The net is that racing a 70.3 within your 140.6 training schedule will punch about a 7- to 10-day "accommodation hole" into your schedule.
You'll likely skip or greatly reduce any bike or run interval sessions in your race and post-race weeks. That's two "get faster" bike and run sessions, gone.
You'll miss your Ironman-specific long bike opportunities for race week, because you'll be racing instead. This is a missed opportunity to continue to dial in pacing, nutrition, and adapting your body to long miles in the aerobars.
A half marathon at 70.3 pace is a solid long run so you're good there?as long as you're smart the week after the race and get in your regularly scheduled long run. Do not miss that run!
The Variable Cost of the Accommodation Hole
Punching this hole into your Ironman training schedule 12 to 16 weeks out is not a big deal; you have plenty of time to put on your serious Ironman hat and get down to business. In fact, we want our athletes to avoid putting their heads in an Ironman training place until 12 weeks out, so we encourage them to schedule races and other events and train for those, not Ironman.
A 70.3 is an excellent tool for this purpose, as the distances are long enough to increase accountability, but manageable enough that they can preserve their heads and SAUs (Spousal Approval Units) for the much more focused training that comes closer to the Ironman.
As you get closer to Ironman race day, your training becomes much more race specific, with critical volume and race rehearsal opportunities carefully scheduled. These training events become extremely important. Scheduling a 70.3 within this window, and punching that accommodation hole into your training schedule, becomes very costly to your ultimate goal of a successful Ironman. For this reason we don't recommend our athletes race anything, within 6 to 7 weeks of their Ironman.
This All Just a Game
That said, this is all just a game, it's supposed to be fun, and if racing a half in route to your full sounds fun, go for it! As I said, we encourage our Ironman athletes to use 70.3s and other fun events as tools to disengage their heads from Ironman training for as long as possible.
So, if you are going to race that half:
- Be smart with race selection.
- 12+ weeks out = totally fine.
- About 7 to 10 weeks out = "mostly" fine, but you're getting into the yellow zone. You must get back onto your regularly scheduled Ironman programing the week after the race.
- Anything less than six weeks out = no go. You will compromise your Ironman-specific critical volume and rehearsal opportunities.
- Race it! Let the big Ironman dog run and have fun.
- Don't do the half as an Ironman race rehearsal because it's not a very good one and you're better off not spending your money, doing a free race rehearsal from your doorstep instead.
Interested in learning more about training and racing an Ironman 70.3? Sign up for Endurance Nation's FREE virtual seminar, and we'll teach you everything you need to know to achieve your best long-course triathlon performance.