Zone X and 70.3

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    I have a cFTP of 222w from a test this week planted entirely in the aerobars. That puts me at 2.9 w/kg. Guided by page 217 in the book that indicates that I should race at 77-80% of FTP in the 70.3 bike course. Workout CAe36 says in the description “80/20 running is built on avoiding Zone X, the ineffective Zone between Zone 2 and 3. However, for 70.3 racing, Zone 2 can be too slow, and Zone 3 is far too high. Therefore, some Zone X is acceptable during these Aerobic intervals.” Given my w/kg and the p 217 guidance should I not go above the Zone 2 ceiling in CAe36? I assume the Zone X suggestion is for someone in the “Excellent” column with a w/kg of 4.0+, where the 70.3 guidance of 82-85% of FTP goes into Zone X, is that correct?

    David Warden

    Ted, this is a tough question. For 70.3 racing and training in those specific CAe and RAe workouts, the line between Zone 2 and X does not need to be as strict. It is a real grey area for 70.3. 77-80% is a solid pace for a 70.3, but depending on appetite for risk and experience level, some athletes can maintain low Zone X for 4.5 hours. If you stay in mid to high Zone 2 in your long bricks and racing, you’ll do well at the 70.3. If you find that after a high Zone 2 brick, you feel fantastic the next day, spend some time flirting with Zone X in the next brick and you might be able to pull it off on race day.


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