12 Weeks to a Successful 70.3

An achievable program for triathletes with a goal to complete a half-IRONMAN

Coach Cal Zaryski competing in the 2021 World 70.3 IRONMAN Championships. Photo by FRAN STEEDS, FINISHERPIX

The 12-week program I have outlined is achievable for anyone who has comfortably completed a few sprint or standard distance triathlons. However, making this jump can be intimidating. The total time to swim, bike and run 70.3 miles (113 km) requires a proper training plan to become ultra-endurance fit. 

It is important to be consistent in training particularly with a weekly routine. Each day of the program and its scheduling has a purpose so stick with it. You may find the overall fatigue running the half-marathon pace similar to the back end of a marathon, so be prepared for the same. In the last six weeks several sessions in each discipline will be beyond the race distance; that is normal. On race day expect the unexpected and celebrate your health and fitness by racing in the moment. The race is a means to challenge yourself physically and mentally. 

Coach’s Tips 

  • No need to swim fast but rather safely with confidence. Open water practice is a must. 
  • Practice your nutrition in training so that you can ingest fuel and hydrate on the bike ride. 
  • Break up the race into these segments: swim start, end of swim, transition 1, first 10 km on bike, halfway on bike, transition 2, first 5 km into the run, halfway into the run, final 5 km. 
  • Accept poor sleep the night before the event. It won’t affect your performance. 
  • Review your training the night before the race to build mental confidence and focus on execution. 
  • Prioritize training in this order: long bike rides, long runs, simulated brick workouts, simulated triathlons, a few open water swims ideally with others.  
  • For more important information on training, you can check out my paper: Training Principles and Issues for Ultra-endurance Athletes (Current Sports Medicine Report, 2005). 


FTP – Functional Training Power or 30 min time trial effort 
TT – Time trial triathlon position 
WU – Warm-up 
CD – Cool down 
R – Rest 
MP – Marathon pace 
HMP – Half-marathon pace

Download a PDF of the training Plan 12 Weeks to a Successful 70.3

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