I always fully expect to feel muscle ache on the fairly rare occasions that I resume biking or running after a hiatus of a week or more, rare for the simple reason that such long hiati are rare for me. Likewise, when I perform unfamiliar or infrequent chores such as excavating concrete rubble from my back forty, aches are expected and of no concern.
Actually, for some reason, muscle aches when resuming biking are negligible to non-existent, even after many weeks of not biking. Perhaps that is because the my biking fitness is covered by my running fitness (which I make a point of never losing to any significant degree, whatever the weather or travel schedule; whereas due to weather or travel I occasionally have no choice but to go without biking for several weeks at a stretch).