Key takeaways

  • 70.3 racing sits between pure endurance and threshold work. The AI structures training with more intensity than full Ironman plans, targeting the 4-6 hour race duration with specific FTP and threshold pace sessions.
  • The bike leg often determines the run. The AI builds your Normalized Power (NP) targets for the 90km ride and trains you to hold them without blowing up for the half marathon.
  • 70.3 is the fastest-growing triathlon distance worldwide, and it rewards athletes who can sustain high percentages of their threshold across all three sports.
  • Transition efficiency matters more at 70.3 than Ironman. The AI programs race-pace brick sessions that teach you to run at target pace within the first kilometer off the bike.

AI Coach for Half Ironman Training

70.3 is the sweet spot of long-course triathlon: hard enough to demand serious training, short enough that you can still race it fast. Your AI coach builds 16-20 week plans that balance volume with intensity for this unique distance.

Threshold-focused periodization

Unlike Ironman, 70.3 rewards athletes who can sustain efforts closer to threshold. The AI builds plans with more tempo and sweet spot work on the bike (88-95% FTP), steady-state swims at CSS pace, and tempo runs at half marathon effort. The intensity mix shifts across base, build, and peak phases.

Bike-to-run pacing strategy

The AI sets Normalized Power targets for your 90km bike leg based on your FTP, then trains you to run at target half marathon pace off that effort. It tracks your brick workout performance over time to build an accurate race-day pacing plan that accounts for fatigue from the bike.

16-20 week progressive build

Plans start with aerobic base work and progressively layer in race-specific intensity. Weekly volume peaks at 10-15 hours for most age-group athletes. The AI uses recovery data to time your hard weeks and easy weeks so you absorb training rather than just accumulate fatigue.

Race simulation sessions

In the final 6-8 weeks, the AI programs key sessions that simulate race demands: sustained bike efforts at target NP followed by runs at goal half marathon pace. These sessions build confidence and give you real data to refine pacing, rather than guessing on race day.

Frequently asked questions

How is 70.3 training different from full Ironman?

70.3 training involves less total volume but more intensity. Peak weeks are typically 10-15 hours instead of 15-20+. You spend more time at threshold and sweet spot intensities on the bike, and tempo pace on the run. The AI adjusts the intensity distribution based on your target distance.

What bike power should I target for the 90km ride?

Most athletes target 70-80% of FTP for the 70.3 bike leg, depending on fitness and how much they want left for the run. The AI calculates your specific NP target based on your FTP, recent long ride data, and your run-off-the-bike performance in training bricks.

How important are brick workouts for 70.3?

Very important. The transition from biking to running is where most athletes lose time. The AI programs 1-2 bricks per week in the build phase, starting with easy runs off moderate rides and progressing to race-pace runs off harder bike efforts. Your brick performance directly informs race-day pacing.

Can I train for 70.3 on 10 hours per week?

Yes. Many age-group athletes complete strong 70.3 races on 8-12 hours per week. The AI maximizes training quality when volume is limited, prioritizing key sessions in each sport and cutting junk miles. It schedules your hardest sessions when recovery data shows you can handle them.

How long should the taper be for 70.3?

Typically 10-14 days with a 30-40% volume reduction while keeping some intensity. The AI monitors your HRV and resting heart rate during the taper to confirm you are freshening up. If recovery metrics plateau early, it may trim an extra day of volume.

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