It's not just you. The first kilometre of a run (or about the first ten minutes of any exercise) sucks for everybody. Go easy on yourself in that first kilometre, though, and you can set yourself up for a great workout or race. Illustration by Sam Woolley.
We ask too much of ourselves, sometimes.
You head out for a 5km run, and you want to be able to say afterward that you ran 5km in a certain time -- let's say 30 minutes. So you step out of your car, or out your front door, and try to immediately keep up a six-minute-kilometre pace.
It sucks, right? You hate your life. You wonder why you ever took up running in the first place. You either slow down, or manage to keep up the pace and endure the suffering. Clearly I can't run six-minute kilometres, you say to yourself. I thought I could, but I haven't been training enough. I shouldn't have eaten that pizza. I'll always be slow. It's only been five minutes and I feel like I'm going to die. I might as well pack up and go home.
Hands up if you've ever had a workout feel so terrible in the first ten minutes that you've abandoned your plan for the day, or worse yet, actually just gone home. Yeah, me too.
Here are the eight words that are going to change your life: The first kilometre is junk. Throw it away.
You should never expect anything good from your first kilometre. It will either be slow, or feel awful, or both. But during that first kilometre, your muscles are transitioning to a more efficient way of working. The slow, stiff, cold, doubtful first kilometre paves the way for the smooth, easy, strong kilometres to follow.
As you begin to exercise, your breathing speeds up, to get more oxygen into your blood. Your heart beats faster and your blood vessels dilate, to get that oxygen-rich blood to your muscles as quickly as possible. And your muscles temporarily make more of the enzymes that turn fuel into energy. Triggering these changes before your workout primes your body to work efficiently, according to Runner's World, even if you take a break between your warmup and your real workout.
How to Use Your First Kilometre as a Warmup
Let's put this in terms of training goals. The first kilometre of your run has one job and one job only: To prepare your body for the rest of the workout, which is where the magic happens. So rather than thinking of your training run as 5km, you're running a 1km warmup and a 4km workout. And you won't start looking at your watch, or asking yourself to do anything strenuous, until that first kilometre is behind you.
The first kilometre will take more time for some people than for others, so just to be clear: we're talking about the first 10 minutes or so of your workout. If you're super speedy, you might want to think of this warmup time as your first two kilometres. Or if you prefer to think in time rather than distance, set your watch for 10 or even 15 minutes.
So, no timing yourself on the first kilometre. Don't try to run a particular speed, or to tackle hills or fast intervals. Just work at an easy pace. That may mean an easy jog or, if you haven't figured out how to run slow, a heart-pumping brisk walk. To fully prime those oxygen-delivery systems, include some mini-intervals, which runners call strides: accelerate to a sprint, hold that speed for 10 seconds or so, then slow back down. Jog for a minute to recover. Work a few of these into the last few minutes of your warmup.
Yes, I know there are unpleasant consequences: the slower kilometre will pull down your Runkeeper stats. Or you can start timing after the first kilometre is over, but then your app won't give you credit for that first kilometre. Here's how much you should care about that: zero. Just because an app gives you numbers to track, doesn't mean chasing those numbers will help your fitness. A log on paper is my solution to that problem: I write down that I ran 5km, and then add a note about what my pace was for the 4km that really count.
It's amazing how good it feels to go easy on yourself during the first kilometre. Try it once or twice, and you'll be hooked. Problem solved. But then what do you do when it's time to run a race?
Trashing the First Kilometre on Race Day
You don't want that junk kilometre messing up your race time, so you'll need to get to the race early, and actually warm up. If you've always shown up to races a few minutes before the starting gun and tried to hit your goal pace right off the bat, this will take some getting used to. I promise it's worth it.
One caveat: In a very long race like a marathon, it may be impossible to warm up beforehand, and that's actually kind of OK. You'll probably be huddling in a crowded start corral for a half hour or more before the race starts. You can do some squats while you wait, to help your muscles get ready to work, but the first mile of the race will be your real warmup. Take it easy. Even if you're a minute or two over goal pace, you'll be able to make it up later in the race because you'll be feeling so great. (That said, marathon racing strategy is a whole field of study unto itself.)
The shorter the race, the more important the warmup. I once ran a 2km and my warmup was longer than the race itself. I jogged around the side streets near the race's start, and once I was feeling good, I ran a few strides, with a minute or two recovery, before moseying over to the starting line. The warmup was 2km and worth every inch.
To allow yourself time and space for your pre-race first kilometre, scope out the area ahead of time, and get there early. Run the same warmup you ran in training. That might be an easy kilometre, or an easy ten minutes, or ten minutes easy plus five minutes of strides to prime your muscles for the challenge to come. There's a benefit beyond the physical: doing a familiar warmup before a race can help to calm your nerves.
With that first kilometre out of the way, you can turn in a great performance without feeling like you're going to die. Races are hard enough with good preparation; trying to run a 5K without a warmup is just making it harder on yourself. Throw away that first kilometre, on race days or training days, and what remains will be your best effort.