Log inStart free
← All skills
Sections

12-week lean bulk

v2

A 12-week surplus of roughly 250-500 kcal above maintenance, with weekly weigh-ins and a hard cap on how fast bodyweight rises. Built to add muscle without adding much fat.

Available
All levelsdietbulksurplus12-weeklean-gain

Get an AI coach that uses this skill

FitnessGrid is an AI coach that plans your week and adapts as you go. Install 12-week lean bulk and your coach will follow this protocol every week, learn from what you actually do, and adjust on the fly.

  • Your coach builds the week from this skill
  • Adapts to your actual progress, not a static template
  • Free to start — no credit card, ~60 seconds to set up

Daily calorie target = maintenance + surplus. Default surplus is 300 kcal/day, intended to drive a bodyweight gain of ~0.25-0.5% per week. Macro split is protein-priority: protein = 1.8g x bodyweight kg, fat = max(0.8g x bodyweight, 60g), carbs fill the remainder.

Lean bulks fail in one of two ways: too small a surplus (no muscle gain, just maintenance with extra food) or too large (gain rate overshoots 0.5%/week, fat goes on faster than muscle). The weekly weigh-in catches both.

Decision rules for the coach

  • Weekly weigh-in is mandatory. At the start of each week, ask for current bodyweight. Use evaluate to compute the running 4-week rate of change. Adjust:
    • Rate > 0.6%/week for 2 weeks: cut surplus by 100 kcal.
    • Rate < 0.15%/week for 2 weeks: add 100 kcal.
    • Hold otherwise — week-to-week noise is normal.
  • Carbs go around training. When the user has a workout card in today's grid, plan ~50-60% of the day's carbs in the pre/peri/post-workout window.
  • Don't moralize. If the user logs a heavy social-eating day 500-1000 kcal over target, acknowledge and roll forward. Don't prescribe a deficit the next day — the body doesn't work that way on weekly averages.
  • Free-text food logging. Use the free-text-meal-log skill for plain-language meals. One clarifying question max.
  • Protein floor. If the user logs a day under 1.4g/kg protein, flag it briefly — muscle is the entire reason for the surplus.
  • Block end. At week 10-12, ask if the user wants to transition to maintenance or run another block. Don't switch programmes mid-week without explicit confirmation.
  • Inline caveats. Bulking touches diet-prescription territory — emit the medical caveat per respond-to-medical on any message that recommends a surplus.