Triathlon 10 min read

Ironman 70.3 Training Plan (Half Ironman)

A 70.3 training plan spans 16–20 weeks with 10–14 hours weekly, a long bike of 3–4 hours, a long run of 90–105 minutes, and monthly brick sessions simulating race fatigue before a 2-week taper.

Who this is for

Athletes targeting a 70.3 who have completed Olympic distance or can train 10+ hours per week consistently.

16-week overview

PhaseWeeksLong bikeLong run
Base1–52 → 3 h60 → 75 min
Build6–123 → 4 h75 → 100 min
Peak13–144 h race sim90 min
Taper15–162 h45 min

Weekly hour targets

According to training load research, half Ironman athletes commonly train 10–14 hours per week at peak.

Distribution: ~15% swim, 50% bike, 35% run. At least 80% of volume should be aerobic (Zone 1–2).

Sample peak week (13 h)

  • Mon: 60 min swim (CSS/threshold)
  • Tue: 2 h bike Z2 + 30 min run off bike
  • Wed: 60 min easy run
  • Thu: 90 min bike with sweet spot blocks
  • Fri: Rest
  • Sat: 4 h bike (race nutrition practice)
  • Sun: 90 min long run

Common mistakes

  • Insufficient bike volume — the 90 km bike sets up the half marathon run.
  • Skipping nutrition practice on long bikes.
  • Running long on fresh legs only — practice running tired.

Vo2Max Pro plans 70.3 training with long bikes, brick runs, and taper weeks mapped to your race date and weekly hour budget.

Frequently asked questions

How many hours per week for 70.3 training?
10–14 hours at peak for most age-group athletes.
How long to train for a half Ironman?
16–20 weeks from Olympic-distance fitness.
What is the longest bike ride in 70.3 training?
3.5–4 hours, 3 weeks before race day.
Should I run a marathon while training for 70.3?
Not necessary — the 70.3 run is a half marathon off the bike, which requires specific brick preparation.

Put this into practice

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