This plan was designed for the triathlete using the principles of The Triathletes Training Bible. It is best started about 23 weeks prior to your first A race of the season. Following this 12-week plan will get you ready to start the Half-Ironman Build period (see Half IM Build-Peak plan above) which specifically prepares you for your A-priority race.
This plan is intended for the under-age-50 triathlete who has been racing for two or more years but may also be used by older athletes who recover well within 48 hours after hard or long workouts and can train with 3 consecutive weeks of quality training before taking a recovery period. To start this plan you should be able to swim 1 hour, bike 1.5 hours, and run 1 hour. Over 12 weeks you will increase your weekly volume from about 13 hours to 19 hours including 4-5 swims, 4 to 6 bikes, 4 to 6 runs, and 1 to 2 strength workouts each week. The exceptions are the R&R weeks every fourth week with volume significantly reduced for 4 to 5 days and self-testing at the end of the week to measure progress.
The plan uses common language to describe the workouts and is easy to follow. By the end of 12 weeks you will have excellent Base fitness and be ready to start the Build period 11 weeks prior to your A-priority, half-Ironman race.