Who it's for
- You're targeting a top-3 age-group finish or a Pro-division time.
- You race doubles and want both partners' splits engineered together.
- You have a specific race in 12–20 weeks and want it built backwards from race day.
- You already train hard and want the details — Roxzone routine, pacing to the second, race-week execution — done properly.
Not sure? Answer four questions in Ask Dina and the site tells you which zone fits — or run your last race through the split analyser and see what it says about where you lose time.