Why is the Beginning of a Run the Hardest?: 4 Reasons Why

Every runner has asked themselves this question before, ‘Why is the beginning of a run the hardest?”

Your excitement for your run is through the roof. You put on your running gear, lace up your shoes, and head out the door.

For the first 10 minutes, you feel like you’re dragging an anchor. You check just to make sure you’re not. There isn’t one.

Then why is this so hard? Is something wrong with me?

Luckily, no, there isn’t anything wrong with you.

The first few miles are the most difficult for various reasons.

1. Your body has to shift from a resting state to an aerobic state.

2. You may have started too fast, and your body hasn’t caught up.

3. The famed “runner’s high” hasn’t kicked in yet.

4. Your legs are into the run, but your mind isn’t in it yet.

Let’s dive deeper into these reasons to investigate what is going on below the surface.

Shifting Into an Aerobic State

Whether you’re an early bird or a night owl, the time before you run, your body is in a resting state.

Your heart rate is lower and is doing its best to save energy. In addition, your body is pumping out a hormone called acetylcholine.

If you’re like me, you probably had trouble pronouncing that word, let alone knowing what it does.

It turns out that this hormone does a few things. It contracts your smooth muscles, dilates your blood vessels, and slows your heart rate down. All things that help promote relaxation.

When you head out for your run, this hormone is still coursing through your body.

Your heart rate still has to catch up to your body. This is why is the beginning of a run the hardest.

It isn’t until stress is introduced (here in the form of your run) that your body kicks into gear to get this hormone out and start introducing the hormones you need to fight it.

In this case, you’re not actually “fighting” anything; you’re just dealing with the stress of a run.

In addition, you’re now requiring more oxygen than you did when resting. This signals to the heart that it needs to increase blood output to deliver more oxygen to your muscles.

This is why your heart rate is usually higher at the beginning of a run before settling into it and gradually decreasing. This is also a key reason of why is the beginning of a run the hardest.

So, your heart is trying to catch up to the demands your muscles are placing on it.

You Started Too Fast

This and the first problem listed above go hand-in-hand.

You’re excited about your run, your legs are pumping, and your pace is excellent! Hell, maybe you even passed some people and unconsciously sped up just so you’d look cool.

Don’t be ashamed; I do it, too, like every other runner.

Coming out too fast places even greater demand on your aerobic system, primarily your heart.

Your muscles require too much oxygen too quickly, and your heart is doing all it can to balance this deficit.

And, by making the run harder, it’s essentially your body’s way of telling you to slow down. If it could send you a text, “Hey bro, you need to cut back; I’m working overtime here,” it would.

But instead, it sends subliminal messages in the form of added difficulty.

The Runner’s High Hasn’t Started Yet

Whether you believe in the runner’s high or not, the thing you can’t deny is that endorphins play a significant role in running.

Science has shown it usually takes around 15-20 minutes before your body releases the first wave of endorphins.

And this is when you start to ease into your run, and that anchor is detached from your body.

The famed runner's high kicks in and your run is fantastic.

If you’re unfamiliar with endorphins, it’s the chemical that relieves your muscles from pain. It’s the “feel-good” chemical every runner raves about (although it’s not just endorphins that produce this feeling.)

For the first mile or two, your body hasn’t released these chemicals, so you feel the full brunt of the workout.

However, once these kick in, they aid in helping you keep pushing on for the duration of your run.

Your Mind Is Just Catching Up

Before going on your run, you were doing one of two things: sleeping or living.

Either way, your brain is preoccupied with other things, whether dreaming or daily life drama.

When you begin your run, your brain doesn’t just kick these things out like they’re bad tenants who haven’t paid rent. It’s still dealing with them and trying to process them.

In other words, you may be on your run, but your brain is still back at your house with its feet kicked up.

And it takes some time to put on its own running shoes and catch up to you.

Running requires focus, and focus doesn’t just come at the flick of a switch (as any adult who’s needed to focus will tell you.)

You’re initially distracted, and you need time to remove these thoughts and put your mind on the run. If you’re like me, this is one of the biggest reasons for why is the beginning of a run the hardest.

But, once your mind is on the run, it’s easy sailing from there (well, mostly.)

How to Help Your Body Get Into Running Mode

Runners are notoriously bad at preparing their bodies for a run. Most will put on their shoes, walk out their door, and begin running straight from their doorstep.

This is almost always a bad idea for a variety of reasons. But, for today’s post, we’re going to focus on how you can help your body to avoid that early run misery.

Warm Up With Dynamic Stretches

You’ve heard it repeatedly, but a warm-up is a crucial way to help your body ease into a run. It also helps avoid injury.

It doesn’t have to be long. But, a warm-up will signal to your body that you’re switching from relaxation mode to exercise mode.

Dynamic warm ups will help ease you into your run. Starting too quickly is why is the beginning of a run the hardest

The best way is to do dynamic stretches which mimic the movements you’ll make during the run.

Given the reasons above, this will help your heart transition smoothly, like a Porsche shifting gears.

It also gives you time to clear your mind of the nonsense going on in life and focus on the beauty of your run.

Walk Then Run

I’d recommend doing the above tip and this tip in combination. But, you could choose to walk or do a slow jog at the beginning of your run.

Starting slow will help keep you from going out too fast and allows your heart time to adjust.

As you increase in speed, your heart can gradually increase its blood output. This delivers oxygen to your muscles at an ideal rate and doesn’t leave your heart racing to catch up (literally.)

Resist your urge to push it as soon as your foot hits the pavement, and you’ll avoid those early run ailments.


It’s natural for you to wonder why is the beginning of a run the hardest.

From biological to mental processes, your body needs time to switch gears and get into running mode.

Once you’re there, you can enjoy the sweet sensation that all runners feel, making us love this beautiful activity.

But, until you get there, don’t ask too much of your body. Treat it right, and it’ll return the favor.

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