When the cast comes off, the muscle underneath is smaller. Starting weaker than you were isn’t starting over.

Muscle disappears quickly when a limb is immobilised, and seeing it thinner is a shock even when you knew it was coming. What has gone is size and strength, not the years of coordination underneath, and those return far faster than they were originally built. Coming back below your old level is a different situation from starting from nothing.

Expect the first few weeks to feel disproportionately hard, and plan them small. Take a measurement or a photo at the start so progress is visible rather than guessed at. Follow the programme you were actually given, not the one your memory of last season suggests.