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2026-05-23 · 4 min read


Granfondo 100K training plan (with vert)


A granfondo isn't "a long ride with a number plate." It's 4-6 hours on the bike, usually with 3,300-8,200 ft of cumulative vert, and a group pace that drags you forward in the first two hours. If you hit mile 43 with no fuel, it's because of something that happened three months earlier in your plan. Here's the framework.


The premises


  • Target time: 4-5 h for flat 100K, 5-6 h with real vert.
  • Estimated FTP: the plan is designed to hold an IF (Intensity Factor) of 0.70-0.78 throughout. If your estimated FTP is 200 W, you'll average ~150 W.
  • CTL on event day: ideally 70-90 if you've been training consistent. Below 50 you're undertrained for 100K.
  • Peak volume: your biggest week should be 8-10 h on the bike.

    • The 12 weeks


    ### Phase 1 · Base (weeks 1-5)


    Build aerobic base with growing volume and very little intensity.


  • Volume peak here: 7-9 h/week at end of phase.
  • 80% in Z2 (low sweet-spot, 65-75% FTP). "Conversational but effort-required" pace.
  • One long ride on the weekend: starts at 2 h and grows to 4 h. Include 2,000-3,300 ft of D+.
  • One weekly "tempo" ride: 60 min with 2×15 min in Z3 (84-90% FTP).
  • Gym 2× per week focused on legs (squat, deadlift, leg press) — 4-6 weeks of gym give you free watts on the bike after phase 1.

    • ### Phase 2 · Specific (weeks 6-9)


    Now you add FTP and sweet-spot work, holding volume high.


  • Sweet-spot intervals: 3×15 min at 88-94% FTP. Hit it 2× per week in early build.
  • FTP intervals: 4×8 min at 95-105% FTP. 1× per week in late build.
  • Long ride keeps growing to 4.5-5 h, with 3,300-5,000 ft D+. Try a route with a similar profile to the race.
  • Climbing day: 5×4-6 min on a 5-8% grade, all out. Trains neuromuscular force.
  • Drop Z3 to 1× week — the body is cooked.

    • ### Phase 3 · Peak (weeks 10-11)


    A "rehearsal race" — a shorter granfondo (60-80 km) or a solo event.


  • Drop volume 15% but lift intensity: 2×20 min sweet-spot + 3×5 min at VO2max.
  • Full fueling rehearsal: in your long ride test the exact combo of bars, gels, fluids and salts you'll use event day. Aim 60-80 g carbs per hour.

    • ### Phase 4 · Taper (week 12)


  • Volume -40%.
  • Hold one quality day (2×8 min at FTP) so you don't go flat.
  • Three days prior: short rides (45-60 min) with 2-3 openers of 1 min at 110% FTP.
  • Day before: 30-45 min spin, no more.

    • Intensity distribution (typical build phase)


    | Zone | Time/week | % |

    |---|---|---|

    | Z1 (recovery) | 30-60 min | 8% |

    | Z2 (aerobic) | 5-6 h | 65-70% |

    | Sweet-spot (high Z3) | 60-90 min | 12-15% |

    | Z4 (threshold) | 30 min | 5-7% |

    | Z5+ (VO2max) | 10-20 min | 2-4% |


    If you have a power meter, the zones are exact. Without one, navigate by HR and RPE — the numbers shift but the logic still holds.


    The fueling math


    The most common rookie mistake is undertraining the gut. Your body is NOT used to processing 60+ g of carbs per hour under exercise. This is trained.


    Required practice on long rides:

  • Gels: one every 30-40 min (25 g carbs each).
  • Fluid: 17-25 fl oz/h with electrolytes (sodium minimum 500 mg/h in heat).
  • Solids: bar every hour from hour 2.
  • Nothing new on event day. What you tested 4 weeks before, that's what you eat.

    • Common mistakes


    1. Trying to stay with the front group the first 12 mi. They'll push 250 W and you'll be toast by mile 31. Ride at YOUR pace (IF 0.75 max) for the first 19 mi.

    2. Zero climbing in the plan. If the race has 5,000 ft D+, you can't arrive having only ridden flat.

    3. Skipping the pure Z2 day. That's where aerobic base is built. Without Z2, your efficiency stalls.

    4. Tapering too late. The taper is 2 weeks minimum. If you only cut the last one, you arrive with tired legs.


    Vetta and the granfondo


    [Vetta Trainer](/signup)'s engine periodizes cycling from day 1. You mark your goal "granfondo 100K, date X", connect Strava, and it builds weeks with sweet-spot and FTP intervals respecting your safe ramp. If you have measured FTP, it prescribes in watts; if not, maps to HR. Default philosophy is Coggan, but you can switch to polarized or sweet-spot.


    Reading


  • *The Cyclist's Training Bible* — Joe Friel.
  • *Training and Racing with a Power Meter* — Hunter Allen, Andrew Coggan.
  • [FTP without a power meter calculator](/blog/ftp-sin-potenciometro).