How to extend 70.3 Base training to 23 weeks?

Hi everyone,

I’m planning to participate in a 70.3 in 2021 (hopefully) and I’m about to officially start my season. I used the ATP from TrainingPeaks, which left me with a total of 23 weeks base phase, namely:

  • 4 weeks Base I
  • 8 weeks Base II
  • 11 weeks Base III

I’m planning to start out with the 70.3 Base plan (High volume) which will cover the first 8 weeks. I definitely want to include power endurance training in Base II and III and based on this, I put together some possible solutions for how to proceed after the 70.3 SS BAse plan. However, I’ve come to a point where I could use some advice because I’m not that experienced with these things. So here are the options:

  • 70.3 SS Base (8wk) -> Century Specialization (8wk) -> 70.3 SS Base (8wk)

  • 70.3 SS Base (8wk) -> 70.3 SS Build (4wk) -> 70.3 SS Base (8wk) > 70.3 SS Build (4wk)
    This option came out of the TR plan builder

  • Traditional Base (12wk) -> 70.3 SS Base (8wk)

Would love to hear some feedback or alternatives from you guys. I also hope it’s fine that I started a new thread on this. I tried to find a solution in the existing forum posts but I couldn’t find one that really answered this specific question (though a lot of related posts).


I think 23 weeks of base is a lot! If you are using TR, have you considered using the full base/build/specialty cycle?

Also, if you are running and swimming alongside, the pure cycling plans (SSB, the builds) can be a bit much. The triathlon plans take into account the competing nature of training three sports simultaneously.

That said, when I’ve had extra weeks to my event, I have done Trad base and then the base/build/specialty cycle. Trad base at LoweR volumes is mellow enough to fit in swimming and cycling too.

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Thanks for your input. 23 weeks feels definitely like a long time for me but it’s as recommended by TrainingPeaks so I didn’t question it (yet).

I also definitely will follow up with the 70.3 build and specialty to complete the full cycle. However, if I do them subsequently -> Base -> Build -> Specialty I will finish them about 10 weeks prior to my main event (Mostly due to the different lengths on TrainerRoad Base vs TrainingPeaks Base).

Hence, I’m looking for some solution to prolong my base training plan. Usually, I would follow the TR recommendation (alternate 70.3 Base with 70.3 Build). It’s just that I read tons of different opinions on that and they got me confused tbh.


Have you tried Plan builder? What did it suggest?

If you still what to do an extended base, you can try to do Sweetspot Base I (6w) + Sweetspot Base II (6w) + 70.3 Base (8w). That’s 20w

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for 23 it will probably be something like… base-build-build-specialty. At least that what it did to me when i used the plan builder back in April.

Yes, it’s actually base - build - base-build-specialty for me (I opted for “having done some interval training”).

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This season I had 4 extra weeks than the regular base-build-specialty, plan builder added a break and back to base after the build. It did not work for me, the change of pace was hard to come back and felt that this break derailed by progress. Personally would have a base-build, take a break and start again with the full Base-Build-Specialty. I think it also depends on how long you can keep your motivation.