Predict

These are heuristic models built on established sports-science rate-of-gain relationships — not precise personalized predictions. Individual response varies a lot, which is why every projection shows a range rather than a single number.

Muscle & weight:lean-mass gain scales with training age (novices gain fastest), and is gated by training frequency, calorie surplus, protein and sleep. Fat change comes from the energy left over after building muscle — so training at maintenance calories shows a “recomp” (muscle up, weight roughly flat).

FTP: modeled as an exponential approach to a personal ceiling — fast early gains that plateau. Both the ceiling and the speed of getting there scale with your training volume and consistency.

Accuracy would improve meaningfully if these were calibrated to your own logged Weight / FTP history — a natural next step.