Is it normal to lose fitness after only a week off

No!

It's mostly in your head that you feel like you have lost fitness.

You're fine. You didn't truly lose fitness.

Actually those other 2 are wrong. You did lose some fitness. That is just a fact. You lose fitness when you are not training. That is not a problem though. You can get that fitness back. Getting back to where you were is always easier than getting there the first time.

Oh yeah! The older you get the quicker it leaves and it takes longer to get it back. The running faster for shorter distances is all part of the tapering process. That is why you cut back mileage a little before a big race. You want your legs and mind fresh for what is ahead.

That is also why sprinters do not do as much mileage as distance runners. Too much distance running would zap their leg speed, and why most distance runners reduce their mileage when doing hard track work. before a peak.

[quote]SLoWpacE. wrote:

Depends on your age.

A week off is nothing at age 20.

Get to mid thirties or so and it takes three weeks to get back to where you were before your week off.

After a week off you're unfit in the same way that a dusty window is hard to see out of - the window isn't any worse than before, you just need to take a bit of time to polish it up again

In that short time frame there isn't really much room for muscle to atrophy, VO2max/Lactate threshold (whatever your preferred flavor is) to drop, or speed to change. Nearly all the lost "fitness" is usually just coordination falling off and that only takes a couple of runs to remind your body that it's a runner. Sprinting coming back earlier could be CNS fatigue fading from a long season. For something with high neural demand I can imagine feeling fresh outpacing and drop in sprint coordination, especially considering most distance athletes rarely sprint multiple times a week so you aren't using those motor patterns any less than before, but the slower motor patters of distance running used to be done daily; 7 days off could certainly affect them.

yeah thanks. I'm already feeling better now when I run. The firts run back was mediocre but now it's much better. I think, like you said that it was because of the coordination. My mechanic was bad on the first run and I was breathing hard. My legs were also sore. A couple of runs after, i'm close to the same fitness I was before. I will slowly increase my mileage and the lenght of my runs.

According to Jack Daniels (PhD), you start losing cardiovascular fitness after 5 days of no running. However, it is a tiny amount of loss.

I've found that a week off hurts me less as I'm getting older. A week off in high school seemed to take a lot out of my fitness but now it's not really noticeable.

12% muscle tone is lost in 5-7 days off. So, yes

Jack Daniels doesn’t know what he’s talking about. I ran a 4 second mile PR after 1 month in the pool.

The good thing about losing fitness, and the reason you want to periodically, is you have something to build to and hopefully toward PRs.

It's my recollection that Roger Bannister purposely took 6-7 days "off" immediately prior to his epic run at Iffley Road track.

I mean, that’s just not true.

I find this thread lacking.

Nobody ever took a week off while healthy that resulted in a meaningful decrease in performance after a few days back in training. Most serious runners would benefit from the rest.

If you're interested here is a decent article describing the 1976 paper by Eric Banister et al, where he establishes a pretty good mathematical model of endurance fitness.

https://science4performance.com/2017/05/05/strava-fitness-and-freshness

Strava recently integrated this into their app using a heart-rate based estimation of power output for runners. The idea is that there is a trade-off between fitness and fatigue. This model doesn't explain why you would feel more fatigued for a certain kind of activity after a rest, but it does quantify a loss of fitness and gain of freshness after some time off. I've found it to be a pretty good predictor of my performance n the near future. It has correctly predicted a few down weeks for me too. I mean weeks where I should have taken a down week deliberately but I tried anyway and but felt so unmotivated that they ended up being defacto down weeks.

Mr. Newton used to tell us "Everyday you eat, you should run". So thereotically, you should never take a day off unless you're into fasting.

Das Unkle wrote:

[quote]SLoWpacE. wrote:

Depends on your age.

A week off is nothing at age 20.

Get to mid thirties or so and it takes three weeks to get back to where you were before your week off.

No it doesn't, 3 weeks?! One week would have zero noticeable effect on fitness. You'll probably feel a bit uncoordinated but after a day or 2 you'll be right back at it. If your not something else if at play, over training probably.