Want to Run a Half Marathon in Less Than Two Hours

Love your website! Today I ran 5 km in my local race. My time was 25 minutes, 38 seconds. I am a 44 year old woman, average height and build (5'5" and 9 stone 2 lbs) and I have been running regularly for the past eight months. This 5km was a mixed race and up one of the hills I pushed a wheelchair and also along the gravelly final stretch. Maybe that added a couple of minutes to my time, hard to say but so worth it to be able to help someone. I did my first half marathon six months ago which was tough. I had a displaced kneecap by the end which I have now fixed with made-to-measure orthopaedic insoles. I finished in 2 hours 24 minutes which I was very disappointed with. It's a hard half, very hilly, very hot, but I was gutted to be so slow. Goal 1. In a month there is a 12 km fundraiser I'd like to participate in, would be nice to finish in 1 hour. How far should I run while training for that and how many times a week? Bearing in mind I have 6 weeks to train. Goal 2. I'm aiming to do another half in six months and want to finish in under 2 hours. Basically I want to nail it. Meanwhile I will put in the hours each week, running three to four times a week and will do some 10 km races to keep me revved up. What is the optimal distance that I should be doing in training please? I eat healthy, am a non-smoker, drink very little and my other hobby is classical ballet, I take a class once a week. I would be able/willing to do some kind of cross training if it will help me do better times in races, I am very motivated to improve; I have a strong competitive streak ;-) Kind regards, Rebecca – Rebecca

Hi Rebecca,

What a letter — and stopping to push a wheelchair mid-race tells me everything I need to know about you. That same grit is exactly what carries you through the tough miles in a half marathon.

Here's what we'll cover:

1. What your 5K time is actually telling you
2. Your 12km in under an hour — the honest picture
3. Building your aerobic base for a sub-2 half marathon
4. Adding one quality session per week
5. Keeping your knee healthy through the build-up

1. What Your 5K Time Is Actually Telling You

Your 25:38 on a hilly course — while pushing a wheelchair over a gravelly final stretch — is a seriously solid result. Run that same distance on a flat road on a fresh pair of legs and you are almost certainly looking at a time somewhere between 23:00 and 24:00. That matters enormously for what's possible at the half marathon distance.

A 25:38 5K converts to a predicted half marathon of roughly 1:55 to 1:58. You read that right. The speed is already there. Sub-2 hours is not a stretch target for you — it is your realistic race outcome, provided you build the endurance to sustain your natural pace for the full 21.1 kilometres.

Sub-2 pace is 5:41 per kilometre. Your recent 5K pace — adjusted for course difficulty — puts you comfortably within reach. The gap between where you are now and where you want to be is almost entirely an endurance gap, not a speed gap. That is good news, because endurance responds very predictably to progressive, consistent training over several months.

Your 2:24 first half marathon tells a different story — but not a discouraging one. You ran it on a very hilly, very hot course after only a few months of running, with a knee problem developing mid-race. That result doesn't represent your potential. It represents a hard day under difficult circumstances. Six months of proper preparation will produce a very different race.

2. Your 12km in Under an Hour — The Honest Picture

A 12km in 60 minutes requires 5:00 per kilometre — eight seconds per kilometre faster than your current 5K pace. In six weeks, that's a genuinely tight ask, but it is possible if the course is flat and the conditions are kind. Think of it as a stretch goal rather than a guaranteed outcome.

For the next six weeks, run four times per week. Keep three of those sessions easy — conversational pace, where you could comfortably hold a full sentence without gasping. Your long run should build gradually from whatever distance feels comfortable now up to 14 kilometres by week four, then hold there. Don't push the long run beyond 14km in this block; you need the recovery for the next session.

Add one quality session each week — nothing elaborate. Try 4 x 6 minutes at your target 5:00/km pace, with 90 seconds easy jogging between each rep. This teaches your legs what goal pace feels like when fatigue is already in them. Do it on Tuesdays or Wednesdays, never the day before or after your long run.

The trick is to treat this 12km race as a stepping stone and a fitness check, not as a make-or-break event. Whether you run 60:10 or 62:00 on the day, what you learn about your current fitness is more valuable than the clock. Race it, enjoy it — then use the result to plan the next six months intelligently.

3. Building Your Aerobic Base for the Half Marathon

Six months is a sensible, generous timeframe — and the most important thing you can do with it is build easy mileage progressively. The aerobic base is everything in a half marathon. Without it, even a runner with good speed will fade badly in the final 5 kilometres.

From week seven onwards — after your 12km race — shift your focus to the half marathon. Run four times per week: one long run, two easy runs, one quality session. Your easy runs should feel genuinely easy. Many runners make the mistake of running their easy days too hard and their hard days too tired — you end up mediocre at everything. Easy means easy.

Build your long run by no more than 10% per week, and take a recovery week every fourth week by dropping back to roughly 80% of the previous week's long run distance. A sensible long-run progression over twelve weeks might look like this: 14km, 15km, 16km, 13km, 17km, 18km, 19km, 15km, 20km, 21km, 18km, then a two-week taper into race day. By the time you line up, running 21km won't feel like an event — it'll feel like a familiar distance with a faster middle section.

Keep your easy runs between 8 and 12 kilometres. They don't need to be long — they need to be consistent. Three months of four-day-per-week running, never skipped, builds more endurance than sporadic big weeks with rest days in between. Consistency is the whole game. Check out the training for a half marathon page for a structured approach to the full build-up.

4. Adding One Quality Session Per Week

From month three onwards, add one proper quality session each week alongside your easy running. For the sub-2 half marathon, the most useful quality work is threshold running — sustained efforts at a pace you could hold for roughly an hour, which is slightly faster than half marathon pace for most runners.

A threshold session doesn't have to be complicated. Twenty to thirty minutes of continuous running at threshold effort — breathing controlled but clearly working — is enough. Alternatively, try 3 x 10 minutes at threshold pace with three minutes easy between reps. Rotate between these two formats and you will rarely get bored.

Threshold pace for you is approximately 5:20 to 5:30 per kilometre based on your current fitness. As you get fitter across the six months, that pace will naturally improve — and your half marathon pace will follow it. The relationship between the two is very consistent. You don't need intervals, hill sprints, or anything complicated. Threshold runs and easy mileage, done consistently, will get you to sub-2 hours.

5. Keeping Your Knee Healthy Through the Build-Up

The insoles have addressed the displaced kneecap — that's the right fix. But for a runner building mileage over six months, the next layer of protection is strengthening the muscles that take load off the knee joint during every stride. Specifically: the hip abductors and the glute medius.

Two short strength sessions per week — 20 minutes each — will make a real difference. Clamshells, side-lying leg raises, and single-leg squats (also called Bulgarian split squats) are the three exercises I'd start with. They are unglamorous. They work. Single-leg squats in particular — do them slowly and with control — are one of the most effective tools for reducing knee load under fatigue.

Your ballet background is genuinely useful here. The balance, proprioception, and body awareness you develop in class directly transfers to running economy and injury resilience. Keep the weekly class going — it is cross-training that many runners would pay good money to access.

Listen to your body through the build-up. A niggle caught early and rested for three days costs you almost nothing. A niggle ignored for three weeks can cost you the race. You've already shown you understand your body — trust that instinct and act on it early if something doesn't feel right.

Rebecca, both your goals are well within reach. Your fitness foundation is better than you realise, your lifestyle is working in your favour, and six months is exactly the right amount of time to build what you need. Stay consistent, keep the easy runs easy, protect the knee — and that sub-2 finish is yours. :)

Kind regards,

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