When planning two Ironman events allow 12-15 weeks to successfully complete the second one. There are four phases of training between each event. You need 10 days for recovery and for tapering, which leaves you with approx.
9-12 weeks. Spend one third rebuilding and two thirds in the competition phase.
Phase 1 After your first Ironman keep moving. Don’t run for the first five days but start training more frequently in the three sports once your desire returns.
Phase 2 Build phase. Get back to 75% of your biggest volume week.
Phase 3 Competition phase. Focus on race-pace swim, bike and run efforts.
Phase 4 The taper will take care of your race-day speed.
Tapering: why it's important and what you should do the week before your triathlon
After your first event, focus on areas that need the most attention and train specifically for the demands of your second Ironman during the build and competition phase.
This article appeared in the December 2017 (345) issue of 220 Triathlon. You can subscribe to the magazine here