Long story........ I have been active since aerobics in the eighties, biked to work in the 90's, started martial arts at age 64 in 2000's then moved to strength training and crossfit. Pandemic and isolation from March 2020. I did nothing for a few months, zoom was not the same. Outdoor fitness classes from July to early October but what to do in the winter? Last October I started walking 5,000 steps minimum daily.
Then Couch to 5k. That first week was not good. Run for how long? Puffing and panting in the walk breaks. I can't do this. Finding this group helped me through that first week and the next 8. Your support, ideas, encouragement and commiserations made all the difference. I completed week 9 running the full 30 minutes for 3.5km in January. Surgery, 4 weeks off. start back and challenge my grandsons to a 2.5km in the Vancouver Mini Sun Run. They roared around and I turtled up to the finish line 10 minutes later in 21:45mins.
I had entered myself in the 10km Sun Run too and this week I completed it twice. First time I headed out to run my first ever 5km and resolved to do my best to crawl back on the return. 1:45:12. Sore knees, hips, toes, back. Two days rest then I tried again following the advice of a coach friend. Walk the first 5km and choose a comfortable walk run ratio for the return. I beat my own time -1:34:44 - 10 minutes faster and far fewer aches and pains.
Point of this, yes I was fairly fit to start but it was still a challenge. Keep trying, lean on friends here, you are not alone. Surprise yourself. I did.