Before I got sick in the beginning of April, I would do my longer endurance rides at a power of 245-250 watts (w) and a heart rate of 130 beats per minute (bpm)
When I started to get on the bike again in late September, I could only do 150w at 130bpm. I lost around 100w.
Today, just seven weeks later, I'm back above 200w and just recorded 204w at 130bpm. That's 54w of progress in 7 weeks - 8w per week.
Expectation is that this linear weekly progress continues more or less until I reach a level that I had already reached before. In ten weeks I could get close to 300w again.
Life is a rollercoaster.