Multiple Half Marathons: Racing Smart vs. Racing Often

Hi Dom, in my region over the next twelve weeks about eight half marathons are being organized. I could literally be doing a half marathon every week or second week. I want to improve my PR and this way I get eight chances to improve upon it. Would running all eight of them be the best idea? I run about 30 miles a week and am 43 years old. Thanks in advance. – Michael

Hi Michael,

I love the enthusiasm — and eight half marathons in twelve weeks is a genuinely tempting proposition. But if improving your PR is the goal, I'd encourage you to think carefully before committing to all of them.

Here's what we'll cover:

1. The real cost of racing too often — the maths might surprise you
2. How to structure a smarter race calendar around one goal race
3. How to use the remaining races without wasting them

1. The Real Cost of Racing Too Often

Let's do the maths. In a normal 12-week training block running 30 miles a week, you might fit in two or three quality sessions per week — threshold efforts, tempo runs, perhaps some longer intervals. That's roughly 28–30 quality workouts over the twelve weeks. Those sessions are where fitness actually builds.

Now add eight races. After each hard half marathon, your legs need 2–3 days of easy recovery before they're ready for anything meaningful. If the next race is 10–11 days away, you're left with a narrow window — maybe one quality session before you need to start tapering again. Suddenly you're getting one quality workout per race cycle instead of three.

Over twelve weeks, with races roughly 10–11 days apart, that's about seven or eight race cycles — call it 7–9 quality sessions instead of 28–30. You've lost the better part of your normal quality volume, not just half of it. That's a significant deficit, and it's very hard to set a PR on a significant deficit.

There's another cost too: cumulative fatigue. A half marathon — even one run at a controlled effort — leaves a mark. The glycogen depletion, the muscle micro-damage, the mental cost of race day. Stack eight of those together without adequate recovery between them and you are not training progressively. You are grinding yourself down.

I notice this myself after any hard effort — even a tough long run leaves my legs feeling like dead wood for a day or two. Racing is harder than a long run. Eight of them back to back with no proper training block in between is unlikely to produce a PR. It is more likely to produce a plateau or, worse, a niggle that sidelines you entirely.

2. How to Structure Your Race Calendar Smarter

The approach that actually produces PRs is quite different — and it's built around one clear goal.

Pick one race as your A race. This is the one you're training specifically for, the one where everything comes together. It should sit towards the end of your 12-week window, ideally around week 10 or 11, giving you a proper build-up and a short taper.

Then pick one or two B races — tune-ups — around weeks 4–6. These serve a real purpose: they give you race practice, sharpen your sense of pace under pressure, and tell you whether your fitness is on track. Race them honestly but not at full red-line effort. Aim for around 90–95% of your A-race effort and treat them as an expensive quality session.

That's three races total — your two tune-ups and your goal race. It's enough to stay sharp and get race experience without burning through your training windows.

The trick is to build your training week around that structure. Weeks leading into a B race look slightly different — a small reduction in volume in the final 3–4 days — but the overall training block stays intact. You're not sacrificing weeks of quality work for the sake of a race that isn't your priority.

At 43, this approach suits you particularly well. The half marathon is a brilliant distance for your age — your endurance base can still grow, your stamina is solid, and recovery from a well-run half is manageable. But improvement at this stage comes from consistent, progressive quality training, not from accumulating race miles. The body builds fitness in the days and weeks between races, not during them.

3. What to Do With the Other Five Races

You don't have to skip them — you just need to be honest about what they are.

If you want to enter two or three of the remaining races, treat them as long runs in a race environment. Start conservatively, well back in the pack. Run the first 10K at your easy training pace. If you feel good in the final 5K, you can push a little — but that's the only moment you get to open up, and only if the legs feel genuinely fresh.

Here's the honest warning though: this requires real discipline. Once you're in a race, the competitive environment takes over. You see someone ahead of you and you want to go with them. The crowd pushes you. Your watch shows a fast split and it feels good. Before you know it, you've run the first 10K ten seconds per mile too fast and you're paying for it in the final 5K.

I've seen this happen to experienced runners who fully intended to run easy. The race environment is powerful — it overrides good intentions. If you're not genuinely confident you can hold back, it's worth asking whether entering those extra races is worth the risk to your A-race preparation.

One option worth considering: volunteer at one of them. Course-marshal, hand out water, cheer at the finish line. You'll get all the atmosphere and community without any of the recovery cost. And you'll want to race even more when your A race finally comes around.

Good luck, Michael — pick your goal race, train for it properly, and give it everything on the day. That's the path to a PR.

Kind regards,

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