At age 39 in January, I weighed about 170. I averaged about 10 miles per week and ran about 23-24:00 for 5K. I added spin bike workouts about 6 times per week x 35-140 minutes + weights. I moved my mileage from 10 miles per week to about 33 by June. My weight dropped to 152 and I ran about an 18:05 I think. Kept going to 140 pounds and 50 miles per week Ave - then ran a HM in 1:25 a few months later at age 40. No idea on a 1K, but my mile was low 5:20s. I could do about 60 push-ups and 18 pull ups. Trashed my adductor, pelvis, and obliques in 1 marathon and that was doneland for 4 years. Quit trying after that. On the comeback to mediocrity trail again 10 years later.
My point was not with regard to the weekly volume. It was the other major contradictions in the OP’s story. A major contradiction is when said he is stuck at 23 min in the original post to this thread, then later says he expects to break 20min soon.
At age 39 in January, I weighed about 170. I averaged about 10 miles per week and ran about 23-24:00 for 5K. I added spin bike workouts about 6 times per week x 35-140 minutes + weights. I moved my mileage from 10 miles per week to about 33 by June. My weight dropped to 152 and I ran about an 18:05 I think. Kept going to 140 pounds and 50 miles per week Ave - then ran a HM in 1:25 a few months later at age 40. No idea on a 1K, but my mile was low 5:20s. I could do about 60 push-ups and 18 pull ups. Trashed my adductor, pelvis, and obliques in 1 marathon and that was doneland for 4 years. Quit trying after that. On the comeback to mediocrity trail again 10 years later.
This is a pretty good story. Dropping weight obviously helped, and the spin-bike was evidently a huge factor, not only for dropping weight, but assisting with key physiological adaptations (aerobic enzymes, mitochondrial changes, capillary beds, etc.).
I started running at 31. I used to be too self conscious to run on the streets but I started doing 5 miles 3 times a week. Did 20:36 parkrun off that. When I started jogging 30 miles a week (8-9 minute miles) I did sub 20, but I could also do 40 for 10k, so early on it was clear my endurance was better than my speed. I never did any intervals. It doesn't matter what your 1000m time is.
At age 39 in January, I weighed about 170. I averaged about 10 miles per week and ran about 23-24:00 for 5K. I added spin bike workouts about 6 times per week x 35-140 minutes + weights. I moved my mileage from 10 miles per week to about 33 by June. My weight dropped to 152 and I ran about an 18:05 I think. Kept going to 140 pounds and 50 miles per week Ave - then ran a HM in 1:25 a few months later at age 40. No idea on a 1K, but my mile was low 5:20s. I could do about 60 push-ups and 18 pull ups. Trashed my adductor, pelvis, and obliques in 1 marathon and that was doneland for 4 years. Quit trying after that. On the comeback to mediocrity trail again 10 years later.
It took me several weeks in HS to go from 22:30 to 20:32, but then a few years to break 19.
I took time off running one year and ran 18:33 after 10 weeks of training years ago.
Since then, it's been hard to even get under 21 (although I ran 21:15 on the track in October 2021). I lost my speed in my late 30s. I'll be happy to break 21 at some point--I think you lose speed at a certain point all at once. Although to be fair, I've been training for longer distances.
I'm just adding noise really, but I do enjoy the fact I actually cannot answer this. My very first 5k race was 22:30 at age 36. I started running coming from cycling, and never had aerobic issues, I had mechanical issues from not being able to take the pounding. My next 5k was 19:3x a few months later, and then a 39:20 10k, and a half at 1:27 a year later. I ran several more mid 120s halves then quit running.
In fact I haven't run since 2015 or so, primarily due to a hip socket issue that keeps occurring when I run. Went back to mountain biking.