Running Faster or Further for My First Marathon?

I have been running every other day for about a month and have made it to 5 miles. Should I work on running those 5 miles at a faster speed (I run it in about an hour) or should I run further and worry about speed later?

My goal is to be able to run a marathon in about a year.

– Rhiannon

Answer by Dom:

Hi Rhiannon,

I'm thrilled you're setting such an ambitious goal for yourself. A year is a generous, sensible runway for a first marathon. You've got time to build this properly rather than rush it.

In one sentence: prioritize distance over speed. At your stage, speed work does very little for you. It's your aerobic engine that needs the work, and that only comes from time spent running easy. Here's the full breakdown:

1. Creating a foundation with slow and easy running
2. A rough weekly timeline for your year
3. Why some faster running is beneficial too

Creating a Foundation with Slow and Easy Running

Building a foundation with easy, slow running is good for your body for a few reasons. Run at a gentle pace for extended periods and your heart gets stronger, pumping more blood to your muscles with each beat. That's exactly what your muscles need when you're covering long distances.

Distance running also develops your stamina. Think about it this way: if you built your longest run up to 15-20 miles, wouldn't your current 5-miler feel easy by comparison? You'd likely run it faster too, without ever training for speed directly. Running longer distances slowly teaches your body to use its energy stores efficiently. That's the endurance you need on marathon day.

So building that foundation through slow, steady running is step one in making you marathon-ready. And here's the pay-off you're really after: as your aerobic engine grows, your easy pace naturally quickens without you chasing it. If you build your base properly, you often find your 12-minute-mile pace has become an 11-minute or 10:30 pace by months six or seven. A stronger heart and more efficient muscles make the same effort produce more speed.

A Rough Weekly Timeline for Your Year

You're at 5 miles in about an hour: roughly 12-minute miles, run every other day. That's a solid, honest starting point. Here's how I'd stretch it out over your year:

• Months 1-3: Stay at 3-4 runs a week, all easy. Add no more than half a mile to a mile onto your long run (the longest run of your week, done at an easy pace) every week or two, and build in a consolidation week every third or fourth week where you hold mileage steady rather than push it. By month three you should be comfortably running 8-10 miles as your long run, with weekly mileage somewhere around 18-22 miles.
• Months 4-6: Keep building the long run, aiming for 12-14 miles by month six. Add a fourth or fifth weekly run if your body's coping well: listen to your body here, niggles are your cue to hold steady rather than push through. Weekly mileage climbs toward 25-28 miles.
• Months 7-9: This is where you introduce structure beyond just easy miles. Long run builds toward 16-18 miles. Weekly mileage sits around 30-35 miles, with a genuine mid-week medium-long run of 8-10 miles alongside the weekend long run.
• Months 10-12: Your marathon-specific block. Push the long run up toward 20 miles once, maybe twice, in this window. Then taper (cutting back your training before the race so your legs feel fresh) properly over the final two to three weeks: cut volume, keep a little sharpness, and arrive on the start line rested rather than exhausted.

None of these numbers are rigid. They're a sensible progression, not a rulebook. If a week feels too much, back off. Consistency across the year matters far more than hitting any single number on schedule. A missed week here and there won't derail a year-long build: three missed months in a row will.

Why Some Faster Running Is Beneficial Too

Easy running builds your endurance base, but mixing in some faster running brings variety and sharpens your running economy (how little energy you use at a given pace). Once you've got three or four months of consistent easy mileage behind you, so somewhere around month four in the timeline above, you can start adding a weekly session with some threshold effort or a handful of strides (short, fast but relaxed pickups of 20-30 seconds). Nothing complicated: something like 15-20 minutes at a "comfortably hard" effort, or 6-8 strides of 20 seconds after an easy run (a run slow enough to chat in full sentences), is plenty at this stage.

Keep it in moderation. One faster session a week is plenty; the rest stays easy. And if your legs feel flat or a niggle shows up, skip it: the easy mileage is what's building your marathon, not the occasional fast session.

A few more articles worth reading as you go:

• Base Running: about the importance of running easy.
• Increasing Mileage Safely: on how to build up your mileage without getting injured.
• Marathon Running Tips for Beginners: a lot more detailed info on how to go about preparing for your first marathon.

One last thing worth saying plainly: don't compare your 5-mile hour to anyone else's pace. Everyone who's ever finished a marathon started somewhere, and an hour for 5 miles a month into running is a completely normal, sensible starting point. The distance-first approach above is exactly how you turn that into 26.2 miles.

Stay consistent, enjoy the miles, and trust the process. You've got a full year to get this right.

For more on this topic, see 18 Months to a Marathon – Is It Doable and Training for a First Marathon in 12 Months.

If you want a training plan built around your own race date and current mileage, PlanMyRace can build one for you.

Kind regards,
Dom

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