How to Run a 1:45 Half Marathon: The Ultimate Guide to Breaking 1 hour 45 Minutes

Starting your running journey should feel exciting, not overwhelming. Our training plans give you the structure, support, and flexibility you need to go from your first step to running a half marathon, no matter your starting point.

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Running a half marathon in 1 hour 45 minutes is one of the most popular milestones for dedicated runners, and with good reason. Hitting that time shows you have built solid endurance, the discipline to train week after week, and enough speed to sustain a strong rhythm for 13.1 miles. For many, crossing the line in 1:45 is proof that you’ve moved past casual running and into racing with purpose, testing what your body and mind can really do.

That said, it’s not a walk in the park. Finishing in 1:45 requires much more than pushing hard on race day. It demands smart training, consistent pacing, and the confidence to lock into your target splits even when fatigue starts to creep in. The good news? With the right approach, you can absolutely make it happen – whether you’re aiming to line up at a city road race, or nail a personal best on your home course.

In this complete guide, you’ll get everything you need to make your 1:45 half marathon goal a reality:

Exact target paces and splits so you know what to hit every kilometre.
Fitness benchmarks to check if you’re ready to take it on.
A proven training plan with the sessions you need to build speed and endurance.
Race-day tactics to pace yourself smartly and finish strong.
Expert tips and real success stories from coaches and runners who’ve cracked 1:45 themselves.

No more guesswork. Just clear, practical advice to help you run your best half marathon yet, and enjoy the journey along the way.

Ready? Let’s go get that 1:45!

What Does It Take to Run a 1:45 Half Marathon?

To finish a half marathon in 1 hour 45 minutes, you need to average about 8 minutes per mile, or roughly 4 minutes 58 seconds per kilometre. That’s your benchmark: mile after mile, kilometre after kilometre, without letting your pace drift.

Put simply, you’ll need to keep each kilometre just under 5 minutes, or each mile right around 8 minutes, from start to finish.

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It might sound straightforward, but when the pace starts to feel tough and your legs grow heavy, sticking with that rhythm requires more than fitness alone. You’ll need strong endurance, the confidence to settle into your goal pace, and the mental resilience to keep pushing when fatigue sets in.

Who is this goal realistic for?

If you’re already running half marathons in the 1:50–2:00 range, you’re in a great position to target 1:45 with the right training. You likely have the base mileage, but now it’s about refining your speed, building strength with tempos and intervals, and learning to pace evenly over 13.1 miles.

And if your PB is still a bit outside that window, don’t worry. Many runners are surprised at how much they can improve with a focused plan. By training smart and hitting the right sessions, that 8:00 mile pace can go from intimidating to totally manageable.

Are You Ready for a 1:45 Half Marathon?

Before you commit to chasing a 1:45 half marathon, it’s worth checking that your current fitness is in the right place. Jumping in too soon can lead to frustration or injury. These simple benchmarks will help you gauge whether you’re ready to train for an 8:00 per mile (4:58/km) pace with confidence.

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Benchmark Sessions

1. The 3 x 2 Mile Repeats Test‍

Find a flat loop, track, or measured road stretch and run 3 x 2 miles with 3–4 minutes of light jogging between efforts.

Aim to hit each rep at or just under 8:00 per mile (4:58/km).‍
If you can get through all three while feeling strong – and know you could manage one more rep if needed – you’re likely in good shape to target 1:45 on race day.

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2. The 10K Time Trial‍

Another option is to run a solo 10K at a controlled, hard effort after a good warm-up.

If you can run close to 47–48 minutes and finish knowing you could keep pushing for a bit longer, that’s a good indicator that 1:45 is within reach with focused training.
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These tests aren’t exhaustive, but they give a clear picture of whether you have the mix of speed and endurance to train at goal pace, or if you’d benefit from a longer base-building block first.

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Check Your Weekly Mileage Base‍

Pace workouts alone won’t get you to the finish line. You’ll need a solid aerobic foundation to handle long runs, recover well, and stay strong over the full distance.

As a guideline:

You should already be comfortable running 25–35 miles (40–55 km) per week for at least 4–6 weeks.
If your mileage is lower, spend a few weeks gradually building volume before adding in race-pace or interval sessions.

A steady mileage base combined with strides, short pickups, and consistent long runs will give you the platform you need to handle tougher workouts and avoid injury as you progress.

Key Training Principles

To run a 1:45 half marathon, your training needs the right mix of endurance, pacing practice, and strength. It’s not simply about running harder - it’s about building a smart routine that prepares you for the full 13.1 miles. Here’s what you should focus on each week:

1. Build Mileage Gradually

A strong aerobic base is the backbone of half marathon success. It allows you to hold pace when fatigue sets in and helps you recover faster between quality sessions.

Aim for 35–45 miles (55–70 km) per week if you’re an intermediate runner.

Increase your mileage slowly (no more than 10% per week) to reduce injury risk.
Keep most of these runs easy and conversational. Your structured workouts will take care of the harder efforts.

2. Include Intervals

Speedwork isn’t just for short races – intervals help half marathoners develop efficiency, sharpen turnover, and make goal pace feel more sustainable.

Try sessions like 6 x 1 mile at goal pace, 800m repeats slightly faster than race pace, or progression intervals.

Always start with a thorough warm-up.
Keep jog recoveries easy to stay fresh for each repeat.

One interval session per week is plenty for most runners.

3. Add Tempo Runs

Tempo runs are essential for half marathon training. They improve your lactate threshold, teaching your body to run faster for longer without fading.

Run these at around 15–20 seconds slower per mile than goal pace, or about 85–90% of max effort.

A good starting workout is 20–30 minutes at tempo pace after a warm-up.
As fitness improves, extend these runs to 40 minutes or more.

4. Don’t Skip the Long Run

The long run is your most important weekly session. It builds the endurance, mental toughness, and fuel efficiency you’ll rely on during the race.

Aim for 90–120 minutes at an easy pace, gradually extending to 14–15 miles in your peak weeks.

Think of it as time on your feet, not a speed test.
Sprinkle in sections at goal pace in the later weeks to simulate race conditions.

5. Strength & Mobility Work

Strength training supports your running by improving form, efficiency, and resilience against injury.

Focus on core stability, glute strength, and single-leg work – all key for maintaining pace over 13.1 miles.
Add mobility work for hips, hamstrings, and calves to stay flexible.
Just 1–2 short sessions per week of 15–20 minutes can have a big impact.

Pacing & Race-Day Strategy

As you step onto the start line, your plan matters just as much as your fitness - and the right pacing strategy can carry you all the way to a 1:45 breakthrough. Here's how to set it up:

1. Warm Up Properly

For a half marathon, a smart warm-up gets your body ready without draining energy you’ll need later.

‍Easy Jog: Start with 8–10 minutes of relaxed jogging to loosen up and ease into the day.
‍Dynamic Stretches: Add moves like leg swings, lunges, or hip openers to activate key muscles.‍
Strides: Finish with 3–4 short strides at slightly faster than goal pace (around 80% effort) to switch on your legs.

By the time you line up, you should feel loose, alert, and ready for a steady first few miles.

2. Start Smart

Going out too fast is the number one mistake in half marathons. Even a few seconds per mile too quick can come back to haunt you late in the race.

Stick to your goal pace: about 8:00 per mile or 4:58 per kilometre.

The opening 2–3 miles should feel comfortable and a little restrained.
If it feels easier than expected, that’s perfect. You’ll need that energy for the second half.

3. Hold Your Rhythm in the Middle

The miles between 5 and 10 are where discipline pays off. Fatigue will start to creep in, and it’s easy to lose focus.

Keep good posture: tall torso, relaxed shoulders, steady arms.
Zone in on a smooth rhythm. Think efficient and controlled rather than pushing.
If possible, tuck in with a group or lock onto another runner holding your pace.

4. Finish the Final Miles Strong

The last 5K is where your race really begins. This is when the work you’ve done in training carries you through.

Break it into small chunks – from mile 11, focus on just getting to the next marker.
At mile 12, remind yourself you have less than 10 minutes of running left at goal pace.
In the final stretch, pick a landmark and drive for the line. Every second counts, and this is where you earn your PB.

Mental Tips for Breaking 1:45

Running a 1:45 half marathon is as much a test of mindset as it is of fitness. Your legs will carry you as far as your training allows, but your mind is what keeps you pushing when fatigue sets in. Here are some ways to build mental strength and stay locked in from start to finish:

Break the Race into Chunks‍

Don’t let the full 13.1 miles feel overwhelming. Mentally divide the race into manageable sections, each with its own mini-goal:

Miles 1–3: Settle in. Get into rhythm, keep things smooth, and resist the urge to start too quickly.
Miles 4–7: Hold steady. Focus on keeping your pace controlled and efficient.
Miles 8–10: Stay engaged. This is often where focus drifts, so remind yourself to stay sharp.
Miles 11–12: This is the grind. Everyone feels tired here, so lean on your training and stay tall.
Final mile: All in. Remind yourself you’ve got just minutes left – dig deep and empty the tank.

Breaking the race into chunks makes the distance feel less daunting and gives you small wins along the way.

Use Positive Mantras‍

When the going gets tough, a simple phrase can help you stay locked in. Choose a short mantra that you can repeat with your stride:

“Calm and strong.”
“Smooth and steady.”
“One more mile.”

These phrases block out negative thoughts and keep your focus on moving forward.

Focus on Your Breath‍

Your breathing can be a powerful anchor. Stick to a steady rhythm – for example, in for three steps, out for two. Staying aware of your breath keeps you calm, relaxed, and efficient, especially as the miles add up.

Visualise Success‍

In your training runs, spend a few minutes imagining race day. Picture yourself holding your goal pace, staying strong through the middle miles, and driving to the finish. See the clock reading 1:45 as you cross the line. Having that mental image ready can give you a boost when you need it most.

Nutrition & Gear for a 1:45 Half Marathon

What you eat and wear can make a big difference. When you’re aiming for a 1:45 finish, you don’t want your stomach, shoes, or kit causing distractions. Keep things simple, familiar, and focused on performance.

The Night Before‍

Your fueling starts well before you line up on race morning.

Have a carbohydrate-focused dinner such as rice, pasta, or potatoes with lean protein.
Keep the meal balanced and avoid anything too rich or heavy. The goal is to fill your glycogen stores without feeling weighed down.
Stay hydrated steadily throughout the day rather than chugging large amounts of water right before bed.

Race Morning‍

A good breakfast will keep you energized without upsetting your stomach.

Stick with tried-and-tested foods: a banana, a slice of toast with honey, oatmeal, or a small bagel.
Eat 2–3 hours before the start to allow time for digestion, then sip on water or an electrolyte drink up until the race begins.
Avoid anything new, spicy, or greasy. Race day is not the time to experiment.

Gear: Keep It Light and Tested‍

Your kit can make or break your run if it’s not dialed in.

Choose running shoes you’ve worn comfortably in training, ideally lightweight but supportive enough for 13.1 miles.
Stick to gear you’ve already tested - new socks, shorts, or tops can mean blisters or chafing that will cost you time and focus.
Dress for the weather on the day. Warm layers are fine for your warm-up, but strip down to your race kit when the gun goes off.

Frequently Asked Questions

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