Due to Covid, I stopped running for like a year and returned to some running for the last two month now. My fitness went from a sub3:30 marathon a year ago to finding it difficult to complete 5k at 5:30 per km pace, despite going out there to run a good 5-10km for the last 1.5 months every second / third day. Very frustrating. Any advice on how to get ack into running smoothly and what's a realistic aim for the year end assuming one trains hard? Targeting to run another marathon by the end of this year (if they are ever held again).