns, but here's a quick reference:

Category	Time Range
Elite	3:50-4:15
Competitive	4:30-5:00
Above Average	5:00-5:30
Average	5:30-6:15
Finisher	6:15-7:30

Stepping Up from Olympic Distance

If you've completed Olympic distance triathlons:

Add 20-30% to training volume over 8-12 weeks
Practice race nutrition on longer training sessions
Extend long rides to 3-4 hours minimum
Build run endurance with longer, slower runs
Add one weekly brick workout

What's Next After 70.3?

Race another 70.3 to improve your time
Step up to full Ironman distance
Focus on age-group podiums and qualification races
Consider coaching for structured improvement

70.3 Calculator - Estimate your finish time
Triathlon Training Guide - Complete training overview
Ironman Pacing Strategy - For when you go longer
FTP Calculator - Establish bike training zones