If you stopped training, how many weeks would it be until you could no longer run a sub-20 5km?

I'm going on about 13 years.

8 weeks

This is an interesting question, but I think the time is too slow to apply to very talented people as they would start to slow down from old age before lack of training slowed them down to over 20-minutes. Assuming they ate relatively healthy and didn't get fat anyway.

I ran sub 18 at my first ever 5k off of about 4 weeks "running training" (20 miles a week no speed work), and had only played football (soccer) before. I'd back my self to run sub 20 in 15 years time assuming I continued playing other sports.

50+. Depends on how many donuts I put down in the meantime.

I'm 45. Was a normal 17:3x guy from ages 40-43. Then I hurt my back, and had to rest 9 months - no running, almost nothing aerobic. Once I started running again (if you can call it that), it took me 6-mo to split under 20-min as part of a tempo workout. Haven't tried to race yet. Don't hurt your back guys...

I guess about six months or even less. But I could then be running sub-17 after a few months of dedicated training. I think my shape starts sliding extremely fast after a month or two of rest. But it's easy to come back, at least some of the way. However, the first run after a long period of rest is just terrible. I can't imagine how awful it would be to run a hard 5k right off the couch then.

I think running just once a week during a down period makes a great difference.

I have taken years off and never slipped outside 20 minutes.

People are way over estimating their abilities here.

At the age of 27 my 5k PR had dropped down to 18:10, and mile PR 5:02

I had a bad injury and by the time I came back to running at age 30, in a 5k time trial I ran over 24 minutes (not a fluke). I don't think you guys realize what several years of no running (with no other aerobic sports) means for your body. You go down hill very quickly.

A couple of years ago, at age 57, I was off for five months - moving to a new area, building a house.

The first day back I ran a solo 5k on the track in 19:45, which was all out.

So I guess at this age, about 6 months of no training before I couldn't break 20:00.

HobbyJoggerToRunner wrote:

People are way over estimating their abilities here.

At the age of 27 my 5k PR had dropped down to 18:10, and mile PR 5:02

I had a bad injury and by the time I came back to running at age 30, in a 5k time trial I ran over 24 minutes (not a fluke). I don't think you guys realize what several years of no running (with no other aerobic sports) means for your body. You go down hill very quickly.

Okay, but if you start with a PR of 14:30, even if your rate of decline is the same, it's going to take a lot longer to get to the point you can't run 6:24 pace for a few miles as that might be what a 14:30 guy runs on his easy 10 mile days now.

Mo Farah would probably kick the bucket before he couldn't run sub-20.

On that note, OP, is EPO considered training?

2 weeks, and I'd be over 20:00.

Up to age 47, I could run under 20 anytime even if I was not currently training. From age 17 to 40, I could go under 17:00 on 10-15 miles per week.

Now, at age 59, I have to be in absolute top shape to run under 20:00 for 5K.

HobbyJoggerToRunner wrote:

People are way over estimating their abilities here.

At the age of 27 my 5k PR had dropped down to 18:10, and mile PR 5:02

I had a bad injury and by the time I came back to running at age 30, in a 5k time trial I ran over 24 minutes (not a fluke). I don't think you guys realize what several years of no running (with no other aerobic sports) means for your body. You go down hill very quickly.

Trolling for hobby jogger comments are we? I'll respond anyway. I think you are way under estimating how many runners on lrc are more talented than you. A thread like this will attract those people (why do you think i'm here). After a car accident I went through almost 2 years of no activity at all, only light rehab exercises. Once cleared by the Dr I did 2 months biking 3days/wk, jogged 10mpw for 4 weeks, then broke 5:00 in a solo TT.

For me, if I truly did no other activity, I think it would be about 4-5 years and i'd struggle with 20min. Given any sort of active lifestyle and it would be a lot longer. For runners more talented than me age and weight gain will be the only thing that pushes them above 20min.

Too many variables to consider.

* Am I allowed to stay my same body weight?

* Am I allowed to bike, hike, etc.?

Sub-18 maybe? wrote:

This is an interesting question, but I think the time is too slow to apply to very talented people as they would start to slow down from old age before lack of training slowed them down to over 20-minutes. Assuming they ate relatively healthy and didn't get fat anyway.

Agreed. I'm 26 and had my ACL reconstructed in mid-February of 2015. My PT let me start running on the track in early April. I remember the first mile I ran was a 6:11. While I wouldn't call it comfortable, it was not all out either. I could have run that pace for a 5k without too much strain and I had been down since I tore my ACL in December.

I'm by no means the most talented runner out there, but I would say age would be the biggest factor in not being able to break 20 before de-conditioning was a factor.

I've always been fascinated by the variable rates of decline runners have once they stop running. As someone who runs, at best, sub-17:00, it wouldn't seem like I would take me too long to inch up to 20:00. But in the several months-long stints off running with no other aerobic exercise I've had, I've generally still been able to run in the 18:00s, whereas I've known guys who were faster than me who would be barely able to break twenty if they took the same amount of time off.

I can see two big things that play a role here: one is that I have genetics on my side for weight gain--or lack thereof (I'm one who loses a little weight initially when I quit running, then levels off to about my regular running weight). The other is that I'm rarely sedentary. I can't seem to sit still for long, especially if I'm not running. I'll be standing at work, walking dogs at home, hanging out and talking with people on my feet, etc. I really think this plays a big role. If I were, say, confined to a wheelchair, I would lose my ability to break 20:00 very quickly.

Five weeks.

around 700

Good question...

Best 5K was 16:25 (splits: 5:00, 5:16, 5:32 so probably a bit better than a well-paced 16:25.)

As long as I was active, at least a year when I was younger (ran 40:30 for 10K after a year layoff but working a job with a lot of walking each day)

Now I'm just getting back after a 5 year+ layoff while at a desk job (age: 36) and am quite slow. Did a test mile on treadmill 4 weeks ago after one week of 2 mile jogs, ran 7:14 and almost had a heart attack.

Have gotten up to 25 miles per week and working out with a PT for an hour and a half 3 times a week. Planning a 5K on Saturday. Goal is sub 22, but I could be over 23 or below 21. We'll see...