How to Train for a Sub-1:45 Half Marathon

Going from a sub-2:00 finisher to a sub-1:45 runner is one of the most rewarding jumps in distance running.

The goal is clean, specific, and just close enough to feel possible.

If you have already broken two hours and want a structured push to the next level, this guide breaks down the workouts, paces, and weekly layout that get most committed runners across the line.

What Sub-1:45 Actually Requires

To finish in 1:44:59, you need to average roughly 7:59 per mile or 4:58 per kilometre. Across 13.1 miles, there is almost zero room for a slow patch.

That pace is significantly faster than the 9:09 mile that gets you under two hours.

The jump in fitness, focus, and pacing skill is real.

You will need a stronger aerobic base, more confidence at threshold, and a polished long run. None of it requires elite genetics, just consistency and smart structure.

Are You Ready for This Goal?

Not every runner is ready to chase 1:45 in the next training cycle. Trying to leap before the base is there is the fastest way to burn out or land an injury.

Baseline Fitness Markers

Before you start, you should already be running consistently for at least six to nine months.

Weekly mileage of around 40 to 55 kilometres should feel sustainable.

Ideally, your 10K time sits between 45 and 50 minutes. A current half marathon time in the range of 1:50 to 1:58 tells you the gap is realistic.

If you are not quite there, spend a cycle on the sub-2:00 half marathon plan first, then come back to this goal.

When to Hold Off

If you are coming back from an injury or your sleep and stress are off the rails, push the goal to a later race.

A 12 to 14 week block of focused work needs a stable foundation.

Trying to crash through on willpower alone almost always ends with a missed taper or a blown-up race day.

The Three Workouts That Get You There

You do not need ten different sessions every week. You need three that you repeat with intent, week after week.

The Tempo Run

The tempo run is your lactate threshold workout. It teaches your body to clear effort byproducts at a faster pace.

Start with 3 to 4 miles at roughly 15 to 20 seconds per mile slower than goal pace. Add a 10 to 15 minute warm-up and cool-down on either side.

Over the cycle, build the tempo segment from 3 miles up to 6 miles.

Our full breakdown of tempo run structure is a useful reference if you want to fine tune the workout.

Half Marathon Pace Intervals

These are your race-pace specific sessions. They train your legs and brain to recognise 7:59 per mile as normal.

A simple version looks like this: 4 to 6 reps of 1 mile at goal pace, with 90 seconds of jogging recovery. Build to 6 to 8 reps over the cycle.

The Long Run With Quality

The long run is more than time on feet. To prepare for 1:45, you need long runs that finish with sharpness.

Run the first 60 to 70 percent at easy conversational pace.

Then close out the final 5 to 7 kilometres at goal pace or slightly faster.

This teaches you to handle a fast finish when your legs are already tired. That is exactly what the second half of your race will feel like.

Weekly Structure and Mileage

A typical week sits at 45 to 60 kilometres across five running days.

Monday: rest or 30 minutes of cross training.

Tuesday: tempo session, building from 3 to 6 miles at threshold pace.

Wednesday: 8 to 10 km easy plus light core work.

Thursday: half marathon pace intervals.

Friday: rest or short recovery jog of 4 to 5 km.

Saturday: 6 to 8 km easy with strides at the end.

Sunday: long run of 16 to 22 km with a fast finish on key weeks. Strength work and mobility fill the gaps on lighter days.

Race Day Pacing

Pace discipline matters more here than at any other distance. Going out 10 seconds per mile too fast can cost you 60 seconds later.

The First 5 Kilometres

Your first 5K should feel almost too easy. Lock into 8:00 to 8:05 per mile and trust the pace.

Adrenaline will tempt you to push. Resist it.

The Middle Miles

This is where the race is won or lost. Hold even splits between kilometre 6 and 16.

If you find yourself drifting up to 8:10 per mile, gently correct without panicking. Your aim is small, smooth adjustments.

The Final 3 Kilometres

The last 5 kilometres should be your strongest of the day. If you have paced correctly, you can drop to 7:50 per mile for the closing stretch.

This is where your long run finishes pay off. Your legs already know what fast feels like at the back end.

Final Thoughts

Cut volume by 30 percent in the second-to-last week and by 50 percent in race week.

Keep one short, sharp session 4 to 5 days out to keep the legs primed.

For a deeper guide to intensity zones and how to gauge race-day effort, the Mayo Clinic exercise intensity guide is a clear reference.

The gap from 2:00 to 1:45 looks small but feels significant. You close it with steady mileage, three quality sessions a week, and disciplined pacing.

Trust the plan. Execute the build. On race day, run the first half with your head and the second half with your heart.