Half marathon 1h45 training plan — 12 weeks

Half marathon 1h45 training plan — 12 weeks

Break the 1:45 half marathon at 5:00/km pace: complete plan for intermediate runners

Create my 1:45 half marathon plan

Running a half marathon in 1:45 means holding 5:00 per kilometre for 21.1 km. It's an ambitious intermediate target: you've either already broken 2:00 and want to push further, or you're targeting your first sub-1:45. This 12-week plan with 4 sessions per week covers the essential physiological bases: VO2max intervals, lactate threshold work and progressive long runs to bring you to race pace on the day.

Why choose RunRun?

5:00/km pace — calibrated to your profile

Enter your VO2max or recent half or 10km time. RunRun automatically calculates all your training paces for each session type.

Interval and threshold work

1000m in 4:20, 2000m in 9:00 and 30' threshold at 5:10/km. The ideal combination to develop your aerobic engine for the half marathon distance.

Progressive long run

Up to 1h55 at easy pace late in the plan, including blocks at half marathon pace to condition muscles for running fast over long distances.

12-week plan, 4 sessions per week

Volume from 45 to 60 km/week. Recovery weeks every 3 weeks. 12-day taper before race day to arrive in peak condition.

Recovery and injury prevention

Active recovery sessions, mobility and strength cues integrated throughout. Finishing the plan healthy is as much a success as the race itself.

Smart RunRun tracking

Connect Strava or Garmin to import sessions automatically. RunRun monitors your data and adjusts your paces if your fitness evolves during the plan.

Overview of the 1:45 half marathon plan

W1

Week 1 — Starting up

Progressive warm-up, easy-pace sessions to assess your current fitness.

  • •45' easy run
  • •6x1000m in 4:35 — 2' jog recovery
  • •40' easy + 6 strides
  • •1h20 long run easy pace
W4

Week 4 — Race-specific work

First threshold sessions. First long run with half marathon pace blocks integrated.

  • •45' easy run
  • •5x1000m in 4:20 — 1:45 jog recovery
  • •25' threshold (5:10/km) in 55' run
  • •1h35 long run with 20' at half marathon pace (5:00/km)
W8

Week 8 — Peak load

High-demand week. Long long run with a major race-pace block. Sensation testing at target paces.

  • •50' easy + 4 strides
  • •3x2000m in 9:00 — 3' jog recovery
  • •35' threshold in 1h run
  • •1h55 long run with 30' at half marathon pace
W12

Week 12 — Taper and race

Volume reduced by 40%, a few sharpeners to stay fresh. Race day: 1:45 in sight.

  • •35' light jog
  • •4x1000m in 4:20 — 2' recovery + 15' easy
  • •25' very easy jog
  • •Race day — half marathon goal 1h45

Tips for the 1:45 half marathon

1

Your current PB should be between 1:47 and 2:00

This plan targets runners whose best half marathon is between 1:47 and 2:00. If you're already comfortably inside 1:50, consider targeting 1:40 instead.

2

Run the first 5km at 5:05/km

Starting slightly slower than target pace avoids early blowups. The first 5km at 5:05/km leaves energy in reserve to accelerate in the second half.

3

Gel at km 7, km 14 and halfway

A gel or sports drink at km 7 and km 14. Over 1:45, glycogen reserves are sufficient, but a mid-race gel keeps your power sustained to the finish.

4

Test your strategy on long runs

Long runs with race-pace blocks are there precisely for this: feeling what 5:00/km feels like after 40, 50 or 60 minutes of running. Adjust the plan based on what you learn.

5

Sleep more in the two weeks before the race

Sleep is your number one ally during taper. 8 hours of sleep per night in the 14 days before the race improves recovery and neuromuscular power on race day.

landing.faq

What pace is required for a 1:45 half marathon?
To finish in 1:45:00, you need to run exactly 5:00 per kilometre over 21.1 km. This corresponds to a VO2max of approximately 14-15 km/h.
What level do I need to target 1:45 in the half marathon?
A runner who can finish a half marathon under 2:00 with good physical comfort and trains regularly 3-4 times per week. If your 10km PB is between 44' and 50', you're in the ideal window for this plan.
Is this plan suitable for runners who train 3 days per week?
The plan schedules 4 sessions per week. If you can only run 3 times, drop the short easy run (session 1 or 3) and keep the intervals, threshold and long run. Progress may be slightly slower but the plan remains effective.
How do I follow this plan with Strava or Garmin?
On RunRun, connect your Strava account or your Garmin watch from your profile settings. Sessions then import automatically after each run. You just need to check that paces match the plan targets.
What is the maximum long run length in this plan?
The maximum long run is approximately 1h55 to 2h00, done around weeks 8-9. It includes 20-30 minute blocks at half marathon pace (5:00/km). It's the key session that gives you the physiological confidence to sustain pace over 21.1 km on race day.

Your 1:45 half marathon is waiting

RunRun generates your personalised 12-week plan to run a 1:45 half marathon, with sessions calibrated to your profile and Strava/Garmin tracking built in.

Create my 1:45 half marathon plan