Age and/or letting fitness levels drop, can be difficult to recover from. Am two decades younger, but ten years back, doing a quick 24 mile round commute, c/w 2300' climb just to get to the gym was routine. As were the routine 70+ mile rides. Only 100+ mile rides felt long
But three yr's with almost rides being a generic 28-30 mile circular, minimal gym, fitness level had dropped through the floor. But ? just finished fourth week prioritising the gym, increased mileage on the side. Realised on finishing yesterdays quick 38 mile spin, half against a 20mph+ head wind, that fitness levels were heading upwards . Felt great, time for a quick 4-5 day coast / coast / lakes / dales