If you ask runners what the hardest part of parkrun is, most will say the final kilometre.
But if you pay close attention to how runners actually feel during the run, a different pattern shows up.
The hardest part for many runners is the first kilometre.
It’s the moment where breathing spikes.
The legs feel heavy.
The pace suddenly feels harder than expected.
And often, by the time runners settle into rhythm, the damage is already done.
They’ve either gone out too hard…
or they’ve spent the first kilometre fighting their body instead of working with it.
The surprising thing is that this problem usually has nothing to do with fitness.
More often, it comes down to something much simpler.
They started cold.
The Typical parkrun Start
Watch what happens at most parkruns.
Runners arrive.
They chat with friends.
They stand around waiting for the start.
They shuffle toward the start line during the briefing.
Then suddenly the countdown begins.
Three…
Two…
One…
And everyone launches into race pace.
From a physiological perspective, that’s a terrible way to start a 5K.
Your body has gone from standing still to race intensity in seconds.
Muscles are cold.
Oxygen delivery hasn’t ramped up yet.
The nervous system hasn’t been primed for the effort.
So the first kilometre feels like a shock to the system.
That’s why so many runners describe the opening minutes as feeling uncomfortable, awkward, or harder than expected.
But it doesn’t have to be that way.
What a Good Warm-Up Actually Does
Many recreational runners skip warm-ups because they assume warm-ups are only for elite athletes.
But the opposite is true.
The less experienced a runner is, the more valuable a proper warm-up becomes.
A good warm-up does three important things.
First, it raises your core temperature.
Warmer muscles contract more efficiently and are less prone to strain.
Second, it improves oxygen delivery.
Your cardiovascular system begins ramping up before the run begins.
Third, and most importantly, it activates your nervous system.
That means your body becomes ready to run at the pace you’re about to ask of it.
Without that preparation, race pace feels like a shock.
With it, race pace feels like something your body already understands.
Why the First Kilometre Matters
The first kilometre of a 5K sets the tone for the entire run.
If you start well, you settle into rhythm early.
Your breathing stabilises.
Your pacing becomes controlled.
But if the first kilometre is chaotic, everything else becomes harder.
You might:
- Start too fast and fade later
- Start too cautiously because the effort feels overwhelming
- Spend the first half of the run trying to find rhythm
That’s why experienced runners focus heavily on preparing properly before the start.
It’s not about doing more work.
It’s about making sure your body is ready to perform.
The Simple parkrun Warm-Up I Recommend
Over the years I’ve coached thousands of runners preparing for parkrun and other 5K races.
Through trial and error (as well as numerous degrees at university), I’ve found that the most effective warm-ups are also the simplest.
This is the routine I recommend most often.
10min Level II
Then:
3 × 60sec Level IV
with 30sec Level II Rest Interval
Finish just before the event briefing, and loosen up with some light leg swings during the briefing.
That’s it.
The whole routine takes about 15 minutes.
But those 15 minutes make a huge difference.
Why This Warm-Up Works
The first part of the routine — the 10 minutes at Level II — gradually raises your core temperature and prepares your aerobic system.
This shouldn’t feel hard.
It’s conversational running.
Comfortable and relaxed.
The second part — the three 60-second efforts at Level IV — primes your body for race pace.
These short efforts activate your neuromuscular system so the pace you’ll run during parkrun doesn’t feel like a sudden shock.
Instead, when the run starts, your body already recognises the effort level.
You simply continue running.
The final step — finishing close to the briefing — ensures you arrive on the start line warm and ready rather than cooling down while standing around.
What Runners Notice When They Use It
Runners who start using this routine consistently usually report three things straight away.
First, the first kilometre feels smoother.
Instead of struggling to settle into the run, they feel like they’re already moving well from the start.
Second, race pace feels more controlled.
Breathing doesn’t spike as dramatically because the body has already adjusted to the effort.
Third, they find their rhythm earlier.
And rhythm is everything in a 5K.
Once you’re in rhythm, the run becomes far more manageable.
The Biggest Mistake With Warm-Ups
Ironically, when runners do start warming up, they sometimes overdo it.
They turn the warm-up into a workout.
That’s not the goal.
A warm-up should prepare you for performance, not tire you out before the run even begins.
That’s why the routine above works so well.
It’s enough to prepare the body, but not enough to create fatigue.
Try It This Weekend
If you’re running parkrun this weekend, try this warm-up exactly as written.
Pay attention to how the first kilometre feels compared to normal.
You may notice that the early part of the run suddenly feels calmer and more controlled.
That’s not magic.
That’s preparation.
Download the Full Warm-Up Blueprint
If you’d like a simple guide you can refer to before parkrun each week, I’ve put together a short resource that walks through this routine step-by-step.
You can download it here:
➡️ Download the parkrun Warm-Up Blueprint
It takes less than two minutes to read, but it can completely change how your next parkrun feels.