IRONMAN 70.3 24-Week Training Plan Framework: From Registration to Finishing the Kenting Race

Introduction

24 weeks (about 6 months) is a solid timeline for preparing for an IRONMAN 70.3, with enough room to balance improvements across all three disciplines, injury prevention, and lifestyle adjustments. This article uses the Kenting IRONMAN 70.3 Taiwan as the target race and provides a structured 24-week periodization framework.

Periodization Phase Breakdown

Weekly Training Distribution Direction

Using a 6-days-on, 1-day-off weekly structure as an example:

• Swim 2–3 sessions: 1 technique + 1 interval + 1 long swim
• Bike 3 sessions: 1 SST/interval + 1 tempo + 1 long ride
• Run 3–4 sessions: 1 LT/interval + 1 tempo/brick + 1–2 easy/long runs
• Strength 1–2 sessions: core, single-leg stability, hip drive

Key Workouts by Phase

Base Phase (W1–W8)

• Heart rate primarily in Z1–Z2; longest bike ride 2.5 hr, longest run 18 km
• Heavy emphasis on swim technique drills (catch, body roll, 6-beat kick)
• Weekly aerobic accumulation should account for 80% or more of total training time

Build Phase (W9–W16)

• Add sweet-spot work (FTP 88–94%) for 30–60 minutes
• Add mile repeats and cruise intervals to running
• Brick: 60–90 min bike followed by 4–8 km tempo run

Peak Phase (W17–W21)

• Simulate race intensity: 3 hr bike at IF 0.78, 90 min run at HM pace + 20s
• Schedule a “simulation day” in W19 or W20: 1.5km swim + 80km bike + 12km run
• Confirm nutrition strategy: 60–90g carbs/hr, salt intake schedule

Taper Phase (W22–W24)

• Cut volume by 40–60%, keep intensity (short intervals plus a little race pace)
• Final week before race: only shakeout runs, easy rides, and technique swimming
• Last 3 days before race: no high-intensity work at all; do gear checks and bank sleep

Practical Tips

• Use both heart rate and power as dual metrics: avoid being misled by a single one, e.g., high summer heat inflating heart rate
• Schedule 1 recovery week every 4 weeks, cutting volume by 25–35%
• Plan one 51.5 standard-distance triathlon or long-distance road race as a mid-cycle test
• Track training load (TSS/CTL): CTL peaking 2 weeks before race day is ideal

Conclusion

24 weeks may look long, but every week should have a clear purpose rather than just “train a little more.” From building the aerobic base in the base phase, to layering on race intensity in the build phase, and finally using the taper to deliver a fresh nervous system to the start line, this framework lets you complete the 1.9/90/21.1 in Kenting with greater composure.

Related Reading

• IRONMAN 36-Week Training Plan: Four Phases of Base, Build, Peak, and Taper
• 70.3 Annual Periodization Template: A Year-Long Plan Peaking at the Kenting Race
• IRONMAN 70.3 Half-Distance Triathlon Training Plan: 24-Week Periodized Race Preparation
• 70.3 Race Week: What to Eat, Sleep, Train, and Pack in the Final 7 Days