Three weeks without running and the fastest kilometre at the very end

On Saturday evening I ran a 10K through the centre of Prague. Since coming back from the mountains I had run twice in a month and not at all in the last three weeks. The estimate I took to the start line was 42 to 43 minutes, so something around 4:15 per kilometre.

I finished in 41:05 at an average pace of 4:05. That's a pace I run when I'm in full shape.

I'm writing about it because the difference isn't about me. It's exactly the situation anyone ends up in when they come back after a break and work out in advance what they can probably manage. And that calculation is usually off, in both directions.

What I didn't count on

I counted what I had run since coming back. What decided it was what came before.

Before the break I had fifty kilometres a week in the mountains behind me. And the mountains were Livigno, so altitude. That's an important detail I didn't include in my estimate. After a stay at altitude, performance often goes up only several weeks after you return, not straight away. In the meantime your body is working on things you can't see.

Training isn't written into your body on the day you do it. It's written in the weeks that follow, and a break isn't an eraser.

What you really lose in three weeks

What drops in three weeks off, enlarge

You lose something, just not what people are afraid of. I wrote about it in detail in Getting back to the gym after a break, but with running the loss looks different.

Strength holds. Within three weeks almost nothing happens to it that you could measure. The muscle remembers. Fitness drops faster than strength, but for someone who had volume behind them, not fast enough to decide a race in three weeks.

What goes faster is how well your tendons and ligaments cope with impact. That takes weeks to build and fades before your breathing does. The main risk of a comeback is therefore injury, not a bad time. A comeback after a break isn't measured by how fast you run, but by whether something hurts the next day.

In practice it means one thing: after a break, trust your pace, but be careful with volume. What I do with runners so their tendons can take that volume is on its own page. In the first weeks add kilometres carefully, and speed only after that.

Pacing decided more than fitness

My kilometres from the 10K, enlarge

This is what the kilometres looked like:

4:09, 4:14, 4:07, 4:08, 4:04, 4:03, 4:07, 4:03, 3:55, 3:48

The fastest kilometre was the last one. The slowest was the second.

This is called a negative split, and it's the most boring advice in running, the one almost nobody follows. The first kilometre is in a crowd, with adrenaline and fresh legs. Nothing is easier than running it fifteen seconds faster than you should. You pay for it at the end, when there's nothing left to draw on.

If you keep the first two kilometres slower than you could, the pace comes on its own afterwards. And above all, you have something left to speed up with at the end. That's the difference between a race you finish and a race you survive.

This is exactly what I advise clients who are coming back after a break. Start below what you can do. This time, the person giving the advice ran by it too.

Heart rate as a check

Average heart rate 146. For a race that's a low number. It doesn't mean I was holding back, it means my body had a reserve.

When you come back after a break, heart rate is more useful than pace. Pace tells you how fast you're running. Heart rate tells you what it cost you, and whether there's room to add more next time or you're at the edge.

And one thing I did wrong

On the same day at ten in the morning I taught a strength class and didn't hold back in it. That isn't recommended before a race, and it should be said even when it turned out well.

That it worked doesn't mean it's a method. It means the reserve was bigger than the plan assumed. If it had been smaller, I would have felt it in the last two kilometres, exactly where this time I could speed up.

What to take from it

Don't calculate your comeback from the last few weeks. What decides it's what you ran or trained before. An estimate based on the break tends to be more pessimistic than reality.

The risk after a break isn't a bad time, but injury. Bring back volume before intensity, and the next day watch whether your tendons complain.

Start slower than you want to. Whether it's a race or your first session after three months. You can always speed up. Easing off once you have already overdone the first kilometres is much harder.

One more thing to finish: write down beforehand what time you expect. When you then compare it with reality, you'll learn more about your training than from the results list.