How to Train for: a 15k Run

I run 30 minutes 5 times a week that includes a 2min brisk walk warm up and a 2min brisk walk cool down. I also do weight training 3-4 times a week. I want to run a 15k in four months' time and want to start serious training for it as soon as possible. what should I incorporate into my workout to better ready myself for this feat?

Answer by Dom:
Hi Shannin,

Thanks for your question about training for your 15k run. You're in great shape already — five 30-minute runs per week plus strength training 3–4 times a week? That's exactly the foundation you need to build from. With four months to prepare, you're in a very good position to tackle this distance successfully.

Looking at your current routine with those 2-minute warm-up and cool-down walks, you're already doing things right. Here's how to build on exactly what you've got:

1. Increase your weekly mileage gradually
2. Add a weekly long run to your schedule
3. Incorporate one quality workout per week
4. Adapt your strength training to support your running
5. Plan your final month taper strategy

1. Increase Your Weekly Mileage Gradually

You're currently running about 2.5 hours per week, which gives you a solid foundation. Start by extending every other run by 5 minutes — so you'd have runs alternating between 30 and 35 minutes for the first two weeks.

After that, push some of your runs up to 45–50 minutes whilst keeping others at 30 minutes. This follows the hard/easy principle that works so well for building endurance — you can't push yourself hard every single day without accumulating fatigue and risking injury.

By month three, aim for runs of 30, 45, 30, 60, and 30 minutes across your five weekly sessions. This gradual progression protects you from injury whilst building the aerobic base running you'll need for race day.

Too many runners try to jump their mileage too quickly and end up sidelined. Your body adapts to increased load over weeks, not days — patience here will pay real dividends.

2. Add a Weekly Long Run to Your Schedule

Your longest run should become the cornerstone of your training. Make one of those longer midweek runs your designated long run day — probably replacing one of your future 60-minute sessions.

Start with a 70-minute long run in month two, then build by 10–15 minutes every couple of weeks until you hit about 75–80 minutes. That'll cover roughly 12–13km at an easy pace, leaving you just 2–3km to cover on race day — and the adrenaline and race atmosphere will carry you the rest of the way.

Here's the key with long runs: you should be able to hold a conversation the whole way. If you can't chat, you're pushing too hard. The pace should feel almost embarrassingly easy whilst you're doing it.

The long run teaches your body to burn fat efficiently and builds the mental toughness you'll need when fatigue hits in the final kilometres. No runner ever regrets doing their long runs — only those who skip them.

3. Incorporate One Quality Workout Per Week

Once you've been doing the increased mileage for three weeks, add one quality session per week. This is where you'll work on your speed and lactate threshold — the pace you can sustain for about an hour.

Start simple with something like 6 x 30 seconds fast with 2-minute easy jogs between each repetition. Do this after a 15-minute warm-up and before a 10-minute cool-down. See how your body responds before progressing to something more demanding.

After a few weeks, move to tempo intervals: 3 x 8 minutes at comfortably hard effort with 2-minute walking recoveries. This pace should feel like you're working hard but could maintain it for 45–60 minutes if you had to.

Quality work will make you faster, but don't let it compromise your base building. It's better to nail every easy run and long run than to push too hard in speed sessions and struggle with the basic mileage. Many runners find success applying similar principles when training for a half marathon, as both distances require that crucial endurance foundation.

4. Adapt Your Strength Training to Support Your Running

Keep doing your strength work — it's brilliant injury prevention. But as your running volume increases, dial back the intensity in the gym rather than the frequency.

Instead of going all-out in every strength session, aim for maintenance mode: two solid sessions per week focusing on your posterior chain, core, and single-leg stability. Think deadlifts, squats, planks, and single-leg glute bridges.

Runners who try to peak in both the gym and on the road simultaneously find that something always gives. Your priority for these four months is the 15k, so let your strength work support that goal rather than compete with it — this is a common adjustment amongst runners stepping up in distance.

Schedule your harder strength sessions on the same days as your quality runs or long runs. This way you get full recovery days rather than spreading the stress unevenly across the week.

5. Plan Your Final Month Taper Strategy

In your final three weeks before the race, you'll need to reduce volume whilst maintaining intensity. Cut your total weekly mileage by about 25% in week three before the race, then 40% in week two, and 60% in race week.

Keep doing one quality session per week right up until five days before the race, but make the intervals shorter. Your last workout might be 4 x 30 seconds fast with long recoveries — just enough to keep your legs sharp without accumulating fatigue.

Your final long run should be three weeks before race day. After that, your longest run shouldn't exceed 45–50 minutes. Trust the fitness you've built rather than trying to squeeze in extra mileage at the last minute.

Remember — you can't gain fitness in the final month, but you can definitely lose it through overtraining or injury. The work's done by then; your job is simply to show up healthy and rested. You can find more detailed guidance on this crucial final phase in the peaking for a 15k guide.

If you're coming from shorter race experience, many of the fundamentals from 10k running tips apply here too, but with the added endurance component that makes the 15k such an interesting challenge.

Hope this helps, Shannin. Wishing you the best of luck with your training and on race day!

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